水电站地下厂房结构抗震分析

发布时间：2018-03-08 16:25

本文选题：粘弹性边界　切入点：地下厂房结构　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国西部大开发战略的大力贯彻和西电东送战略决策的持续推进,一大批新型单机容量达世界级的巨型水电站正在兴建或设计中。这些水电站多处为强震频发的高烈度地震区且其厂房结构设计形式也多采用地下厂房结构。这些地下水电站厂房结构尺寸和洞室开挖规模巨大,刚度相对较低,使得作为机组支撑结构的厂房的强度、振动及稳定性问题愈益凸出。在水电工程界,长期以来人们认为地下厂房的抗震性能优于地面厂房,按地上一般工业厂房对水电站地下厂房进行抗震设计即可满足要求。但关于水电站地下厂房的震害,已有相关文献报道,很多学者也都在呼吁应重视和加强地下厂房结构的抗震研究。然而,在现有的地下厂房抗震分析中,大部分文献都将研究重点放在分析地下厂房洞室群的地震反应上,而着重于厂房结构本身的抗震分析却相对较少；而且,迄今为止,我国仍没有独立的地下结构抗震设计规范,主要还是由于基础研究工作开展不够,相关资料积累不足,对地下结构灾害性动力反应和抗震设计方法缺乏系统性研究。因此,对于大型水电站地下厂房的地震反应机理和抗震性能的研究既是十分必要的也是具有极其重要意义的。针对地下厂房结构抗震研究中存在的相关问题,本文基于粘弹性边界理论和等效地震荷载输入方法,运用显式动力有限元分析软件LS-DYNA构建三维有限元模型,计算分析了水电站地下厂房结构的地震反应。主要工作介绍如下： (1)基于显式有限元分析软件,运用时程分析法得出水电站地下厂房结构在地震单独作用下的地震反应,通过对厂房结构各主要部位的地震反应如位移、加速度、应力和内力等的分析,了解地下厂房结构地震反应规律。 (2)将一种基于显式有限元计算结构静动力组合效应的方法应用到水电站地下厂房结构抗震分析之中,得到了地震工况下地下厂房结构的静动力组合效应,并将其与厂房结构在地震单独作用下的地震反应进行了对比分析。 (3)通过分析比较厂房结构在地震单独作用下和在静动组合作用下的立柱内力,发现通过锚杆与岩体连接的上下游侧立柱的内力均较其它立柱的内力要大。为进一步考察上下游侧立柱与围岩连接方式对地下厂房结构地震反应的影响,又分别计算了地震单独作用与静动组合作用两种情况下柱岩连接方式对地下厂房结构地震反应的影响。结果发现将上下游侧立柱与岩体分离对减小地下厂房结构的地震反应更为有利。
[Abstract]:With the continuous advance of China's western development strategy to implement and gingral strategy, a large number of new stand-alone capacity of world-class giant hydropower station under construction or in the design of hydropower station. These places for the earthquake prone area with high seismic intensity and the structure design of the underground powerhouse structure form the underground powerhouse structure size and large scale excavation, the stiffness is relatively low, which is the unit support structure building strength, vibration and stability problems increasingly protruding. In Hydropower Engineering for a long time, people think better seismic performance than the powerhouse of underground powerhouse, according to the general industrial workshop of hydropower the underground power plant can meet the requirements of seismic design. But the damage of the underground hydropower station has been reported in the literature, many scholars have called for attention and add in Seismic research on the structure of strong underground powerhouse.
However, in the seismic analysis of underground powerhouse in the existing literature, most of the research focused on the analysis of seismic response of Underground Powerhouse Caverns, and seismic analysis focuses on the building structure itself is relatively small; but, so far, seismic design of underground structures in China is still not independent, mainly because of basic research the work is not enough, the lack of accumulation of relevant information, the lack of systematic research on disaster underground structure dynamic response and seismic design method. Therefore, it is necessary for the seismic response mechanism of large underground hydropower station and the seismic performance of the research is also very important.
According to the related problems of seismic research of underground powerhouse, the viscoelastic boundary theory and equivalent seismic load method based on the use of explicit dynamic finite element analysis software LS-DYNA to establish three-dimensional finite element model, the calculation and analysis of the seismic response of underground powerhouse structure. The main work is introduced as follows:
(1) the explicit finite element analysis software based on the seismic response time history method is used for the underground structure in the earthquake alone under the action of hydropower, the main part of the building structure seismic responses such as displacement, acceleration, stress analysis and internal force of the building structure to understand earthquake reaction rules.
(2) a method of explicit finite element static and dynamic combination effect calculation based on the structure of the application to the analysis of hydropower station underground powerhouse structure, the seismic condition of static and dynamic combination effect of underground powerhouse structure, and the building structure seismic response in the earthquake under single load were compared.
(3) through the analysis and comparison of building structure in the earthquake alone under the action of static and dynamic combination of internal forces and in the column under the action of internal force, found on the downstream side of the upright post is connected by bolt and rock mass are compared with other post internal force should be large. For further investigation on the downstream side of the column and the surrounding rock of underground powerhouse structure connection on seismic response influence and calculate earthquake effect and separate static and dynamic effect of column rock under two conditions for connection to the earthquake underground powerhouse structure reaction. It was found that the separation on the downstream side of the column and the rock for reducing the seismic response of underground powerhouse structure is more favorable.

【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV731.6;TV312

【参考文献】