高填方路堤段桩网复合地基承载机理及桩土应力比计算方法

发布时间：2018-02-28 17:44

本文关键词： 地基处理高填方路堤桩网复合地基土拱效应桩土应力比　出处：《湖南大学学报(自然科学版)》2015年05期 　论文类型：期刊论文

【摘要】：针对高填方段软土路基在路堤荷载下桩网复合地基的受力特点,分析了其自上而下的荷载传递机理.首先,将路堤简化为内外土柱,通过内外土柱的整体微分平衡关系,得到了等沉面高度的理论计算式,由此较为合理地模拟了高填方段的土拱效应.而后,针对荷载传递至土工垫层阶段,采用薄膜模拟了桩土之间的荷载分配关系.在此基础上,将桩网复合地基划分为众多土工格栅、桩及桩间土单元体,桩体及桩间土简化为弹性支撑,进一步得到了高填方段桩网复合地基桩土应力比计算式.最后,对影响高填方段桩网复合地基桩土应力比的各主要影响参数进行了初步研究.结果表明,桩土应力比随路堤高度增大逐渐减小,即填土高度增加后桩土荷载分配趋于均匀,而桩间距、填土的压缩模量的增大将导致桩土应力比增加.此外,土工格栅抗拉强度的增大将加大桩土应力比值,但影响幅度较小.
[Abstract]:According to the stress characteristics of soft soil subgrade in high fill section under embankment load, the load transfer mechanism from top to bottom is analyzed. Firstly, the embankment is simplified as inner and outer soil column, and through the integral differential equilibrium relationship between inside and outside soil column, the mechanism of load transfer from top to bottom is analyzed. The theoretical formula of equal settlement surface height is obtained, and the soil arch effect of high fill section is simulated reasonably. Then, the load distribution relationship between pile and soil is simulated by thin film in view of the load transfer to the earth cushion. The pile net composite foundation is divided into many geogrid, the pile and the soil unit body between piles, the pile body and the soil between piles are simplified as elastic support, and the formula for calculating the pile-soil stress ratio of high fill section pile net composite foundation is obtained. The main parameters affecting the pile-soil stress ratio of high fill section pile-net composite foundation are studied. The results show that the pile-soil stress ratio decreases gradually with the increase of embankment height, that is, the pile-soil load distribution tends to be uniform when the filling height increases. In addition, the increase of the tensile strength of the geogrid will increase the pile-soil stress ratio, but the influence range is small. The pile spacing and the compression modulus of the fill will increase the pile-soil stress ratio, and the increase of the tensile strength of the geogrid will increase the pile-soil stress ratio.
【作者单位】：湖南大学岩土工程研究所;
【基金】：国家自然科学基金资助项目(51278184,50708030) 教育部新世纪优秀人才支持计划资助项目(NCET-13-194) 湖南大学青年教师成长计划资助项目~~
【分类号】：U416.16

【参考文献】