利用强夯模拟试验研究饱和砂土强夯动本构关系

STUYD ON THE DYNAMIC CONSTITUTIVE LAW OF SATURATED SANDY SOIL BY DYNAMIC CONSOLIDATION MODELLING TESTS

饱和土是孔隙中充满水的松散介质 ,在强夯冲击荷载作用下的变形是非线性变形 ,因此 ,饱和土强夯动本构关系有其特殊性。本文利用具有 90年代先进水平高精度、高灵敏度的MTS810土动三轴仪对强夯加固饱和土地基进行了全面、系统的模拟试验 ,试验按模型比设计 ,试验条件与实际土体工况符合 ,通过多组不同条件的组合试验 ,获得了大量强夯数据 ,在此基础上结合强夯现场试验对强夯过程中各种变量的变化过程及其相互关系进行了分析研究 ,推导出强夯冲击荷载作下饱和土的动本构关系 。

Saturated soil is a kind of loosed medium filled with water in the pores. Such soil will be deformed nonlinearly when subjected to the dynamic load, hence its constitutive law has its specific features. A dynamic triaxial soil testing system MTS-810 with high precision and high sensitivity is used to conduct a series of modelling tests for assessing the dynamic consolidation effects on soil foundation for the first time. The test conditions are in full accord with the actual soil conditions. The test data including dynamic stress and displacement as well as pore pressure can be collected with the time interval of millisecond. By combining with different test conditions, a lot of test data with high precision were obtained. On such a basis, the variation of all variables with time in process of dynamically consolidation as well as their interralation are comprehensively studied. The result provides a scientific base for dynamic consolidation research. Using the modelling test results, the dynamically constitutive law for dynamic consolidated saturated soil is derived. It is obtained based on the precise dynamic consolidation modelling test. Therefore it can reflect the actual soil state of dynamic consolidation and relevant problems can be solved with the improved model.