Author(s): Jia Qiang, LuanShu, Li Jiping, School of Civil Engineering, Shandong Jianzhu University, Shandong Provincial Key Laboratory of Appraisal and Retrofitting in Building structures
Pages: 103-108+124
Year: 2016 Issue:  2
Journal: Journal of Shandong Jianzhu University
Keyword:  soil excavation around the pile; bucking stability; stability coefficient;
Abstract: The underpinning pile can be used to support the existing building for construction of basement.The soil excavation around the pile can decrease the bearing capacity of piles.The piles bucking stability in different excavation depth was tested in model box by pry bar loading devise.Then,the stability coefficient was calculated.The test results indicate:when the loads on the top of the pile reaching ultimate load,the body of the pile appears the buckling deformation.At the beginning of soil excavation,the buckling location of pile is near the interface of the pile and soil.The deeper soil excavation,the higher location of pile buckling;The stability coefficient decreases with the soil excavation around the pile;the stability coefficient with end build-in is higher than with end non embedded;the stability coefficient of piles increases obviously after the horizontal components installed on the piles;the stability coefficient of piles with high radius of gyration is bigger than with low radius of gyration when the ratio of excavation depth to length of pile over 0.5;on the contrary,the stability coefficient of piles with high radius of gyration is smaller than with low radius of gyration when the ratio of excavation depth to length of pile under 0.5.