22 126 Section 5: Please note that the side Contractor has to do the Sub Specifications scan scanner and Bottom Profiling investigation Clause 4.3 : profiler for surveys (SBP) as mentioned in the bid are possible only in the documents, which meets the Second Last Para water depths in excess of 5 specified accuracy. meters to record Before dredging of interoretable data. High During selection of the the sediments starts resolution sub bottom proposed (combination of) the Contractor has profiler’s accuracy / methodology (ies) the to conduct a resolution is 15 to 20 cms. Contractor has to take into continuous survey of account the shallow water the thickness of the We understand that the conditions of the site. sediment layer in max depth at NMK lake is Lake NMK and the 3.5 m, hence please Contents of the clause holds height and position suggest alternate (or) you good of the top of the clay may provide the design layer in this lake. depth of dredging required. This survey has to result in a digital 3D model of the sediment and clay layer. The accuracy of the 3D model should be such that the thickness of the
22 126 Section 5: Specifications Clause 4.3 : Second Last Para Before dredging of the sediments starts the Contractor has to conduct a continuous survey of the thickness of the sediment layer in Lake NMK and the height and position of the top of the clay layer in this lake. This survey has to result in a digital 3D model of the sediment and clay layer. The accuracy of the 3D model should be such that the thickness of the Please note that the side scan scanner and profiler for surveys are possible only in the water depths in excess of 5 meters to record interoretable data. High resolution sub bottom profiler’s accuracy / resolution is 15 to 20 cms. We understand that the max depth at NMK lake is 3.5 m, hence please suggest alternate (or) you may provide the design depth of dredging required. Contractor has to do the Sub Bottom Profiling investigation (SBP) as mentioned in the bid documents, which meets the specified accuracy. During selection of the proposed (combination of) methodology (ies) the Contractor has to take into account the shallow water conditions of the site. Contents of the clause holds good
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