路堤下复合地基的垫层对桩土应力比的影响分析  

Analysis of the impact of composite foundation cushion under embankment on pile-soil stress ratio

作　　者：杨宝平 温新昌 王国宝 赖天文[2] Yang Baoping;Wen Xinchang;Wang Guobao;Lai Tianwen(Gansu Jiaoda Engineering Testing Technology Co.,Ltd.,Lanzhou Gansu 730070,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou Gansu 730070,China)

机构地区：[1]甘肃交达工程检测科技有限公司,甘肃兰州730070 [2]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《山西建筑》2024年第23期108-111,共4页Shanxi Architecture

基　　金：甘肃省自然科学基金资助项目(编号:22JR5RA1076)。

摘　　要：垫层是复合地基的核心,其主要作用是调节桩土应力比。但是,目前复合地基的垫层多采用厚度约30 cm的砂石垫层。简单模式的垫层,尚不能充分发挥垫层对桩土应力比的调节作用,使得复合地基的工作性状最优。针对路堤下不同黏结强度桩复合地基垫层的弹性模量、厚度对桩土应力比的影响展开数值模拟分析,得出:复合地基桩土应力比随垫层弹性模量和垫层厚度的增加而提高,但它的提高幅度反而逐步缩小。每种复合地基垫层都有其敏感厚度,垫层的敏感厚度可以作为垫层厚度设计的参考。垫层的敏感厚度与复合地基桩本身的黏结强度、垫层的弹性模量有关。桩的弹性模量越大,桩土应力比对垫层的弹性模量和厚度变化越敏感,变化幅值也越大。可以通过改变复合地基垫层材料、密实度、黏结强度、厚度等来改变垫层对桩土应力比的调节作用,改善复合地基的工作性状。The cushion is the core of the composite foundation,and its main function is to adjust the pile-soil stress ratio.However,the current composite foundation cushion generally uses about 30 cm-thickness-sandstone cushion.Due to the simple mode cushion,the adjustment effect of the cushion on the pile-soil stress ratio cannot be fully exerted,so that the working property of the composite foundation cannot be optimized.In this paper,the numerical simulation analysis is carried out on the influence of the elastic modulus and thickness of the composite foundation cushion of different bond strength piles on the pile-soil stress ratio under the embankment.It is concluded that the pile-soil stress ratio of composite foundation increases with the increase of the elastic modulus of the cushion,and also increases with the increase of the thickness of the cushion,but the increase range gradually decreases.Each composite foundation cushion has its sensitive thickness,and the sensitive thickness of the cushion can be used as a reference for the thickness design of the cushion.The sensitive thickness of the cushion is related to the bond strength of the composite foundation pile itself and the elastic modulus of the cushion.The greater the elastic modulus of the pile,the more sensitive the pile-soil stress ratio is to the elastic modulus and thickness variation of the cushion,and the larger the variation amplitude.The adjustment effect of the cushion on the pile-soil stress ratio can be changed by changing the composite foundation cushion material,compactness,bond strength,thickness,etc.,and the working property of the composite foundation can be improved.

关 键 词：路堤 复合地基 桩土应力比 垫层 厚度 弹性模量 

分 类 号：TU473[建筑科学—结构工程]