Destructive field tests on mobilization of end resistance of cast-in-situ bored piles  

作　　者：刘念武 张忠苗 张乾青 房凯 

机构地区：[1]Key Laboratory of Soft Soils and Geoenvironmental Engineering of Ministry of Education (Zhejiang University) [2]Institute of Geotechnical Engineering, Zhejiang University [3]Geotechnical and Structural Engineering Research Center,Shandong University

出　　处：《Journal of Central South University》2013年第4期1071-1078,共8页中南大学学报（英文版）

基　　金：Project(51078330) supported by the National Natural Science Foundation of China;Project(2012MS21339) supported by China Postdoctoral Science Foundation;Project(2012GN012) supported by the Independent Innovation Foundation of Shandong University, China

摘　　要：A series of well-designed full-scale destructive load tests were conducted on six bored piles to investigate the influence of loose debris at the pile tip on end resistance. The results show that soft debris below the pile tip will weaken the mobilization of end resistance. The ultimate tip resistance of post-grouted pile is 2.05 times that of the pile without post-grouting and the ultimate tip resistance in the second load cycle is 2.31 times that of pile in the first load cycle. The relationship between unit end resistance and displacement follows a linear model and a bilinear mode in the first load cycle and the second load cycle, respectively, whereas the unit end resistance-displacement response of post-grouted bored pile can be simulated using a bilinear mode. The critical end resistance ranges between 2 000 kN and 3 000 kN and the critical displacement ranges between 2.5 mm and 4.5 mm in the bilinear mode. As for piles rested on moderately-weathered peliticsiltstone, the socketed length has no effect on the end resistance because of the existence of loose debris.A series of well-designed full-scale destructive load tests were conducted on six bored piles to investigate the influence of loose debris at the pile tip on end resistance. The results show that soft debris below the pile tip will weaken the mobilization of end resistance. The ultimate tip resistance of post-grouted pile is 2.05 times that of the pile without post-grouting and the ultimate tip resistance in the second load cycle is 2.31 times that of pile in the first load cycle. The relationship between unit end resistance and displacement follows a linear model and a bilinear mode in the first load cycle and the second load cycle, respectively, whereas the unit end resistance-displacement response of post-grouted bored pile can be simulated using a bilinear mode. The critical end resistance ranges between 2 000 kN and 3 000 kN and the critical displacement ranges between 2.5 mm and 4.5 mm in the bilinear mode. As for piles rested on moderately-weathered peliticsiltstone, the socketed length has no effect on the end resistance because of the existence of loose debris.

关 键 词：static load test SETTLEMENT POST-GROUTING end resistance socketed depth 

分 类 号：TU473.1[建筑科学—结构工程]