变截面与等截面管桩复合地基承载特性对比研究

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1、分类号密级变截面与等截面管桩复合地基承载特性对比研究研究生姓名：黄礼胜指导教师姓名、职称：刘杰教授学科专业：岩土工程研究方向：地基处理湖南工业大学二〇一四年六月八日万方数据万方数据万方数据摘要本文依托国家自然科学基金资助的“阶梯型混凝土预制管桩单桩承载性能及接管关键技术研究”项目，在较系统地分析传统等截面管桩复合地基在实践中所存在的不足的基础上，通过室内模型试验及数值的模拟等手段，对比研究了阶梯形变截面管桩与等截面管桩复合地基的工作性状，总结了阶梯形变截面管桩复合地基的优点。主要研究内容如下。(1)基于室内复合地基大比例模型静载试验，对比

2、研究了阶梯形变截面管桩与等截面管桩复合地基的工作性状。获得了如下结论：阶梯形变截面管桩单桩刚度明显要大于等截面管桩的单桩刚度；阶梯形变截面管桩复合地基中的桩-土应力比及桩侧摩阻力要高于等截面管桩复合地基中的桩-土应力比及桩侧摩阻力；在相同荷载作用下，阶梯形变截面管桩复合地基的沉降及桩端反力明显低于等截面管桩复合地基的沉降及桩端反力。因此，采用阶梯形变截面管桩复合地基技术，对充分利用浅层土的承载能力来改善单桩的荷载传递性状，提高复合地基的承载能力，降低地基沉降具有很好的效果。(2)基于FLAC3D建立了阶梯形截面管桩复合地基数值模拟模型，室

3、内复合地基大比例模型静载试验结果验证了数值模拟模型的正确性与合理性，为阶梯形变截面管桩复合地基承载及沉降性状的全面分析奠定了理论基础。关键词：阶梯形变截面管桩，复合地基，荷载–沉降，桩土应力比，桩身荷载传递规律I万方数据ABSTRACTThethesisissupportedby“Studyonsinglepilebearingcapabilityandconnectionkeytechnologyofstepssectionconcreteprecastpipepile”program,whichisfoundedbyNationalN

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