加劲U型钢板桩失稳临界荷载动态配位系数法

Dynamic Coordination Coefficient Method for Critical Buckling Load of Stiffened U-Shaped Steel Sheet Pile

针对U型钢板桩插打容易发生屈曲的问题,提出U型钢板桩局部加劲效应理论计算的“动态配位系数法”,建立了局部加劲U型钢板桩失稳临界荷载计算式,并分析了加劲面积、加劲位置、加劲板数量对加劲效应(即失稳临界荷载)的影响规律.研究结果表明:加劲总面积(即加劲板累计宽度)一定时,对于长度确定的U型钢板桩,存在使构件临界荷载值最大化的加劲板布置方案,并揭示了块数太多时由于单块加劲板宽度太小而引起的局部失稳规律;以10 m长U型钢板桩为例,构件临界荷载值随单块加劲板布置位置的变化可提高13.55%,并求得20 m长的U型钢板桩不同加劲总面积对应的加劲板布置优化理论方案,为实际工程中U型板桩局部加劲方案设计提供了理论依据和参考.

Since U-shaped steel sheet piles(USSSPs)are prone to buckle,a dynamic coordination coefficient method for theoretically calculating the local stiffening effect of USSSPs is proposed,and a formula for calculating the critical buckling load of locally stiffened USSSPs is established.The influence of different stiffening areas,stiffening positions,and number of stiffened plates on the stiffening effect(i.e.,critical buckling load)is analyzed.The study shows that when the total stiffening area(i.e.,cumulative width of stiffened plates)is constant,for the USSSP with determined length,there is a stiffened plate arrangement scheme to maximize the critical load value of the component,and the local buckling law caused by too small width of a single stiffened plate when the number of plates is too large is revealed.As an example,the critical load value of the component of the USSSP with a length of 10 m can be increased by 13.55%with the change of the position of the single stiffened plate,and the optimal theoretical scheme of stiffened plate arrangement corresponding to different total stiffening areas of the USSSP with a length of 20 m is obtained.This paper provides a theoretical basis and reference for the design of the local stiffening scheme of USSSPs in practical engineering.