5.0PENSTOCK CONSTRUCTION AND INSTALLATIONITEM 5.1CLEARING AND GRUBBING(Same as Item 2.2)

ITEM 5.2EARTH EXCAVATION(Same as Item 2.3)

ITEM 5.3ROCK EXCAVATION(Same as Item 2.4)

ITEM 5.4HAULING OF MATERIALS(Same as Item 2.5)

ITEM 5.5BACKFILLING5.5.1 GENERAL5.5.1.1 DESCRIPTIONThis item shall consist of furnishing all materials, equipment and labor for backfilling to install or construct the penstock and other accessories as shown on the Plans and referred to in these specifications.Backfill Term used to describe the material used in the fill zones of excavation. Backfill shall consist of earth removed from excavation or sand backfill approved by the Engineer. Debris or large rocks shall not be used as backfill material.Compaction The process whereby the density of a soil mass is increased by mechanical, usually dynamic means. This typically involves tamping, rolling, or vibration, or a combination of these processes. This will result in relocation of soil particles and the expulsion of air from the soil mass, but usually without significantly altering the amount of water in the soil. 5.5.2MATERIAL REQUIREMENTSExcept as otherwise specified by the Engineer, the material excavated shall be used as backfill material.No large stones or debris shall be in the trench at any point. All backfill materials shall be free from cinders, refuse, sod, organic materials and other materials which in the opinion of the Engineer is unsuitable. The trench may be backfilled by machine or by hand, but the work shall be done in such a way as to prevent dropping of materials directly on top of the pipe or through any great vertical distance onto the material covering the pipe so as not to cause additional load on the pipe.5.5.3 EXECUTION5.5.3.1 PLACEMENT AND COMPACTIONThe Contractor shall not place any backfill material until the Engineer has inspected and accepted the placement of the bedding. The Contractor must not place the overlay material until the concrete has obtained its initial set.Backfill must not be placed within twenty four (24) hours of placing concrete. Backfill shall be excavated granular material free of, debris, organic matter, and rocks larger than four (4) inches across their greatest dimension.All compaction shall be by hand operated, plate type, vibratory, or other suitable hand tampers in areas not accessible to larger rollers or compactors. Extreme care shall be taken to avoid damage to conduits, pipes, and any appurtenances.The backfill material shall be placed and compacted in layers not exceeding two hundred (200) millimeters loose thickness, and shall be moisture conditioned as required to facilitate adequate compaction.The Contractor is responsible for monitoring and rectifying any subsidence that occurs as a consequence of the Works. The Contractor shall pay any damage caused as a consequent of subsidence.5.5.4 MEASUREMENT/BASIS OF PAYMENTThe volume that is to be backfilled to be paid for will be the volume of fill acceptably cleared in conformity with the plans or as directed by the Engineer.The accepted quantities, measured as prescribed above shall be paid for at the contract unit price for each of the particular pay items listed and included in the Bill of Quantities. The payment shall constitute full compensation for the removal and disposal of cleared and grubbed materials including all labor, equipment tools and incidentals. ITEM 5.6REINFORCING BARS GRADE 40(Same as Item 2.8)

ITEM 5.7FORM/DEFORM WORKS(Same as Item 2.9)

ITEM 5.8CONCRETING WORKS (3000 PSI)(Same as Item 2.10)

ITEM 5.9STEEL PIPE FABRICATION AND INSTALLATION5.9.1 GENERAL5.9.1.1 DESCRIPTIONThis item shall cover all related Specifications for the supply, fabrication and installation of steel pipes.5.9.2 CONTRACTORS SCOPEThe Contractor shall supply, install, test and commission fully operational low pressure steel pipes. Methodology shall be submitted to the Engineer as instructed as well as the material specification of the pipe taking into account the requirements specified herein.Plans are in accordance with the provisions of these Specifications or as instructed by the Engineer.

