大宁水库水下第三系黏土岩地基承载力分析  

Analysis of Bearing Capacity of the Tertiary of Clay Rock Foundation of Daning Reservoir

作　　者：赵志江[1] 范子训[1] ZHAO Zhijiang;FAN Zixun(Beijing Institute of Water,Beijing 100048,China)

机构地区：[1]北京市水利规划设计研究院,北京100048

出　　处：《人民黄河》2018年第4期103-107,共5页Yellow River

基　　金：北京市南水北调配套工程河西支线工程项目(NSBD-PT-HXZX-KS)

摘　　要：针对水下第三系黏土岩地基承载力评价存在的问题,以大宁水库地区新建泵站为案例,采用土、岩分类对比试验方法,分析水下第三系黏土岩的力学性质和物理力学指标,并通过原位测试、波速测试、旁压试验等多种手段对黏土岩的地基承载力进行了综合分析,并利用波速-旁压联合测试法定量分析评价黏土岩的地基承载力。结果表明:第三系黏土岩具有明显的土岩二象性,其含水率对土体的力学性质影响较大而对岩体的力学性质影响相对较小;单独采用旁压试验法计算黏土岩地基承载力特征值为未经过开挖卸荷和扰动的岩体承载力,其结果大于天然岩体的承载力特征值;剪切波速试验和波速-旁压联合测试求得的承载力较为符合实际情况,波速-旁压联合测试法可以作为原位测试的理论参考,定量评价地基承载力。Accordingto the existing problems on the evaluation of the bearing capacity of clay rock foundation under water of tertiary series,based on soil test and in-situ test accurate quantitative analysis as the goal and taking the newly built pumping station in Daning Reservoir area as an example,the test method for classification of rock soil,comparative analysis of the tertiary series of clay rock,the water of the clay rock mechanical properties and physical and mechanical index were conducted.The clay rock foundation through a variety of test and in situ test,wave velocity test,pressure-meter test method of bearing capacity were analyzed,combined with other parts of the country of similar rock field had been carried out by using velocity-pressure test method combined with quantitative analysis and evaluation of the clay rock foundation bearing capacity.The results show that the tertiary series of clay rock has the nature of rock and soil simultaneously,the influence of water content on mechanical properties of soil is larger and influence on mechanical properties of rock mass is relatively smaller;the pressure-meter test method to calculate the clay rock characteristic value of sub-grade bearing capacity for rock excavation and unloading without disturbance of the bearing capacity the characteristics of the results of the bearing capacity is greater than that of the natural rock mass;shear wave velocity and wave velocity-pressure joint test obtained is in accordance with the actual situation of the bearing capacity,the velocity-pressure meter test method can provide a theoretical reference combined with in situ test,the quantitative evaluation of the foundation bearing capacity.

关 键 词：黏土岩 承载力 土岩二象性 波速-旁压联合测试 大宁水库 

分 类 号：TU471.6[建筑科学—结构工程]