深厚软土地层小型浅层地下室基坑优化设计

Optimization Design of Small Shallow Basement Foundation Excavations in Thick Soft Soils

为探索深厚软土地层条件下小型浅层地下室基坑开挖绿色且经济的解决方案,依托汉川某厂房项目一层地下室的基坑支护设计,对软土地区常用的支护形式进行了对比分析。选用SMW工法桩作为支护桩,结合被动区搅拌桩加固作为暗撑的方案,设计了经济合理的支护结构,解决了场地紧张的超深淤泥层中浅层基坑方案设计的诸多问题。项目实施过程中,通过对支护桩顶水平位移、周边地面沉降的实时监测,绘制了桩顶位移和周边沉降的时程曲线,变形和沉降趋势与设计吻合,证明了设计方案的合理性。该项目的顺利实施,解决了软土地区浅层小型基坑以往偏安全设计导致的经济性差的问题,为类似项目的经济性优化提供了可行的思路,具有借鉴意义。

In order to explore a green and economical solution for the small shallow basement excavations in thick soft soils,different types of deep excavation support methods are compared and analyzed in a single story basement foundation excavation project in Hanchuan.An economical and reasonable supporting system is designed by using the soil mixing wall(SMW)method as supporting structure and the soil-cement column reinforcement in the passive zone as the concealed bracing,which solves many problems in the design of the shallow foundation excavations in thick silty layers.In the process of the project implementation,the time history curves at the column top displacement and the surrounding settlement are presented through the realtime monitoring of the horizontal displacement of supporting column top and the surrounding ground settlement.The trend of deformation and settlement is consistent with the design,which proves the rationality of the design scheme.The smooth implementation of this project provides a feasible idea for the economical optimization of similar projects and solves the problem of poor economic efficiency caused by the previous excessive design of shallow small foundation excavations in the soft soil area.