Application Of Super-long Larsen Steel Sheet Pile In Deep Support Of Foundation Pit Of Bridge Main Pier

With the rapid development of economy in our country,more and more bridges have been built to form urban expressway networks.The support of deep water foundation is a difficult problem in bridge construction.The key to determine the form of support is that the support should meet the requirements in safety and economical at the same time.There are many lakes in Wuhan area,but most of them do not have the navigation function,so it is economical to adopt the supporting method of island cofferdam and Larsen steel sheet pile in Wuhan area.Based on the construction of grand bridge in Fu River Fourth ring road Wuhan city.Firstly,considering the complex engineering geological conditions,a supporting scheme of 21 m super-long Larsen steel sheet pile is put forward based on the goal of cost-effectiveness and safety.Then the stress and deformation of supporting system are calculated by two software of Lizheng and FLAC 3D.Secondly,trial construction has been conducted to study construction techniques to solve difficult problems,then,the techniques of this project are summarized and examined in practice.At the same time,the process of excavation is monitored,and the actual deformation characteristics of steel sheet piles are studied by classifying the monitoring data.Finally,the numerical results are compared with the field data to verify the reliability of the numerical method.Based on above studies,some conclusions can be drawn: The construction technology of super-long Larsen steel sheet pile is different from steel sheet pile.The horizontal displacement and settlement of foundation pit increased with the excavation,and the maximum displacement of deep soil occurs near the bottom of the pit.The axial force are larger when the distance between steel support and excavation face is closer.The results calculated by Lizheng and FLAC 3D are similar,but the results of FLAC 3D are more accurate than Lizheng.