addendum number: 4 modifying: specifications...

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DATE: September 3, 2009 ADDENDUM NUMBER: 4 MODIFYING: Specifications No. 1629 PROJECT: Robert B. Diemer North Access Road BID TIME AND DATE: 2:00 p.m., September 9, 2009 FROM: THE METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA

700 North Alameda Street, Third Floor – Specifications Desk Los Angeles, California 90012 (213) 217-6515

TO: All prospective bidders This addendum forms a part of the contract documents. Use Specifications No. 1629 as originally issued to submit bids, in conjunction with this addendum and all previously issued addenda, and acknowledge receipt of this addendum by completing Document 00420, “Bidder's General Information,” in the specifications. This addendum consists of 10 pages of text, 44 pages of attached documents, and 8 sheets of 11”x17” drawings. CHANGES TO BIDDING REQUIREMENTS:

1. In Document 00200, “Information Available to Bidders,” add the following report (attached) to the end of the table:

3. Geotechnical Memorandum –Supplemental Subsurface Data for Diemer North Access Road Project – Project No. 103527 August 3, 2009 MWD

2. Delete Document 00310, Bidding Sheet, dated May 2009 and replace with the attached Document 00310, dated September 2009.

CHANGES TO SPECIFICATIONS:

3. In Section 01025, “Measurement and Payment,” delete Paragraphs 1.05C and D in their entirety and replace with the following:

C. BID ITEM 3 (LS): Construction of all work included in the Contract except for work covered under the other bid items on this bidding sheet, as specified and shown on the drawings (lump sum).

1. The price bid shall compensate the Contractor for performance of all work not included in other bid items.

4. In Section 02015, “Abandonment of Oil Well,” after Paragraph 1.01A, add the following new Paragraph 1.01B:

B. The work under this section, if required, shall be as directed and approved by the Engineer. Payment shall be handled as extra work in accordance with Article 11 of the General Conditions.

5. In Section 02200, “Earthwork,” in Paragraph 1.03E, change the end station number “43+30” to read: 43+25

6. In Section 02200, in the table under Paragraph 3.02B, in the row for Coarse Puente Formation change the station number “40+50” to read: 40+20

7. In Section 02200, in the table under Paragraph 3.02B, in the row for Fine Puente Formation, change the station number “43+00” to read: 43+25

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8. In Section 02200, add the following sentence to the end of subparagraph 3.08B.3:

The minimum embedment depth at the face of the SCRW systems shall begin below this 3-foot thick top layer.

9. Delete Section 02252, “Soldier Pile-Tieback Retaining Wall,” dated July 2009, and replace with the attached Section 02252, dated September 2009.

10. In Section 02260, “Segmental Concrete Retaining Wall (SCRW) System,” add the following subparagraph 1.02F.4 at the end of subparagraph 1.02F.3.a:

4. United States Naval Facilities Engineering Command (NAVFAC)

a. NAVFAC Design Manual 7.01, Soil Mechanics

b. NAVFAC Design Manual 7.02, Foundations & Earth Structures

11. In Section 02260, subparagraph 1.03A.5, change the end station number “43+30” to read: 43+25

12. In Section 02260, add the following subparagraph 1.03A.11 after subparagraph 1.03A.10:

11. Alluvium—Unconsolidated, non-indurated natural topsoil materials not on the surface of the slope.

13. In Section 02260, delete the table under subparagraph 1.04E.1 and replace with the following:

Earth Materials Road Station In-situ Properties

Moist Density (pounds per cubic foot)

Angle of Internal Friction

Cohesion (pounds per square foot)

Alluvium 20+00 to 29+50 110 pcf 31° 100 psf Coarse Puente

Formation 29+50 to 40+20, 48+00 to 55+25 118 pcf 42° 350 psf

Fine Puente Formation 43+25 to 48+00 110 pcf 36° 330 psf

Fernando Formations 55+25 to 61+00, 65+75 to 68+49 118 pcf 35° 1,000 psf

Artificial Fill 61+00 to 65+75 116 pcf 29° 850 psf

14. In Section 02260, Paragraph 1.04G, delete the words: except for Retaining Walls “A” and “B”

15. In Section 02260, after Paragraph 1.04H add the following Paragraph 1.04I:

I. At the Contractor’s option, Retaining Walls “A” and “B” can utilize a composite tiered wall system consisting of a vertical cantilever reinforced concrete retaining wall at the bottom and a SCRW system above. The composite tiered wall systems shall conform to the following design criteria:

1. The composite tiered wall system shall occur within the retaining wall stations indicated below and shall conform to the indicated dimension parameters.

Retaining Wall

Retaining Wall Station

Max. Height of Vertical Cantilever Reinforced Concrete Retaining Wall

Above Lowest Adjacent Finished Grade

Min. Horizontal Distance from the Property Line to the Face of Wall

or Outer Footing Face “A” 0+00 to 1+24.85 5 feet 1 foot “B” 1+70 to 3+89.14 7 feet 1 foot

2. Design loads for the vertical cantilever reinforced concrete retaining wall shall be as specified below. These values of the design loads apply to a horizontal retained compacted backfill at the elevation of the bottom of the SCRW system that overlies the retained compacted backfill.

a. Active lateral earth pressures: 45 pcf equivalent fluid pressure.

b. Seismic induced lateral earth pressure: Inverted equivalent fluid pressure of 40 psf over the entire wall height.

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c. All applicable surcharge loads from the overlying SCRW system traffic loads and construction loads.

d. For Retaining Wall “A,” allowable passive lateral earth pressure for passive resistance: 37 pcf equivalent fluid pressure up to a maximum value of 370 psf.

e. For Retaining Wall “B,” allowable passive lateral earth pressure for passive resistance: 65 pcf equivalent fluid pressure up to a maximum value of 650 psf.

f. The passive lateral earth pressure shall begin at a depth of 2 feet, minimum, below the lowest adjacent finished grade.

g. For Retaining Wall “A,” allowable base coefficient of friction for frictional resistance: 0.35.

h. For Retaining Wall “B,” allowable base coefficient of friction for frictional resistance: 0.50.

i. The total allowable passive resistance (including the maximum value) can be increased by one-third for short-duration loads.

4. The design of the vertical cantilever reinforced concrete retaining wall shall include provisions to provide for fully drained backfill conditions of the retained materials.

3. Embedment depth for the reinforced concrete retaining walls shall conform to the same depth as the SCRW system specified herein and shown on the Drawings within the indicated retaining wall stations. At a minimum, the bottom outer edge of the footings for the reinforced concrete retaining wall shall be located at a minimum horizontal slope setback distance of 5 feet for Retaining Wall “A” and 10 feet for Retaining Wall “B,” as measured from the outer footing face to the slope face.

4. Embedment of the SCRW system shall be 2 feet, minimum, below the top of the reinforced concrete retaining wall.

5. The allowable bearing capacity for the footings of the reinforced concrete retaining wall shall be based on the earth material parameters specified in Paragraph 1.04E of this section and the gradient of the actual descending slope in front of the wall. Industry standard accepted methods of analyses shall be used, including but not limited to, the AASHTO Standard Specifications for Highway Bridges, and the NAVFAC Design Manual 7.01 and Design Manual 7.02. Factor of safety to calculate the allowable bearing capacity value shall be 3.0, minimum. The bearing capacity shall subtract the effect of the earth material overburden from the elevation at the bottom of footing upward to the surface of the lowest adjacent grade, in order to obtain a net bearing capacity value. The allowable net bearing capacity can be increased by one-third for short-duration loads.

16. In Section 02260, at the end of subparagraph 1.05A.2.f, add the following subparagraph 1.05A.2.g:

g. The working drawings for composite tiered wall systems for Retaining Walls “A” and “B,” if used at the Contractor’s option, shall include all applicable requirements as specified above.

17. In Section 02260, after subparagraph 1.05A.2 add the following new subparagraph 1.05A.3:

3. If composite tiered wall systems are used for Retaining Walls “A” and “B” at the Contractor’s option, then the design calculations and the working drawings shall also include: configuration of the composite tiered wall systems; all vertical and lateral loads, allowable net bearing capacity, and passive resistance values used to design the reinforced concrete retaining wall; embedment depth of the reinforced concrete retaining wall; embedment depth of the SCRW system in the retained soils of the reinforced concrete retaining wall; and drainage provisions and details for the reinforced concrete retaining wall and SCRW system. Structural calculations and shop drawings, including, but not limited to, plans and sections, reinforcement details, all connections, and drainage provisions and details for the reinforced concrete retaining walls shall also be submitted.

18. In Section 02260, delete Paragraph 1.05B in its entirety and replace with the following:

B. SCRW system design calculations, working drawings, and shop drawings shall be prepared, signed, and stamped by a civil or geotechnical engineer currently registered in the State of California. If used at the

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Contractor’s option for Retaining Walls “A” and “B,” the design calculations, working drawings, and shop drawings for the vertical cantilever concrete retaining wall of the composite tiered wall systems shall be prepared, signed, and stamped by a civil or structural engineer currently registered in the State of California. The working drawings shall include plan and elevation views of each wall, cross sections and all details, dimensions and quantities necessary to construct the wall systems.

19. In Section 02260, add to the end of Paragraph 2.01F the following sentence: Acceptable planter cell unit products are Keystone Standard Plantable Unit, Verdura 60 and 60W, or equal.

