水泥土搅拌桩加固饱和黄土地基承载特性研究

Study on Bearing Capacity of Saturated Loess Foundation Reinforced by Cement Soil Mixing Pile

以兰州至中川机场城际铁路为工程依托,对水泥土搅拌桩复合地基承载特性进行研究,在不同的水泥粉煤灰(以下简称"二灰")掺入比下进行单桩静载荷试验,分析荷载-沉降变化规律,并用FLAC 3D软件进行数值模拟,与现场实测数据进行对比.结果表明:水泥土搅拌桩复合地基承载力较原位地基土有显著提高,二灰掺量16%的水泥土搅拌桩已满足符合地基承载力要求.用FLAC 3D软件模拟数据与二灰掺量16%的现场实测数据对比,两者曲线基本吻合,说明数值模拟能够较准确的模拟现场实测情况.

The intercity railway from Lanzhou to Zhongchuan airport is saturated loess foundation,with high compressibility and low bearing capacity.The cement soil mixing pile is used to reinforce the saturated loess foundation.In this paper,the bearing characteristics of cement soil mixing pile composite foundation are studied.The static load test of single pile is carried out under the mixing ratio of different flyash cement(hereinafter referred to as"two-ash").The law of load-settlement change is analyzed,and the numerical simulation is carried out with FLAC3D software,and the measured data are compared with the field measured data.The test shows that the bearing capacity of the cement soil mixing pile composite foundation is significantly higher than that in the ground soil,and the cement soil mixing pile with two-ash content of16%is satisfied with the requirement of the bearing capacity of the foundation.By comparing the measured data of the two-ash content of160%FLAC with the measured data of the3D software,the two curves basically coincide,indicating that the numerical simulation can be more accurate onsite measurement.