structural geotechnical report

Structural Geotechnical Report

Retaining Wall Replacements

Various Locations DuPage County, Illinois

Prepared for

Design Section Engineer Team: Knight E/A, Inc.

Prepared by:

April 18, 2018

.

April 18, 2018 Mr. Frank Williams, P.E. Knight E/A, Inc. 631 East Boughton Road Bolingbrook, IL 60440 Structural Geotechnical Report Retaining Wall Replacements Various Locations DuPage County Dear Mr. Williams: Attached is a copy of the Structural Geotechnical Report for the above referenced project. The report provides a brief description of the site investigation, site conditions and foundation recommendations. The project includes the replacement of 4 individual walls at various locations in DuPage County. The site investigation included advancing one (1) soil boring to a depth of 20 feet at each of the wall locations. Should you have any questions or require additional information, please call us at 630‐994‐2600. Sincerely,

Charlie Johnson, P.E. Dawn Edgell, P.E. Project Engineer Sr. Project Engineer

623 Cooper Court Schaumburg, IL 60173

Integrity | Quality | Reliability

TOC- 1

TABLE OF CONTENTS 1.0 INTRODUCTION ................................................................................................................. 1

1.1 Site Conditions ......................................................................................................... 2

1.2 Proposed Retaining Wall Information ........................................................................ 2

1.3 Regional Geology ...................................................................................................... 3

2.0 SITE SUBSURFACE EXPLORATION PROGRAM ........................................................... 4

2.1 Subsurface Exploration Program ................................................................................ 4

2.2 Laboratory Testing Program ...................................................................................... 5

2.3 Subsurface Conditions ............................................................................................... 5

2.3.1 Soil Conditions ‐ Eola Road (RWB‐01) ........................................................................................ 6

2.3.2 Soil Conditions ‐ Winfield Road (RWB‐02) .................................................................................. 6

2.3.3 Soil Conditions ‐ Yackley Road (RWB‐03) ................................................................................... 6

2.3.4 Soil Conditions ‐ 55th Street (RWB‐04) ........................................................................................ 7

2.3.5 Groundwater Conditions ........................................................................................................... 7

3.0 GEOTECHNICAL ANALYSES ..................................................................................................... 9

3.1 Derivation of Soil Parameters for Design .................................................................... 9

3.2 Seismic Parameters ................................................................................................. 12

4.0 GEOTECHNICAL RECOMMENDATIONS ...................................................................... 14

4.1 Retaining Wall Design Analysis ................................................................................ 14

4.1.1 Wall and Embankment Settlement........................................................................... 15

4.1.2 Slope Stability Analyses ........................................................................................... 15

4.1.3 Slope Stability Results .............................................................................................................. 16

4.2 Retaining Wall Design Recommendations................................................................. 17

4.2.1 Lateral Earth Pressures and Loading ......................................................................................... 19

5.0 CONSTRUCTION CONSIDERATIONS ....................................................................................... 22

5.1 Existing Utilities ...................................................................................................... 22

5.2 Excavations ............................................................................................................ 22

5.3 Borrow Material and Compaction Requirements ...................................................... 22

5.4 Groundwater Management ..................................................................................... 24

6.0 LIMITATIONS ...................................................................................................................... 25

Figure Figure 1 Project Location Maps Tables Table 1 Wall Summaries Table 2 Boring Summary Table 3 Groundwater Summary Tables 4a to 4d Summary of On‐site Soil Parameters Table 5 Seismic Parameters Table 6 Proposed Wall Design Summaries Table 7 Wall Descriptions Table 8 Stability Analyses Results Table 9 Foundation Recommendations Table 10 LRFD Load Factors for Retaining Wall Design Table 11 Lateral Earth Pressures Soil Parameters Table 12 Equivalent Height of Soil for Vehicular Loading on Retaining Wall Table 13 Structural Fill Soil Properties Appendices Appendix A Site Photographs Appendix B Retaining Wall Boring Location Plans Appendix C Soil Boring Logs Appendix D Slope Stability Analyses Exhibits

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Structural Geotechnical Report Multiple Retaining Wall Replacements

Various Locations DuPage County, Illinois

1.0 INTRODUCTION GSG Consultants, Inc. (GSG) completed a geotechnical investigation for the replacement of 4 separate retaining wall structures. The walls are located in Aurora, Warrenville, Lisle and Hinsdale in DuPage County, Illinois. The purpose of the investigation was to explore the subsurface conditions, to determine engineering properties of the subsurface soils, and develop design and construction recommendations for each of the projects.

Figure 1: Overall Project Location Map

Retaining Wall Replacements DuPage County

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1.1 Site Conditions The project in Aurora is located on North Eola Road, north of the intersection with North Aurora Road. There are residential neighborhoods on either side of the roadway, and immediately behind the existing wall, with a high school just to the north. The existing wall is a timber wall, approximately 6 feet high. The project in Warrenville is located along South Winfield Road. Winfield road runs north‐south crossing Warrenville Road just south of the site location. There are residential neighborhoods on either side of the roadway, and immediately behind the existing wall, with a commercial area just south at Warrenville Road. The existing wall is a brick/stone wall, approximately 4 feet high. The project in Lisle is located along southbound Yackley Avenue, which runs north‐south crossing Ogden Avenue about ½ mile north of the site location. There is a residential neighborhood to the west and an industrial/commercial park to the east. The existing wall is a modular block wall approximately 4.5 feet high. The project in Hinsdale is located on 55th Street immediately adjacent to the high school. 55th Street runs east‐west crossing Route 83 just west of the site location. The existing wall is a modular block wall approximately 2.5 feet high. The curb line for 55th Street is located on the top of the wall, with a sidewalk and fence along the bottom of the wall. Photographs of each site and the existing walls are included in Appendix A.

1.2 Proposed Retaining Wall Information A technical memo (dated November 2, 2017) prepared by Knight for DuPage County Department of Transportation provided a structural review of various retaining walls on routes across DuPage County. Based on the review of the existing walls, several repair or replacement options were provided based on the overall condition of the existing structures. Knight has provided preliminary plans for four of the walls based on the structural recommendations. Table 1 presents a summary of the existing retaining walls at each location and the proposed repair or replacement option for each site.