20. In Section 02260, change subparagraph 2.02B.1.d to read:

d. The minimum creep reduction factor, RFCR, shall be based on a 100-year design life of the SCRW system, and shall be ≥ 1.50.

21. In Section 02260, at the end of subparagraph 2.02B.1.f, add the following subparagraph 2.02B.1.g:

g. The term [Ta / ( RFID × RFD × RFCR )], or the value of the long-term design strength (LTDS) provided by the manufacturer, shall be a minimum of 3,900 pounds per foot, or greater as required by design. The reduction factors applied to calculate the LTDS shall not be less than the minimum values specified in this section.

22. In Section 02260, change subparagraph 2.02B.8 to read:

8. Acceptable geogrid reinforcement products: Tensar UXMSE Structural Geogrids; Mirafi Miragrid XT Geogrids; Huesker Fortrac Geogrids; Strata Stratagrid Geogrids; or equal.

23. In Section 02260, change Paragraph 3.01B to read:

B. Earthwork for SCRW system construction and for composite tiered wall system (if used at the Contractor’s option for Retaining Walls “A” and “B”) construction shall be in accordance with Section 02200.

24. In Section 02261, “Reinforced Soil Slopes,” add the following subparagraph 1.03A.10 after subparagraph 1.03A.9:

10. Alluvium—Unconsolidated, non-indurated natural topsoil materials not on the surface of the slope.

25. In Section 02261, delete the table under subparagraph 1.04E.1 and replace with the following:

Earth Materials Road Station In-situ Properties

Moist Density (pounds per cubic foot)

Angle of Internal Friction

Cohesion (pounds per square foot)

Alluvium 20+00 to 29+50 110 pcf 31° 100 psf Coarse Puente

Formation 29+50 to 40+20, 48+00 to 55+25 118 pcf 42° 350 psf

Fine Puente Formation 43+25 to 48+00 110 pcf 36° 330 psf

Fernando Formations 55+25 to 61+00, 65+75 to 68+49 118 pcf 35° 1,000 psf

Artificial Fill 61+00 to 65+75 116 pcf 29° 850 psf

26. In Section 02261, at the end of subparagraph 2.01B.1.f, add the following subparagraph 2.01B.1.g:

g. The term [ Ta / ( RFID × RFD × RFCR ) ], or the value of the long-term design strength (LTDS) provided by the manufacturer, shall be a minimum of 2,400 pounds per foot, or greater as required by design. The reduction factors applied to calculate the LTDS shall not be less than the minimum values specified in this section.

27. In Section 02261, change subparagraph 2.02B.1.d to read:

d. The minimum creep reduction factor, RFCR, shall be based on a 100-year design life of the SCRW system, and shall be ≥ 1.50.

28. In Section 02261, change subparagraph 2.01B.6 to read:

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6. Acceptable geogrid reinforcement products: Tensar UXMSE Structural Geogrids; Mirafi Miragrid XT Geogrids; Huesker Fortrac Geogrids; Strata Stratagrid Geogrids; or equal.

29. In Section 02620, “High Density Polyethylene Piping,” delete Paragraph 2.01C and replace with the following:

C. The firewater line shall have the following dimensional ratio and pressure rating:

Station or Location Standard Dimensional Ratio (SDR) Pressure Rating

Sta. 4+56 to Sta. 43+50 SDR 7 260 psi

Sta. 43+50 to Sta. 68+50 SDR 9 200 psi

30. In Section 02922, “Site Seeding,” Paragraph 2.01A, change the second sentence to read:

Seeds shall be collected within 20 miles of the project site by S&S Seeds or equal. Seeds from San Bernardino County and San Diego County will not be accepted.

31. In Section 02952, “Erosion Control,” Paragraph 3.01D, delete the following words in the first sentence, “with the exception of slopes receiving duff and topsoil material”

32. After Section 15080, add Section 15100, “Valves for Piping Systems,” attached herewith.

CHANGES TO DRAWINGS:

33. The following drawings have been revised, as shown on the prints of the attached drawings. These drawings as revised shall be controlling for the purposes of the required work in lieu of the drawings previously issued. The changes made on each drawing are indicated in the revision block on each drawing.

Reference No. Sheet No. Drawing No. Revision No.

1. G-2 B-130447 2

2. C-3 B-130456 1

3. C-5 B-130461 1

4. C-8 B-130458 1

5. C-9 B-130462 1

6. C-28 B-130481 2

7. C-29 B-130482 2

8. C-31 B-130484 1

34. Metropolitan has made changes to the following drawings without issuing revised drawings at this time; however, Metropolitan will issue revised drawings showing these changes after the contract is awarded.

Reference No.

Sheet No.

Drawing No.

Description of Changes

1. G-7 B-130452 In Construction Note 59, delete “(SDR-9)”

2. C-24 B-130477 Change Note 3 to read: LIMITED VEGETATION REMOVAL SHALL TAKE PLACE DURING FENCE REPLACEMENT WORK, AS IDENTIFIED IN THE FIELD BY THE CONTRACTOR AND AS APPROVED BY THE ENGINEER. WHEN NECESSARY, VEGETATION REMOVAL SHALL OCCUR WITHIN METROPOLITAN’S PROPERTY AND CANNOT EXCEED 12 FEET IN WIDTH IN ANY LOCATION.

Change Note 4 to read: HAND WORK IS STRONGLY ENCOURAGED WHEREVER POSSIBLE DURING FENCE REPLACEMENT WORK TO MINIMIZE IMPACTS TO EXISTING TERRAIN AND VEGETATION. FOR STEEP TERRAINS, IF NECESSARY, USE ONLY A SKIP LOADER

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Reference No.

Sheet No.

Drawing No.

Description of Changes OR SMALL TRUCK EQUIPMENT.

3. C-25 B-130478 Change Note 3 to read: LIMITED VEGETATION REMOVAL SHALL TAKE PLACE DURING FENCE REPLACEMENT WORK, AS IDENTIFIED IN THE FIELD BY THE CONTRACTOR AND AS APPROVED BY THE ENGINEER. WHEN NECESSARY, VEGETATION REMOVAL SHALL OCCUR WITHIN METROPOLITAN’S PROPERTY AND SHALL NOT EXCEED 12 FEET IN WIDTH IN ANY LOCATION.

Change Note 4 to read: HAND WORK IS STRONGLY ENCOURAGED WHEREVER POSSIBLE DURING FENCE REPLACEMENT WORK TO MINIMIZE IMPACTS TO EXISTING TERRAIN AND VEGETATION. FOR STEEP TERRAINS, IF NECESSARY, USE ONLY A SKIP LOADER OR SMALL TRUCK EQUIPMENT.

4. C-32 B-130485 In Note 3, change the note to read: BALL VALVE SHALL BE IN ACCORDANCE WITH SECTION 15100. MECHANICAL JOINTS OR COUPLERS SHALL BE USED TO JOIN THE VALVE TO THE HDPE CORRUGATED PIPE.

5. C-34 B-130487 In Note 2 of the Fire Hydrant Construction Notes, change note to read: 6” ISOLATION VALVE PER SECTION 15100.

In Note 3 of the Fire Hydrant Construction Notes, change note to read: FLANGE JOINT

QUESTIONS AND CLARIFICATIONS:

Requests for clarification of details on the drawings or of provisions of the specifications have been identified. The questions with the appropriate Metropolitan responses are as follows:

(1) Question: Regarding the answer to question #10 in Addendum #2, a vertical SCRW system that provides 30% plantability is not possible. For both the Keystone Wall System and the Verdura Wall System, a horizontal batter of 1H:4V is required to allow for 30% plantability. The Keystone system can not be built near vertical and provide 30% plantability. The Verdura unit is designed to be planted and has a minimum fixed batter of 1H:4V. It is not possible to make the Verdura Wall System more vertical to meet the specifications. Please clarify the requirement for SCRW incorporation into Walls “A” and “B”. Reference Sections 2260, subparagraphs 1.04.F.7.a, 1.04G, and 2.01.A.1.

Answer: The specifications have been revised to indicate, at the Contractor’s option, a composite tiered wall system consisting of a vertical cantilever reinforced concrete retaining wall at the bottom and a SCRW system above can be used for Retaining Walls “A” and “B.” Refer to Changes to Specifications for Section 02260 in this addendum, and Changes to Drawings for Sheet C-29 in Addendum 3.

(2) Question: Please review the specifications for the Vertica Pro anchor product and add this product to the list of pre-approved SCRW products for use on this project.

Answer: Vertica Pro product does not have the pin connection in its design and is not approved. Due to the close proximity of the active Whittier fault (approximately 1/2 kilometer to the north) to the project site, Metropolitan is strictly adhering to the FHWA design guideline on facing connection using devices such as pins or rods between the segmental concrete units and the geogrid reinforcement. This guideline can be found on page 122 in the publication FHWA-NHI-00-043. Other products proposed by the Contractor after award may be evaluated and considered as “equal” if they meet the requirements of the specifications in accordance with Section 01300. Refer to Changes to Specifications for Section 02260 for additional information.

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(3) Question: A. Subparagraph 2.02B.8 of Section 02260 specifies three reinforcement products that can be used in the design of the SRW systems. Since this is a design-build function, the geosynthetic selection for brand and strength should be guided by the designer of the wall system. Further, the three products provided as equals vary dramatically in long term design strength and engineering characteristics. Please change the specification to simply require a minimum long term design strength for the wall designs.

