双排钢板桩围堰支护结构参数优化及稳定性验算

Parameter Optimization and Stability Checking of Double-row Steel Sheet Pile Cofferdam

双排钢板桩围堰具有稳定性较好、止水性能强等优点,广泛应用于水利工程。为研究围堰支护结构的优化设计,以竺山湖隧道施工现场围堰为实例,在满足稳定性要求的前提下,对施工现场的双排土芯钢板桩围堰参数进行优化,利用三维数值模拟软件PLAXIS 3D建立施工现场的三维模型,分析钢板桩在不同水位、不同桩间距下的变形情况,并进行稳定性验算,进而得出最佳参数。结果表明:(1)随着围堰水位升高,钢板桩呈现中间“鼓肚”减小、顶部位移有所增大的变化特征;(2)为提高工程经济效益,建议桩间距减小至4.5 m,此时水平位移与桩间距6 m相近,“鼓肚”现象及钢拉杆所在高程的弯矩相应有所减小,稳定性满足要求。

Considering the economic benefits of double-row steel sheet pile in the actual engineering,taking the cofferdam of Zhushanhu tunnel construction site as an engineering example,the parameters of the doublerow soil-core steel sheet pile cofferdam at the construction site were optimized in the early stage of meeting the stability requirements,and the three-dimensional model of the construction site was established by using the three-dimensional numerical simulation software PLAXIS 3D.Through numerical simulation,the deformation of steel sheet pile under different water levels and different pile spacings is analyzed,and the stability checking is carried out to obtain the optimal parameters.The results show that:(1)With the increase of the cofferdam water level elevation,the steel plate pile shows the change characteristics of decreasing the“bulging”phenomenon in the middle and increasing the top displacement.(2)In order to improve the economic benefit of the project,it is suggested to reduce the pile spacing to 4.5 m.At this time,the horizontal displacement is similar to the pile spacing of 6 m.The“bulging”phenomenon and the bending moment of the steel pull rod are correspondingly reduced,and the stability meets the requirements.