Field tests on excess pore pressure and soil pressure of pile-soil interface for a single pile during pile-sinking in clay
WANG Yong-hong1,2, ZHANG Ming-yi1,2, LIU Jun-wei1,2, BAI Xiao-yu1,2, YANG Su-chun1, SANG Song-kui1, YAN Nan3
1. School of Civil Engineering,Qingdao University of Technology, Qingdao 266033, China; 2. Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone, Qingdao 266033, China; 3. School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
Abstract:Stress change of pile-soil interface for jacked-in piles during pile-sinking in clay is a topic of concern in the geotechnical engineering. A full-scale jacked-in pile is penetrated into the clay in Dongying city of China and studied by monitoring the laws of the excess pore water pressure and soil pressure of pile-soil interface with depth at different pile locations of h/L. The relationship between the excess pore water pressure of pile-soil interface and the effective pressure of superimposed soil at different pile locations of h/L and the characteristics of soil pressure of pile-soil interface at the same penetration depth are analyzed. Especially the causes to influence the distribution of the effective soil pressure of pile-soil interface are studied. The test results show that the maximum ratio of the excess pore water pressure of pile-soil interface to the effective pressure of superimposed soil during pile-sinking is 1.08 at different pile locations of h/L and decreases gradually along the pile from pile tip to pile top. The soil pressure of pile-soil interface presents “lateral pressure degradation” with the relative depth of the increasing pile tip(h/L)at the same penetration depth. The “lateral pressure degradation” presents obviously with the relative depth of the increasing pile tip(h/L). The effective soil pressure of pile-soil interface is only 10 kPa at the location of h/L=11/12, and that of certain interface at other different pile locations of h/L is 1.88~2.20 times the excess pore water pressure of pile-soil interface. The proposed solution is of great engineering significance for jacked pile construction and bearing capacity design in clayey foundation.
王永洪, 张明义, 刘俊伟, 白晓宇, 杨苏春, 桑松魁, 闫楠. 黏性土中单桩贯入桩-土界面超孔压和土压测试现场试验[J]. 岩土工程学报, 2019, 41(5): 950-958.
WANG Yong-hong, ZHANG Ming-yi, LIU Jun-wei, BAI Xiao-yu, YANG Su-chun, SANG Song-kui, YAN Nan. Field tests on excess pore pressure and soil pressure of pile-soil interface for a single pile during pile-sinking in clay. Chinese J. Geot. Eng., 2019, 41(5): 950-958.
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