B. While it is possible to design-in any of the three products required for incorporation into the walls, incorporating them at 16 – 24-inch intervals is neither design nor cost efficient. Please remove any reference to specific products that are pre-approved for use in the design and replace the geosynthetic products portion of the specification with a more open guidance specifications similar to what Caltrans employs or simply list several geogrid manufacturers that are pre-approved, such as Mirafi, Strata, Heusker and Tensar. Metropolitan is clearly open to other products since the reinforced slope portions of the specifications include several other lower strength products which are typical for wall and slope projects of this magnitude.

Answer: A. The specifications have been revised to specify the required minimum long-term design

strength of the geogrid reinforcements for SCRW system design. Refer to Changes to Specifications for Section 02260 in this addendum.

B. The vertical spacing of the geogrid reinforcement shall be as specified. Other products proposed by the Contractor after award may be evaluated and considered as “equal” if they meet the requirements of this section in accordance with Section 01300. Refer to Changes to Specifications for Section 02260 in this addendum for a revised list of approved products.

(4) Question: For the 2-ft high, 2-strand fence to be installed on top of the walls, the socket insert detail shown on Sheet S-9, Detail 4, identifies a 3” OD std. steel pipe. Can a 2-7/8” OD std. steel pipe be used instead?

Answer: Yes.

(5) Question: For the 2-ft high, 2-strand fence, there is no detail on how the steel tension wire connects to the posts. Please provide connection details and tensioning details.

Answer: See Changes to Drawings for Sheet C-31 in this addendum for the requested details.

(6) Question: For the 2-ft high, 2-strand fence, is it the Contractor’s choice whether to use coil spring wire or smooth wire? Please clarify.

Answer: 1/4” - 6x7 galvanized iron regular lay fiber core wire rope shall be used. Refer to Changes to Drawings for Sheet C-31 in this addendum.

(7) Question: Where are the specifications for the valves found?

Answer: The specifications for the valves are in Section 15100 issued by this addendum. Refer also to Changes to Drawings for Sheets C-32 and C-34 in this addendum for other changes to the valve specifications.

(8) Question: Section 01060, Paragraph 1.14H, identifies the post-construction BMPs and are incorporated as part of the construction plans with the exception of the “bonded fiber matrix.” Please provide the plant identifying where the fiber rolls will be placed.

Answer: This section specifies that other erosion control measures shall be implemented on all disturbed and native ground surfaces throughout the entire project. Implementation of these post-construction BMPs shall be identified and methods of installation shall be submitted by the Contractor for review and approval by the Engineer as part of the SWPPP.

(9) Question: We received pricing and available seed sources for the access road which only 6 of the 20 species are collected within 10 miles (specified on Section 02922, 2.01A); 4 species are in Puente Hills or

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Irvine Ranch; 4 species in San Bernardino; 1 species in San Diego; and 5 species are commercial sources. If the seed species are not available within 10 miles, can we get seed outside the 10 mile radius?

Answer: In this addendum, the radius was increased to 20 miles except in San Bernardino County and San Diego County, which will not be accepted. Refer to Changes in Specifications for Section 02922.

(10) Question: Section 02252, 3.06B: 5. states “Do not place grout in the no-load zone”. 7. requires backfilling the “unbonded portion of the tieback anchor with bedding sand” and allows the use of a small amount of cement to facilitate pumping of the backfill. The tieback hole diameter is 6”. For drill hole diameters of 6”, industry specs (e.g., Caltrans, PTI, FHWA) all allow grouting of the unbonded length prior to testing. The initial grout is typically filled to within 6” or so of the bottom of the trumpet (that is connected to bearing plate and is typically 1.5 ft to 3 ft long) so that the tieback is not stressed against the grout column. Upon completion of the testing and locking off of the anchor, the second stage grout completes the grouting to the bearing plate.

Requiring the drill hole to be ungrouted prior to testing may result in caving of the soil within the unbonded length. It will also be difficult if not impossible to pump (using a tremie pipe) a sand-cement mix where the tremie pipe would have to fit between the DCP bar and the outside edge of the 6” hole. Will you modify this procedure to allow initial grouting to within 6” of the end of the trumpet as is industry accepted practice?

Answer: The requirements have been modified in revised Section 02252 issued by this addendum.

(11) Question: What is the availability of water to be used for construction?

Answer: Three main sources of water are available: A) Limited quantities (less than 10,000 gal/day) of service/filtered water source may be drawn out from the East Wash Water Tank (see Sheet G-8, Grid H-7). Prior to drawing and tapping, a 4-inch double backflow preventor valve shall be installed by the Contractor; B) Fire hydrants located along the east and north side of the water treatment plant may be used to fill up water trucks. Adequate volume and pressure are available to draw out raw water from these fire hydrants; C) Raw water may be drawn out from an existing manhole located in Sheet G-8, grid D-2. Please note that withdrawing raw water from these sources is contaminated with Quagga Mussels; and therefore, the use of raw water is restricted. If the Contractor proposes a different plan other than filling up water trucks at these raw water sources, the Contractor shall devise a plan(s) and submit to the Engineer for approval to ensure that the raw water does not enter and flow into the existing swales and water paths that drain offsite and/or to Carbon Canyon Creek. Note that water may not be available during water source shutdowns or flow restrictions. Refer to Section 01510 for additional requirements.

(12) Question: What do we do with an abandoned metal handrail and flat form located west of Basin 6 (designated stockpile area shown in Sheet G-8)?

Answer: If the Contractor proposes to use this area as a storage and work area, the Contractor shall remove and dispose of the metal handrail and flat form.

(13) Question: Per Construction Note No. 3 on Sheets C-24 & 25, “Contractor Shall Not Remove Any Existing Vegetation During Fence Replacement Work”. There are numerous areas along the fence alignment where the existing vegetation has grown through the chain link mesh. Is providing vegetation removal services? If so, how wide of a footprint will the vegetation be removed to along the fence alignment? If the Owner is not providing vegetation removal services, please clarify the intent of this statement. Can the vegetation be cut down side-cast adjacent to the fence alignment?

Answer: When necessary, limited vegetation removal may take place, as identified in the field by the Contractor, and approved by the Engineer. Vegetation removal can only take place on Metropolitan property and cannot exceed 12 feet in width in any location. See Changes in Drawings for Sheets C-24 and C-25 in this addendum.

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(14) Question: Per Construction Note No. 4 on Sheets C-24 & 25, “No Heavy Machinery Is Allowed During Fence Replacement Work”. Please clarify what classifies “Heavy Machinery”. Is it the engine size (>50 HP)? Is it the impact of the terrain?

Answer: Due to the steep terrain, limited access, and sensitive nature of the habitat along portions of the fence alignment, hand work is strongly encouraged wherever possible. The Contractor shall minimize the impact of its work to the terrain and vegetation. It would be acceptable to use a skip loader or small truck equipment in the steep terrain areas. See Changes in Drawings for Sheets C-24 and C-25 in this addendum.

(15) Question: On Sheet C-24, the plans identify the 7-ft high chain link fence that is to be removed and replaced across from Basins No. 4, 5, & 6. Several of the post footings and portions of the existing grades beneath the fence have been eroded away by the adjacent stream, located in the “Environmentally Restricted Area” identified on Sheet C-2. This has suspended portions of the fence in mid-air. The earthwork operations in this area do not included any improvements along the fence alignment. In order to re-install fence in this area and at the same elevations as the removed fence, the stream bank needs to be stabilized and re-constructed, or the new fence alignment needs to be moved. Please clarify the requirement for the fence re-installation in areas where the existing terrain is unstable and has eroded away.

Answer: Replacement of the chain link fence at these areas will be determined in the field after award. The Contractor shall bid as currently shown on the drawings under the assumption that the existing terrain is stable.

(16) Question: On Sheet C-29, note 9 states “temporary cut slope shall not extend beyond or undercut toe of permanent slope.” In the 130% of the wall height geogrid situation, the toe of the permanent cut slope will be undercut at a .5:1 backcut when the wall is greater than 21’ high (wall at 1 to 4 batter). When the wall is 30’ high, the toe of the cut slope will be undercut 14.5’. In order to achieve the proper geogrid lengths, a tie back shoring system would have to be implemented. Can the cut slope above the wall be undercut?

Answer: No.

(17) Question: In 02200-6, Paragraph 3.02B states “maximum allowable inclinations of temporary cut slopes without surcharge loads are listed in the following table.” There is always a significant slope above the backcut. Is the slope a surcharge? Please clarify what is or isn’t a surcharge load on the temporary backcut.

Answer: The slope configuration above the temporary cut slope was incorporated in the determination of the maximum allowable inclination of temporary cut slope. Surcharge loads would include any additional loads imposed onto the existing configuration of the slope above the temporary cut slope.

(18) Question: Addendum 3, Sheet C-29 Section Q (Soldier Pile Wall) depicts free draining material behind the lagged wall. Please clarify if geocomposite drainage boards will be acceptable as gravel is not practical with respect to constructability and nearly economically feasible in our opinion?

Answer: Geocomposite drainage boards are not acceptable. The Contractor shall bid as specified.

(19) Question: Section 01065, Paragraph 1.02D, calls for the Contractor to comply with several permits. None are provided in the specifications. Please provide.

