基础刚度对刚性桩复合地基三维性状影响分析

3D Performance Analysis of Rigid Pile Composite Foundation Effected by Ground Stiffness

采用通用有限元程序ANSYS,建立刚性桩复合地基三维群桩的有限元模型,研究了基础刚度对地基承载力和变形、不同桩位桩身应力、不同区域桩间土附加应力、桩土应力比等的影响.研究表明,地基承载力随着基础刚度的增大而提高,达到一定值以后变化不大;中桩桩身应力随着基础刚度的增加逐渐减小,而边中桩和角桩的应力则随基础刚度的增加逐渐增大;不同桩位桩身应力随着基础刚度的增加,差异逐渐显著;桩间土的附加应力随着基础刚度的增加逐渐减小;不同区域桩间土的附加应力随基础刚度的增加差别变大,基础边缘应力大于基础中央区域;桩土应力比随基础刚度的增加迅速增大,最后逐渐趋于一定值.

Based on the common software ANSYS, A three-dimensional finite element model of rigid pile group composite foundation was established to study the effect of ground stiffness on the foundation bearing capacity and deformation, the pile axial stress in different location, the subsidiary stress of soil around piles in different zone, the pile-soil stress ratio and so on. Research results confirmed that with the increasement of ground stiffness, the ground bearing capacity is improved but nearly makes no change after certain value, the axial stress of mid-piles is decreased but that of side-piles and corner-piles are increased, the axial stress is increased and the diversity among piles becomes gradually obvious, the subsidiary stress of soils around piles is reduced and the diversity goes up in different location, the pile-soil stress ratio is improved rapidlly but gradually turns to a certain value. Besides the edge stress in the foundation is bigger than the central one.