碎石桩与包裹碎石桩复合地基现场静载试验对比研究  

Comparisons and Research on Field Static Load Test of Composite Foundation of Gravel Piles and Wrapped Gravel Piles

作　　者：刘梦捷 常光磊 LIU Meng-jie;CHANG Guang-lei(CSCEC Road and Bridge Group Co.Ltd.,Shijiazhuang 050001,China;Sichuan Metallurgical Exploration Design Group Testing Co.Ltd.,Chengdu 610000,China)

机构地区：[1]中建路桥集团有限公司,石家庄市050001 [2]四川省冶勘设计集团有限公司,成都市610000

出　　处：《公路》2022年第9期61-69,共9页Highway

基　　金：海南省自然科学基金项目,项目编号519QN184。

摘　　要：针对包裹碎石桩与传统碎石桩复合地基承载性能缺乏实际工程数据支持的问题,开展了碎石桩与包裹碎石桩复合地基现场静载试验对比研究。采用土压力计、位移传感器及静载测试读数仪分别对桩体轴力、顶端位移及承载力进行监测,由此得到桩体的轴应力传递规律图和荷载~沉降曲线图。结果表明:(1)土工布袋的约束作用能减小碎石桩鼓胀变形,从而增大复合地基的承载力;(2)采用土工布包裹碎石桩能有效提升桩身轴应力的传递效果;(3)包裹碎石桩复合地基在各加载阶段的桩身轴应力传递系数随荷载增加呈U型变化,在加载值较小的阶段其传递系数已经达到较高值。该试验为粉质黏土地区的包裹碎石桩加固地基的理论分析和数值模拟研究提供了可靠的现场实测数据。In view of the lack of actual engineering data support for the bearing performance of the composite foundation with the wrapped gravel pile and the traditional gravel pile,a comparative study on the field static load test of the composite foundation of the gravel pile and the wrapped gravel pile was carried out.The axial force,top displacement and bearing capacity of the pile body are monitored by soil pressure gauge,displacement sensor and static load test reader,respectively,and the axial stress transfer law and load-settlement curve of the pile body are obtained.The results show that:(1)The constraining effect of the geotextile can reduce the bulging deformation of the gravel pile,thereby increasing the bearing capacity of the composite foundation.(2)The use of the geotextile to wrap the gravel pile can effectively improve the transfer effect of the axial stress of the pile body.(3)The stress transfer coefficient of the pile shaft in each loading stage of the wrapped gravel pile composite foundation changes in a U-shape with the increase of the load,and the transfer coefficient has reached a higher value in the stage of small loading value.This test provides reliable field measurement data for the theoretical analysis and numerical simulation study of the wrapped gravel piles in the silty clay area.

关 键 词：复合地基 包裹碎石桩 静载试验 荷载~沉降曲线 

分 类 号：U416.1[交通运输工程—道路与铁道工程] TU472.3[建筑科学—结构工程]