基于模态测试的挡土墙土压力计算方法

对考虑位移的土压力计算方法进行研究，提出了一种基于模态测试和参数识别的土压力计算方法。首先，将土体等效成一系列弹簧来模拟，土压力统一表示为静止土压力和土压力增量之和，并假定土压力增量等于土体的地基反力系数和墙体位移的乘积；其次，建立了墙土系统简化动测模型，根据墙土系统的动力特性，提出采用改进多种群遗传算法识别土体的地基反力系数；最后，结合共同变形理论，进行迭代计算得到土压力分布形式，并通过与库伦土压力理论、实验结果进行比较，表明计算结果和实验结果吻合得较好。为未预先埋设土压力盒的在役挡墙的土压力确定提供了一种行之有效的方法。

Calculation method of earth pressure on retaining wall based on modal test

The earth pressure calculation method considering displacement was studied. A new method was proposed based on modal test and parameter identification. First, the soil mass was made equivalent to a set of springs, and the earth pressure was expressed as the sum of the static earth pressure and the increment of earth pressure. The increment of earth pressure was assumed to the coefficient of subgrade reaction by the wall displacement. Then, the simplified dynamic detection model of soil wall system was established. Meanwhile, according to the dynamic characteristics of soil wall system, the improved multi population genetic algorithm (IMGA) was developed in order to identify the coefficient of the subgrade reaction. Finally, combined with common degeneration theory, the earth pressure distribution form was obtained by iterative calculation. By comparing the calculation results of the Coulomb's earth pressure theory with the experimental ones, the conclusion is drawn that the calculation results agree well with experimental data. So the presented method is effective and reasonable, and it provides a new determination way for the earth pressure of the service retaining wall not pre plugged earth pressure cell.