CFG桩褥垫层厚度设计  

Design of CFG pile mattress thickness

作　　者：宋桂红 周鹏 胡其志 SONG Guihong;ZHOU Peng;HU Qizhi(College of Civil Architecture and Environment, Hubei University of Technology, Wuhan 430068, China)

机构地区：[1]湖北工业大学土木建筑与环境学院,武汉430068

出　　处：《中国科技论文》2021年第6期592-596,共5页China Sciencepaper

基　　金：国家自然科学基金资助项目(51609081)。

摘　　要：针对水泥粉煤灰碎石(cement fly-ash gravel,CFG)桩加固软土地基时褥垫层厚度的设计问题,通过计算CFG桩顶应力扩散厚度与桩体刺入褥垫层的厚度来确定褥垫层的最优厚度。计算结果表明,桩顶应力扩散厚度与上部路基填土荷载大小有关,且荷载越大,桩体刺入褥垫层厚度越大。通过FLAC3D有限差分软件模拟发现:由于CFG桩的承载作用,路基填土的最大沉降量并非出现在路基中心,而是在路基中心两侧;改变褥垫层厚度对路基沉降有一定影响,但过度增加褥垫层厚度对软基加固效果并不明显。对武穴长江大桥路基沉降监测数据分析表明:该工程最优褥垫层厚度为0.5 m,且FLAC3D模拟与路基监测沉降数据的变化规律基本相同。Aiming at the design problem of mattress thickness when cement fly-ash gravel(CFG)pile was used to strengthen soft soil foundation,the optimal thickness of the mattress was determined by calculating the stress diffusion thickness of the CFG pile top and the thickness of the pile piercing the mattress.The calculation results show that the stress diffusion thickness of the pile top is related to the load of the upper subgrade soil filling.The greater the load,the greater the thickness of the pile penetrating into the mattress.With the help of FLAC3D finite-difference software simulation,it is found that due to the bearing effect of CFG piles,the maximum settlement of the embankment fill does not occur in the center of the embankment,but on both sides of the embankment center.Changing the thickness of mattress has a certain effect on subgrade settlement,but excessive increase of mattress thickness has no obvious effect on soft foundation reinforcement.Based on the analysis of subgrade settlement monitoring data of Wuxue Bridge,the optimal mattress thickness of the project is 0.5 m,and the variation laws of FLAC3D simulation and subgrade settlement monitoring data are basically the same.

关 键 词：软基加固 褥垫层厚度 CFG桩 数值模拟 沉降监测 

分 类 号：U416.1[交通运输工程—道路与铁道工程]