冲击荷载下淤泥地基上覆土层合理厚度试验研究

基于某大面积深厚淤泥软基加固处理工程试验，从淤泥地基承载特征考虑，为定量确定软土之上覆盖层（包括原覆盖层及人工填土层）并反映静动力排水固结法中静力、动力荷载和排水体系的相互适应关系，建立了冲击荷载下淤泥地基上覆土层合理厚度 的定量模型。对该模型参数地基压力扩散角 、地基承载力特征值 、冲击荷载允许应力比R进行分析讨论。模型中变化的允许应力比R直观和定量地反映了冲击荷载大小与软土层排水体系布置方式、软土覆盖层厚度的相互适应关系，也可作为评判软基加固效果的参数。相关试验结果还表明，对于淤泥地基，实际夯击作用下 大于《建筑地基基础设计规范》中的23°～30°。工程应用表明，建立的模型与实际情况有较好的一致性，其定量的表达式也为工程人员设计应用提供了便利，对类似的软土地基处理工程有借鉴或指导意义。

In-situ tests and analyses of reasonable covering thickness for muck foundation under impact load

Based on engineering tests of muck foundation treatment project, a model of the reasonable thickness of overburden on muck foundation (including the original covering and artificial filling soil) is established using static-dynamic drainage consolidation method under impact loading. The basic considerations of the model are the bearing stratum capacity of muck foundation and the adaptive relations among static loading, dynamic loading and drainage system. Further analysis is made of the model parameters including foundation pressure diffusion angle , bearing capacity eigenvalues of muck foundation and maximum allowable stress ratio R. The parameter R in the model visually and quantitatively reflects the mutual adaptation relationships among impact loading, distribution of drainage system and thickness of overburden. In addition, the parameter R can be used as evaluation parameter for muck foundation reinforcement effects. And the results of relevant tests also show that parameter has a larger value under actual tamping than the 23°-30° in the Code for Design of Building Foundation of China. Engineering applications indicate that the model is in good agreement with the reality; and the quantitative relation also provides convenience in design and application for general engineering staff, which can be used for reference or guidance in similar soft foundation treatment projects.