黔桂线车河站斜坡软土成因及治理措施

Forming Causes and Treatment Measures for Slope Soft Soil at Chehe Station in Guiyang-Liuzhou Railway

研究目的:位于山前缓坡上的车河站横穿21条自然沟,施工开挖及试填筑时发现大部分沟内分布斜坡软土,需查明其成因、范围、厚度及工程性质,为设计提供依据。研究方法:参考我院设计的内昆线、水柏线等铁路项目山区斜坡软土研究结论,采用试抗、钻探、静探、轻型动探及试验等综合勘探手段进行研究。研究结果:车河站共有16条沟内分布斜坡软土,厚度差异较大,共同特点是土质软、成分杂、分布和性质不均匀,且夹有较多碎块石。最后选择了强夯碎石墩对基础进行复合地基加固。研究结论:地层结构造就了特别的水文地质环境,从而为形成山前缓坡沟槽软土创造条件。治理包括排水、地基置换及挡护3个方面。从施工结果看,采用强夯置换法处理车河站斜坡软土操作容易,效果明显。

Research purposes： Chehe station lied in the gentle slope pass across 21 natural gulleys. It is discovered that the slope soft soil is distributed in a majority of gnlleys when excavating and testing filling. Therefore, it is necessary to find out the forming causes, range, thickness and engineering property of the soft soil for providing basis to design. Research methods： Based on research conclusions of mountainous slope soft soil of such railway projects as NeiKun and ShuiBo, etc. designed by our institute, the research is carried out by comprehensive exploring measures including test pit, drilling, static cone penetration test, light- type dynamic cone penetration test and tests. Research results：Soft soils with different depth are distributed in 16 gulleys at Chehe station, of which the common characters are soft in quality of soil, various in composition, uneven in distribution and property and mingled with plenty of rock fragments. At last the foundation is consolidated by the heavy -tamping broken stone piers. Research conclusions：Particular geohydrologic environment formed by stratum structure provide conditions for forming of gentle slope gulley soft soil. The treatment measures of slope soft soil include drainage, foundation replacement and retaining. According to the construction results, it is easy to treat the slope soft soil at the Chehe station with heavy - tamping replacement method and its effects are obvious.