SMW工法桩在厚砂层基坑中的应用与监测分析

APPLICATION AND MONITORING ANALYSIS OF SMW METHOD PILE IN FOUNDATION PIT IN THICK SAND

合信广场基坑施工中,对坑顶水平位移、型钢受力、锚索应力、深层土体水平位移、周边沉降及地下水位进行监测,并对SMWT法桩在厚砂层基坑中的应用效果进行分析。监测数据表明,随基坑开挖深度增加,桩顶变形和锚索应力呈阶梯式增长,锚索应力设计存在优化空间;型钢的受力最大值位置逐渐往下偏移,水泥土可分担桩体所受的弯矩;施工过程中,涌砂、涌水导致坑外地下水位的下降,会使周边沉降增大;SMW工法桩能有效控制基坑周围土体的变形并起止水作用。

Based on the monitoring consist of the top horizontal displacement, steel stress, anchor stress, deep soil level displacement, surrounding ground settlement and underground water levels during the construction process of Hexin square foundation pit, the application eflect of SMW Method pile in thick sand foundation pit is analyzed. Results indicate that with the increase of depth of the excavation, the top horizontal displacement and anchor stress showed a ladder type growth. There is room for anchor stress design optimization. The position of the maximum stress of the steel is gradually downward, and soilcement can share the bending moment of the pile. The drop of underground water levels outside the pit caused by sand and water gushing will make the surrounding ground settlement increases. SMW Method pile could effectively control the deformation of soil around the foundation pit, and cut off the water seepage.