铁路客运专线CFG桩复合地基沉降监测与分析

Settlement monitoring and analysis of GFG pile composite foundation for railway passenger dedicated line

介绍了武广铁路客运专线路基典型断面变形、应力监测方案,对CFG桩复合地基中桩身压缩量、不同深度范围内桩间土压缩量的监测结果进行整理分析,探讨了路基填筑、停载、超载预压、超载卸除等施工过程中CFG桩复合地基的变形发展规律。现场实测结果表明:在施工过程中,CFG桩复合地基中的桩、土变形并不协调,其变形差随着复合地基中应力不断调整而逐步减小;基于复合地基压缩变形的93.4%发生在CFG桩加固深度内,准确计算加固区沉降是提高复合地基沉降计算精度的关键。

The deformation and stress monitoring plan of representative section of Wuhan - Guangzhou railway passenger dedicated line was introduced. The monitored compressions of piles and soil between piles in different depths were analyzed. Then deformation development trends of piles and soil between piles in CFG pile composite foundation was investigated according to the construction processes of railway subgrade, namely filling, rest of loading, surcharge precompression, unloading surcharge, and so on. In -situ monitored results show that the compression of pile is not equal to compression of soil among piles during construction of subgrade, and their difference reduces gradually with the stress adjust among composite foundation. 93.4% of the compression deformation of composite foundation is from the depth of soil stratum improved by CFG piles, the crucial strategy to improve the precision of settlement calculation for composite foundation is to calculate accurately the settlement from improved soil stratum.