矿区煤炭开采对建筑物抗震性能扰动研究

发布时间：2018-04-02 07:23

本文选题：采动　切入点：地震动力　出处：《辽宁工程技术大学》2015年硕士论文

【摘要】：目前,煤矿采动区建筑物抗震性能的研究,多是以刚性地基假设为条件,本文考虑了上部结构-基础-地基三者的相互协调作用,深入探讨煤矿采动与地震联合作用下煤矿采动区建筑物的抗震性能劣化规律。基于损伤力学理论,引入改进的双参数损伤模型计算地震作用下煤矿采动区建筑物的楼层损伤值。在已有研究的基础上,选用有限元分析软件ANSYS进行数值计算,量化分析了煤矿采动损伤建筑在地震动力作用下的损伤演化过程,对煤矿采动损害影响下的建筑物的抗震性能劣化规律进行了分析探讨,以期得到矿区地下煤炭开采对建筑物抗震性能的扰动规律。计算结果表明：(1)由于SSI(土-结构相互作用,下文均简称SSI)效应的存在,地震波在土体传播过程中高频部分被滤弱,低频占主导作用,一定程度上接近结构共振频率的分量增加；考虑SSI效应后,改变了建筑结构的自振特性,结构的动力反应曲线变得更加均匀；(2)由于SSI效应的存在,结构自振周期变大,自振频率变小,结构的整体刚度变柔。同时,结合结构的顶点位移、顶点加速度和底部剪力时程曲线可知,刚性地基底部结构较早的发生塑性损伤,耗散地震的输入能量,计算结果明显大于柔性地基；(3)由于煤矿采动的影响,建筑结构的地震动力反应增大,并且位移时程曲线普遍朝着建筑物倾斜的方向增幅较大；这是由于煤矿采动作用引起的地表移动变形,导致建筑倾斜致使建筑物重心位置发生偏移所导致的,加大了重力二阶效应对水平力作用下结构位移的不利影响；结构底部产生附加变形和附加应力,采动造成的初始损伤会使结构提前形成“柱铰机制”或“梁铰机制”,加剧了地震对煤矿采动建筑物的破坏效应。(4)受煤矿采动的影响,结构的刚度分布发生变化,地震动力作用下结构底部的刚度退化加快,结构整体刚度中心下移,一、二层层间弹塑性位移角超过规范值1/50,薄弱层位置下移,主要集中在一、二层;受煤矿采动的影响,底部结构楼层损伤值急剧增加,底部结构的易损性增加,严重削弱了建筑结构的抗震性能。
[Abstract]:At present, the research of seismic behavior of buildings in coal mining area is mostly based on the assumption of rigid foundation. In this paper, the interaction of superstructure, foundation and foundation is considered.This paper probes into the law of deterioration of seismic performance of buildings in coal mining area under the combined action of coal mining and earthquake.Based on the theory of damage mechanics, an improved two-parameter damage model is introduced to calculate the floor damage value of buildings in mining area under earthquake.On the basis of existing research, the damage evolution process of mining damaged building in coal mine under seismic dynamic action is analyzed quantitatively by using finite element analysis software ANSYS to carry out numerical calculation.The deterioration law of seismic performance of buildings under the influence of mining damage is analyzed and discussed in order to obtain the disturbance law of underground coal mining on the seismic performance of buildings.The calculation results show that due to the existence of SSI (soil-structure interaction, hereinafter referred to as SSI) effect, the high frequency part of seismic wave is filtered in the process of soil mass propagation, the low frequency dominates, and the component close to the structural resonance frequency increases to a certain extent.Considering the SSI effect, the natural vibration characteristics of the building structure are changed, and the dynamic response curve of the structure becomes more uniform. (2) because of the existence of the SSI effect, the natural vibration period of the structure becomes larger, the natural vibration frequency becomes smaller, and the overall stiffness of the structure becomes flexible.At the same time, combined with the vertex displacement, the acceleration of the vertex and the shear history curve at the bottom of the structure, the plastic damage of the structure at the base of the rigid foundation occurred earlier and the input energy of the earthquake was dissipated.The calculated result is obviously larger than that of flexible foundation) because of the influence of coal mining, the seismic dynamic response of building structure increases, and the displacement time history curve generally increases in the direction of inclined building.This is caused by the ground movement and deformation caused by the mining action of coal mine, which leads to the deviation of the center of gravity of the building caused by the building inclination, which increases the adverse effect of the second-order gravity effect on the structural displacement under the horizontal force.Additional deformation and additional stress are produced at the bottom of the structure, and the initial damage caused by mining will lead the structure to form "column hinge mechanism" or "beam hinge mechanism" in advance, which intensifies the damage effect of earthquake to mining buildings in coal mines.The stiffness distribution of the structure changes, the stiffness degradation at the bottom of the structure accelerates under the earthquake dynamic action, the center of the overall stiffness of the structure moves down. The elastic-plastic displacement angle between the first and second layers exceeds the standard value by 1 / 50, and the weak layer position moves down, mainly concentrated in one.Under the influence of coal mining, the damage value of floor of bottom structure increases sharply, and the vulnerability of bottom structure increases, which seriously weakens the seismic performance of building structure.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD82;TU352.11

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