土与地下结构动力相互作用的大型振动台试验与计算

Large-Sized Shaking Table Test and Calculation for Soil-Substructure Dynamic Interaction

本文首先用大型振动台进行了土—地下结构的动力相互作用试验。采用加重乳胶制成的方形管道作为地下结构,将它预埋在大型刚性容器内的填砂中,该容器装置在振动台上,用简谐波在垂直于结构轴线的方向振动。测定了地下结构内的动应力以及砂与地下结构接触面上的动土压力及加速度。在这种试验的基础上提出了土—地下结构动力相互作用的计算模型。用等参数有限元法对这个小结构系统进行动力分析。结果证明,当考虑土的静、动力非线性并在两介质间使用薄层单元时,计算结果与试验结果吻合较好。

Soil-substructure dynamic interaction was studied by large-sized shaking table test. A square pipe made of accentual emulsion was chosen as a substructure model and was buried in sand inside a large-sized rigid container, installed on the shaking table. The model was snaked with simple harmonic wave in the direction perpendicular to the substructure axis. The dynamic stresses in substructure and dynamic earth pressures and accelerations on interface between sand and substructure were measured. Based upon the test results a calculation modeling the soil-substructure dynamic interaction was carried out. The dynamic analysis of this small substructure system was made by FEM with quadrilateral isoparametric elements. The results obtained indicated that when static and dynamic nonlinear behaviors are taken into account and thin-layer elements are used in the interface between two media, the calculated results are in fairly good agreement with test results.