复杂环境下桩锚土钉复合支护分析

摘要

The research focus on the pile-anchor soil-nailing composite supporting method under complex environment which nearby electric tunnel and anti-air cavity.The finite element method is used to simulate the construction progress and the electric tunnel and anti-air cavity considered.During the study vertical and horizontal displacements of the roof of the support structure,horizontal displacement of the deep soil and the settlement of the surrounding buildings and the displacement and internal force of the pile are analyzed.Meanwhile the simulation results are compared with the measure results.The results show that during the construction progress,the maximum vertical and horizontal displacements at the top of the support structure are 20.6 mm and 7.4 mm,the maximum deep horizontal displacement of soil is 8.4 mm and maximum the settlement of surrounding buildings is 2.1 mm.All above results meet the standard requirements.In conclusion,for the complex environment of deep excavation with electric tunnel and anti-air cavity,the pile-anchor soil-nailing supporting system is effective for the stability and safety of pit foundation and nearby buildings.%目的 针对郑州地区某基坑工程存在电力隧道和防空洞等复杂情况进行研究,提出采用桩锚土钉复合支护体系处理该类深基坑的方法,为类似工程提供参考.方法 采用有限元软件建立同时存在电力隧道和防空洞的深基坑桩锚土钉复合支护有限元模型,模拟分析复杂环境条件下基坑工程施工过程中支护结构坡顶竖向和水平位移、深层土体水平位移以及周边建筑物的沉降以及桩身位移及内力,并与相应的监测结果进行对比分析.结果 施工过程中实测基坑坡顶水平最大位移20.6 mm,沉降7.4mm、土体深层水平位移8.4mm,周边建筑物沉降2.1mm,均满足规范要求.结论 深基坑工程存在电力隧道和防空洞的复杂环境条件下,采用桩锚土钉复合支护体系能满足基坑的安全稳定要求和周边建筑物的保护要求.