城市地下综合管廊工程勘察技术与支护设计方法

Survey Technology and Support Design Method for Urban Underground Comprehensive Pipe Gallery Engineering

针对富水地质条件的复杂性,结合实际的城市地下综合管廊工程,研究勘察技术和支护方法。采用钻孔深度为25 m、孔间距为20 m钻探方法,获取土样和岩芯样本,通过GPS观测和物性试验、固结试验、剪切试验获得地质数据。勘察结果表明,强风化混合花岗岩和中风化混合花岗岩为较硬岩层,工程性质较好,可直接作为持力层。地下管廊基坑支护体系采用SMW工法桩,部分地段设置上下两道锚固支护体系进行加强。监测数据显示,基坑顶部最大水平位移为8.47 mm,内支撑轴力最大值为1 042 kN,最大地表沉降量为11.81 mm,均低于预警值,项目整体可控,施工安全。

In response to the complexity of water rich geological conditions,combined with actual urban underground comprehensive pipe gallery engineering,research is conducted on survey techniques and support methods.The soil samples and Core sample were obtained by the drilling method with a drilling depth of 25 m and a hole spacing of 20 m.Geological data were obtained through GPS observation,physical property test,consolidation test and shear test.The survey results indicate that strongly weathered mixed granite and moderately weathered mixed granite are relatively hard rock layers with good engineering properties and can be directly used as bearing layers.The foundation pit support system of the underground pipe gallery adopts SMW construction method piles,and some sections are equipped with two anchoring support systems for strengthening.The monitoring data shows that the maximum horizontal displacement at the top of the foundation pit is 8.47 mm,the maximum axial force of the internal support is 1042 kN,and the maximum surface settlement is 11.81 mm,both of which are lower than the warning value.The project is overall controllable and construction safety is ensured.