5.9.3MATERIAL REQUIREMENTQuality in all materials shall be ensured to meet all required parameters as shown on the designs. Ultimate strength, elasticity limit, ductility, hardness, durability, suitability for the intended service and best engineering practice shall be considered. All materials shall comply with the latest applicable standards of the ASTM, unless otherwise specified or approved by the Engineer.Steel plates declared by the Engineer to have been defective at the time of delivery will be replaced by the Contractor with all costs of replacement endured by the Contractor. All materials that develop defects during or after fabrication shall be rejected notwithstanding that they have previously passed specified tests and inspections, and met the applicable requirements stated herein.The size and thickness indicated in the Plans shall be adopted. Furnish suitable and compatible anchors and pipe sleepers and fasteners that support the pipes.a.Corrosion ResistanceThe pipes shall have the best performance with respect to inhibiting corrosion caused by natural environmental action. Rust converter will be applied to pipes prior to application of red oxide paint. The Contractor shall provide adequate corrosion protection for the works in accordance with Section Surface Finishes, of these specification.Comment by jeally arabos: Section of Surface Finishb.Materials Environmental CompatibilityThe Contractor shall select the materials in consideration of its environmental impact, including such effects as noise, vibration, and air pollution, adaptability to recycling from the viewpoints of resource management and environmental damage reduction as well as its harmony with the local ecology. c.Fabrication of PipeThe Contractor shall supply/fabricate and install steel pipe. Welding and cutting works shall be in accordance with all welding specification as stated in this Specification.d.JointsJoints shall be fabricated accurately for close fit. Weld exposed joints continuously unless otherwise indicated or approved. Dress exposed welds flush and smooth. All welds shall be according to the applicable provisions as stated herein.e.Procedure for Installation of Embedded ItemsTemporarily brace and secure items which are to be built into concrete.Isolate non ferrous metal surfaces to be permanently fastened in contact with ferrous metal surfaces, concrete, or masonry by coating non ferrous metal surfaces with bituminous mastic, prior to installationFit and set fabricated metal work accurately in location, alignment, and elevation. Securely fastened in place.5.9.4MEASUREMENT/BASIS OF PAYMENTThe method of measurement is as per accomplishment of installed steel pipes. Fabrication, supply and installation of pipes shall be included in the Bill of Quantities. The quantities measured as prescribed above shall be paid for at the contract unit price of the pay item that is included in the Bill of Quantities. Payments shall be the compensation for all materials, labor, equipment, tool, and incidentals to complete the work prescribed in this item.

ITEM 5.10 PENSTOCK PIPELINE SUPPORT FABRICATION AND INSTALLATION5.10.1 GENERAL5.10.1.1 DESCRIPTIONThis item shall consists steel structures of any structural shape as shown on the Plans approved by the Engineer. The structure will rest on pedestal with a given height as required on site.5.10.2 CONTRACTORS SCOPEThe Contractor shall be responsible for the accurate location of all steel works including items used to attach materials to other parts of the work.The Contractor shall see to it that any or all items of work which, are to be built into the work of other trades are installed at the proper time.The Contractor shall notify the Engineer if the steel work shall be fabricated in a shop other than the site, so that arrangements can be made together with the Engineer in the inspection of the delivered materials and in the fabrication of the steel work.5.10.3 SUBMITTALSFurnish complete detailed fabrication and erection shop drawings including details of all connections for review and approval of the Engineer.The Engineer will review all shop drawings. Re submit if any corrections are required.5.10.4 MATERIAL REQUIREMENTSFurnished materials, tools, equipment, labor and other services required to complete fabrication and erection of all structural steel structures shall be administered by the Contractor.Where so indicated on the Plans, structural members shall be joined by welding. The welds shall be of size and type indicated and shall be made by competent welders.5.10.4.1 DELIVERYShipping statements shall be delivered in the jobsite. The Engineer shall inspect the materials per delivery and may request additional tests on the materials delivered, if in their opinion, there is reasonable doubt as to the materials specification. The fabrication and delivery of the fabricated structural steel should conform to the Approved Schedule of Erection and items such as anchor bolts, anchorage and other that have been placed in concrete which shall be in the jobsite before such concrete structural member is poured. Erection marks shall be painted on structural steel members and fabricated sections. Small structural members such as rivets, bolts, nuts, washers, etc., should be shipped and kept in properly marked, suitable containers.

