软土深基坑双排桩支护结构的变形性状分析

Analysis of deformation behavior of double-row piles supporting structure in soft-soil deep foundation pit

结合具体工程实例,采用规范中平面刚架结构模型对软土深基坑双排桩支护结构的变形性状进行了深入分析,并将规范方法的计算结果与实测结果进行对比分析,最后利用有限元软件PLAXIS 2D对双排桩支护结构的受力和变形进行复核。研究结果表明,规范方法高估了后排桩的作用,建议适当增强桩间土传递土压力的作用,增强前排桩抵抗变形作用,弱化后排桩抵抗变形的作用;建议开挖段与嵌固段采取不同的土压力分配比例,且嵌固段的土压力分配比例宜较开挖段大。

Combined with specific engineering example,the plane frame structure model in the code was adopted to carry on the thorough analysis of deformation behavior of double-row piles supporting structure in soft-soil deep foundation pit,and the calculation results according to the code method were analyzed and compared with the experimental results.Finally,the finite element software PLAXIS 2 D was used to review the stress and deformation of double-row piles supporting structure.The study results show that the code method over estimates the effect of piles in back rows,and it is recommended to appropriately strengthen action of soil between piles to transfer soil pressure,to enhance the ability of the front piles to resist deformation and weaken the ability of the back piles to resist deformation; it is proposed that excavated section and the embedded section adopt different earth pressure distribution ratios,and the earth pressure distribution ratio of embedded section has better to be larger than that of the excavated section.