预压固结地基单桩承载力随固结度变化的模拟

摘要

The prediction of the load capacity of single pile in the costal reclamation area is significant, especially at the preliminary design stage for the reclamation project.In this paper,we study the variations of vertical and horizontal ultimate load capacity of single pile with different consolidation degree of soil.Based on one reclamation project dealing with soft soil foundation under sluice,we analyze the relations of shear strength indexes and compression modulus of soft soil with consolidation degree,and use the geotechnical professional finite element software MIDAS/GTS NX to establish the soil-pile interaction model.Through the reasonable values of compression modulus,shear strength indexes and soil-pile interaction parameters, the vertical and horizontal load capacity of single pile can be predicted effectively under different consolidation degree.The results show that at consolidation degree of 80%,the vertical and horizontal load capacity of single pile are respectively about 1.8 times and 1.7 times higher than that at original state without consolidation.The load capacity of single pile is greatly increased with the consolidation of the soil around the pile.%针对滩涂围垦工程初步设计阶段单桩承载力预测的问题,结合某围垦工程中水闸下软土地基处理工程实例,研究软土抗剪强度指标和压缩模量在不同固结度下的变化规律,进而使用岩土有限元分析软件MIDAS/GTS NX建立了软土体和桩-土相互作用模型,通过对各土层压缩模量、抗剪强度指标和桩-土参数的合理取值,得出单桩竖向、水平向极限承载力随土体固结程度的变化规律.结果表明,固结度为80%时单桩竖向承载力比不固结时提高约1.8倍;单桩水平向承载力提高约1.7倍,单桩承载力随着桩周土体的固结得到较大程度的增长.