基于离心模型试验的近断层单桩水平承载特性研究  

Horizontal bearing characteristics of near-fault single pile based on centrifugal model test

作　　者：张聪[1] 冯忠居[1] 王富春[1] 关云辉 张福强[3] ZHANG Cong;FENG Zhong-ju;WANG Fu-chun;GUAN Yun-hui;ZHANG Fu-qiang(Highway School,Chang’an University,Xi’an 710064,China;SCEGC Mechanized Construction Group Limited Company,Xi’an 710064,China;Hainan Province Transportation Hall,Haikou 570204,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]陕西建工机械施工集团有限公司,陕西西安710064 [3]海南省交通运输厅,海南海口570204

出　　处：《浙江大学学报（工学版）》2023年第3期542-551,共10页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51708040);中央高校基本科研业务费专项资金资助项目(300102218115);福建省交通运输科技项目(JXFZ2020-XM0189);海南省交通科技项目(HNZXY2015-045R).

摘　　要：为了探明断层发育区桥梁单桩的水平承载特性及受力机理,通过土工离心模型试验,选取断层与桩基水平距离、断层埋深变化参数为变量,研究近断层桥梁单桩水平极限承载力、桩侧土抗力、桩身弯矩及桩身剪力变化规律.试验结果表明:断层的存在抑制了桩侧土抗力的发挥,进而影响单桩水平承载特性.当断层与桩基水平距离由1倍桩径增加至5倍桩径时,断层两侧桩基水平极限承载力影响度为1.38%~61.47%,桩身弯矩逐渐减小且衰减较快,桩身剪力逐渐减小;当断层埋深由0 cm减至28 cm时,桩基水平极限承载力影响度为13.07%~51.60%.近断层单桩水平承载力设计时,可以根据桩侧岩土体受断层影响范围,确定断层与桩基水平距离临界值与合理桩长.In order to explore the horizontal bearing characteristics and stress mechanism of bridge pile foundations in fault development areas,through the geotechnical centrifugal model test,the selected variables were horizontal distance between the fault and the pile foundation,and the buried depth of the fault.The variation rules of horizontal ultimate bearing capacity,pile side soil resistance,pile bending moment,and pile shear force of a single pile near-fault bridge were studied.Test results show that the existence of faults inhibits the development of soil resistance on the side of the pile,and affects the horizontal bearing characteristics of a single pile.When the horizontal distance between the fault and the pile foundation increased from 1 to 5 times the pile diameter,the influence degree of the horizontal ultimate bearing capacity of the single pile on both sides of the fault was 1.38%-61.47%.The bending moment of the pile decreased gradually and attenuated rapidly,and the shearing force of the pile decreased gradually.When the buried depth of the fault was reduced from 0 cm to 28 cm,the influence degree of the horizontal ultimate bearing capacity of the single pile on both sides of the fault was 13.07%-51.60%.In the design of horizontal bearing capacity of the single pile near-fault,the critical value of the horizontal distance between fault and pile foundation and reasonable pile length can be determined according to the range of rock and soil affected by the fault.

关 键 词：桩基础 单桩 断层 离心模型试验 水平承载特性 

分 类 号：U433.15[交通运输工程—道路与铁道工程]