山洪对陡坡桥梁桩基功能的影响及其安全评价

发布时间：2018-04-07 15:02

本文选题：岩土工程　切入点：山洪　出处：《长安大学》2014年硕士论文

【摘要】：山区地段的陡坡桥梁桩基由于其所处环境的特殊性，往往会遭受山洪的冲刷及其携带滚石的撞击作用，对桩基功能的正常发挥和安全性构成威胁。因此，为保障陡坡桥梁桩基功能的正常和桥梁的安全，需对山洪作用下陡坡桥梁桩基承载特性的变化及其安全性进行研究。本文基于国内外学者的研究，通过建立分析模型，采用理论计算和数值模拟，研究了山洪对陡坡桥梁桩基功能的影响。并依托福永高速实际工程，通过现场调研，建立安全评价体系，对发生山洪病害的桥梁桩基进行了安全评价。论文主要结论如下： 1.在对国内外研究成果调研的基础上，归纳总结了陡坡区山洪灾害的特征及其对陡坡桥梁桩基功能的影响类型。 2.在分析山洪作用对陡坡区桥梁桩基冲刷深度的基础上，建立山洪发生后桩基竖向承载特性的计算公式；基于数值模拟，分析了在不同工况下山洪冲刷对陡坡桥梁桩基竖向承载特性的影响。 3.分析了陡坡环境下滚石的运动轨迹及其作用于桥梁墩台与基础上的撞击力；建立了不同滚石撞击桩基的力学模型并推导了桩基内力及桩顶水平位移量的计算公式，，在此基础上提出了陡坡桥梁桩基可承受的临界撞击力的计算方法。 4.采用模糊综合评价法，建立了山洪作用对陡坡桩基功能影响的安全评价体系，并结合实际工程对山区陡坡地段桥梁桩基进行了安全评价，提出了山洪作用下陡坡桥梁桩基的安全防护技术。
[Abstract]:Because of the particularity of the environment, the pile foundation of steep slope bridge in mountainous area is often subjected to the flushing of mountain torrents and the impact of carrying rolling stones, which threatens the normal exertion and safety of the function of pile foundation.Therefore, in order to guarantee the normal function of pile foundation of steep slope bridge and the safety of bridge, it is necessary to study the change and safety of pile foundation bearing characteristics of steep slope bridge under the action of mountain flood.Based on the research of scholars at home and abroad, this paper studies the influence of mountain torrents on the function of pile foundation of steep slope bridge by establishing an analytical model and using theoretical calculation and numerical simulation.The safety evaluation system of bridge pile foundation caused by mountain torrents is established through field investigation and investigation. The safety evaluation of bridge pile foundation caused by mountain torrents is carried out based on Fuyong Expressway practical project.The main conclusions are as follows:1.Based on the research results at home and abroad, the characteristics of mountain torrents in steep slope region and their influence types on the function of pile foundation of steep slope bridge are summarized.2.Based on the analysis of the effect of mountain torrents on the erosion depth of bridge pile foundation in steep slope area, the formula for calculating the vertical bearing characteristics of pile foundation after the occurrence of mountain torrents is established, and based on the numerical simulation,The influence of mountain torrents scouring on the vertical bearing characteristics of steep slope bridge pile foundation is analyzed.3.In this paper, the motion track of rolling stone and its impact force acting on bridge pier and foundation under steep slope environment are analyzed, the mechanical models of different rolling stones impacting pile foundation are established, and the calculating formulas of pile foundation internal force and pile top horizontal displacement are derived.On this basis, the calculation method of the critical impact force on the pile foundation of steep slope bridge is put forward.4.The fuzzy comprehensive evaluation method is used to establish the safety evaluation system of the effect of mountain torrents on the function of steep slope pile foundation, and the safety evaluation of bridge pile foundation in steep slope section in mountainous area is carried out in combination with the actual project.The safety protection technology of pile foundation of steep slope bridge under the action of mountain flood is put forward.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U443.15

【参考文献】