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Table 1 – Wall Summaries

Wall Location Wall Designation

Existing Wall Type

Proposed Repair or

Replacement

Estimated Wall Length

(ft)

Maximum Wall Height

(ft) Eola Road and Haverhill

Road, Aurora, IL CH 14 Timber Wall Replacement 295 6

Winfield Road and Main Street, Warrenville, IL

CH 13 Modular Concrete Block

Replacement 90 4

Yackley Road and Hitchcock Avenue, Lisle,

IL CH 40

Modular Concrete Block

Replacement 141 4.5

55th Street and Madison Street, Hinsdale, IL

TBD Modular Concrete Block

Replacement 320 2.5

1.3 Regional Geology GSG reviewed several published documents in an effort to determine the regional geological setting in the area of the site. The subject area is located in the eastern portion of DuPage County, Illinois. The surficial geologic deposits in this area are typically glacial drift deposited during the Wisconsin Glacial Age. The geology of the subject area consists of deposits of grey silty clay till as much as 100 feet thick in the subject area. Deposits in the area of RWB‐1 are primarily from the Yorkville Member of the Wedron Formation, described as “characteristically gray clayey till, locally silty, generally with few cobbles and boulders but with abundant small pebbles.” The Deposits in the areas of RWB‐2, RWB‐3, and RWB‐4 are primarily from the Wadsworth Member of the Wedron Formation, described as “mostly grey clayey till”, not conspicuously different from the Yorkville Member, with the exception of the West Chicago Moraine (Present in RWB‐2 and RWB‐3) which is lighter, slightly more silty and contains more gravel lenses. The Wadsworth Member also contains “an abundance of black shale from Mississippian and Devonian formations.” These formations overlie the Silurian System Dolomite (undifferentiated) which consists of almost entirely dolomite that varies from extremely argillaceous, silty, and cherty to exceptionally pure. The bedrock dips slightly east with an average depth of 70 feet below ground surface in the area of RWB‐1 and an average depth of 100 feet below ground surface in the area of RWB‐4.


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2.0 SITE SUBSURFACE EXPLORATION PROGRAM This section describes the subsurface exploration program and laboratory testing program completed as part of this project. 2.1 Subsurface Exploration Program The proposed locations of the soil borings were provided by Knight and were completed in the field based on field conditions and accessibility. The proposed depths of the soil borings were determined by GSG in accordance with the IDOT procedures and requirements, which requires borings to a minimum depth of 20 feet for retaining structures The site subsurface exploration was conducted between March 19th and March 29th, 2018, and included advancing one (1) standard penetration test (SPT) boring to a depth of 20 feet in the vicinity of each of the proposed walls. A summary of the boring completed at each wall location is provided in Table 2 ‐ Boring Summary. All locations were drilled at the base of the wall with the exception of RWB‐4 at 55th Street, which was drilled at the top of the wall. At three locations (Eola, Winfield, and Yackley), hand augers were also completed at the top of each wall, where accessible, to confirm the soil types behind each of the existing walls. The locations of each of the soil borings at each site location are shown in Appendix B – Retaining Wall Boring Location Plans.

Table 2 – Boring Summary Boring

Designation Wall Location Surface Elevation (ft)

Boring Location Drill Rig

RWB‐1 Eola Road and Haverhill Road, Aurora, IL

727.0 North of Wall in Roadway Mobile 57

RWB‐2 Winfield Road and Main Street, Warrenville, IL

714.0 North of Wall in Roadway CME‐75

RWB‐3 Yackley Road and Hitchcock Avenue, Lisle, IL

691.0 Center of Wall in Roadway Mobile 57

RWB‐4 55th Street and Madison Street, Hinsdale, IL

721.0 Center of Wall in Roadway Mobile 57


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The soil borings were drilled using either a truck‐mounted Mobile 57 or CME‐75 drill rig using 3¼‐inch I.D. hollow stem augers. Soil sampling was performed according to AASHTO T 206, "Penetration Test and Split Barrel Sampling of Soils." Soil samples were obtained at 2.5‐foot intervals to the termination depths of 20 feet. Water level measurements were made in each boring when evidence of free groundwater was detected on the drill rods or in the samples. The boreholes were also checked for free water immediately after auger removal, and before filling the open boreholes with soil cuttings and bentonite and surface patched with concrete. GSG’s field representative inspected, visually classified and logged the soil samples during the subsurface exploration activities. They then performed unconfined compressive strength tests on cohesive soil samples using a calibrated Rimac compression tester and a calibrated hand penetrometer in accordance with IDOT procedures and requirements. Representative soil samples were collected from each sample interval and were placed in jars and returned to the laboratory for further testing and evaluation. 2.2 Laboratory Testing Program All samples were inspected in the laboratory to verify the field classifications. A laboratory testing program was undertaken to characterize and determine engineering properties of the subsurface soils encountered in the area of each proposed retaining wall. Moisture content laboratory tests (ASTM D2216/ AASHTO T‐265) were performed on representative soil samples. The laboratory tests were performed in accordance with test procedures outlined in the IDOT Geotechnical Manual (2015), and per ASTM and AASHTO requirements. Based on the laboratory test results, the soils encountered were classified according to the AASHTO and the Illinois Division of Highways (IDH) classification systems. The results of the laboratory testing program are shown along with the field test results in Appendix C ‐ Soil Boring Logs.

2.3 Subsurface Conditions This section provides a brief description of the soils encountered in the borings performed. Variations in the general subsurface soil profile were noted during the drilling activities. Detailed descriptions of the subsurface soils are provided in Appendix C ‐ Soil Boring Logs. The soil boring logs provide specific conditions encountered at each boring location. The soil boring logs include soil descriptions, stratifications, penetration resistance, elevations, location of the samples, and laboratory test data. Unless otherwise noted, soil descriptions indicated on


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boring logs are visual identifications. The stratifications shown on the boring logs represent the conditions only at the actual boring locations and represent the approximate boundary between subsurface materials; however, the actual transition may be gradual. 2.3.1 Soil Conditions ‐ Eola Road (RWB‐01) The pavement thickness at the surface of RWB‐01 consisted of 12 inches of asphalt and 12 inches of sand and gravel base course materials. Immediately below the pavement, sand fill materials were encountered to a depth of 3.5 feet. Below the fill, the boring encountered medium stiff to hard, brown and gray to gray silty clay through the depth of the boring. The boring was terminated in stiff clay at a depth of 20 feet. The hand auger soil sample taken behind the wall contained brown clay similar to the near surface materials in the soil boring. A relatively thin layer of brown and gray clay at a depth of 5 feet had an unconfined strength of 0.5 tsf. Generally, the native clay materials had unconfined compressive strengths ranging from 1.5 to 5 tsf. Groundwater was not encountered either while drilling or after drilling in this boring. 2.3.2 Soil Conditions ‐ Winfield Road (RWB‐02) The pavement thickness at the surface of RWB‐02 consisted of 14 inches of asphalt. Immediately below the asphalt pavement, sand with gravel fill materials were encountered to a depth of 8.5 feet. Cobbles and large gravel were encountered throughout this level. Below the fill, the boring encountered medium dense to dense, brown sand with gravel to the termination depth of 20 feet. The hand auger soil sample taken behind the wall contained brown clay. The SPT N values of the native sands ranged from 21 to 40 blows per foot. Groundwater was encountered while drilling at a depth of 13.5 feet but was not encountered after drilling in this boring. 2.3.3 Soil Conditions ‐ Yackley Road (RWB‐03) The pavement thickness at the surface of RWB‐03 consisted of 12 inches of asphalt and 8 inches of sand and gravel base course materials. Immediately below the pavement, a layer of clay fill materials was encountered to a depth of 3.5 feet. Below the fill, the boring encountered very stiff to hard, brown and gray silty clay to a depth of 12 feet, underlain by medium dense to very dense, brown and gray sand with gravel. Some occasional rock fragments were encountered at a depth of 13.5 feet. The boring was terminated at a depth of 20 feet in the native sands and gravels. The hand auger soil sample taken behind the wall contained brown sand and gravel. Generally, the native clay materials had unconfined compressive strengths ranging from 2.75 to 4.6 tsf. The native sands had SPT N values ranging from 17 to in excess of 50 blows per foot.


