随机动载作用下混凝土桥梁铺装层力学行为分析

发布时间：2018-06-07 12:25

本文选题：桥梁工程 + 桥面铺装　；参考：《长安大学》2016年硕士论文

【摘要】：为了探讨车辆随机动载作用下,混凝土桥梁铺装层表面不平整度、行车速度以及铺装层结构形式对铺装层内部控制应力的影响规律,本文采用具有典型性的双自由度1/4车辆模型,通过软件MATLAB/SIMULINK仿真得到基于铺装层不平整度的车辆随机动载,运用有限元软件ANSYS建立车—桥—铺装层耦合振动模型,施加仿真得到的随机动载,考虑桥面铺装的不平整情况条件,分析随机动载作用下铺装层结构动态响应的变化规律,并与移动恒载作用下的理想桥面模型进行比较,研究了在不平整度及速度的共同影响下,铺装层的动态响应变化规律,分析了铺装层分别在固定恒载、移动恒载和考虑不平整度的随机动载作用下,沥青铺装层的模量及厚度、混凝土整平层的厚度及横坡对铺装层内控制应力的影响规律。主要研究结论如下:(1)当考虑桥面不平整度时,车轮产生附加动载;在随机动载和移动恒载的作用下,沥青铺装层内部及防水粘结层层间的各项应力的极值响应曲线具有相同的变化趋势,但随机动载作用下的破坏效应要大于移动恒载。(2)在同一不平整度条件下,各项控制应力响应的极值放大系数非常接近;相比于固定位置节点的应力时程曲线,各应力的极值响应曲线能更好地反映车辆荷载的随机特征。(3)在桥面平顺性很好时,铺装层的应力极值响应随着车速的增加先增大后减小,而在平顺性一般及较差时,应力极值响应曲线有一个极大值点和一个极小值点,即车速过慢对铺装层受力状况影响十分不利。(4)车辆荷载作用下,铺装层内各项控制应力随着沥青弹性模量的增大基本上呈线性增长;沥青层过薄或过厚对铺装层受力情况均产生不利影响,增大横坡坡度有助于减小铺装层控制应力。
[Abstract]:In order to investigate the influence of surface irregularity, driving speed and pavement structure on the internal control stress of concrete bridge pavement under the action of random dynamic load of vehicle. In this paper, a typical 1 / 4 vehicle model with two degrees of freedom is adopted, and the random dynamic load of vehicle based on the unevenness of pavement is obtained by software MATLAB/SIMULINK simulation. The coupled vibration model of vehicle-bridge and pavement is established by using the finite element software ANSYS. By applying the random dynamic load obtained by simulation, considering the unevenness condition of bridge deck pavement, the changing law of dynamic response of pavement structure under random dynamic load is analyzed and compared with the ideal bridge deck model under moving dead load. Under the influence of irregularity and velocity, the dynamic response of pavement is studied. The modulus and thickness of asphalt pavement are analyzed under the action of fixed dead load, moving dead load and random dynamic load considering irregularity. The influence of the thickness of concrete leveling layer and the horizontal slope on the stress control in the pavement. The main conclusions are as follows: (1) when considering the unevenness of the bridge deck, the wheel produces additional dynamic load; under the action of random dynamic load and moving dead load, The extreme value response curves of various stresses in asphalt pavement and between waterproof and bonded layers have the same changing trend, but the failure effect under random dynamic load is greater than that under moving dead load. The maximum magnification factor of each control stress response is very close, compared with the stress time history curve of the node at fixed position, the extreme value response curve of each stress can better reflect the random characteristic of vehicle load. 3) when the ride comfort of bridge deck is very good, the maximum value response curve of each stress can better reflect the random characteristic of vehicle load. The stress extremum response of the pavement increases first and then decreases with the increase of the speed. However, when the ride comfort is general and poor, the stress extreme response curve has a maximum point and a minimum point. That is to say, when the speed is too slow, the control stress in the pavement increases linearly with the increase of the elastic modulus of asphalt. Too thin or too thick asphalt layer has a negative effect on the stress of pavement, and increasing the slope of transverse slope will help to reduce the stress of pavement control.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U441;U443.33

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