Answer: The permits will be provided to the Contractor after NTP. Metropolitan does not anticipate any new requirements in the permits that will change the specifications or affect the Contractor’s work.

(20) Question: I would just like to confirm that there are no special insurances on this project, such as Builder’s Risk, flood, or earthquake.

Answer: Special insurances such as Builder’s Risk, flood, or earthquake are not required on this project.

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(21) Question: You require us to bid on the oil well abandonment. After several dissussions with an oil well abandonment company, there is not a way the contractor can give an accurate number for this work. The range for this work was $30,000.00 to $75,000.00, and as tight as bidding is these days, that could lose a bid. Please inform.

Answer: This work will be treated as extra work. Refer to Changes to the Bidding Sheet, and Sections 01025 and 02015 in this addendum.

END OF ADDENDUM

September 2009 00310 1629 (construction contract) Addendum No. 4

DOCUMENT 00310 BIDDING SHEET

Price for construction of Robert B. Diemer Water Treatment Plant North Access Road

Item Description Amount

1 Mobilization ……………………………………………………………………… $ 400,000

2 Construction of 7-ft chain link fence including three double swing gates...

Estimated Quantity Unit Unit Price

$___________ 5,000 L. F. $___________

3 Construction of all work in the contract, except for work covered under the other bid items on this bidding sheet, as specified and shown on the drawings for the lump sum of…

$___________

Total of items 1 through 3…………….…….…….……….……………….……………..…

$___________

Notes: 1. The low bid will be determined by adding the amount entered for Bid Items 1 through 3. 2. The bidder is required to enter an amount for all bid items. Any bid submitted without all items completed will be

considered non-responsive and will be rejected.

END OF DOCUMENT

September 2009 02252-1 1629 (construction contract) Addendum No. 4

SECTION 02252 SOLDIER PILE-TIEBACK RETAINING WALL

PART 1 GENERAL

1.01 GENERAL

A. This section specifies the requirements for the permanent soldier pile-tieback retaining wall shown on the Drawings that is required to retain the clayey rubble creep zone that underlies the roadway alignment and the compacted backfill to support the roadway to the lines and grades shown on the Drawings.

B. The work consists of designing, furnishing, and constructing a soldier pile-tieback retaining wall, including but not limited to, drilling holes, installing H-piles, concrete lagging, and tieback anchors, earthwork, and incidental materials required for soldier pile-tieback retaining wall construction to the lines and grades shown on the Drawings and specified herein.

C. All temporary shoring and temporary excavation activities not specified herein shall be in accordance with Section 02200.

1.02 REFERENCES

A. General

1. The publications listed below form a part of this specification to the extent referenced.

2. Where a date is given for reference standards, the edition of that date shall be used. Where no date is given for referenced standards, the latest edition available on the date of Notice Inviting Bids shall be used.

B. American Association of State Highway Transportation Officials (AASHTO)

1. AASHTO Standard Specifications for Highway Bridges, 17th Edition

C. American Concrete Institute (ACI)

1. ACI 318, Building Code Requirements for Structural Plain Concrete

2. ACI 336.3R, Design and Construction of Drilled Piers

D. American Institute of Steel Construction (AISC)

1. Manual of Steel Construction

E. American Welding Society (AWS)

1. AWS D1.1, Structural Welding Codes, Steel

F. American Society for Testing and Materials (ASTM)

1. ASTM A36, Standard Specification for Carbon Structural Steel

2. ASTM A185, Standard Specification for Steel Welded Wire Fabric, Plain, for Concrete Reinforcement

3. ASTM A416, Standard Specification for Steel Strand, Uncoated Seven-Wire for Prestressed Concrete

4. ASTM A572, Standard Specification for High-Strength, Low-Alloy, Columbium-Vanadium Structural Steel

5. ASTM A615, Standard Specification for Deformed and Plain Billet-Bars for Concrete Reinforcement

6. ASTM A4435, Standard Test Method for Rock Bolt Anchor Pull Test

G. California Building Code (CBC)

H. Standard Specifications for Public Work Construction (SSPWC)

I. United States Naval Facilities Engineering Command (NAVFAC)

1. NAVFAC Design Manual 7.01, Soil Mechanics

2. NAVFAC Design Manual 7.02, Foundations & Earth Structures

J. United States Army Corps of Engineers (USCOE)

Soldier Pile-Tieback Retaining Wall

1629 02252-2 September 2009 Addendum No. 4 (construction contract)

1.03 DEFINITIONS

A. Fill—For the purposes of this section, the words “fill,” “backfill,” and “embankment” are synonymous and refer to soils, rock, or soil-rock combinations that are conditioned, placed or replaced, and compacted to the percent compaction specified.

B. Formation, Formational Material, Bedrock, Rock—For the purpose of this section, these terms are synonymous and refer to soft sedimentary rock of the Puente Formation, Lower Fernando Formation, and Upper Fernando Formation.

1. Fine Puente Formation—Claystone and siltstone

2. Coarse Puente Formation—Sandstone, conglomeratic sandstone, and conglomerate

C. Clayey Rubble Creep Zone—Earth materials that occur from approximate retaining wall “D” Stations 3+75 to 6+75, and consist of unconsolidated, non-indurated clay soils with sandstone clast embedment and interbeds of sheared sandstone and clay/claystone.

D. Colluvium—Topsoil and slopewash materials are unconsolidated, non-indurated soils on the surface of the slope.

E. Bond Length—The length of the tieback anchors which is bonded to the ground and transmits the tensile force of the anchors to the competent formational materials.

F. Free-Stressing or Unbonded Length—The portion of the tieback anchor length that is not bonded to the ground during the anchor stressing procedure.

1.04 DESIGN CRITERIA

A. General

1. The Drawings include the design concept and configuration for the soldier pile-tieback retaining wall, which is not intended to be a final design. The Contractor shall be responsible for the detailed final design of the soldier pile-tieback retaining wall, and shall be fully responsible for the adequacy of the design and construction. The final design of the soldier pile-tieback retaining wall shall require Metropolitan’s review and acceptance in accordance with the provisions of these specifications prior to excavation at the site related to solider pile or tieback anchor installation.

2. The soldier pile-tieback retaining wall is shown on Sheet C-9 as part of retaining wall “D” between Station 3+75 and Station 6+75. This section of retaining wall “D” is located across the clayey rubble creep zone. The entire limits of the clayey rubble creep zone are within the indicated station limits of the soldier pile-tieback retaining wall, but the exact longitudinal extent of the clayey rubble creep zone shall require field verification.

3. Design Thickness/Construction Limits for Clayey Rubble Creep Zone

a. The design of the soldier pile-tieback retaining wall shall be based upon a thickness of clayey rubble creep zone materials of 25 feet below the existing ground surface between retaining wall “D” Stations 4+50 and 6+00 feet. The thickness of the clay rubble creep zone materials at retaining wall “D” Stations 3+75 and 6+75 for design shall be considered to be 10 feet below the existing ground surface, and vary linearly between this thickness at these end stations and the 25-foot thickness indicated between retaining wall “D” Stations 4+50 and 6+00.

b. The actual longitudinal extent of the clayey rubble creep zone may not extend completely across the indicated portion of retaining wall “D” between Stations 3+75 to 6+75. The actual limits of the clayey rubble creep zone shall be determined by the Engineer on the basis of actual geologic observation and determination during excavation. Based upon the actual limits of the clayey rubble creep zone as determined by the Engineer, the Contactor may be directed to decrease the constructed longitudinal length of the soldier pile-tieback wall within retaining wall “D.” The shortening of the soldier pile-tie back wall on either or both ends of the indicated stations, if so directed, will necessitate an equivalent lengthening of the adjacent segmental concrete retaining wall (SCRW) systems.

4. The design of solider pile-tieback retaining wall shall comply with accepted design practices, as well as standard geotechnical practice that includes, but not limited to, NAVFAC Design Manuals DM 7.01, NAVFAC Design Manual DM7.02, USCOE design documents, and current ACI, CBC, and AISC code provisions, unless design criteria specified herein or on the Drawings are more stringent.



5. The solider pile-tieback retaining wall shall have continuous lagging to fully support retained earth materials. The fascia of the solider pile-tieback retaining wall shall include design provisions and planter features to allow coastal sage scrub vegetation to grow within at least 30 percent of the total retaining wall face and to blend-in with the adjoining vegetated SCRW system indicated in Section 02260. The color of the concrete lagging shall be the same as the approved color of the segmental concrete units used in the construction of the adjoining SCRW systems.

B. Design Requirements and Parameters

1. The design of the solider pile-tieback retaining wall with continuous lagging required to retain the clayey rubble creep zone and the compacted backfill to support the roadway as specified herein shall be subject to the following requirements.

a. The soldier pile-tieback retaining wall shall be comprised of steel H-piles, concrete lagging, and tieback anchors to provide continuous support of the clayey rubble creep zone and the compacted backfill supporting the roadway.

b. Design loads for the soldier pile-tieback retaining wall shall be as specified below. These values of the design loads apply to a horizontal retained compacted backfill at the top of the solider pile-tieback wall.

(1) Active lateral earth pressure: 50 pounds per cubic foot (pcf) equivalent fluid pressure.

