碎石墩复合地基的承载机理及破坏过程

Bearing mechanism and destruction process of stone column composite foundations

基于实际工程,利用工程中地质勘察所得土体参数,运用大型岩土工程专用软件FLAC3D,模拟了碎石墩复合地基的破坏过程。在模拟过程中考虑了实际变形条件,通过提取墩体、墩间土的单元应力及变形获得相应的p-s曲线,研究了墩体和墩间土极限承载力与垫层厚度、置换率、墩体长度和墩体直径等的关系曲线。从其变化趋势得出墩间土的极限承载力并非等于天然地基土的极限承载力,同时并非墩体极限承载力越大复合地基极限承载力越大,因为复合地基的破坏并不都是由墩体破坏引起的。从墩体、墩间土在承载过程中相互协调的角度对复合地基的承载机理和破坏过程进行了剖析。

Based on the soil paramiters obtained from geological investigation, using software FLAC3D, the damage process of stone column composite foundations is simulated. Taking into account the deformation conditions, both the stress and deformation are examined, so are the p-s curves of the piers and the soil between the piers. The relationships between ultimate bearing capacity and the cushion thickness, replacement rate, the length of pier body and diameter of the pier are discussed. It is concluded that the ultimate bearing capacity is not equal to that of the natural foundation, and the bearing capacity of the composite foundation is not just related to that of piers, because not all the damage of composite foundation is caused by pier body damage. Using the relationship between pier and soil, the bearing mechanism of composite foundation and destruction process are analyzed.