高速铁路泥岩地基膨胀特性试验研究

Experimental study on swelling characteristic of mudstone foundation of high-speed railway

以兰新高铁一处典型膨胀泥岩路段为研究对象,在此现场取样,室内自制试验箱进行厚度分别为20,40和60cm的泥岩地基膨胀模型试验研究。研究结果表明:随着注水量和时间的增加,地基膨胀量整体呈外凸弧线增长;含水率小的地基膨胀潜势大,地基易膨胀,含水率大的地基反之;不同深度处的泥岩膨胀量不同,随着深度的增加,膨胀量逐渐减小;不同厚度地基含水率与膨胀量均呈良好指数关系;对地基膨胀量与含水率及地基厚度耦合作用下的计算模型进行探讨,计算模型所得膨胀量与实际室内试验量测数据拟合良好。研究成果可为膨胀泥岩地区高速铁路修建提供参考依据,对该地区同类工程建设具有借鉴意义。

A typical swelling mudstone section of Lanzhou-Xinjiang high speed railway was taken as the research object. Samples were taken at this site, experimental study on the swelling of mudstone foundation was carried out with thickness of 20, 40 and 60 cm in self-made test box. The results show that with the increase of water injection and time, the swelling amount of the foundation is increased in an outer convex curve;the foundation with small water content has large swelling potential, the foundation is easy to swell, and the foundation with large water content is opposite;the swelling of mudstone at different depths is different, and the swelling amounts gradually decreases with the increase of depth;the water content and the swelling amount of foundation show a good exponential relationship;the calculation model of the foundation swell with the coupling of water content and the thickness of the foundation was discussed. The swelling amounts of the calculation model is well fitted to the actual test data in the laboratory. The research results can provide reference for the construction of high-speed railway in the swelling mudstone area, and can be used for reference in similar projects in this area.