(2) Traffic loads: Uniform lateral pressure of 250 pounds per square foot (psf) over the entire wall height or HS-20 traffic load in accordance with AASHTO Standard Specifications for Highway Bridges, whichever is greater.

(3) Construction equipment-induced lateral pressure: Uniform lateral pressure equal to the traffic loading herein, plus any additional lateral pressures in excess of that imposed by the traffic loading using the actual loads from the equipment traveling or to be used next to the wall.

(4) Seismic induced lateral earth pressure: Inverted equivalent fluid pressure of 40 pounds per square foot (psf) over the entire wall height.

c. Soldier piles shall be designed using the following criteria.

(1) The maximum spacing of soldier piles shall be 6 feet on center.

(2) The soldier piles shall be steel H-piles placed in 24-inch minimum-diameter drilled holes.

(3) The embedment of the solider piles shall meet the following criteria:

(a) Minimum embedment depth of 25 feet into competent formational materials.

(b) Below the elevation of the bottom of the lagging of the soldier pile-tieback retaining wall, the drilled holes shall be filled with structural concrete (Class A) around the soldier piles.

(c) Above the elevation of the bottom of the lagging of the soldier pile-tieback retaining wall, the Contractor shall select material to be used to backfill soldier piles to facilitate the placement of concrete lagging.

(4) Soldier piles shall be designed to provide a minimum bending stiffness (EI) of 6 x 107 lbs-ft2/ft.

(5) The passive resistance shall be as specified below. These values of passive resistance are based on a two-layer system using p-y curves in lateral pile capacity analysis.

(a) Upper layer of clay rubble creep zone: Unit weight of 125 pcf, angle of internal friction of 30 degrees, and p-y soil modulus of 50 pounds per cubic inch (pci).

(b) Lower layer of competent formation material: Unit weight of 125 pcf, angle of internal friction of 42 degrees, and p-y soil modulus of 1,500 pounds per cubic inch (pci).

(6) Every solider pile shall have at least one tieback anchor.

2. Tieback anchors shall be designed using the following criteria.

a. Tiebacks shall be steel anchors with Portland cement pressure-grouted bond lengths; epoxy-grouted anchors or mechanical anchors shall not be used.



b. Tiebacks shall be designed and installed at an inclination of between 15 and 25 degrees below the horizontal.

c. The free-stressing length of tiebacks shall extend completely beyond the clayey rubble creep zone and shall be a minimum length of 20 feet.

d. Tiebacks shall have a minimum bonded length of 30 feet in competent formational materials.

e. At least one tieback shall be installed for each solider pile at an elevation 3 feet above the horizontal bench at the base of the exposed portion of the wall.

f. Drilled holes for tieback installation shall have a minimum diameter of 6-inches.

g. To calculate the bonded length of a pressure grouted tieback anchor, the maximum allowable ground shear resistance shall be taken as 4,000 pounds per square foot, based upon the drilled diameter of the tieback anchor installation hole. The specified ground shear resistance value shall not be increased for seismic loads.

h. The tieback anchors shall be designed such that the grout/anchor bond strength (per manufacturer’s recommendations) and ground/grout bond strengths do not control the capacity of the individual tiebacks.

i. The tieback anchors shall have double corrosion protection in accordance with manufacturer’s guidelines.

j. If tiebacks anchors are installed closer than 6 feet to another anchor, vertically or horizontally, the capacity of each affected tieback anchor shall be reduced due to group action.

k. Tieback anchors shall maintain a minimum separation of 10 feet from any utility or pipeline.

3. Lagging shall be designed using the following criteria:

a. Lagging shall be designed using a minimum load of the product of (0.6 × total design lateral load) up to a maximum of value of 400 psf. The load on the lagging shall be a uniform rectangular distribution.

b. Acceptable lagging materials shall consist of reinforced concrete or precast concrete. Steel, wood, gunite, plastics, or shotcrete lagging are not permitted.

c. The design of the lagging shall include a continuous drain system behind the lagging to maintain fully-drained conditions of the retained backfill.

d. The design of the lagging shall incorporate provisions and plantable features to allow vegetation growth within the face of the wall. The vertical spacing of these plantable features shall not exceed 32 inches, center to center, and shall be consistent with the vertical spacing of the plantable cells of the adjacent SCRW systems.

e. Lagging shall be securely attached to the H-beams of the soldier piles.

4. The soldier pile-tieback retaining wall design shall limit lateral deflection at the top of the wall to a maximum of 1.0 inch.

5. The design shall include a horizontal bench not less than 4 feet in width measured from the face of the solider pile-tieback retaining wall as shown on the Drawings.

1.05 SUBMITTALS

A. General Requirements

1. The Contractor shall submit the qualifications of the design engineer of the soldier pile-tieback retaining wall within one week after receipt of the Notice to Proceed.

2. The Contractor shall incorporate Metropolitan review and acceptance time into its schedule as specified in Section 01300.

3. The Contractor shall submit the information requested herein regarding the soldier pile-tieback retaining wall design and construction for review and approval prior to purchase of materials and excavation related to soldier pile or tieback anchor installation.

B. Excavation Plan, Sequence, Staging, and Schedule

1. Review record and reference drawing information, including locations of buried structures and pipelines. The Contractor shall submit locations of pot-holes necessary to ensure that proper clearances are maintained between shoring elements and existing facilities.



2. The Contractor shall submit a plan of the overall sequence, staging, and schedule of earthwork activities for and construction of solider pile-tieback retaining wall required by this section and Section 02200 of the specifications. The submittal shall illustrate the location, construction sequence, transition, and schedule of the submitted solider pile-retaining wall relative to all other excavations, support of excavation systems, and segmental concrete retaining wall (SCRW) systems intended and required for this Contract.

C. The Contractor shall submit working drawings for the soldier pile-tieback retaining wall that include the following:

1. Detailed engineering designs to the Engineer for review and acceptance. Design calculations in accordance with the design criteria set forth in Design Criteria Article 1.04 of this section, including anticipated deformations of the submitted soldier pile-tieback retaining wall design.

2. Design calculations for the soldier pile-tieback retaining wall prepared, signed, and stamped by a Professional Civil or Structural Engineer registered in the State of California.

3. Sizes, details, dimensions, arrangement of elements, method of assembly, lists of materials, and other appropriate data for all wall elements as required to check the adequacy of the proposed soldier pile-tieback retaining wall construction.

4. Solider pile-tieback retaining wall element and segment identification numbers presented on the working drawings.

5. Show existing and future structures, pipelines, utilities, and other facilities and improvements located from the face of soldier pile-tieback retaining wall to the ends of all tieback anchors.

6. Proposed methodology to be used for construction of all soldier pile-tieback retaining wall elements including but not limited to the following:

a. Procedures and specifications of construction equipment to be used for the installation of soldier pile-tieback retaining wall elements shall be submitted to the Engineer for review and acceptance a minimum of 30 days prior to starting excavation related to soldier pile or tieback anchor installation.

b. Procedures and specifications of construction equipment to be used for the installation of drilled soldier piles for the soldier pile-tieback retaining wall elements described in this specification section shall be submitted to the Engineer for review and acceptance a minimum of 30 days prior to starting excavation related to soldier pile or tieback anchor installation.

c. Procedures and data on equipment for tieback anchor installation, tensioning, pressure grouting and testing shall be submitted. The Contractor shall provide written documentation that the tieback anchors used will perform at their design strength for at least 25 years.

d. Sequence of excavation, installation of the wall, placement of compacted backfill, and construction of roadway elements (traffic barriers, utilities and pipelines, drainage, asphalt concrete pavement section, permanent cut above the roadway).

7. Dimensions, spacing, tolerances, and general pattern of construction of soldier pile-tieback retaining wall system with respect to excavation and finish grades of the roadway.

8. Plantable features layout and design.

D. Shop drawings for all fabricated materials, including:

1. Complete dimensions.

2. Details of soldier pile-tieback wall system, connections, end hardware, connectors, shim plates, and other accessories.

3. Details of tieback anchors including bars, centralizers, spacers, couplers, face plates, washers, and nuts.

4. Details of concrete lagging. The shop drawings shall show the material, dimensions, method of fabrication, type of reinforcement, and detail of field joints.

E. Quality Control

1. Health and safety procedures shall be in accordance with California Code of Regulations (CCR) Title 8, addressing soldier pile-tieback retaining wall construction and load testing of tieback anchors.



2. Submit qualifications of Contractor’s soldier pile-tieback retaining wall design engineer as specified herein above.

3. Submit qualifications of Contractor’s tieback anchor installer

4. Product data:

a. Manufacturer’s product data and certification for all materials to be incorporated into the soldier pile-tieback retaining wall shall be submitted. The certification shall state that the material and assemblies to be provided will fully comply with these specifications.

b. Mix designs and product data for cement grouts, and concrete used for the soldier pile-tieback retaining wall shall be submitted.

c. Mix designs and supporting test data for grout and manufacturer’s data on grout materials shall be submitted.

d. Manufacturer’s product data and recommended installation, calibration, and testing procedures for tieback anchors shall be submitted.

e. Manufacturer’s product data and certification of the double corrosion protection for the tieback anchors shall be submitted.

5. The Contractor shall submit test results and interpretation of test results for all tieback anchor installations. Calibration certificates for each testing jack, pressure gauge, reference pressure gauge, and dial gages to be used for testing of the tieback anchors shall also be submitted.

