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DETENTION TANK DESIGN: <br />Design loads are for the actual dead loads, soils loads as <br />determined from the Civil Engineering Plans and an N820 <br />vehicle AASBTO distributed. <br />Construction should be in accordance with latest edition of <br />UBC Section 108 and should include; <br />1. All concrete work phases and strength. <br />2. Provide special inspection by Geotechnical Engineer <br />confirming assumed soils parameters. <br />3. Any fill placed below footings or slab has <br />sufficient compaction to at least 95% ASTM D-1557. <br />Prior to excavation the Contractor will determine if any <br />underground utilities exist in the area of work. <br />Tank foundations have been designed based on; <br />Allowable Bearing 3000 PSF (in Fill 2000 PSF) <br />Active Earth Pressure 35 PCF (Retaining) <br />Active Earth Pressure 50 PCF (Restrained) <br />Passive Earth Pressure 400 PCF <br />Soil Wt 130 PCF (120PCF) Coef. of Friction .50 (SF= 1.5) <br />Foundation excavation shall extend into undisturbed soil. <br />Should filling occur it will be place to 95% compaction and <br />shall be inspected for adequacy. <br />Back -filling of the walls shall be accomplished using a free <br />draining material. When required, a sub -drain should be <br />installed to carry away any local ground water which might <br />accumulate in the back -fill or pond behind wall. Raise fill <br />evenly around tank to prevent overloading walls at any <br />specific point. <br />Concrete construction for cast -in -place concrete shall be <br />inspected and tested. The concrete shall attain a minimum <br />28 day strength of fc'= 3000 psi. Use of add mixtures <br />shall have Owner approval. (Strength required to back -fill.) <br />Reinforcing steel shall conform to ASTM A-615-68, Grade 60. <br />Lap splices shall be a minimum of 30 bar diameters. <br />Fy= 60,000 psi. All horizontal reinforcing bars in walls <br />shall be lapped around the corners. The reinforcing shall <br />be protected by minimum cover as detailed on the plans, or <br />when not detailed per UBC Concrete Construction. <br />Pre -cast prestressed hollow -core concrete planks shall be <br />designed and detailed by the Manufacturer. Shop Drawings <br />shall be provided for approval prior to fabrication. Design <br />and fabrication shall be under the Manufacturer's Quality <br />Control and Calculated Data. Approved Shop Drawings, <br />handling and erection details are to be shipped to the job <br />site with the prestressed concrete planks. <br />