大直径变径桩横向承载特性模型试验  

Model Test on Lateral Bearing Behaviors of Large Diameter Pile with Variable Cross Section

作　　者：刘新荣[1,2] 方焘[1,3] 耿大新[3] 吴泽军[3] 纪孝团[3] 

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [3]华东交通大学土木建筑学院,江西南昌330013

出　　处：《中国公路学报》2013年第6期80-86,190,共8页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(50908086);铁道部重点科技开发项目(2009G010-D);教育部新世纪优秀人才支持计划(NCET-05-0763)

摘　　要：为研究变截面单桩在横向静载荷作用下的变形及承载特性，选取4根不同变径位置的模型桩，设计了可以在同一介质中同时完成4根桩的模型箱和模型加载设备，开展了变截面单桩横向静载荷作用下变形及承载特性模型试验研究。运用EVD，DPL等方法对桩周介质材料和填筑参数进行了测试与评价，测试分析了4种不同变截面位置的阶梯型变截面桩桩身拉、压应变曲线、桩顶水平荷载位移曲线。研究结果表明：变截面桩横向受力比直桩合理；变截面桩变径段长度占整个桩长40％～50％时效率最高，变径段长度超过桩长50％时，对提高桩横向承载力作用有限；桩顶荷载一位移曲线呈现典型的非线性特征。In order to study the behaviors of piles with variable cross section under lateral static load, 4 model piles were adopted for the model test. At the same time, a special load instrument was designed to complete the test of the four piles simultaneously. The mechanic parameters of the soil were examined by using several methods, such as EVD and DPL etc. The compressive and tensile strain curve of pile body with four types of variable cross sections under lateral static load as well as load-displacement curve of the pile top were analyzed. The results indicate that the use of the piles with enlarged diameter with variable cross section is highly effective in resisting lateral load. It is most effective when the enlarged pile section is 40% - 50% of its length. But when the enlarged pile section is over 50% of its length, the effect is limited. The curve of load- displacement of the pile top is nonlinear.

关 键 词：桥梁工程 大直径变截面桩 模型试验 承载特性 变形 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]