6. Daily reports, including the following information:

a. An accurate and detailed drill log shall be kept by the Contractor for each drilled hole excavation, indicating:

(1) Date and time excavation started.

(2) Drilled hole and identification.

(3) Drilled hole diameter as indicated on the drawings and as constructed.

(4) Equipment and method used for installation.

(5) Ground surface elevation

(6) Top of concrete elevation as indicated on the approved submittal and as constructed.

(7) Bottom of drilled hole elevation as indicated on the approved submittal and as constructed.

(8) Linear footage of soldier pile drilling

(9) Comments on water conditions, if encountered (i.e: [a] depth at which groundwater was encountered, [b] water conditions during drilling and concrete placement, [c] hydrostatic head, and [d] volume of flow).

(10) Detailed description of drilled holes and the geotechnical aspects of the excavated materials within the soldier pile drilled hole excavations. These descriptions shall be performed by a geotechnical consultant, which shall be either a professional geologist, certified engineering geologist, or geotechnical engineer currently registered in the State of California.

(11) Volume of concrete placed and concrete invoice or batch number

(12) Date and time excavation completed

(13) Date and time concrete placed

(14) Nature, location, and other details of any obstructions encountered during drilling

(15) Other comments as deemed necessary for the project including any nonstandard methods of construction which may have been required and affect the soldier pile configuration or construction

b. All detailed drill logs shall be signed daily in ink by the Contractor and the Contractor’s geotechnical consultant, and a copy filed with the Engineer.

c. Records of all installed soldier pile-tieback retaining wall elements, including locations, lengths, types, and number.

d. Records of all tieback anchor testing performed



7. Results of strength testing for concrete and grout shall be submitted.

8. The Contractor shall allow the Engineer sufficient time to observe, verify, and log the earth materials in the drilled holes for the solider piles.

1.06 QUALIFICATIONS OF SOLDIER PILE-TIEBACK RETAINING WALL DESIGN ENGINEER AND INSTALLER

A. The designer of the soldier pile-tieback retaining wall shall be a Professional Civil or Structural Engineer registered in the State of California with a minimum of 5 years of experience in the design of permanent soldier pile-tieback retaining walls. The designer shall have successfully designed at least three similar projects in the last 5 years. The experience of the designer shall include the design of similar type retaining wall systems to those required and proposed for this work.

B. The tieback anchor installer shall have a minimum of 5 years of experience in the installation similar tieback anchors.

1.07 SOLDIER PILE-TIEBACK RETAINING WALL DESIGN ENGINEER COORDINATION

A. The design engineer of the soldier pile-tieback retaining wall system shall perform periodic on-site inspections as the system is being constructed. As a minimum, the periodic inspections shall occur a minimum of once every week during soldier beam and tieback anchor installation.

B. The design engineer shall provide written certification that all design loads have been considered, that the site conditions and configuration of the soldier pile-tieback retaining wall system is consistent with the basis of the system design, and that the excavation support system is adequate for these loads.

C. Following completion of construction of the soldier pile-tieback retaining wall, the designer shall provide written certification that the soldier pile-tieback retaining wall was constructed in accordance with the design engineer’s plans based upon the designer’s review of site conditions, installation procedure and records, and test data.

PART 2 PRODUCTS

2.01 MATERIALS

A. Structural steel shall be in accordance with ASTM A36, minimum Grade 36, or ASTM A572 Grade 50.

B. Tieback anchors shall be commercially available products. Strand anchors shall be 0.6-inch-diameter, 7-wire strands with an ultimate tensile strength of 270 kips per square inch (ksi) in accordance with ASTM A416. Bar anchors shall be 1 to 1.375-inch-diameter deformed bars with an ultimate tensile strength of 150 to 160 ksi in accordance with ASTM A615. Tieback anchors shall have double corrosion protection in accordance with the Manufacturer’s recommendations specific to the corrosivity of the on-site ground conditions. Bonded length of the tieback anchors shall be fully encapsulated by cement grout.

C. Concrete and cement grout materials shall be in accordance with Section 03300.

D. Precast concrete shall be in accordance with Section 03300, Class F.

E. Reinforcing steel shall be deformed bars in accordance with ASTM A615, Grade 60, and Section 03210.

F. Backfill slurry shall be in accordance with Section 03300, Class N mix.

2.02 EQUIPMENT

A. Provide and maintain in good working condition, a full set of pre-stressing and anchor testing equipment. Equipment shall include as a minimum:

1. Hydraulic jack and pump, pressure gauges, bearing truss, and other required materials and equipment to perform testing of installed tieback anchors. The jack and pump shall have a minimum capacity of not less than 125 percent of the maximum anticipated load needed for testing or pre-stressing.

2. The jack and calibrated pressure gauges shall be used to measure applied loads. The pressure gauge assembly shall be capable of reading applied testing loads to an accuracy of 500 pounds. The jack and pressure gauge shall be calibrated as a unit by an independent firm. The calibration shall be performed within 45 working days of actual jobsite use. Testing shall not commence until the Engineer has accepted the calibration. Calibration shall be performed at least once every 30-day period or as directed by the Engineer.

3. A dial gauge or vernier scale capable of measuring to 0.001 inch shall be used to measure anchor movement. The movement-measuring equipment shall have sufficient length of travel to measure the longest anticipated



anchor elongation without resetting the device. The measuring device shall be capable of being mounted to allow measurements of anchor movement without being adversely affected by load application to the anchor.

PART 3 EXECUTION

3.01 GENERAL

A. The Contractor shall design, furnish, install, and test the soldier pile-tieback retaining wall specified herein and conceptually shown on the Drawings to support the clayey rubble creep zone up slope of the soldier pile-tieback retaining wall and to retain compacted backfill to support the roadway to the lines and grades shown on the Drawings.

B. The constructed solider pile-tieback retaining wall shall be consistent with the design criteria and the specified lateral deflection limitation at the top of the wall in accordance with requirements specified herein.

C. The Contractor’s furnished design shall be consistent with the design concept shown on the drawings; alternate earth-retaining/support systems or concepts shall not be permitted.

D. The installed soldier pile-tieback retaining wall system shall be permanent. In addition, the plantable feature of the lagging shall be consistent and visually compatible with the planter layout in the adjacent SCRW wall systems.

E. Excavation for the installation of soldier piles and tieback anchors shall not commence before receipt of the Engineer’s acceptance of the design of the soldier pile-tieback retaining wall.

F. Distress or overstress of the tieback anchors or solider piles is not allowed.

G. Perform structural welding in accordance with the applicable requirements of AWS D1.1.

H. Control of surface water shall be in accordance with Section 02200.

3.02 CONSTRUCTION SEQUENCE

A. The sequence to construct the soldier pile-tieback retaining wall shall be in accordance with the approved submittals.

B. Excavation activities associated with the installation of the soldier pile-tieback retaining wall system required herein, shall not commence until the design of the retaining wall system has been submitted, reviewed, and accepted by the Engineer.

C. The backfill of the retaining wall shall be systematic with the installation of the lagging. Backfill placement and compaction shall not advance ahead (higher elevation) of the installation of the lagging.

D. The backfill of the retaining wall shall not proceed more than 2 feet above the level of a tie-back anchor until the anchor has been installed, tested, and accepted by the Engineer.

3.03 SOLDIER PILES

A. Soldier pile installation shall be consistent with the design criteria requirements and installation restrictions specified herein and in accordance with the approved submittals.

B. Soldier piles shall be installed in 24-inch minimum-diameter drilled holes. Drilled hole diameter at any cross section shall not be less than the diameter specified in the approved design submittal.

C. Soldier pile drilling operations shall not commence until approved by the Engineer.

D. The Contractor shall provide drilling equipment having sufficient torque capacity and downward thrust capacity for the site conditions. The drilled holes for the soldier piles spaced at 6 diameters or less shall be drilled and filled alternately, with the concrete permitted to set at least 8 hours before drilling an adjacent hole.

E. Driven piles are prohibited.

F. Temporary steel casing shall be used as necessary to prevent caving or movement of earth into the drilled excavation. Withdrawal of temporary casing shall conform to Section 3.6 of ACI 336.1-01.

G. Each drilled hole shall extend to the required length as indicated on the approved drawings and as specified in the design criteria herein. The Engineer will observe the drilling operation and verify that the drilled hole has penetrated to the specified embedment length into competent formational materials. Drilled hole bottom shall be excavated to a level plane and machined cleaned.

H. Soldier piles shall conform to SSPWC Section 205 or ACI 336.3R, whichever is more stringent.



I. A continuous log of the geotechnical aspects encountered within each soldier pile drilled hole excavation shall be performed by a professional geologist, certified engineering geologist, or geotechnical engineer currently registered in the State of California.

J. Accurately align exposed faces of flanges to vary not more than 0.1 foot from a horizontal plane and not more than 1:200 out of vertical alignment.

K. The holes in which any soldier piles are removed for any reason shall be backfilled with backfill slurry.

3.04 CONCRETE PLACEMENT

A. At the time concrete is placed, the drilled hole excavation shall be free from loose material, debris, and accumulated water from seepage.

B. In the event that subsurface water is encountered, all drilled hole excavations shall be dewatered prior to placing concrete. Pumping shall be performed in a manner that will not create ground loss problems that might adversely affect the drilled hole as determined by the Engineer.