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Groundwater was encountered while drilling at a depth of 18.5 feet but was not encountered after drilling in this boring. 2.3.4 Soil Conditions ‐ 55th Street (RWB‐04) The pavement thickness at the surface of RWB‐04 consisted of 6 inches of asphalt, 6 inches of concrete and 8 inches of sand and gravel base course materials. Immediately below the pavement, a layer of clay fill materials was encountered to a depth of 3.5 feet. Below the fill, the boring encountered very stiff, brown and gray to gray silty clay through the depth of the boring. The boring was terminated in very stiff clay at a depth of 20 feet. Generally, the native clay materials had unconfined compressive strengths ranging from 2 to 3.75 tsf. Groundwater was not encountered either while drilling or after drilling in this boring.

2.3.5 Groundwater Conditions Water levels were checked in each boring to determine the general groundwater conditions present at the site, and were measured while drilling and after each boring was completed. None of the borings were left open after completing the boring, and no 24 hour reading was collected due to safety concerns. A summary of the groundwater conditions encountered in each boring is included in each section above and in Table 3.

Table 3 – Groundwater Summary

Boring Designation

Surface Elevation (ft)

While Drilling (ft) Depth/Elevation

After Drilling (ft)

Estimated Long Term Groundwater* (ft)

RWB‐1 727.0 None None 11.5/715.5

RWB‐2 714.0 13.5/700.5 None 19.5/694.5

RWB‐3 691.0 18.5/672.5 None Greater than 20 feet

RWB‐4 721.0 None None 13.5/707.5

*Estimated based on color change of soils from brown to gray

Based on the color change from brown to gray, the anticipated long term groundwater level was estimated for each boring location as shown in Table 3. Water level readings were made in the boreholes at times and under conditions shown on the boring logs and stated in the text of this report. Long term observations in cased borings or piezometers would be necessary to more


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accurately evaluate the long‐term groundwater conditions at the site. However, it should be noted that fluctuations in groundwater level may occur due to variations in nearby creeks, rainfall, other climatic conditions, or other factors not evident at the time measurements were made and reported herein.


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3.0 GEOTECHNICAL ANALYSES This section provides GSG’s geotechnical analysis and recommendations for the design of each of the proposed retaining walls based on the results of the field exploration, laboratory testing, and geotechnical analysis. Subsurface conditions in unexplored locations may vary from those encountered at the boring locations. If structure locations, loadings, or elevations are changed, we request that you contact GSG so that we may re‐evaluate our recommendations. 3.1 Derivation of Soil Parameters for Design GSG determined that the geotechnical parameters to be used for the project design based on the results of field and laboratory test data on individual boring logs as well as our experience. Unit weights, friction angles and shear strength parameters were estimated using corrected standard penetration test (SPT) using published correlations for N values results for the fill and cohesionless soils and in‐situ and laboratory test results for cohesive soils. The SPT values were corrected for hammer efficiency. The hammer efficiency correction factor considers the use of a safety hammer/rope/cat‐head system, generally estimated to be 60% efficient. Thus, correlations should be based upon what is currently termed as N60 data. The efficiency of the automatic hammer for the truck‐mounted Mobile B‐57 and CME‐75 drill rigs are based on previous efficiency testing of the drill rigs. The correction for hammer efficiency is a direct ratio of relative efficiencies as follows:

N60 = N * (98/60) Mobile 57 N60 = N * (72/60) CME‐75

*Where the N value is the field recorded blow counts. Based on the field investigation data collected, generalized soil parameters for use in design are presented in Tables 4a to 4d.


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Table 4a – Summary of On‐Site Soil Parameters Eola Road ‐ RWB‐1

Depth/Elevation (feet) Soil Description

In situ Unit

Weight

γ (pcf)

Undrained Drained

Cohesion c (psf)

Friction Angle φ (Degrees)

Cohesion c (psf)


New Engineered Granular Fill

125 0 32 0 32

Existing Embankment

Brown Clay 130 1,500 0 100 28

725‐723.5 Brown and Gray Sand with Gravel Fill

130 0 30 0 30

723.5‐715.5 Brown and Gray, Stiff to Hard Silty Clay

136 3,300 0 125 28

715.5‐707 Gray, Stiff to Very Stiff

Clay 134 2,900 0 100 28

Table 4b – Summary of On‐Site Soil Parameters

Winfield Road ‐ RWB‐2


In situ Unit

Weight

γ (pcf)

Undrained Drained

Cohesion c (psf)


Cohesion c (psf)



125 0 32 0 32

Existing Embankment

Brown Clay 130 1,500 0 100 28

714‐705.5 Brown Sand with Gravel Fill

130 0 30 0 30

705.5‐694 Brown, Medium Dense to Dense Sand with Gravel

134 0 38 0 38


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Table 4c – Summary of On‐Site Soil Parameters Yackley Road ‐ RWB‐3


In situ Unit

Weight

γ (pcf)

Undrained Drained

Cohesion c (psf)


Cohesion c (psf)



125 0 32 0 32

Existing Embankment

Brown Sand with Gravel Fill

130 0 36 0 36

690‐687.5 Black and Gray

Clay Fill 130 3,500 0 100 28

687.5‐679

Brown and Gray, Very Stiff to Hard Silty

Clay

138 3,700 0 125 32

679‐671

Brown, Medium Dense to Very

Dense Sand with Gravel

136 0 40 0 39


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Table 4d – Summary of On‐Site Soil Parameters 55th Street ‐ RWB‐4


In situ Unit

Weight

γ (pcf)

Undrained Drained

Cohesion c (psf)


Cohesion c (psf)



125 0 32 0 32

720‐717.5 Black and Brown

Clay Fill 130 2,500 0 100 28

717.5‐707 Brown & Gray, Very Stiff Silty

Clay

135 2,800 0 100 28

707‐701 Gray, Very Stiff

Silty Clay 133 2,500 0 100 28

3.2 Seismic Parameters The seismic hazard for the site was analyzed per the IDOT Geotechnical Manual, IDOT Bridge Design Manual, and AASHTO LRFD Bridge Design Specifications. The Seismic Soil Site Class was determined per the requirements of All Geotechnical Manual Users (AGMU) Memo 9.1, Design Guide for Seismic Site Class Determination, and the “Seismic Site Class Determination” Excel spreadsheet provided by IDOT. A global Site Class Definition was determined for this project, and was found to be Soil Site Class D. The Seismic Performance Zone (SPZ) was determined using Figure 2.3.10‐2 in the IDOT Bridge Manual and was found to be Seismic Performance Zone 1. The AASHTO Seismic Design Parameters program was used to determine the peak ground acceleration coefficient (PGA), and the short (SDS) and long (SD1) period design spectral acceleration coefficients. For this section of the project, the SDS and the SD1 were determined using 2014 AASHTO Guide Specifications as shown in Table 5. Given the site location and materials encountered, the potential for liquefaction is minimal.


