深厚软土区根键桩竖向承载特性的现场试验  

Experimental Study on Vertical Bearing Capacity of Root-pile Foundation in Deep and Soft Soil Areas

作　　者：林友当 夏理巧 李凌志 祝凤金 袁梦军 LIN You-dang;XIA Li-qiao;LI Ling-zhi;ZHU Feng-jin;YUAN Meng-jun(Wenzhou Expressway Investment Co.Ltd.,Wenzhou 325000,China;School of Engineering and Technology,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]温州市高速公路投资有限公司,温州市325000 [2]中国地质大学(北京)工程技术学院,北京市100083

出　　处：《公路》2020年第11期143-148,共6页Highway

基　　金：浙江省交通运输厅科研计划项目,项目编号2014H27。

摘　　要：为揭示根键桩的承载机理,推进根键桩在滨海软土地区的应用,以满足实际工程对沉降控制特性的要求,通过现场试验,采用静载荷方法测试了普通桩和根键桩的承载性能,得出其位移~荷载曲线和轴力传递曲线;并根据场地工程地质条件,建立数值模型,分析了桩体与桩周土体在极限荷载作用下的位移关系。结果表明:与普通桩相比,根键桩竖向极限承载力增大,且随根键布置数目的增多而增大。本试验中,在相同桩长和桩径下,根键桩竖向极限承载力提高了23.75%~33.33%;此外根键桩桩顶沉降量明显减少,桩体沉降控制特性优于普通桩。数值模拟结果也表明了根键有利于调动桩周土体的承载性能,加强桩土的耦合作用。In order to promote the application of root-pile foundation in coastal soft soil area and meet the requirements of engineering on the control of settlement characteristics,the mechanical behavior of the root-pile foundation is analyzed with field test.The bearing capacity of ordinary pile foundation and root-pile foundation with different numbers of roots are tested by static load test,then the displacement-load curve and axial force transfer curve are obtained.According to the engineering geological conditions of the site,numerical simulation model is established,and the displacement of pile body and soil under ultimate load are analyzed.The results show that:the bearing capacity of root-pile foundation is improved comparing with the ordinary pile foundation.In this test,the ultimate vertical bearing capacity of root-pile foundation increase by 23.75%~33.33%.Besides,the settlement of root-pile foundation is significantly reduced,and its settlement control performance is better than the ordinary pile foundation.The numerical simulation results also show that the roots are important to strengthen the coupling effect of the pile body and soil.

关 键 词：桥梁工程 承载性能 静载试验 根键桩 竖向荷载 数值模拟 试验 

分 类 号：U441.2[建筑科学—桥梁与隧道工程]