利用静探成果确定基床系数的方法研究  

Study on the determination of foundation coefficient by using static cone penetration test results

作　　者：彭友君 

机构地区：[1]北京城建勘测设计研究院有限责任公司,北京100101

出　　处：《工程勘察》2015年第9期28-32,共5页Geotechnical Investigation & Surveying

摘　　要：基床系数是隧道结构变形计算的重要参数,在地铁勘察中关注度很高。为了探索其取值,分析了地铁隧道围岩的基本规律,基于平板载荷试验确定承载力特征值的规定,充分考虑标准载荷试验承压板与基础的尺寸效应,引入静力触探确定地基承载力的回归方程,利用非线性广义的文克尔地基模型给出的沉降比,将基床系数表达式进行推导、简化,得到了黏性土和砂土以锥头阻力计算基床系数的公式。通过对几个城市不同地层基床系数的计算,证明了利用该计算公式得到的基床系数与地铁设计实际使用的数值基本一致,因此合理使用计算结果可作为地铁隧道设计重要的参考依据。Foundation coefficient is an important parameter in calculating the deformation of tunnel structure, and the degree of concern in the subway exploration is very high. In order to explore its value, the basic rules of the subway tunnel surrounding rock are analyzed. Based on the regulations of the plate loading test to determine the bearing capacity characteristic value, the size effects of the bearing plate and foundation for the standard load tests are fully taken into account, which is considered in the regression equation of the foundation bearing capacity and static cone penetration test. Using the nonlinear generalized Winkler foundation model to give the settlement ratio, the expressions for the coefficient of subgrade reaction are derived and simplified, and the calculation formula by using cone resistance for the coefficient of subgrade reaction of clay soil and sand are obtained. Through the calculation for the coefficient of subgrade reaction of different strata in several cities, it is proved that the numerical calculation results are completely accord with the values of the actual design of the subway. The rational use of the calculation results can be used as an important reference data of subway tunnel design.

关 键 词：基床系数 静力触探 地铁勘察 弹性地基 地基模型 沉降计算 K30试验 地基反力系数 

分 类 号：TU413[建筑科学—岩土工程]