02-11-1985 Council Packet - Laserfiche WebLink

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35,1nO.3. PUMP _CHAMRF:R: The pump chamber shown on the plans shall be con- structed of a pour.,od-in-place base sla►,, precast manhole sections and a precast top slap. Manhole sections shall conform to A.S.T.m. Designation C-748 using gasketed joints, ,r approved equal. The pump chamber shall be watertight with all lifting holt,s, j,,ints, etc, neatly mortared up. The pump chamber shown on the plans is designed to be constructed in a dewatered, open ex, avarion. However, the contractor may h,e•l(1 ►he pump •hamher using a caisson method with the following requirements-. 1. The contractor shall obtain the Fngineer's approval nrinr tc proceeding with the caisson merhod. 2. The contractor shall submit a detail sketch showing all structure modifications necessary to use the caisson method for buiIdinit, the pump chamber. These modifications include, but are not limited a method nr attaching the precast sections !ogether, a concrete bottom seal, a reinforced concrete bottom slat), adequate structural integrity rn assure resiRtAnce to up -lift or buovancv, anv modification to the bottom <)f the vertica` walls needed ro build the structure a5 a raiser-1. 3. The contractor shall cuhmir fo,er (4) copies of al' ske.tchea re the Fngineer for approval. 4. The contractor shall outline to the Engineer, the construction procedure to be used for h,eildinR the structure as a r.Hicsnn. 5. The contractor shall ;ubmit, for reference, A Iiat of projects completed by the contractor where the caisvnn method has `+een used. The lift station shall he backf11led with selected material from the site free Of organi-9, wood fragments, roots, stumps, rubbish, frozen materials or similar art .^les whose presence would cans.- settlement. In the event that an insufficient ,mount of suitable material is available on Rite, the :ontractor shall provide Oditional common borrow material subject to the approval of the Fnxineer. Bal 'll shall bP placers in h inch !nose lifts ovenly around structure and _omp.-tetd by mechanical means. Any settlement around the station occurring. within ,:ne year shall tie repaired by the contractor.. includ- ing anv surface materials. If dewnterinle equipment is being .iced for cnn- stnu:tion, it shAl! not he turned off until backfiiling is complete. The contractor shall grout the bottom of the pump chsmherr as recommended by the pump manutacturer or O nwn on the plan to efficiently remove and prevent scrrmulAtion of waste materials. ('11- 5 941 c. "')pvriI"t 19A5 p,lnastroo, Rnsernr, AndPr 1 ik Go As saci.Rtra, inc. 35,1nA-2