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Table 5 – Seismic Parameters

Building Code Reference

PGA SDS SD1

2014 AASHTO Guide for LRFD Seismic Bridge Design 0.048g 0.161g 0.089g


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4.0 GEOTECHNICAL RECOMMENDATIONS This section provides recommendations regarding foundation and design parameters for the proposed retaining walls that are to be replaced. The recommendations were developed based on the project information provided by Knight and the results of the site investigations. If there are any significant changes to the project characteristics or if significantly different subsurface conditions are encountered during construction, GSG should be consulted so that the recommendations of this report can be reviewed. The foundation design recommendations were completed per the AASHTO LRFD 7th Edition (2014). 4.1 Retaining Wall Design Analysis The preliminary information provided by Knight indicate that the existing walls will be replaced with either a timber wall with dead man or a modular concrete block wall. Each of these wall types will be supported on shallow foundation systems. The proposed replacement wall type and anticipated wall heights for each of the locations is shown in Table 6.

Table 6 – Proposed Wall Summary

Wall Location Proposed Wall Type

Proposed Repair or

Replacement

Maximum Wall Height (ft)

Eola Road and Haverhill Road, Aurora, IL

Timber with Deadman Spacing

Replacement 6

Winfield Road and Main Street, Warrenville, IL


Replacement 4

Yackley Avenue and Hitchcock Avenue, Lisle, IL


Replacement 4.5

55th Street and Madison Street, Hinsdale, IL


Replacement 2.5


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GSG evaluated the bearing capacity, settlement and global stability to determine the suitability of the proposed retaining systems at each location. 4.1.1 Wall and Embankment Settlement All of the wall locations are to be constructed in embankment cut areas. The estimated settlement due to the placement of fill materials for the construction of the proposed wall is anticipated to be less than 1 inch. 4.1.2 Slope Stability Analyses The wall contractor should confirm stability requirements based on the final wall configuration. The following parameters were used to evaluate each wall:

Table 7 – Wall Descriptions

Eola Road – Timber Wall

Maximum total exposed height of the retaining wall (H)*

6 feet

Estimated total height of retaining wall (H) 7 feet

Winfield Road – Modular Block


4 feet

Estimated total height of retaining wall (H) 5 feet

Yackley Ave – Modular Block


4.5 feet

Estimated total height of retaining wall (H) 5.5 feet

55th Street – Modular Block


2.5 feet

Estimated total height of retaining wall (H) 3.5 feet

All Wall Locations

Unit weight of the retained fill (embankment)

125 pcf

Internal friction angle for the select backfill (native soils)

32 degrees

*Based on preliminary design provided by Knight


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Slide 7.0 is a comprehensive slope stability analysis software that performs limit equilibrium analysis and was used to evaluate the proposed retaining wall geometry for the project. The proposed designs were analyzed based on the preliminary grading and the soils encountered while drilling. Based on the geometry, and the soil borings, global stability analyses were performed for circular failure analysis using the simplified Bishop and Janbu analyses methods. The analyses were performed using the soil parameters in Tables 4a to 4d. 4.1.3 Slope Stability Results Circular failure analyses were evaluated using Bishop and Janbu analyses methods for a short term (undrained) condition and long term (drained) condition for each of the proposed retaining wall geometries. The analyses were performed at the highest elevation/maximum wall height of each proposed wall. Table 8 provides a summary of the stability analyses.

Table 8– Stability Analyses Results

Analysis Exhibit Station Failure Type Factor of Safety Required Minimum

Factor of Safety

Exhibit 1 Eola

Circular – Short Term

7.8 1.5

Exhibit 2 Circular – Long Term

2.3 1.5

Exhibit 3 Winfield


2.1 1.5


2.1 1.5

Exhibit 5 Yackley


9.5 1.5


3.5 1.5

Exhibit 7 55th Street


25.5 1.5


5.1 1.5


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Based on the analyses results, each of the proposed retaining walls meets the minimum factor of safety of 1.5. Appendix D presents copies of the slope stability analyses. 4.2 Retaining Wall Design Recommendations Based on the preliminary design information, GSG understands that the proposed new retaining walls will be either timber with deadman spacing or modular block walls. Based on the results of the subsurface investigation and the design information provided, the proposed retaining walls could be supported upon a shallow, strip footing system, bearing on the very stiff native silty clay materials. Any existing fill materials or soft native clays should be removed down to the suitable native soils. The foundations could then either be designed at the lower elevation or the over excavation should be backfilled to the bearing grade with structural fill. The granular structural fill should be placed in accordance with the construction considerations section of this report. The lateral limit of the engineered fill placed beneath the foundation should extend a minimum 1 foot beyond the outside edges of the footing and from that point outward laterally 1 foot for every 2 feet of fill thickness below the footing. These wall types are typically founded a minimum of 1‐foot, or 1 block height, below finished grade on a 6‐inch thick granular leveling pad. A summary of the anticipated bearing elevation and recommended allowable bearing capacity for each wall location is in Table 9.

Table 9 – Foundation Recommendations

Wall Location

Wall Type

Estimated Bearing Elevation

(ft)

Recommended Allowable Bearing Capacity (psf)

(ASD)*

Comments Anticipated Settlement (inches)

Eola Road and Haverhill

Road, Aurora, IL

Timber with

Deadman Spacing

726.0 3,000**

Undercut soft materials to a depth of 2 feet and replace with structural fill

<1 inch

Winfield Road and

Main Street, Warrenville,

IL


713.0 4,000 None <1 inch


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*Includes a factor of safety of 3. **Based on recommendations for undercuts discussed further in this report. The actual strip foundation thickness and reinforcement should be determined by a structural analysis. The allowable bearing capacity is based on an allowable total settlement of one inch and differential settlement of one half inch. If any assumptions or design loading information above is not correct or has been changed, GSG should be contacted to re‐evaluate the foundation design recommendations. If the native soils at the base of the foundation become disturbed during excavation, the exposed subgrade should be compacted prior to placing any structural fill. All localized soft or otherwise unsuitable soils should be over‐excavated and replaced with granular structural fill to the proposed foundation grade elevation. Engineering analyses and design of the proposed walls shall be performed using the current AASHTO Load and Resistance Factor Design (LRFD) Methodology as required by the IDOT. LRFD methodology incorporates the use of load factors and resistance factors to account for uncertainty in applied loads and load resistance of structure elements separately. The AASHTO LRFD Bridge Design Specifications outline load factors and combinations for various strength, extreme event, service, and fatigue limit states. Section 11, which outlines geotechnical criteria for retaining walls, of the AASHTO Specifications requires the evaluation of bearing resistance failure, lateral sliding, and overturning at the strength limit state and excessive vertical displacement, excessive lateral displacement, and overall stability at the service limit state. Table 10 provides the load factors to be used in the design of the retaining walls in accordance with AASHTO Table 3.4.1‐1, Load Combinations and Load Factors, and Table 3.4.1‐2, load Factors for Permanent Loads.

