【作者】 朱自强；

【导师】 朱国元； 蒋军；

【作者基本信息】 浙江大学 ， 防灾减灾及防护工程， 2006， 硕士

【摘要】 通过对桩承加筋土复合地基的发展历史、工程应用、作用机理、现有计算方法及目前存在的问题等几个方面进行分析,提出了桩承加筋土复合地基的沉降、侧向变形和稳定性计算的理论和有限元分析新方法,并对现有桩承加筋土复合地基的设计施工提出了合理的改进建议: (1) 基于弹性地基理论和张拉薄膜理论,通过取典型“土工合成材料—桩—土”分析单元,建立了一个在大面积柔性均布荷载下,桩承加筋土复合地基中“土工合成材料—桩—土”三者共同作用的分析模型,并推导出土工合成材料、桩和土三者各自的沉降计算公式,并对桩土应力集中系数和土工合成材料的张拉力进行了分析。最后,通过参数分析,研究了桩模量、桩间距对差异沉降、土工合成材料的水平张拉力、桩顶应力集中系数的影响,结果与已有数值分析较为吻合,并对桩的使用和布置提出了合理的建议。 (2) 采用Plaxis 2D有限元软件,对不同工况下的桩承加筋土复合地基中的土工合成材料和桩进行受力和变形分析,揭示了桩承加筋土复合地基的受力性能和沉降变形规律,验证了理论推导的公式,并对土工合成材料的铺设位置提出了合理的改进建议。此外,还利用Plaxis模拟施工过程,分析了影响桩承加筋土复合地基稳定性的主要因素,为实际工程设计施工提供必要的参考。更多还原

【Abstract】 Geosynthetic-Reinforced and Pile-Supported (GRPS) Composite Foundation is a kind of foundation composed of vertical enhancement and horizontal enhancement. Firstly, the thesis introduced its development history, application in projects, mechanisms of load transfer, existing computational methods and unfathomed problems. Then, a new method was put forward in designing and calculations, which gave a valuable reference for further researchs.Main works in the thesis are listed as below:(1) Based on elastic theory and tensioned membrane theory, a study has been conducted to investigate geosynthetic-pile-soil interactions. A simple theoretical approach to predict the deformation behavior of geosynthetics is presented in this thesis. The effects of pile modulus and pile spacing on the differential settlement, the stress concentration ratio and the tension in geosynthetics are discussed. The proposed method is verified with existing finite element analysis and a reasonable agreement is obtained.(2) A set of numerical modeling are performed using Plaxis program. The results of the numerical study demonstrated that inclusion of geosynthetic in earth platforms can reduce the total and differenial settlements above the pile heads, and at the ground surfaces, promote efficient load transfer from the soil to the piles and reduce the possibility of soil yielding above the pile heads. Analysis data indicated that the soil arching ratio decreases with an increase in the height of embankment fill, an increase in the elastic modulus of the pile material, and a decrease in the tensile stiffness.更多还原