软土区CFG桩复合地基加固效果及现场试验研究  

Study of the Improvement Effect and Field Test of CFG Composite Columns in Soft Soils

作　　者：刘朋 谷立强 张召彬 王亮 张力峰 谷志超 LIU Peng;GU Liqiang;ZHANG Zhaobin;WANG Liang;ZHANG Lifeng;GU Zhichao(Hebei Shuangcheng Construction Engineering Inspection Co.Ltd.,Shijiazhuang 050000)

机构地区：[1]河北双诚建筑工程检测有限公司,石家庄050000

出　　处：《土工基础》2024年第6期1059-1063,共5页Soil Engineering and Foundation

摘　　要：为探究CFG桩对软土地基的加固效果,依托实际工程项目,采用数值模拟结合现场试验的方法开展研究,运用FLAC3D有限差分软件建立CFG桩复合地基模型,探究褥垫层工程特性及荷载水平、面积置换率、基桩强度等条件对地基沉降变形的影响。开展静载和延时静载现场试验,对比分析两种静载试验方法下复合地基的变形规律,通过延时静载试验快速预测和验算地基的最终沉降值。得到结论如下:(1)由数值分析可知,改变褥垫层设置等条件可以有效控制地基沉降变形,并可确定最优褥垫层参数,以达到最佳沉降控制效果;(2)现场通过对比弹性垫层法和规范法两种静载试验,认为弹性垫层法更加接近地基真实堆载情况;(3)通过延时静载试验预测了实际工程地基沉降,结果满足规范要求。This paper presents a case study of the improvement effect of the CFG columns in soft soils.The numerical simulation of the CFG column composite soil is established by using FLAC3D finite difference software.At the same time,the in-situ tests are also performed.The engineering characteristics of the cushion and the influence of the loading level,the area replacement ratio,the column strength and other conditions on the composite soil settlement and deformation are also evaluated.The in-situ static quick load and sustained static load tests are performed to compare and to analyze the deformation characteristics of the composite soils under the two static load test methods.The final settlement value of the composite is quickly predicted and validated by the sustained static load test.The conclusions are as follows:(1)according to the numerical analysis results,the settlement and deformation of the composite soil can be effectively controlled by changing the cushion thickness and materials.The optimal cushion thickness therefore be determined in order to achieve the best settlement control effect.(2)by comparing the in-situ loading tests using the elastic cushion method and the code method,it is concluded that the elastic cushion method is closer to the actual loading condition of the foundation.(3)the settlement of the composite soil can be effectively predicted by the sustained static load test,and the results meet the code requirements.

关 键 词：CFG桩复合地基 褥垫层 数值模拟 现场试验 

分 类 号：TU472[建筑科学—结构工程]