Yackley Avenue and Hitchcock Avenue, Lisle, IL


690.0 3,000 None <1 inch

55th Street and Madison

Street, Hinsdale, IL


715.0 3,000 None <1 inch


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Table 10 ‐ LRFD Load Factors for Retaining Wall Design

Type of Load

Bearing Resistance Strength IA

Sliding and Eccentricity Strength IB

Settlement Service I

Load Factors for Vertical Loads

Dead Load of Structural Components (DC)

1.25 0.90 1.00

Vertical Earth Pressure Load (EV) 1.35 1.00 1.00 Earth Surcharge Load (ES) 1.50 1.00 Live Load Surcharge (LS) 1.75 1.00

Load Factors for Horizontal Loads

Horizontal Earth Pressure Load (EH) Active At‐Rest AEP for anchored walls

1.50 1.35 1.35

1.00 1.00

Earth Surcharge (ES) 1.50 Live Load Surcharge (LS) 1.75 1.00 1.00

4.2.1 Lateral Earth Pressures and Loading The wall shall be designed to withstand earth and live lateral earth pressures. The lateral earth pressures on retaining walls depend on the type of wall (i.e. restrained or unrestrained), the type of backfill and the method of placement against the wall, and the magnitude of surcharge weight on the ground surface adjacent to the wall. Cast‐in‐Place walls are considered rigid and as such the earth loads may be calculated using active earth pressure for load above the design grade, and both active and passive earth pressures below the design grade. The active earth pressure coefficient (Ka), and the passive earth pressure coefficient (Kp) were determined in accordance with AASHTO Section 3.11.5.3 and 3.11.5.4, respectively. Table 11 presents the recommended lateral earth pressures soil parameters to be used for the proposed wall designs based on the anticipated soil types at each of the sites.

Table 11 – Lateral Earth Pressures Soil Parameters

Soil Type

In‐situ Unit

Weight (pcf) (γ)

Angle of

Internal Friction (φ)

Active Earth

Pressure Coefficient

(Ka)

Passive Earth


(Kp)

Coefficient of

Subgrade Modulus (pci)

Soil Strain Parameter

E50


125 32 0.28 3.53 90 N/A


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Soil Type

In‐situ Unit

Weight (pcf) (γ)

Angle of


Active Earth


(Ka)

Passive Earth


(Kp)

Coefficient of



E50

Eola Road

Brown & Gray, Sand with Gravel

Fill 130 30 0.33 3.0 225 N/A

Brown & Gray, Stiff to Hard Silty

Clay 136 28 0.35 2.77 1,680 0.005

Gray, Stiff to Very Stiff Clay

134 28 0.35 2.77 1,450 0.005

Winfield Road

Brown Sand with Gravel Fill

130 30 0.33 3.0 90 N/A

Brown, Medium Dense to Dense Sand with Gravel

134 38 0.23 4.33 225 N/A

Yackley Road

Black and Gray Clay Fill

130 28 0.35 2.77 1,750 0.005

Brown & Gray, Very Stiff to Hard

Silty Clay 138 32 0.31 3.25 1,850 0.005

Brown, Medium Dense to Very

Dense Sand with Gravel

136 40 0.22 4.51 225 N/A

55th Street


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Soil Type

In‐situ Unit

Weight (pcf) (γ)

Angle of


Active Earth


(Ka)

Passive Earth


(Kp)

Coefficient of



E50

Black and Brown Clay Fill

130 28 0.35 2.77 1,250 0.005

Brown and Gray, Very Stiff Silty Clay

135 28 0.35 2.77 1,470 0.005

Gray, Very Stiff Silty Clay

133 28 0.35 2.77 1,250 0.005

Traffic and other surcharge loads should be included in the retaining wall designs as applicable. A live load surcharge shall be applied where vehicular load is expected to act on the surface of the backfill within a distance equal to one‐half the wall height behind the back face of the wall in accordance with Article 3.11.6.4 of AASHTO LRFD Bridge Design Specifications. The live load surcharge may be estimated as a uniform horizontal earth pressure due to an equivalent height (Heq) of soil. Table 12 provides the equivalent heights of soils for vehicular loadings on retaining walls. Table 12 ‐ Equivalent Height of Soil for Vehicular Loading on Retaining Walls Parallel to Traffic

(AASHTO LRFD Manual ‐ Table 3.11.6.4‐2)

Retaining Wall Height (ft) Heq Distance from Wall Back face to Edge of Traffic 0 feet 1.0 feet or Further

5 5.0 feet 2.0 feet 10 3.5 feet 2.0 feet ≥20 2.0 feet 2.0 feet

GSG recommends designing the retaining walls using the drained condition. This could be accomplished by placing a minimum of 2 feet of free draining materials, Porous Granular Embankment, as measured laterally from the back of the wall. The backfill should be placed in accordance with the IDOT SSRBC. Heavy compaction equipment should not be allowed closer than five (5) feet to the retaining wall to prevent inducing high lateral earth pressures and causing wall yielding and/or other damage.


22

5.0 Construction Considerations All work performed for the proposed project should conform to the requirements in the IDOT SSRBC (2012). Any deviation from the requirements in the manuals above should be approved by the design engineer. 5.1 Existing Utilities Before proceeding with construction, any existing underground utility lines that will interfere with construction should be completely rerouted or removed from beneath the proposed construction areas. Existing utility lines that are to be abandoned in place should be removed and/or plugged with a minimum of 2 feet of cement grout. All excavations resulting from underground utilities removal activities should be cleaned of loose and disturbed materials, including all previously‐placed backfill, and backfilled with suitable fill materials in accordance with the requirements of this section. During the clearing and stripping operations, positive surface drainage should be maintained to prevent the accumulation of water. 5.2 Excavations The contractor will be responsible to provide a safe excavation during the construction activities of the project. All excavations should be conducted in accordance with applicable federal, state, and local safety regulations, including, but not limited to the Occupational Safety and Health Administration (OSHA) excavation safety standards. Excavation stability and soil pressures on temporary shoring are dependent on soil conditions, depth of excavations, installation procedures, and the magnitude of any surcharge loads on the ground surface adjacent to the excavation. Excavation near existing structures and underground utilities should be performed with extreme care to avoid undermining existing structures. Excavations should not extend below the level of adjacent existing foundations or utilities unless underpinning or other support is installed. It is the responsibility of the contractor for field determinations of applicable conditions and providing adequate shoring for all excavation activities. 5.3 Borrow Material and Compaction Requirements If borrow material is to be used for onsite construction, it should conform to Section 204 “Borrow and Furnish Excavations” of the IDOT Construction Manual (2017). The fill material should be free of organic matter and debris and should be placed and compacted in accordance with Section 205, Embankment, of the IDOT Construction Manual. Earth‐moving operations should be avoided during excessively cold or wet weather to avoid freezing of softening subgrade soils. Suitable structural fill should have the following soil properties:


23

Table 13 – Structural Fill Soil Properties

REQUIRED TEST AASHTO METHOD PERMISSIBLE LIMIT

Standard Dry Density (SDD) T 99 (Method C) 90 pcf min.* Organic Content T 194 10 % max.* Percent Silt and Fine Sand T 88 65 % max. ** Plasticity Index T 90 12 % min. ** Liquid Limit T 89 50 % max. Shear Strength (c) at 95 % T 208 or T 234 1,000 psf min.

