Research On Design And Construction Technology Of Steel Sheet Pile Cofferdam In Water For Pier Of Nantong Jiuwei Port Sluice Gate

Nantong City,nine polder port water sluice is a key part of the Yangtze River Road West Extension Project of Nantong ? standard construction content,four piers are all located in the water,combined with hydrogeological conditions,considering the construction period,cost and other factors,determine the use of water steel sheet pile cofferdam.Steel sheet pile cofferdam construction with assembled flexible and reusable material and construction cost is low,less environmental pollution,this paper design of steel sheet pile cofferdam by Tongji calculate stress QIMINGXING pit supporting structure of special software,and studied the following four aspects of the construction practice:(1)According to the construction conditions,the construction scheme was studied and four inner supports were set up,and the stress calculation of the cofferdam under the simulated working conditions was carried out.At the same time,considering the demolition conditions,the design of the third inner support design changes,effectively prevent the deformation and stress caused by the steel sheet pile demolition.(2)The construction practice,the steel sheet piles,purlin support installation,support for demolition and removal of construction process quality control points,the key construction techniques focus on the prevention and control of the cofferdam seepage Water Leakage.Practice has proved that although the steel sheet pile cofferdam is completely in the water,the cofferdam construction is safe and controllable.(3)The construction technology of underwater suction and bottom sealing concrete pouring of cofferdam is studied.The implementation of the credit flow,scour and other compensation measures in construction,especially in the lateral cofferdam riprap protection around,effectively reduce the impact of the cofferdam of the bottom soil water erosion.Therefore,underwater suction mud,bottom sealing concrete,riprap protection is an important guarantee for construction.(4)Carry out construction monitoring technology research,through manual inspection and instrument monitoring methods,timely grasp deformation and stress conditions.At the same time,through the comparative analysis of simulation results and monitoring results,both changes are basically consistent,that software design model used is reasonable,reliable parameters,the construction scheme is feasible and safe.