静力与交通荷载作用下悬索桥隧道式锚碇及其边坡的力学响应研究

发布时间：2018-03-27 14:56

本文选题：隧道式锚碇　切入点：交通荷载　出处：《西南交通大学》2017年硕士论文

【摘要】：悬索桥隧道式锚碇是一种能充分利用桥位岸坡工程地质条件、工程量相对较小、性价比较高、对周边环境扰动较小的锚碇式结构,广泛应用于山区高速公路大跨度桥梁工程中。本文依托四川雅安至康定高速公路泸定大渡河桥隧道式锚碇工程,在静力分析的基础上,着重讨论在交通荷载作用下隧道式锚碇承载特性与锚碇边坡稳定性。主要研究结果如下:采用弹性理论和极限平衡分析方法,推导出隧道式锚碇承载力近似理论计算公式。揭示了静力条件(1、3.5、7、10.5倍设计缆力)、动力条件(满载、超载、超速)下隧道式锚碇的承载特性及响应规律。得出在10.5倍设计缆力作用下,锚碇围岩局部发生破坏,锚碇摩阻应力将重分布,并给出应力重分布曲线。基于理论分析方法得到,在1倍缆力作用下,锚碇重力对锚碇的侧摩阻力影响显著,侧摩阻力分布模式与3.5倍、7倍、10.5倍缆力作用下的结果差异明显。在锚碇的不同受力状态下,对比分析了理论计算与数值模拟结果,二者误差大小为 10%～30%。采用FLAC3D数值模拟与理论分析方法计算了交通荷载下隧道式锚碇动力响应特征,得到车辆运行速度是锚碇承载性波动周期的主要因素,而超载与满载是影响锚碇的受力大小的主要因素,但并不是响应周期的主要影响因素。采用FLAC3D模拟分析了隧道式锚碇边坡在自然状态、设计缆力、缆索超张拉、交通荷载满载、超载、低速、常速、高速、超速等工况下的稳定性及锚碇承载特性。隧道式锚碇边坡在自然状态、隧道开挖工况下存在浅表层潜在失稳模式,相应稳定系数为1.52,但在其他工况下,因对边坡浅表层的潜在滑动面进行支护处理,稳定性提高,相应稳定系数约为1.64。在超速(150km/h)和10倍超载的情况下,交通荷载对边坡稳定性几乎没有影响,但对锚碇受力则产生显著影响,其作用相当于88.9%的1倍设计缆力作用。本研究得到的在静力与交通荷载作用下隧道式锚碇及其边坡力学响应的相关结果,可以为悬索桥隧道式锚碇及其边坡的工程设计提供理论指导和参考。
[Abstract]:The suspension bridge tunnel Anchorage is a kind of Anchorage structure which can make full use of the engineering geological conditions of the bank slope of the bridge position, with relatively small amount of work, high ratio of performance to price and less disturbance to the surrounding environment. This paper relies on the tunnel Anchorage project of Luding Dadu River Bridge of Ya'an to Kangding Expressway in Sichuan Province, on the basis of static analysis, The load-bearing characteristics of tunnel Anchorage and the stability of Anchorage slope under traffic load are discussed emphatically. The main results are as follows: elastic theory and limit equilibrium analysis method are used. An approximate theoretical formula for calculating the bearing capacity of tunnel Anchorage is derived. Under the action of 10.5 times of designed cable force, the local failure of surrounding rock of the Anchorage will occur, and the stress distribution curve of the Anchorage will be redistributed, and the stress redistribution curve will be given based on the theoretical analysis method. Under the action of one-fold cable force, the influence of Anchorage gravity on the lateral friction resistance of the Anchorage is significant, and the distribution pattern of lateral frictional resistance is obviously different from that of 3.5 times and 7 times to 10.5 times cable force. The results of theoretical calculation and numerical simulation are compared and analyzed. The error between them is 100.The dynamic response characteristics of tunnel Anchorage under traffic load are calculated by FLAC3D numerical simulation and theoretical analysis method. The results show that the vehicle speed is the main factor of the load bearing fluctuation period of the Anchorage, and the overload and the full load are the main factors that affect the force size of the Anchorage. But it is not the main factor of the response period. The natural state of tunnel Anchorage slope, the design cable force, cable overtension, traffic load, overload, low speed, constant speed and high speed are simulated by FLAC3D. The stability of tunnel Anchorage slope in natural state and the potential instability mode of shallow surface in tunnel excavation condition, the corresponding stability coefficient is 1.52, but under other working conditions, the stability of tunnel Anchorage slope under the same condition is 1.52. The stability of the potential sliding surface of the shallow surface of the slope is improved, and the corresponding stability coefficient is about 1.64.The traffic load has little effect on the slope stability under the condition of 150 km / h overspeed and 10 times overload. However, it has a significant effect on the anchorage force, which is equivalent to 88.9% of the designed cable force. The results obtained in this study are related to the mechanical response of the tunnel Anchorage and its slope under the static and traffic loads. It can provide theoretical guidance and reference for the engineering design of suspension bridge tunnel Anchorage and its slope.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.25

【参考文献】