C. A minimum clearance of 3 inches from the drilled hole sidewalls shall be maintained around the entire perimeter of the H beams of the soldier piles.

D. Structural concrete shall be used to backfill the drilled hole and around the soldier piles below the elevation of the base of the soldier pile-tieback retaining wall lagging. The Contractor shall select material to be used to backfill soldier piles above the elevation of the base of the soldier pile-tieback retaining wall, in order to facilitate the placement of concrete lagging.

E. Concrete Placement

1. Placement of concrete shall begin as soon after drilling, soldier pile placement, inspection, and Engineer approval as possible. The drilled holes shall not be left open overnight. Concrete shall be placed from the bottom up with the use of a concrete pump and tremie pipe, or other means acceptable to the Engineer so that the concrete is not allowed to fall freely more than 5 feet and to prevent concrete from hitting the sides of excavation. The soldier pile and the drilled hole shall be free of obstructions which could cause segregation of concrete. Only the top 5 feet of concrete below existing finish grade shall be vibrated

2. As placed, the concrete shall be plastic but not free flowing. If there is an accumulation of scum or laitance on the top of the concrete, the scum or laitance shall be removed, and additional concrete shall be placed to bring the pier back to the proper elevation. During the filling of the drilled holes, if water begins to accumulate on the top of the concrete, the amount of water in succeeding batches shall be reduced

3. Concrete shall be placed in one continuous operation.

4. The actual volume of concrete installed in each drilled hole shall be recorded and shall be compared to the theoretical volume of concrete to check for possible pinching, collapse, or segregation of the concrete. If for a given drilled hole the actual volume of concrete is less than the theoretical volume of concrete, that drilled hole will be considered questionable. It is the responsibility of the Contractor to demonstrate that the questionable drilled hole has the minimum required dimensions and quality by means of a nondestructive testing procedure per-formed by an independent qualified testing firm. The testing firm shall certify based on the test results that the drilled hole meets the specified requirements. All soldier piles not meeting the specified requirements shall be replaced or the design modified at the Contractor's expense in a manner satisfactory to the Engineer.

3.05 LAGGING

A. The compacted backfill for the soldier pile-tieback retaining wall shall be continuously supported by lagging.

B. Lagging shall be installed and securely attached to the soldier piles prior to the placement of the adjacent retained backfill at any level of the soldier pile-tieback retaining wall.

C. The backfill immediately adjacent to the lagging shall be brought up uniformly and compacted together with the rest of the retained backfill materials.

D. The lagging shall be concrete lagging with plantable features as approved in the submittals.

E. Install concrete lagging with weep holes, drains or other drainage provisions that ensure free-draining conditions in the retained compacted backfill of the soldier pile-tieback retaining wall. Spacing of weep holes shall not exceed 18 feet.



F. Synthetic drain materials, including geotextiles and geocomposites, are not allowed to be put behind the lagging.

3.06 TIEBACK ANCHORS

A. General

1. Install tieback anchors in accordance with the manufacturer’s recommendations, the requirements specified herein, and the approved submittals.

B. Installation

1. Tie-back anchor installation operations shall not commence until approved by the Engineer.

2. Tieback anchors shall be installed in the presence of the Engineer. The height of compacted backfill behind the solider piles and lagging shall not proceed 2 feet higher than the planned level of a tieback row until all tiebacks of the row have been completely installed, tested, and approved by the Engineer.

3. Holes drilled for tieback anchors shall be the diameter(s) shown on the approved submittals. The diameter of the drill holes shall remain constant for the entire length of hole for each tieback anchor. Neck downs to holes of smaller size will not be allowed.

4. Use rotary drilling with or without casing as required by the prevailing ground conditions.

5. Upon completion of drilling each hole, the tieback anchor shall be placed into the hole. Use centralizers to insure that the anchor does not contact the walls of the drill hole.

6. The bonded length of tieback anchors as specified in the Design Criteria Article of this section shall be filled with grout placed by pumping the grout from the tip out.

7. The remaining free-stressing length (unbonded length) of tieback anchors shall be filled with bedding sand in accordance with Section 02200. Upon approval of the Engineer, a small amount of cement may be used to allow the sand to be placed by pumping. As an alternate, if the anchor bars or strands in the free-stressing length portion of the anchors are greased and encapsulated in a smooth PVC sleeve or polyethylene shield, then the free-stressing length (unbonded length) of tieback anchors may be filled with unpressured grout.

8. Pressure-grouting of anchors shall be performed as indicated in the approved submittal.

9. After pressure-grouting of the anchor has been completed and the grout has cured, each tieback anchor shall be performance or proof tested, and pre-loaded, as specified herein.

10. Tensioning of Tieback Anchors

a. The tensioning equipment shall be placed over the tieback anchor in such a manner that the jack or torque wrench, faceplates, and anchorage are axially aligned and centered within the equipment.

b. Tensioning (pre-loading) of the tieback anchor shall not begin until the grout has set. Performance or proof tests shall not commence until the grout in the bonded length has reached a sufficient strength to prevent slippage.

c. Pre-load each tieback anchor to the minimum design load indicated on the working drawings in the approved submittals. Nuts, face plates, and associated hardware shall be tightened against the soldier pile such that the locked off load is within 15 percent of this pre-load.

C. Testing

1. General

a. All testing shall be conducted in the presence of the Engineer and the design engineer responsible for the design of the soldier pile-tieback retaining wall.

b. Provide personnel and equipment to set-up and operate the test equipment and provide access to test locations.

c. The load test equipment shall be placed over tieback anchors in such a manner that the jack or torque wrench, faceplates, load cells, and anchorage are axially aligned and centered within the equipment.

d. No “alignment load” greater than 15 percent of the design load shall be applied to an anchor prior to testing. The maximum test load shall not exceed 80 percent of the minimum specified ultimate tensile strength of the anchor.



2. Performance Testing

a. The Engineer shall select four of the tieback anchors to perform 24-hour creep tests. These tests shall be performed in accordance with ASTM D4435, except as modified herein. These tests shall consist of loading and unloading of the anchor, in increments of the Design Load (P) as shown in Table 1, and the measuring and recording of the elongation of the anchor.

b. The Engineer shall select twelve of the tieback anchors to perform 200% design load tests. These tests shall be performed in accordance with ASTM D4435, except as modified herein. These tests shall consist of loading and unloading of the anchor, in increments of the Design Load (P) as shown in Table 2, and the measuring and recording of the elongation of the anchor.

c. Load application and reduction during the testing sequence shall be performed in a controlled manner. Movement measurements recorded to the nearest 0.001 inch shall be taken with respect to a fixed reference point at the Alignment Load (AL) used to seat the anchor and jack/jack chair assembly, and at each load increment.

d. The sequence of load applications shall be as follows:

Table 1 – 24-Hour Creep Test Loading Schedule Sequence No. Load Sequence No. Load

1 AL 9 AL 2 0.25 P 10 0.25 P 3 0.50 P 11 0.50 P 4 AL 12 0.75 P 5 0.25 P 13 1.00 P 6 0.50 P 14 1.25 P 7 0.75 P 15 1.50 P 8 1.00 P 16 1.75 P 17 2.00 P *

AL = Alignment Load.

P = Design Load indicated on the working drawings. * = Hold last load for creep testing before adjusting to lock off load.

Table 2 – 200% Design Load Test Loading Schedule Sequence No. Load Sequence No. Load

1 AL 6 1.25 P 2 0.25 P 7 1.50 P 3 0.50 P 8 1.75 P 4 0.75 P 9 2.00 P * 5 1.00 P

AL = Alignment Load. P = Design Load indicated on the working drawings. * = Hold last load for creep testing before adjusting to lock off load.

e. Hold each load, except the maximum test load, long enough to obtain the movement reading. Measure

movement and load immediately prior to advancing the test to the next loading increment.

f. Hold and maintain the maximum test load for 24 hours for the 24-hour creep test, and 30 minutes for the 200% design load test.

(1) During this hold period for the 200% design load test, record movements at total elapsed times of 1, 2, 3, 4, 5, 10, 15, and 30 minutes (the load hold time starts when the load is initially increased to the maximum test load).

(2) If the total movement between 1 and 30 minutes exceeds 0.25 inch, hold the test load for an additional 3 hours. Record total movements during this extended hold period at total elapsed times of 1, 2, and 3



hours, or if directed by the Engineer, continue testing and movement measurements as indicated for the 24-hour creep test.

(3) During the hold period for the 24-hour creep test, record movements as indicated for the 200% design load test, including the extended test portion. After the initial 4 hours of the hold period, continue recording movements at 4-hour increments thereafter throughout the total 24-hour testing period.

(4) Plot the load/elongation relationship (creep curve) for all performance tests.

g. Performance tests shall be considered acceptable if:

(1) For a 24-hour creep test, the total deflection does not exceed 12 inches and the creep movement at the maximum test load does not exceed 3/4 inch over a 24-hour period, measured after the 200% test load is applied.

