桩网复合地基桩顶土拱形态分析

桩网复合地基垫层与填土中的土拱对桩顶应力调节和沉降控制效果起着重要作用.在对比现有桩网复 合地基桩顶土拱效应计算方法的基础上,通过单桩数值模拟和数学解析,对桩顶土拱形态进行分析.结果表明,桩网复合地基桩顶土拱区域内的主应力迹线是一族自桩顶平面向上曲率逐渐增大的变曲率曲线,其中,接近桩帽边缘的一条主应力迹线线形近似于抛物...

Analysis on Conformation of Soil Arch on the Pile Head of Composite Pile-net Foundations

The soil arch in the fill on the composite pile-net foundations plays an important role in pile-soil stress adjusting and settlement control.On the basis of comparison with the existing calculation methods for soil arching effect of composite pile-net foundations,the conformation of soil arch is analyzed by single-pile numerical simulation and algebraic analysis.The analytical results show as follows:The principal stress trajectory of soil arch on pile top is a group of curves whose curvatures are growing gradually in the way from the pile top plane and in the upward direction;the principal stress trajectory near the margin of the pile cap is almost the same with the shape of a parabola which decides the height of the soil arch;the height of the soil arch is related to the friction angle of fill,the bigger the friction angle is,the higher the soil arch becomes;usually,the height of the soil arch equals to the maximum inter-pile distance.The small hole expansion theory model and parabolic arch model methods are put foward to calculate the pile-ptop pressure and the inter-pile soil pressure.The calculated results accord with the results measured on site.