基坑格构柱端部位移对承载力的影响

The Bearing Capacity Influence of End Displacement on the Lattice Column of Foundation Pit

基坑工程竖向支撑体系主要采用型钢格构立柱,在施工过程中立柱两端均会发生不同程度的位移,构件受压偏心距进一步增大,降低了格构柱的竖向承载力。通过概化立柱的力学模型,结合基坑工程中最常用的型钢型号、组合截面尺寸,分别量化分析了不同的格构立柱长度、端部位移条件下格构立柱两端位移差对于其竖向承载力的影响,并结合数值模拟,比较了计算结果的合理性,为格构立柱的设计和增设格构立柱两端位移差的监测提供有效的参考。

The vertical support system of foundation pit engineering mainly adopts section steel lattice column.During the construction process,the two ends of the column will have different displacement,and the compression eccentricity of members will further increase,which will reduce the vertical bearing capacity of lattice column.Based on the mechanical model of the generalized column,combined with the most commonly used steel type and combined section size in foundation pit engineering,the influence of the displacement difference at both ends of the lattice column on its vertical bearing capacity is quantitatively analyzed under the conditions of different lengths of lattice column and ends displacement.Combined with numerical simulation,this paper analyzes the rationality of the calculation results.It provides an effective reference for the design of lattice column,and provides a theoretical basis for the monitoring of displacement difference between two ends of lattice column.