邻近堆载对深厚软土地区高速铁路桥梁桩基内力与变位影响分析

发布时间：2018-04-05 02:11

本文选题：堆载　切入点：桥梁桩基　出处：《中南大学》2014年硕士论文

【摘要】：摘要：为实现高速、安全的运营目标,新建高速铁路普遍采用无砟轨道,如何保证其平顺性是高速铁路建设和运营过程中的关键技术。深厚软土地区高速铁路桥梁普遍采用桩基础,沿线区域经济发展过程中,不可避免地会遭遇到邻近堆载的作用,导致地基中附加应力增加,引起影响线路的平顺性。本文采用理论分析、现场调研和数值模拟相结合的方法,针对邻近堆载对高速铁路桥梁桩基内力与变位的影响开展研究,主要工作和成果如下： (1)通过对国内外相关研究现状的综合分析,制定了本文的研究内容和技术路线； (2)基于弹性半空间理论,编制了用于计算堆载引起的桩侧应力的计算程序。将堆载引起的侧应力分段简化为集中荷载作用于基桩上,对不同土层施加不同的弹簧劲度系数,改进了有限差分求解弹性地基梁的计算程序,并用于实际工程,效果较好； (3)将平面刚架静力分析程序中的水平杆件视为弹性支撑,用于计算侧向力对基桩内力的影响,并与有限差分法求解弹性地基梁的结果进行对比分析,验证了该方法的可行性； (4)采用控制变量法,分析了堆载宽度、堆载间距、堆载高度等变化的情况下桩身弯矩与墩顶位移的变化规律； (5)采用FLAC有限差分软件,分析了邻近堆载对深厚软土地区桥梁桩基变位的影响,获得了一些对设计和施工有参考价值的结果。
[Abstract]:Abstract: in order to realize the goal of high-speed and safe operation, ballastless track is widely used in newly built high-speed railway. How to ensure its smoothness is the key technology in the construction and operation of high-speed railway.Pile foundation is widely used in high speed railway bridges in deep soft soil area. In the process of regional economic development, it will inevitably encounter the effect of adjacent surcharge, which will lead to the increase of additional stress in the foundation, which will affect the smoothness of the line.In this paper, theoretical analysis, field investigation and numerical simulation are used to study the influence of adjacent surcharge on the internal force and displacement of pile foundation of high-speed railway bridge. The main work and results are as follows:1) based on the comprehensive analysis of the current research situation at home and abroad, the research content and technical route of this paper are worked out.Based on the elastic half-space theory, a program for calculating the lateral stress of piles caused by heaps is developed.The lateral stress caused by surcharge is simplified as a concentrated load acting on the foundation pile, different spring stiffness coefficient is applied to different soil layers, the calculation program for solving elastic foundation beam by finite difference method is improved, and it is used in practical engineering with good results.(3) the horizontal member in the static analysis program of plane rigid frame is regarded as elastic support, which is used to calculate the influence of lateral force on the internal force of foundation pile, and compared with the result of solving elastic foundation beam by finite difference method, the feasibility of this method is verified.(4) the variation law of pile bending moment and pier top displacement is analyzed under the condition of the variation of the surcharge width, the distance between the piles and the height of the pile load by using the control variable method.Using FLAC finite difference software, the influence of adjacent surcharge on displacement of bridge pile foundation in deep soft soil area is analyzed, and some results of reference value for design and construction are obtained.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U443.15

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