5.10.5 EXECUTION5.10.5.1 WELDING TECHNIQUEConform the technique of welding employed in terms of quality and aesthetic of the weld and the method used in correcting defective work to the requirements of the Standard Code for Welding in Building Construction of the American Welding Society.The following procedures shall govern in all welding processes unless otherwise initiated by the Engineer.a. Surfaces to be welded shall be free from loose scale, slag, rust, grease, paint, and any other foregoing material except that mill scale which withstands vigorous wire brushing may remain.b.Prepare edges by gas cutting, whenever practicable, cut by a mechanically guided torch.c.Let gas cut edges which will be subjected to substantial stress or which are to have weld metal deposited on them be free from gauges. Remove by grinding any gouge that remains from cutting.d.Shape all re entrant corners notch free to a radius of at least twelve (12) millimeters or one half () inches.e.Bring in to a close contact as practicable parts to be fillet welded and in no event separate by more than four (4) millimeters (3/16 inches). If the separation is one (1) millimeters (1/16 inches) or greater, increase the size of the fillet welds by the amount of the separation.f.Never exceed the separation between laying surfaces of lap joints and butt joint on a backing structure by one and five tenths (1.5) millimeters (1/16 inches).g.Bring the fit of joints at contact surfaces which are not completely sealed by welds, close enough to exclude water after painting.h. Align all abutting parts to be welded carefully. Correct misalignment greater than three (3) millimeters (1/8 inches) in making the correction, never draw parts into a slope sharper than two (2) degrees 11 millimeters in 300 millimeters (7/16 inches in 12 inches).i.Position the work for flat welding whenever practicable.j.In assembling and joining parts of structure or of built up members, avoid unnecessary distortion and minimize shrinkage stresses, where it is impossible to avoid high residual closing welds in compression elements.k.In the fabrication of cover plated beams and built up members, make all shop splices in each component part before such is welded to other parts of the member.l.Let all complete penetration butt welds made by manual welding except when produced with the aid of backing material or welded in the flat position from both sides in square edge material not more than seven (7) millimeters (5/16 inches) thick with opening not less than one half () the thickness of the thinner part joined, have the root of the initial layer gouged out on the back side before welding is started on the side. Weld so as to secure sound metal fusion throughout the entire cross section. With butt welds made with use of a backing of the same material as the base metal, have the weld metal thoroughly fused with the backing material.m. Backing strips may be removed by gouging or gas cutting after welding is completed, provided no injury is done to the base metal and weld metal. Weld metal surface is left flush or slightly convex with full throat thickness.n.Terminate butt welds at the ends of a joint in a manner that will ensure soundness.o.Where possible, do the latter procedure by the use of extension bars or run off plates. Remove extension bars or run off plates upon completion of the welds. Make the ends of the welds smooth and flush with abutting parts.5.10.5.2 BOLTS a.Tighten all bolts to a bolt tension not less than the proof load given in the applicable ASTM specifications for the type of bolt used.b.Do tightening with properly calibrated wrenched or by the turn of nut method.c.Let completed member be free from twist, bends and open joints. Sharp or bends shall be a cause of rejection of materials.5.10.5.3PAINTINGa.Clean all steel work specified for painting by hardware brushing, or other methods chosen by the fabricator for cleaning loose mill scale, lose rust, weld slag, or flux deposit, dirt and other foreign matter after inspection, approval and before leaving the shop.b.Give all steel work that is to be encased in concrete two coat of epoxy zinc chromate paint. Clean oil or grease with solvent cleaners. Remove dirt and foreign materials through sweeping with a fiber brush. c.Remove oil and grease deposits by solvents.d.The Contractor shall provide adequate corrosion protection for the works in accordance with, Section of this specification.Comment by jeally arabos: Section of Surface Finishes5.10.5.4TESTS AND INSPECTIONAll expenses for testing and inspection shall be shouldered by the Contractor.5.10.5.4.1 VISUAL INSPECTION OF WELDINGAfter the welding is accomplished, hand or power wire brush welds, and thoroughly clean them before the inspection. Welds shall be inspect to detect flaws such as undercut, overlap and other surface flows. Magnifier devices shall be used under strong, adequate light for surface cracking, porosity, and slag inclusion; excessive roughness; unfilled craters; gas pockets; undercuts; overlaps; size and insufficient throat and concavity. Inspect the preparation of groove welds for adequate throat opening and for snug positioning of the backup bars.

