粉土地区后注浆灌注桩承载力试验研究  

Static Load Tests for Post-grouting Cast-in-situ Piles in Silt Region

作　　者：吴义章[1] 

机构地区：[1]郑州大学土木工程学院,河南郑州450001

出　　处：《建筑科学》2013年第7期66-70,共5页Building Science

基　　金：河南省自然科学基金资助项目(102300410002)

摘　　要：对粉土地区某工程中采用桩端桩侧后注浆技术的4根试桩进行了竖向静荷载试验。为量测桩身轴力,在桩体不同截面处埋设了钢筋应力计。分析了后注浆钻孔灌注桩的承载性状,并研究了不同深度处桩侧摩阻力与桩土相对位移之间的关系。试验表明:后注浆技术可有效提高单桩承载力和减小沉降量;桩侧后注浆可有效提高侧摩阻力。本试验场地,桩侧摩阻力达到极限摩阻力时的桩土相对位移约为5mm～10mm,后注浆侧阻力增强系数约为1.8～2.7。The static load tests are carried out for four piles using the technique of side-top post-grouting in a silt region.The steel stress gauges are embedded in different cross-sections of the piles in order to obtain the axial forces.Then the load-bearing performance of the pile is analyzed,and the relations between the shaft resistance and the relative displacement of pile and soil at different depths are investigated.The test results show that the post grouting for cast-in-situ pile can be used to improve the bearing capacity of the pile and decrease the pile top subsidence,and the skin grouting can be used to improve the shaft resistance of the pile.The relative displacement between pile and soil is about 5mm^10mm at the ultimate shaft resistance,and the shaft resistance of the post-grouting cast-in-situ pile is about 1.8~2.7 times that of cast-in-situ pile at the test site.

关 键 词：钻孔灌注桩 后注浆 轴力 侧摩阻力 相对位移 

分 类 号：TU473.14[建筑科学—结构工程]