长短桩复合地基沉降试验模型与研究（论文）.pdf

70 施 工 技 术 CONSTRUCTION TECHNOLOGY 2018年 1月上 第 47卷 第 l期 DOI：10．7672／sgjs2018010070 长 短 桩 复 合 地 基 沉 降 试 验 模 型 与 研 究 冰 张 丽 华 ，张 昌 进 ，程 一 杰 ，耿 琳 苑 (华北科技学院，河北 廊坊 101601) [摘要]复合地基的沉降特性是一个非常复杂的问题，尤其是在长短桩复合地基方面。通过室内长短桩复合地基 模型试验对复合地基在竖向荷载作用下的沉降进行分析，研究分析长短桩共同加固区、短桩与下卧层交接面的沉 降变化规律，同时分析了在竖向荷载作用下的下卧层应力变化规律。试验表明：①长短桩复合地基的沉降与桩长 的变化呈负相关。桩长越长 ，总沉降量越小；桩长越短，总沉降量越大。长桩作为主控桩对沉降量的控制有显著效 果。②在长短桩共同加固区域，桩体沉降变化幅度不大；长桩单独加固区对沉降控制效果比较明显。③受到加固 区桩土相互作用的影响，下卧层中的附加应力和桩间土附加应力的受力机理相反。长桩受迫沉降，带动桩间土协 同变形，以致使中心桩下卧层应力最大。 [关键词]地基；复合地基；刚性长短桩；试验；研究；沉降 [中图分类号]TU753 [文献标识码]A [文章编号]1002—8498(2018)01—0070—04 Experim ental M odel and Study of Long-short-pile Com posite Foundation Settlem ent ZHANG Lihua，ZHANG Changjin，CHENG Yijie，GENG Linyuan (North China Institute ofScience and Technology，Langfang，Hebei 101601，China) Abstract：The settlement characteristics of composite foundation is a very complex problem，especially in the long—short—pile composite foundation．The settlement of the composite foundation under the vertical load is analyzed by the model test of the long—short—pile composite foundation in the laboratory．The settlement variation law of the long and short pile joint area，the short pile and the underlying layer is studied．At the same time，under the action of the stress law is also studied．According to the test results：①The settlement of long short pile composite foundation is negatively related to the change of pile length．The longer the pile length，the smaller the total settlement，the shorter the length of the pile，the greater the total settlement．The long pile as the main control pile has a significant effect on the control of the settlement．② In the long and short pile common reinforcement region，the settlement variation of the pile is not great：the control effect of the single pile reinforced area is obvious．③ Influenced on the interaction of the pile and soil in the reinforcement area，the stress mechanism of the additional stress in the underlying layer and the additional stress of the pile is opposite．Forced settlement of long piles， drives the pile of soil collaborative de~rmation，results in the maximum stress of the center pile under the stress． Key words：~undations；composite~undation；rigid long—short pile；testing；study；settlement 0 引言 长 短桩复 合地 基 是 在 等长 桩 复 合地 基 理 论 国家自然科学基金面上项目：刚性基础下组合桩复合地基沉降特 性及预测方法研究(51178185)；中央高校基本科研业务费资助 (3142015145) [作者简介]张丽华，建