Mechanical Behavior Analysis And Process Monitoring Of Double-wall Steel Cofferdam With Large Variable Amplitude Water Level

With the development and construction of long-span bridges,the foundation engineering of bridge piers needs to be constructed under the conditions of large water level variation and complicated geological conditions.It requires a large safety reserve and a wide application range.Double-wall steel Cofferdams are well suited for such projects.Based on the structural form and force behavior of the MP4# double-walled steel cofferdam of the Changjiang Sixth Bridge in Luzhou,this paper studies the double-wall steel cofferdam of the same type.Mainly carried out the following aspects of research:(1)According to the relevant construction experience and the concise calculation manual,the traditional double-wall steel cofferdam components are separated by the traditional approximate simplification method,and the mechanical performance analysis is carried out separately.The main components of the cofferdam are calculated.Support and the strength and rigidity of the vertical ribs.Analyze the advantages and disadvantages of this traditional method by traditionally simplifying hand calculation results;(2)Using the finite element general calculation software Midas Civil to establish a finite element model of double-wall steel cofferdam,introduce the modeling method and ideas,apply various loads existing on the site,and analyze the strength and stiffness of steel cofferdam under different working conditions.And stability;(3)Comparing the traditional calculation results with the finite element calculation results,and analyzing the reasons for the difference between the two methods;(4)Under the premise of the behavior analysis of the double-wall steel cofferdam of the Six Bridges in Luzhou,with the calculation advantage of the finite element software,the influence of the parameters selection of the key components of the double-walled steel cofferdam on the structural stress is studied.Dimensional,horizontal comparison of the resulting data to obtain relatively good design parameters,to provide reference for the design of subsequent engineering projects;(5)According to the finite element calculation results and the parametric research results,select the engineering example double-wall steel cofferdam to carry out construction monitoring work with unfavorable position,develop monitoring plan,provide construction monitoring and early warning value,and ensure on-site double-wall steel cofferdam construction Safety and safety in the later period under the action of large variable water level,and finally analyze the monitoring data to verify the correctness of the finite element calculation results.