* As per IDOT Standard Specifications. ** Frost Susceptibility Criteria

Structural fill should be placed in lifts not to exceed 8 inches in loose thickness and compacted to a minimum of 95% of the material’s standard proctor maximum dry density obtained according to the ASTM D698/AASHTO T 99 method. Materials unsatisfactory for use as structural fill include soils classified as silt or organic silt (ML, MH, PT, OL, and OH) in the Unified Classification System (ASTM D2847). Soils with these classifications may be used for general purpose landscaping and in areas where uncontrolled settlement is acceptable. Should fill be placed during cool, wet seasons, the use of granular fill may be necessary since weather conditions will make compaction of cohesive soils more difficult. If water seepage while excavating and backfilling procedures, or where wet conditions are encountered such that the water cannot be removed with conventional sump and pump procedures, GSG recommends placing open grade stone similar to IDOT CA‐7 to stabilize the bottom of the excavation. The CA‐7 stone should be placed to 12 inches above the water level, in 12‐inch lifts, and should be compacted with the use of a heavy smooth drum roller or heavy vibratory plate compactor until stable. The remaining portion of the excavation should be backfilled using approved engineered fill. GSG recommends that foundation excavations, subgrade preparation, and structural fill placement and compaction be inspected by a GSG geotechnical engineer to verify the type and strength of soil materials present at the site and their conformance with the geotechnical recommendations in this report.


24

5.4 Groundwater Management GSG does not anticipate groundwater related issues during construction activity at any of the subject sites; however, water may become perched in the existing fill material encountered at the surface of each location. If rainwater run‐off or perched water is accumulated at the base of excavation, the contractor should remove accumulated water using conventional sump pit and pump procedures, and maintain a dry and stable excavation. The location of the sump should be determined by the contractor based on field conditions. During earthmoving activities at the site, grading should be performed to ensure that drainage is maintained throughout the construction period. Water should not be allowed to accumulate in the foundation area either during or after construction. Undercut and excavated areas should be sloped toward one corner to facilitate removal of any collected rainwater or surface run‐off. Grades should be sloped away from the excavations to minimize runoff from entering the areas. If water seepage occurs during footing excavations or where wet conditions are encountered such that the water cannot be removed with conventional sumping, we recommend placing open grade stone similar to IDOT CA‐7 to stabilize the bottom of the excavation below the water table. The CA‐7 stone should be placed to 12 inches above the water table, in 12‐inch lifts, and should be compacted with the use of a heavy smooth drum roller or heavy vibratory plate compactor until stable. The remaining portion of the excavation beneath the footings should be backfilled using approved structural fill.


25

6.0 LIMITATIONS

This report has been prepared for the exclusive use of the DuPage County Department of Transportation and its structural consultant. The recommendations provided in the report are specific to the project described herein, and are based on the information obtained at the soil boring locations within the proposed retaining wall area. The analyses performed and the recommendations provided in this report are based on subsurface conditions determined at the location of the borings. This report may not reflect all variations that may occur between boring locations or at some other time, the nature and extent of which may not become evident until during the time of construction. If variations in subsurface conditions become evident after submission of this report, it will be necessary to evaluate their nature and review the recommendations presented herein.

APPENDIX A

SITE PHOTOGRAPHS

Retaining wall on Eola Road facing South at staked location.

RWB‐1 on Eola Road facing North with cleared utilities.

Retaining wall on Winfield Road facing South at staked location.

RWB‐2 on Winfield Road facing South with cleared utilities.

Retaining wall on Yackley Avenue facing West at staked location.

RWB‐3 on Yackley Avenue facing North with cleared utilities.

Retaining wall on 55th Street facing North, wall is left of guardrail.

RWB‐4 on 55th Street facing East with cleared utilities.

APPENDIX B

RETAININGWALL BORING LOCATION PLANS

APPENDIX C

SOIL BORING LOGS

12 inches of Asphalt

12 inches of Sand and Gravel Base

FILL: SAND, with gravel - Brown and Gray - Moist

SILTY CLAY, trace gravel (CL/ML) - Brown and Gray - MediumStiff to Hard - Moist

SILTY CLAY, trace gravel (CL/ML) - Gray - Stiff to Hard - Moist

Bottom of borehole at 20.0 feet.

SS

SS

SS

SS

SS

SS

SS

SS

5-20-18(38)

1-2-2(4)

2-4-5(9)

3-5-7(12)

3-5-7(12)

3-4-5(9)

2-3-4(7)

2-2-3(5)

0.5

4.58

5.00

4.58

3.5

2.08

1.46

56

33

83

67

89

78

89

89

NOTES

LOGGED BY JJR

DRILLING METHOD HSA

HOLE SIZE 3 1/4''

DRILLING CONTRACTOR GSG Drilling GROUND WATER LEVELS:

CHECKED BY CDJ

DATE STARTED 3/19/18 COMPLETED 3/19/18

AT TIME OF DRILLING --- NONE

AT END OF DRILLING --- N/A

AFTER DRILLING --- N/A

GROUND ELEVATION 727.00 ft

GR

AP

HIC

LOG

MATERIAL DESCRIPTION

SA

MP

LE T

YP

EN

UM

BE

R

BLO

WC

OU

NT

S(N

VA

LUE

)

UN

CO

NF

INE

DC

OM

PR

ES

SIO

N(t

sf)

Moisture Content10 20 30 40

SPT N VALUE20 40 60 80

DE

PT

H(f

t)

0

5

10

15

20

Unconfined Compression (tsf)2 4 6 8

RE

CO

VE

RY

(%)

PAGE 1 OF 1BORING NUMBER RWB-1

PROJECT NAME Retaining Wall Repairs

PROJECT LOCATION Dupage County - Eola Road

CLIENT Knight/Dupage County

PROJECT NUMBER 18-2016

GE

OT

EC

H B

H P

LOT

S -

GIN

T S

TD

US

.GD

T -

4/4

/18

08:

14

- \\G

SG

FS

02\P

RO

JEC

TS

- E

NG

INE

ER

ING

\KN

IGH

T\D

UP

AG

E D

OT

- R

ET

AIN

ING

WA

LL R

EP

AIR

\GE

OT

EC

HN

ICA

L\F

IELD

TE

ST

ING

\BO

RIN

G L

OG

S_3

-20-

18.

GP

JGSG Consultants, Inc.623 Cooper CourtSchaumburg, IL


FILL: SAND, with gravel - Brown - Moist

Cobbles at 3.5 feet

Cobbles at 6.5 feet

SAND, with gravel (SPG) - Brown - Medium Dense to Dense -Moist to Wet

SAND, with gravel (SPG) - Gray - Medium Dense - WetBottom of borehole at 20.0 feet.

