摘要
广州市地铁公园前地下空间基坑依据地质条件分段确定挖孔灌注桩加内支撑、挖孔灌注桩加预应力锚索、土钉墙放坡等多种综合支护方案。由于该基坑平面不同位置深度差异大、紧邻地铁一号线与地铁二号线以及已有车站风井、地下通道等地下构筑物,且地处商业繁华地带。为确保基坑安全,布置详细监测方案。基坑工程实行信息化施工并获得了丰富的监测数据,通过对数据分析结果表明:实测主动土压力小于计算主动土压力,实测主动土压力随时间延长变小;土体中孔隙水压力随时间增长而减小,孔隙水压力随深度增加而呈非线性增加;基坑冠梁协同作用明显,冠梁减小了基坑变形;锚索轴力比较稳定,钢撑轴力变化相对较大,且二者轴力仍富余较大,该设计比较安全。
The cut-cast piles with interior support, prestressed anchor and soil nail were combined to form the optimized comprehensive retaining structure. Owing to large difference of foundation pit depth in different zones, neighbouring metro line No.l and No.2, existing wind wells and underground lane, etc., the monitoring project was prepared in detail to make construction of foundation pits be informationized, thus the full data were obtained. Based on the analysis of the above data, several laws were summarized. It was shown that the measured active soil pressures were smaller than the theoretical values and diminished with time, the measured pore water pressure decreased with the time and increased with the depth of soil, the combinative effects of cap girder and supporting structure were obvious which diminished the displacement of foundation pits, and the measured axial force of the anchor and interior steel beam were far less than the design force, indicating that the design safety factor of the foundation pit was too large to be economical.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2007年第6期872-879,共8页
Chinese Journal of Geotechnical Engineering
关键词
综合支护
信息化施工
基坑监测
comprehensive retaining
informationized construction
monitoring
