基于有限元分析的钢板桩间锁口摩擦对其抗弯特性的影响研究

发布时间：2019-03-21 18:43

【摘要】：钢板桩由于具有强度高、隔水性能好、施工方便、经济环保等特点，经常用于围堰和基坑支护结构中。近年来，钢板桩被广泛地应用于截水抗渗、基坑支护、桥梁围堰、船坞建设、污水处理、市政工程等项目中。钢板桩通过位于两侧的锁口连接成桩墙进行受力的。对于工程中应用最广泛的U型钢板桩，其锁口位于桩墙的中心线上，由于受到剪力，锁口间发生相对滑移导致钢板桩的刚度达不到组合桩墙的刚度，工程中把这种现象称为“折减效应”（Reduce ModulusAction）。在以钢板桩作为支护结构的设计中，折减效应导致支护结构的变形和位移等计算无法得到准确的结果，给钢板桩支护结构的设计和广泛使用带来了很大的困难，目前在这些方面还缺乏实质性的研究和分析。因此对钢板桩墙锁口剪力的传递对钢板桩抗弯特性的影响的研究，，有利于工程师更好的把握钢板桩墙的受力特性，从而更好的发挥钢板桩的优势，指导工程实践。本文利用组合梁知识对钢板桩中性轴的移动对惯性矩和截面模量的影响进行了讨论，得出了惯性矩和截面模量随中性轴移动的变化规律；利用有限元软件Abaqus进行了钢板桩的数值实验，得到了在不同边界（两端简支、一端固支另一端简支）和不同锁口状态下（新桩墙、锈蚀的桩墙、填砂的桩墙）刚度随位移的变化规律，当两端简支时刚度发挥比一端固支另一端简支时大，并且跨长越大时最终发挥的刚度也越大；针对刚度和强度的变化特点，本文给出了刚度折减和强度折减的范围；本文采用等效刚度的简化方法来考虑刚度的非线性变化对位移的影响，其计算结果与进行非线性计算所得位移较为接近；最后本文模拟工程中抽水和安装支撑的工况，得出了钢板桩墙在不同工况下的刚度值，可为工程实践提供参考。
[Abstract]:Steel sheet pile is often used in cofferdam and foundation pit support structure because of its high strength, good performance of water insulation, convenient construction, economic and environmental protection and so on. In recent years, steel sheet piles have been widely used in water interception and impermeability, foundation pit support, bridge cofferdam, dock construction, sewage treatment, municipal engineering and so on. The steel sheet pile is attached to the wall of the pile by means of a lock port located on both sides of the pile. For the most widely used U-shaped steel sheet pile in engineering, the locking mouth is located on the center line of the pile wall. Due to the shear force and the relative slip between the locking openings, the stiffness of the steel plate pile cannot reach the stiffness of the composite pile wall. In engineering, this phenomenon is called "reduction effect" (Reduce ModulusAction). In the design of steel sheet pile as supporting structure, the calculation of deformation and displacement of supporting structure caused by the effect of reduction can not get accurate results, which brings great difficulty to the design and widespread use of steel sheet pile supporting structure. At present, there is a lack of substantive research and analysis in these aspects. Therefore, the research on the influence of the transfer of locking shear force on the bending behavior of steel sheet pile is helpful for engineers to grasp the mechanical characteristics of steel plate pile wall better, so as to give full play to the advantages of steel plate pile and guide the engineering practice. In this paper, the influence of composite beam knowledge on the moment of inertia and cross-section modulus of steel plate pile is discussed, and the variation of inertia moment and cross-section modulus with neutral axis is obtained. The numerical experiments of steel sheet pile are carried out by using the finite element software Abaqus. The results show that under different boundary (two ends of simple support, one end of fixed support on the other end) and different locking states (new pile wall, corroded pile wall), The stiffness of sand-filled pile wall changes with displacement. When the two ends are simply supported, the stiffness is larger than that of the other end, and the greater the span length is, the greater the ultimate stiffness is. According to the variation characteristics of stiffness and strength, the range of stiffness reduction and strength reduction is given in this paper. In this paper, the simplified method of equivalent stiffness is used to consider the influence of nonlinear variation of stiffness on displacement. The calculated results are close to those obtained by nonlinear calculation. Finally, the stiffness of steel sheet pile wall under different working conditions is obtained by simulating the working conditions of pumping and installing support in the engineering, which can be used as a reference for engineering practice.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU473.1

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