SS1

SS2

SS3

SS4

SS5

SS6

6-12-20(32)

25

20

22-20-20(40)

9-9-22(31)

6-9-12(21)

11

6

17

56

83

78

NOTES

LOGGED BY CDJ

DRILLING METHOD HSA

HOLE SIZE 3 1/4''


CHECKED BY MC


AT TIME OF DRILLING --- 13.5




GR

AP

HIC

LOG


SA

MP

LE T

YP

EN

UM

BE

R

BLO

WC

OU

NT

S(N

VA

LUE

)

UN

CO

NF

INE

DC

OM

PR

ES

SIO

N(t

sf)



DE

PT

H(f

t)

0

5

10

15

20


RE

CO

VE

RY

(%)



PROJECT LOCATION Dupage County - Winfield Road



GE

OT

EC

H B

H P

LOT

S -

GIN

T S

TD

US

.GD

T -

4/4

/18

08:

15

- \\G

SG

FS

02\P

RO

JEC

TS

- E

NG

INE

ER

ING

\KN

IGH

T\D

UP

AG

E D

OT

- R

ET

AIN

ING

WA

LL R

EP

AIR

\GE

OT

EC

HN

ICA

L\F

IELD

TE

ST

ING

\BO

RIN

G L

OG

S_3

-20-

18.

GP



8 inches of Sand and Gravel Base

FILL: CLAY, trace gravel - Black and Gray - Moist

SILTY CLAY, trace gravel (CL/ML) - Brown and Gray - Very Stiffto Hard - Moist

SAND, with gravel (SPG) - Brown and Gray - Medium Dense toVery Dense - Moist

occasional rock fragments


SS

SS

SS

SS

SS

SS

SS

SS

3-6-6(12)

3-8-9(17)

3-6-7(13)

2-6-7(13)

2-4-8(12)

15-50

8-11-12(23)

4-8-9(17)

3.5

4.5

4.58

2.75

3.0

67

89

89

44

83

44

67

56

NOTES

LOGGED BY JJR

DRILLING METHOD HSA

HOLE SIZE 3 1/4''


CHECKED BY CDJ


AT TIME OF DRILLING --- 18.5




GR

AP

HIC

LOG


SA

MP

LE T

YP

EN

UM

BE

R

BLO

WC

OU

NT

S(N

VA

LUE

)

UN

CO

NF

INE

DC

OM

PR

ES

SIO

N(t

sf)



DE

PT

H(f

t)

0

5

10

15

20


RE

CO

VE

RY

(%)



PROJECT LOCATION Dupage County - Yackley Road



GE

OT

EC

H B

H P

LOT

S -

GIN

T S

TD

US

.GD

T -

4/4

/18

08:

16

- \\G

SG

FS

02\P

RO

JEC

TS

- E

NG

INE

ER

ING

\KN

IGH

T\D

UP

AG

E D

OT

- R

ET

AIN

ING

WA

LL R

EP

AIR

\GE

OT

EC

HN

ICA

L\F

IELD

TE

ST

ING

\BO

RIN

G L

OG

S_3

-20-

18.

GP


6 inches of Asphalt6 inches of Concrete8 inches of Sand and Gravel Base

FILL: CLAY, trace sand and gravel - Black and Brown - Moist

SILTY CLAY, trace gravel (CL/ML) - Brown and Gray - Very Stiff -Moist

SILTY CLAY, trace gravel (CL/ML) - Gray - Very Stiff - Moist


SS

SS

SS

SS

SS

SS

SS

SS

3-3-4(7)

1-2-3(5)

3-4-5(9)

2-3-5(8)

3-5-6(11)

2-4-6(10)

2-4-6(10)

3-3-5(8)

2.5

2.0

2.92

3.12

3.75

2.5

2.5

2.5

56

78

83

89

100

100

100

100

NOTES

LOGGED BY JJR

DRILLING METHOD HSA

HOLE SIZE 3 1/4''


CHECKED BY CDJ


AT TIME OF DRILLING --- NONE




GR

AP

HIC

LOG


SA

MP

LE T

YP

EN

UM

BE

R

BLO

WC

OU

NT

S(N

VA

LUE

)

UN

CO

NF

INE

DC

OM

PR

ES

SIO

N(t

sf)



DE

PT

H(f

t)

0

5

10

15

20


RE

CO

VE

RY

(%)



PROJECT LOCATION Dupage County - 55th Street



GE

OT

EC

H B

H P

LOT

S -

GIN

T S

TD

US

.GD

T -

4/4

/18

08:

17

- \\G

SG

FS

02\P

RO

JEC

TS

- E

NG

INE

ER

ING

\KN

IGH

T\D

UP

AG

E D

OT

- R

ET

AIN

ING

WA

LL R

EP

AIR

\GE

OT

EC

HN

ICA

L\F

IELD

TE

ST

ING

\BO

RIN

G L

OG

S_3

-20-

18.

GP


Unified Soil Classification Soil Classification is based on the Unified Soil Classification System and ASTM Designations D-2487 and D-2488. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; they are described as: clays, if they are plastic, and silts if they are slightly Plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the basis of their relative in-place density and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trace gravel, stiff (CL); silty sand, trace gravel, medium dense (SM).

Drilling & Sampling Symbols

SS : Split Spoon Water Level (ft) ST : Thin-Walled Tube While Drilling HA: Hand Auger After Drilling AU: Auger Sample 24-hour

HS: Hand Sample Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2 inch OD split spoon, except where noted.

Major Divisions Group

Typical Names Consistency of Cohesive Soil Symbols

Coa

rse

Gra

ined

Soi

ls

(Mor

e th

an H

alf o

f mat

eria

l is l

arge

r tha

n N

o. 2

00 si

eve

size

)

Gravels (More than hall of

coarse fraction is larger than No. 4

sieve size)

Cle

an G

rave

ls

(Litt

le o

r no

fines

)

GW

Well graded gravels, gravel- sand mixtures, little or no fines

Unconfined Compressive

strength, Qu, tsf N-

Blows/ft. Consistency

GP Poorly graded gravels, gravel-sand mixtures, little or no fines

< 0.25 Below 2 < Very Soft

0.25 - 0.50 2-4 - Soft

Gra

vels

with

fin

es

(App

reci

able

amou

nt o

f fin

es)

GM d Silty gravels, gravel-sand-

clay mixtures 0.50 - 1.0 4-8 - Medium Stiff

u 1.0 - 2.0 8-15 - Stiff

GC Clayey gravels, gravel-sand- clay mixtures 2.0 - 4.0 15-30 - Very Stiff

4.0 - 8.0 30-50 - Hard

Sands (More than hall of

coarse fraction is smaller than No.

4 sieve size)

Cle

an S

ands

(Litt

le o

r no

fines

)

SW Well graded sands, gravelly sands, little or no fines > - 8.0 > 50 - Very Hard

SP Poorly graded sands, gravelly sands, little or no fines

Relative Density of Coarse-Grained Soils

Sand

s with

fin

es

(App

reci

able

amou

nt o

f fin

es) SM d Silty sands, sand-silt

mixtures N-Blows/ft. Relative Density u 0-3 Very Loose

SC Clayey sands, sand-clay mixtures 4-10 Loose

11-29 Medium Dense

Fine

Gra

ined

Soi

ls

Mor

e th

an h

alf o

f mat

eria

l is s

mal

ler t

han

No.

