Field tests on squeezing effects of the rigid-drainage pile
Jiang Qiang1,2,4 Chen Yumin1,2 Wang Xiangying1,2 Liu Hanlong1,2,3
1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, China;
2. College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China;
3. Chongqing University, Chongqing 400045, China;
4. Jiangyin Construction Project Management Office, Jiangyin 214400, China
Abstract：The rigid-drainage pile is a new type of pile which combines a rigid pile with vertical drainage components. Based on the pile foundation project in new campus of Jiangyin No.1 High School, field tests on pile driving of the rigid-drainage pile and the ordinary rigid pile without drainage were carried out. The horizontal displacements, soil stresses and excess pore water pressures around drainage piles and ordinary piles were monitored and compared to study the squeezing effects of the rigid-drainage pile. The results show that the rigid-drainage pile can reduce the horizontal displacement of surrounding soil during the pile driving. At the position of 3 times the pile’s diameter from the pile center, the maximum horizontal displacement of soil for the rigid-drainage pile is 1/6 of that for the ordinary pile. At the distance of 6 times, the ratio is 2/5. The rigid-drainage pile can greatly reduce the excess pore water pressure and soil stresses caused by the pile driving. At the location of 2 times the pile’s diameter far from the pile center in the depth of 15m, the peak excess pore water pressure is only 1/4 of that of the ordinary pile, and the ratio of the peak earth pressure between two types of piles is 1/4. The field test data provide the design reference for practical applications of the rigid-drainage pile.