5.10.5.4.2 NONDESTRUCTIVE TESTINGThe following methods for Nondestructive Testing can be adopted as specified herein considering utmost into account the Engineers decision.a.Liquid Penetrant Inspections a dye must be applied to the weld. After a few minutes, the dye should be cleaned from the weld and a developer is applied. Any dye trapped in a flaw is developed, revealing the location of the flaw.b.Magnetic Particle Inspections the surface must be cleaned first before magnetic particles are applied to the surface. Then a strong magnetic field is applied. The fine magnetic particles are drawn toward any flaw at the surface very near the surface of the part.c.Ultrasonic inspections This method can locate internal flaws using sound waves.d.X ray Inspections film is placed on one side of the part to be inspected. X rays pass through the part and expose the film. After the film is developed, any flaw in the weld can be observed.e.Air pressure/Water Pressure Leak Tests this method is best for pipes that are to contain liquid or gasses.Reference to AWS D1.1 Test locations shall be selected by the Engineer but shall not be less than twenty five (25) percent of the total number of joints. If more than twenty (20) percent of welds contain defects, all welds shall be tested by ultrasonic testing, magnetic particle testing shall be used only in areas inaccessible to ultrasonic testing. Retest defective areas after repair.5.10.5.5 IDENTIFICATIONa.Mark to identify the ASTM Specifications of steel for main components.b.Identify such steel in completed members or assembles by painting designation of the place over any shop coat of paint, prior to shipment from fabricator plant.5.10.5.6ERECTION5.10.5.6.1 GENERALThe Contractor shall schedule, coordinate and sequence structural steel erection in cooperation with the delivery of the structural steel by the structural steel fabricator. The Contractor shall take special care in unloading, handling and erecting the steel. Avoid any activities that will cause distortion to the steel member. Tack welds shall be ground smooth and holes shall be filled with weld metal or body solder and smoothed by grinding or filling. Any structural steel components that in the opinion of the Engineer have been damaged or otherwise rendered useless by the improper handling by the Contractor shall be replaced by the Contractor at his own expense.5.10.5.6.2BRACINGThe frame of the steel structure shall be carried up true and plumb and temporary bracing shall be introduced wherever necessary to take care of all loads to which the structure maybe subjected, including equipment and the operation of the same. Such bracing shall be left in place as long as may be required for safety. Wherever of piles of materials, erection equipment or other loads are varied during erection, proper provisions shall be made to take care of stresses resulting from such loads. As erection progresses, the work shall be securely bolted, or welded, to take care of all dead load, wind and erection stresses.5.10.5.6.3ALIGNMENTNo riveting, permanent bolting or permanent welding shall be done until the structure has stiffened with the resulting stresses properly aligned.5.10.5.6.4FIELD WELDINGAny shop paint on surface adjacent to joints to be field welded shall be wire brushed, to reduce paint film to a minimum.5.10.5.6.5WORKMANSHIPStructural steel sheets, members and struts/columns shall be aligned, plumbed, straight in fabrication, welding and installation.After erection, all unpainted areas including any marred or damaged surfaces shall receive one coat of same rust inhibitive paint as used in the shop painting.5.10.6 MEASUREMENT/BASIS OF PAYMENTThis item will be paid as indicated in the contract which is per accomplishment or can be converted into a lump sum basis.The accepted quantities, measured as prescribed above shall be paid for at the contract unit price for each of the particular pay items listed and included in the Bill of Quantities. The payment shall constitute full compensation for the fabrication, installation and supply of materials including all labor, equipment tools and incidentals necessary to complete the work prescribed in this item.

ITEM 5.11EXPANSION JOINTS FABRICATION AND INSTALLATION5.11.1 GENERAL5.11.1.1 DESCRIPTIONThis item shall include complete supply, fabrication, and installation of the expansion joints to identified location as shown on Plans or as specified by the Engineer.5.11.2EXECUTIONThe material shall be made of A36 steel and an approved kind of sealer for the joints either a rubberized or compact cork material.Bolts shall conform on the Drawings in terms of size and materials. The bolts shall be made of required tensile strength steel.5.11.3MEASUREMENT/BASIS OF PAYMENTPayment will be made as a lump sum basis or as per quantity installed.The installed item will be tested to assure that there is no leak and shall be paid for at the Contract unit price for the expansion joint pay item that is included in the Bill of Quantity, which price and payment shall be for full compensation for furnishing all labor, equipment, tools and incidentals necessary to complete the Work prescribed in this item.