Experimental Study On The Uplift Bearing Behavior Of Prestressed Bamboo Square Pile With Screw-locked Connection

Prestressed bamboo square pile with screw-locked connection(PBSPWSC)is a new uplift pile improved on the basis of ordinary equal-section square pile.The structural form and stress mechanism effectively improve the pull-out bearing capacity;in addition,the bamboo square pile adopts the screw-type connection method to efficiently connect the piles,and cancelled welding and traditional mechanical connection methods.At present,The PBSPWSC have been put into use in some projects in coastal areas,but overall they are still in the stage of technical development and application research.This paper mainly studies the bearing behavior of PBSPWSC under uplift load through indoor model experiments.The main research contents are:(1)Introduce the bamboo square pile in detail,including the pile type characteristics and classification of the PBSPWSC,manufacturing process,transportation and stacking,pile connection technology and construction process.(2)Using the load transfer method based on the Hirayama hyperbolic model,the load-displacement calculation formula for the slub pile under uplift load is established.(3)Designed and conducted a comparative test of the equal cross-section square pile and PBSPWSC with different pitch.By analysis of the difference in the bearing behavior of the equal cross-section square pile and the PBSPWSC,the uplift performance of the PBSPWSC was obtained;by analyzing the difference and reason of the uplift bearing capacity of the PBSPWSC under different pitch,the law of the uplift bearing capacity of the PBSPWSC varying with the pitch is discussed.(4)A set of comparative tests of PBSPWSC with different bamboo thicknesses were designed and conducted,and the law of the uplift bearing capacity of the PBSPWSC with the bamboo thickness was discussed.(5)A set of comparative tests of PBSPWSC with different bamboo widths were designed and conducted,and the law of the uplift bearing capacity of the PBSPWSC with the slub width was discussed.