200

siev

e si

ze)

Silts and Clays

(liquid limit less than 50)

ML

Inorganic silts and very fine sands, rock flour, silty or claye fine sands or clayey silts with slight plasticity

30-49 Dense

50-80 Very Dense

CL

Inorganic clay of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays

>80 Extremely Dense

Description Term(s) of Components Present in Sample

OL Organic silts and organic silty clays of low plasticity

Trace < 10% Little 10-19% Some 20-34% And 35-50%

Silts and Clays

(liquid limit greater than 50)

MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts

CH Inorganic clays of high plasticity, fat clays

OH Organic clays of medium to high plasticity, organic silts

Highly

Organic Soils

Pt

Peat and other highly organic soils

APPENDIX D

SLOPE STABILITY ANALYSES EXHIBITS

7.87.8

W

7.87.8

Material Name Color Unit Weight(kN/m3) Strength Type Cohesion

(kPa)Phi(deg)

New Engineered Granular Fill 125 Mohr‐Coulomb 0 32

Brown Clay 130 Mohr‐Coulomb 1500 0

Brown and Gray Sand with Gravel Fill 130 Mohr‐Coulomb 0 32

Brown and Gray Silty Clay 136 Mohr‐Coulomb 3300 0

Gray Silty Clay 134 Mohr‐Coulomb 2900 0

Timber 120 Infinite strength

Safety Factor0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.53.84.04.34.54.85.05.35.55.86.0+

3020

100

-10

-30 -20 -10 0 10 20 30

Analysis Description Exhibit 1 - Eola Road - Circular Short TermCompany GSG ConsultantsScale 1:287Drawn By CDJFile Name Eola Road - Circular Short Term.slimDate 4/10/2018, 11:41:51 AM

Project

DuPage County Retaining Wall Repairs

SLIDEINTERPRET 7.010

2.32.3

W

2.32.3


(kPa)Phi(deg)


Brown Clay Drained 130 Mohr‐Coulomb 100 28

Brown and Gray Sand with Gravel Fill Drained 130 Mohr‐Coulomb 0 32

Brown and Gray Silty Clay Drained 136 Mohr‐Coulomb 125 28

Gray Silty Clay Drained 134 Mohr‐Coulomb 100 28

Timber 120 Infinite strength

Safety Factor0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.53.84.04.34.54.85.05.35.55.86.0+

2010

0-10

-30 -20 -10 0 10 20 30

Analysis Description Exhibit 2 - Eola Road - Circular Long TermCompany GSG ConsultantsScale 1:278Drawn By CDJFile Name Eola Road - Circular Long Term.slimDate 4/10/2018, 11:41:51 AM

Project



2.12.1

W

2.12.1


(kPa)Phi(deg)

Phi b(deg)

Air Entry(kPa)

New Engineered Granular Fill 125 Mohr‐Coulomb 0 32 0 0

Brown Clay 130 Mohr‐Coulomb 1500 0 0 0

Brown Sand with Gravel Fill 130 Mohr‐Coulomb 0 30 0 0

Brown Sand with Gravel 134 Mohr‐Coulomb 0 38 0 0

Concrete 120 Infinite strength 0 0

Safety Factor0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.53.84.04.34.54.85.05.35.55.86.0+

100

-10

-20

-20 -10 0 10 20 30

Analysis Description Exhibit 3 - Winfield Road - Circular Short TermCompany GSG ConsultantsScale 1:250Drawn By CDJFile Name Winfield Road - Circular Short Term r1.slimDate 4/9/2018, 12:55:01 PM

Project



2.12.12.12.1


(kPa)Phi(deg)


Brown Clay Drained 130 Mohr‐Coulomb 100 28

Brown Sand with Gravel Fill Drained 130 Mohr‐Coulomb 0 30

Brown Sand with Gravel Drained 134 Mohr‐Coulomb 0 38

Concrete 120 Infinite strength

Safety Factor0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.53.84.04.34.54.85.05.35.55.86.0+

100

-10

-20 -15 -10 -5 0 5 10 15 20 25 30

Analysis Description Exhibit 4 - Winfield Road - Circular Long TermCompany GSG ConsultantsScale 1:225Drawn By CDJFile Name Winfield Road - Circular Long Term r1.slimDate 4/9/2018, 12:55:01 PM

Project



9.59.5

W

9.59.5


(kPa)Phi(deg)

Black and Gray Clay Fill 137 Mohr‐Coulomb 3500 0


Brown and Gray Sand with Gravel 136 Mohr‐Coulomb 0 39


New Engineered Cohesive Fill 128 Mohr‐Coulomb 1500 0

New Engineered Granular Fil 125 Mohr‐Coulomb 0 32

Safety Factor0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.53.84.04.34.54.85.05.35.55.86.0+

2010

0-10

-20

-40 -30 -20 -10 0 10 20 30

Analysis Description Exhibit 5 - Yackley Ave - Circular Short TermCompany GSG ConsultantsScale 1:301Drawn By CDJFile Name Yackley Ave - Circular Short Term.slimDate 4/9/2018, 12:55:01 PM

Project



3.53.5

W

3.53.5

Material Name Color Unit Weight(kN/m3)

Strength Type Cohesion(kPa)

Phi(deg)

Black and Gray Clay Fill Drained 137 Mohr‐Coulomb 125 28


Brown and Gray Sand with Gravel Drained 136 Mohr‐Coulomb 0 39


New Engineered Cohesive Fill 128 Mohr‐Coulomb 1500 0

New Engineered Granular Fil 125 Mohr‐Coulomb 0 32

Safety Factor0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.53.84.04.34.54.85.05.35.55.86.0+

2010

0-10

-20

-40 -30 -20 -10 0 10 20 30

Analysis Description Exhibit 6 - Yackley Ave - Circular Long TermCompany GSG ConsultantsScale 1:300Drawn By CDJFile Name Yackley Ave - Circular Long Term.slimDate 4/9/2018, 12:55:01 PM

Project



25.525.5

W

250.00 lbs/ft2

25.525.5

Material Name Color Unit Weight(lbs/ 3) Strength Type Cohesion

(psf)Phi(deg)


Black and Brown Clay Fill 130 Mohr‐Coulomb 2500 0


Gray Silty Clay 133 Mohr‐Coulomb 2500 0

Safety Factor0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.53.84.04.34.54.85.05.35.55.86.0+

2010

0-1

0

-30 -20 -10 0 10 20 30

Analysis Description Exhibit 7 - 55th Street - Circular Short TermCompany GSG ConsultantsScale 1:79Drawn By CDJFile Name 55th Street - Circular Short Term.slimDate 4/6/2018, 9:15:43 AM

Project



5.15.1

W

250.00 lbs/ft2

5.15.1

Material Name Color Unit Weight(lbs/ 3) Strength Type Cohesion

(psf)Phi(deg)


Black and Brown Clay Fill Drained 130 Mohr‐Coulomb 100 28


Gray Silty Clay Drained 133 Mohr‐Coulomb 100 28

Safety Factor0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.53.84.04.34.54.85.05.35.55.86.0+

2010

0-1

0

-30 -20 -10 0 10 20 30

Analysis Description Exhibit 8 - 55th Street - Circular Long TermCompany GSG ConsultantsScale 1:82Drawn By CDJFile Name 55th Street - Circular Long Term.slimDate 4/6/2018, 9:15:43 AM

Project



structural geotechnical report

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