旁压试验在西安地铁岩土工程勘察中的应用研究

摘要

Research purposes:A systematic study on pressure meter results based on geotechnical investigation of Xi′an subway No 3 Line in loess area,analysis of a reasonable method for calculating lateral pressure coefficient and horizontal foundation coefficient by the curves of pressure meter in loess area,the objective is to get accurate coefficients,and provide theoretical basis for scientifically analyzing mechanical characteristics of subway tunnel lining and design parameters. Research conclusions:(1 )The lateral pressure coefficient results of pressure meter test are quite close to that of traditional method,the result did not change significantly with depth arden,and pressure meter test takes the advantages of simple operation and economical compared with other methods,therefore it is perfectly suitable for geotechnical in -situ test in loess area.(2)The result of pressure meter test has suggested the change of horizontal foundation coefficient with soil,the soil limit pressure and deformation property parameters can be measured by pressure meter test. But it should be multiplied by 0.3 ~0.5 in calculation of horizontal foundation coefficient when used in parameter design of tunnel lining.(3)The research results will provide theoretical support for reasonable design of subway tunnel lining in loess area.%研究目的：通过黄土地区西安地铁3号线岩土工程勘察中的旁压试验结果的系统研究，分析黄土地区由旁压曲线计算土的静止侧压力系数和水平基床系数的合理方法，目的是得到准确的静止侧压力系数和水平基床系数，为科学合理的分析地铁隧道衬砌受力特性和设计衬砌参数提供理论依据。　　研究结论：（1）采用旁压试验获得的静止侧压力系数与传统方法的结果接近，随深度的变化不明显，且旁压试验有操作简单、经济实用的优势，因此该试验完全适用于黄土地区岩土工程的原位测试；（2）旁压试验结果能较好反应水平基床系数随土层的变化，能同时测得土的极限压力、变形特性和土性参数；（3）旁压试验在计算地基土的水平基床系数时建议乘以0．3～0．5的修正系数后再用于地铁隧道衬砌的设计；（4）研究成果可为黄土地区地铁隧道衬砌合理设计提供理论支撑。