大直径变截面桩与等截面桩的横向承载特性对比研究  

Difference of Lateral Bearing Characteristics between Large Diameter Variable Cross-section Pile and Constant Cross-section Pile

作　　者：冯忠居[1] 陈露 蔡杰 赖德金 孟莹莹 朱继新 赵瑞欣 张聪[1] FENG Zhong-ju;CHEN Lu;CAI Jie;LAI De-jin;MENG Ying-ying;ZHU Ji-xin;ZHAO Rui-xin;ZHANG Cong(School of Highway,Chang’an University,Xi'an 710064,China;Fujian Provincial Transportation Construction Quality and Safety Center,Xiamen 361006,China;Xiamen Road and Bridge Project Investment and Development Co.Ltd.,Xiamen 361006,China)

机构地区：[1]长安大学公路学院,西安市710064 [2]福建省交通建设质量安全中心,厦门市361006 [3]厦门路桥工程投资发展有限公司,厦门市361006

出　　处：《公路》2022年第9期189-195,共7页Highway

摘　　要：为对比研究大直径变截面桩与等截面桩在横向荷载作用下的承载特性,使用有限元软件进行数值模拟,考虑变截面位置的差异对桩基横向承载特性的影响,建立了变截面位置在-8 m、-18 m及-28 m处的桩基模型以及大直径等截面的桩基模型,研究了大直径变截面桩与等截面桩在横向荷载作用下的位移、剪力与弯矩变化规律。结果表明:变截面在-8 m且位于砂土层的桩基位移大于等截面桩基的位移,变截面位置在-18 m、-28 m处的桩基与大直径横向位移相近;随着变截面位置的加深,桩基剪力变化逐渐与等截面桩基剪力变化规律相近;变截面位置在-8 m处的桩基桩身最大弯矩位于其变截面处,变截面位置在-18 m时,桩基弯矩变化规律逐渐与等截面桩基桩身弯矩一样。综合考虑桩基的横向承载特性,建议结合实际工程情况,确定变截面桩基位置在距桩顶2/3以下。In order to compare and study the bearing characteristics of large diameter variable cross-section pile and constant cross-section pile under lateral load,the numerical simulation is carried out by MIDAS/GTS finite element software,considering the influence of the difference of variable cross-section position on the lateral bearing characteristics of pile foundation,the pile foundation model of variable cross-section position at-8 m,-18 m and-28 m and the pile foundation model of large diameter constant cross-section are established.The variation rules of displacement,shear force and bending moment of large diameter variable cross-section pile and uniform cross-section pile under lateral load are studied.The results show that the displacement of pile foundation with variable cross-section at-8 m and located in sandy soil is larger than that of pile foundation with uniform cross-section,and the pile foundation with variable cross-section at-18 m and-28 m is close to the lateral displacement of large diameter.The change of shear force of pile foundation is gradually similar to that of pile foundation with constant cross-section.When the position of variable cross-section is-8 m,the maximum bending moment of pile foundation is located at its variable cross-section.When the position of variable cross-section is-18 m,the variation law of bending moment of pile foundation is gradually the same as that of pile foundation with constant cross-section.Considering the lateral bearing characteristics of pile foundation,it is suggested that combined with the actual engineering situation,the position of variable cross-section pile foundation should be determined that the position of variable cross-section pile foundation is less than 2/3 from the top of the pile.

关 键 词：大直径变截面桩 等截面桩 数值模拟 横向承载特性 对比研究 

分 类 号：U441.5:U443.15[建筑科学—桥梁与隧道工程]