季节性冻土深基坑支护技术研究

Investigation on technology of retaining and protection for seasonal frozen soil deep foundation pit

通过对中国地质大学(北京)综合游泳馆工程拟建场地土层的土质、深度及基坑深度的分析与比较,确定出基坑深度范围内土层的土质。介绍了季节性冻土深基坑支护经常出现的问题,并分析了这些问题出现的原因。对常用土钉支护方法在季节性冻土深基坑支护中运用的局限性做了总结,最后提出一种改进的土钉支护方法。该法针对冻土发生冻融循环时冻胀与融沉的特点采取了相应的控制措施,从而保证了季节性冻土深基坑的稳定性。该法操作简单可行,实践证明效果明显。

Through comparison and analysis of the quality and depth of soil and the depth of foundation pit for the building site in planning of the multi-functional swimming gymnasium in China University of Geosciences,the soil condition in the scope of the foundation pit depth was confirmed.The common problems of the retaining and protection for seasonal frozen soil deep foundation pit were described,and reasons for these problems were analyzed.The limitation of soil nailing retaining system in the retaining and protection for seasonal frozen soil deep foundation pit was summarized,and a new method to improve the soil nailing retaining system was proposed.The method takes the appropriate control measures from these characteristics of frost heaving and thawing settlement for the freeze-thaw cycle from frozen soil,and guarantees the stability of seasonal frozen soil deep foundation pit.This method is simple and effective for operation.