基于承载板试验的双参数地基基床系数的获取方法和试验研究

基于Pasternak地基模型的基本理论,利用能量法建立双参数地基-刚性板系统的能量方程;根据最小势能原理,建立双参数地基基床系数、承载板尺寸、荷载和沉降变形之间的关系式.基于此关系式和已有基床系数确定规则,通过不同尺寸承载板的荷载试验,可以建立以双参数地基基床系数为未知数的方程组,从而解得双参数地基基床系数表达式.通过4块不同形状和尺寸刚性板(直径0.3m、0.6m圆板和边长0.54m、0.71m方板)的实测试验获取实际场地下砂性地基土的双参数基床系数值,验证了上述方法的可行性;结合基础沉降和相邻基础相互影响的算例说明了双参数地基的工程意义;结合已有研究成果给出了不同状态的黏性土和砂性土的双参数基床系数的建议值.本文方法为双参数地基模型的推广及工程应用提供一定的借鉴与参考.

Experimental Study and Evaluation Methodology of Foundation Coefficients for Two-parameter Foundation Model Based on Rigid Plate Loading Tests

Energy equation of two-parameter foundation - rigid plate system was established by using energy method based on the basic theory of Pasternak model. In the principle of the minimum potential energy, the relationships of foundation coefficient, foundation size, load and surface displacement of soil were obtained. The foundation coefficient expression was obtained by solving the equation system which was established with two rigid plates loading test of different size based on the above relationships and the existing determining rules of foundation coefficient. Four sandy soil-rigid plate loading tests were performed to verify the validity of this method, where the circular plates with diameter of 0.3 m and 0.6 m, and square plates with the size of 0.54 m × 0.54 m and 0.71 m ×0.71 m were used. Examples of calculating foundation settlement and considering the influence of adjacent foundation were given to illustrate the engineering significance of the two-parameter foundation model, and empirical values of two-parameter foundation coefficient for clayey soil and sandy soil were estimated for the popularization and application of the two-parameter foundation model.