基于离心模型试验的近断层桥梁桩基竖向承载特性研究  

Study on vertical bearing characteristics of pile foundation of near-fault bridge based on centrifugal model test

作　　者：张聪[1] 冯忠居[1] 王富春[1] 关云辉 吴敬武 张福强[3] Zhang Cong;Feng Zhongju;Wang Fuchun;Guan Yunhui;Wu Jingwu;Zhang Fuqiang(Chang'an University,Xi'an 710064,China;China Highway Engineering Consulting Corporation,Beijing 100089,China;Hainan Province Transportation Hall,Haikou 570204,China)

机构地区：[1]长安大学,陕西西安710064 [2]中国公路工程咨询集团有限公司,北京100089 [3]海南省交通运输厅,海南海口570204

出　　处：《土木工程学报》2023年第6期108-116,共9页China Civil Engineering Journal

摘　　要：为探明断层发育区桥梁桩基的竖向承载特性及受力机理,通过土工离心模型试验,以桩基与断层水平距离及断层埋深变化为工况,开展近断层桥梁桩基础的竖向极限承载力、轴力和桩侧摩阻力演化规律研究。结果表明:断层的存在,抑制了桩侧摩阻力的发挥,进而影响近断层桥梁桩基础的竖向承载特性。桩基与断层水平距离由1D增加至5D,断层两侧桩基竖向极限承载力影响度平均降低16.62%~19.24%,桩身轴力逐步增大且衰减变缓,桩侧摩阻力逐步降低;断层埋深由0cm增加至32cm时,桩基竖向极限承载力影响度降低了9.16%~15.22%。近断层桥梁桩基设计时,可根据桩侧岩土体受影响范围,以此确定桩基与断层水平距离临界值与合理桩长。In order to ascertain the vertical bearing characteristics and mechanism of pile foundations of bridge in faultdeveloped areas,the rules of vertical ultimate bearing capacity,pile axial force and pile shaft friction of pile foundation of near-fault bridge are studied through the geotechnical centrifugal model test.The horizontal distance between the pile foundation and the fault and the burial depth of fault are taken as variables in various cases.The results show that the existence of faults restrains the shaft friction of the pile,and then affects the vertical bearing characteristics of the pile foundation.When the horizontal distance between the pile foundation and the fault is increased from 1D to 5D,the influence of the vertical ultimate bearing capacity of the pile foundation on both sides of the fault is reduced by 16.62%~19.24%.The pile axial force gradually increases and attenuates slowly,and the shaft friction resistance of the pile decreases gradually.When the burial depth of fault increases from O cm to 32 cm,the influence of the vertical ultimate bearing capacity of the pile foundation is reduced by 9.16%~15.22%.When designing the pile foundation of near-fault bridge,the critical value of the horizontal distance between the fault and the pile foundation and the reasonable pile length can be determined according to the affected range of the rock and soil adjacent to the pile.

关 键 词：桩基础 断层 离心模型试验 竖向承载特性 

分 类 号：U443.1[建筑科学—桥梁与隧道工程]