Vertical bearing capacity of large-diameter bored pile
LIU Nian-wu1,2, GONG Xiao-nan1,2, YU Feng3
1.Research Center of Coastal and Urban Geotechnical Engineering, Zhejiang University, Hangzhou 310058, China; 2. MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China;3. School of Civil Engineering and Architecture, Zhejiang Sci-Tech University, Hangzhou 310018, China
The self-balancing test was conducted on two 2.2 m diameter drilled piles in order to analyze the bearing capacity of large diameter bored piles. The test results were compared with in-situ test results. Results show that the change of load-displacement of pile with post-grouting is slower than pile without post-grouting. The end resistance reached the limit state when pile tip displacements approached 20 mm (1% D, D is the pile diameter). The side resistance increased firstly and maintained a stable trend with the increase of pile-soil relative displacement. The critical displacement was 1.5-3.0 mm. Post-grouting can improve the side resistance over a certain depth from the pile tip, and the improvement in round gravel mixed pebble bed is 18 percent. Resistive loads up and down the side of the load cell is different and transformation coefficient is 0.92 and 0.91, respectively. Side resistance and undrained vane-shear strength has a linear relationship and has a better goodness of fit. The ultimate side resistance of round gravel mixed can be estimated by dynamic sounding (63.5 kg) hits.
LIU Nian-wu, GONG Xiao-nan, YU Feng. Vertical bearing capacity of large-diameter bored pile. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2015, 49(4): 763-768.
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