(2) For a 200% design load test, the total deflection does not exceed 12 inches and the creep movement at the maximum test load does not exceed 1/4 inch over the initial 30-minute period.

h. After a satisfactory test, each anchor shall be locked off at the design load. The lock-off load shall be verified by rechecking the load in the anchor. If the lock-off load varies by more than 10 percent from the design load, the load shall be reset as required until the anchor is locked off within 10 percent of the design load.

i. 200% design load performance tests which fail to meet the acceptance criterion for creep movement specified above may be considered acceptable by the Engineer if the creep curve plotted from the movement data, including the extended hold period, indicates creep movement of less than the creep movement measured during the first 4 hours of all 24-hour creep tests, and the concurrence of the shoring design engineer.

j. Tieback anchors that fail performance testing shall be replaced.

3. Proof Testing

a. All tieback anchors which are not selected for performance tests shall be proof tested in accordance with ASTM D4435, except as modified herein.

b. The sequence of load applications shall be in accordance with Table 3 herein.

Table 3 – Proof Test Loading Schedule

Sequence No. Load

1 AL

2 0.25P

3 0.50P

4 0.75P

5 1.00P

6 1.25P

7 1.50P AL = Alignment Load. P = Design Load indicated on the working drawings.

c. Load application during the testing sequence shall be performed in a controlled manner. At each load

increment, including the alignment load (AL), record the movement of the anchor to the nearest 0.001-inch with respect to a fixed reference point.

d. Hold each load increment long enough to record the movement readings, but not for more than 1 minute.

e. Upon reaching the 150 percent load, hold the load for 15 minutes, and record movements at total elapsed times of 1, 2, 3, 4, 5, 6, 10, and 15-minute intervals.

(1) If the total movement recorded during this 15-minute hold period exceeds 0.1-inches, maintain the



150 percent load for 45 more minutes. Additional anchor movements shall be recorded at total elapsed times of 15, 20, 25, 30, 45, and 60-minute intervals.

(2) The time interval for holding the 150 percent test load shall commence at the instant the load is increased to this load.

(3) Upon completion of the hold period, reduce the load to the lock off load, P, tighten down the nut to the face plate and lock off the load.

f. Results from the proof tests shall be compared to the results from successfully installed and performance tested tieback anchors. Any significant variations to the results between the two tests, may, at the direction of the Engineer, require that the next anchor be performance-tested.

g. Proof tests will be accepted if:

(1) The total deflection does not exceed 12 inches and the creep movement under the 150 percent load does not exceed 0.1 inch over the initial 15-minute hold period.

(2) Proof tests which fail to meet the acceptance criterion for creep movement specified above will be acceptable if the maximum load is held for 60 minutes and the creep curve plotted from the movement data indicates a maximum creep movement of less than 0.05-inch during the last 45 minutes of the test.

h. Tieback anchors that fail proof testing shall be replaced. At the discretion of the soldier pile-tieback wall design engineer and with the approval of the Engineer, partial capacity may be assigned to the proof test failing anchor, and a second anchor may be installed nearby with a different inclination angle to supplement the first anchor.

i. After a satisfactory test, each anchor shall be locked off at the design load. The lock-off load shall be verified by rechecking the load in the anchor. If the lock-off load varies by more than 10 percent from the design load, the load shall be reset as required until the anchor is locked off within 10 percent of the design load.

3.07 EARTH WORK

A. A horizontal bench measuring 4 feet in width shall be constructed in front of the solider pile-tieback retaining wall as shown on the Drawings.

B. The existing clayey rubble creep zone soils behind the solider pile-tieback retaining wall shall be removed to the elevation of the 4-foot-wide horizontal bench. Removal limits of the clayey rubble creep zone shall consist of a prism defined at the bottom by the elevation of the 4-foot-wide horizontal bench, and at the rear by a 1/2:1 (horizontal to vertical) downward projected plane starting from the intersecting point between the existing ground surface and the finished grade of the roadway, and ending at the previously defined prism bottom. All clayey rubble creep zone materials and colluvium within this prism shall be removed.

C. All earthwork activities, including but not limited to, subgrade preparation, benching into cut slopes, and placement and compaction of fill shall be performed in accordance with Section 02200.

3.08 FIELD QUALITY CONTROL ASSURANCE

A. The soldier pile shall be constructed to the following tolerances:

1. The face of the soldier pile-tieback retaining wall at the top of the wall shall not deviate more than 0.1 foot from the lines and grades of the North Access Road alignment shown on the Drawings.

2. Deviation from the vertical shall be within 0.1 foot for the construction of the traffic barriers.

3. Long-term differential settlement of the segmental concrete units shall not exceed 1/4 inch over 40 feet.

END OF SECTION

September 2009 15100-1 1629 (construction contract) Addendum 4

SECTION 15100

VALVES FOR PIPING SYSTEMS PART 1 GENERAL

1.01 REFERENCES

A. General

1. The publications listed below form a part of this specification to the extent referenced.

2. Where a date is given for reference standards, the edition of that date shall be used. Where no date is given for reference standards, the latest edition available on the date of Notice Inviting Bids shall be used.

B. American National Standards Institute (ANSI)

1. ANSI B16.5, Pipe Flanges and Flanged Fittings

C. American Society for Testing and Materials (ASTM)

1. ASTM A536, Standard Specification for Ductile Iron Castings

2. ASTM D1784, Standard Specification for Rigid Poly (Vinyl Chloride) (PVC) Compounds and Chlorinated Poly (Vinyl Chloride) (CPVC) Compounds

D. American Water Works Association (AWWA)

1. AWWA C504, AWWA Standard for Rubber-Seated Butterfly Valves

E. National Fire Protection Association (NFPA)

1. NFPA 24, Standard for the Installation of Private Fire Service Mains and their Appurtenances

1.02 SUBMITTALS

A. Product data including the following:

1. Type

2. Dimensional outlines

3. Cross-sectional assemblies

1.03 QUALITY ASSURANCE

A. Qualifications

1. The valve manufacturer shall have designed and manufactured valves that are similar in size and type to the products required herein for at least 5 years.

PART 2 PRODUCTS

2.01 GENERAL

A. Valves shall be permanently marked for identification. The identification may be cast into the valve body. Each valve shall have a brass, aluminum, or stainless steel nameplate securely attached to the valve. The nameplate shall show the following:

1. Manufacturer's name and trademark

2. Serial number

3. Size

4. Pressure rating

5. Other necessary information regarding the valve

2.02 VALVES

A. Unless specified otherwise, valve operators shall be as follows: butterfly valves 4 inches and smaller shall have a locking lever actuator and butterfly valves 6 inches and larger shall have a manual gear actuator with memory stops and a position indicator.

Valves for Piping Systems

1629 15100-2 September 2009 Addendum 4 (construction contract)

B. Butterfly valves shall be in accordance with AWWA C504, Class 150B, and except as modified herein, shall have a ductile iron body in accordance with ASTM A536, Grade 60-40-18 or better.

C. Ball valve operators shall be full-bore with socket end connections in accordance with ASME B16.5, Class 150, unless shown otherwise on the drawings. The body, ball, and stem shall be PVC in accordance with ASTM D1784.

D. Other requirements for valves shall be as specified in Table 1 below.

2.03 VALVE BOX

A. The Contractor shall furnish and install valve boxes for buried valves.

B. For valves larger than 1 inch, boxes shall be cast-iron and shall be either screw-type or slip-adjustment-type.

C. The word WATER shall be cast in large letters into the outside of the valve box cover.

D. The Contractor shall provide 3 sets of each type of T-handle wrench, combination key, or other special wrench required to operate the valve stop and to remove the cover.

E. Acceptable Manufacturers: Alhambra Foundry Company, Mueller Company; or equal.

PART 3 EXECUTION

3.01 INSTALLATION

A. Valves, operators, stem extensions, valve boxes, and appurtenances shall be installed in accordance with the manufacturer's written instructions, these specifications, and the drawings. Valves shall be supported to avoid undue stresses on the pipe.

B. Valves shall be firmly supported at each end to avoid undue stresses on the pipe.

C. Valves shall be installed to provide easy access for operation, removal, and maintenance and to avoid interference of the valve operators with structural members, piping, grates, or any other feature in close proximity to the valve.

D. Where combinations of valves, sensors, switches, and controls are specified, the Contractor shall assemble and install these items to be compatible and operate properly.

TABLE 1 - VALVES

Valve

Type and Service

Size

End Conn. and Rating

Body Material

Description

Manufacturer's Catalog Number

Butterfly Valve

For Buried Service

6” to 10” Sta. 68+50 to Sta. 43+50, use 150-lb flanges

Sta. 43+49 to Sta. 4+56, use 300-lb flanges

Ductile Iron (Extra Heavy) Meeting AWWA C504

1. FF flanged 2. One-piece shaft 3. 304- 18.8 SST 4. Buna N rubber seat on body 5. 316 SST disc edge 6. Self-adjusting packing 7. Self-lubricated bearings 8. Buried service actuator 9. Ground level position indicator 10. Assembly w/ 2” square nut 11. NFPA 24 compliant

PRATT (Groundhog) or equal

Ball Valve

Socket ends

150 lb

PVC Class 12454-B

1. PVC body, ball and stem 2. PTFE Seats 3. Full- bore 4. EPDM or Viton seals (O-ring) 5. True Union Design 6. Stem extension

Spears True Union 2000, Hayward, or equal.

NOTE: Operators shall be capable of providing an output torque that is at least 1.5 times greater than that required to operate the valve at design pressure. The design pressures are 285 psi for Class 150 valves and 740 psi for Class 300 valves.

END OF SECTION

addendum number: 4 modifying: specifications...

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