地下结构动力变形分析及其对地表建筑地震响应的影响研究

发布时间：2018-06-12 11:55

本文选题：地下结构 + 动力分析　；参考：《大连理工大学》2013年博士论文

【摘要】：随着经济的飞速增长,我国城市化进程日益加快,人口和物质财富逐渐向城市高度集中,开发地下空间,建立以地铁为主体的城市地下交通系统作为缓解城市交通最快捷、最有效的途径越来越引起重视。城市地下空间的飞速开发,其抗震安全性必然会成为建筑工程抗震和城市防灾减灾研究的重要内容。大型地下结构内部人口比较集中,空间受限,疏散缓慢,一旦遭受地震破坏,直接造成的生命和财产损失与地上结构相比将更为严重,而且地下结构的修复工作相对困难,间接经济损失同样巨大。地铁交通工程大都贯穿于城市内部,其地表附近一般都已经存在建成的建筑物,或者为了交通方便而在地铁工程附近新建商业区、居民小区等,地下空间结构的存在将改变临近建筑物的地基条件,并改变地震波的传播路径,进而影响地表建筑的地震响应。本文针对上述问题,重点分析了地下结构的动力变形特性,以及地下结构的存在对地表临近建筑结构地震响应的影响,主要研究内容如下： (1)根据土-地下结构拟静力相互作用法,分析排水和不排水条件土体中,地下结构剪切变形与输入激励波波长的关系。研究了土-地下结构拟静力相互作用法的计算原理和适用条件；建立有限元模型,输入由地下结构横截面尺寸所确定的不同频率的正弦波作为激励,分析在排水和不排水条件下,不同高宽比地下结构的剪切变形与激励波波长的关系,给出了不排水条件时采用静力代替动力荷载进行计算的适用条件；同时分析了柔度系数以及土体与地下结构的相对刚度两因素的影响规律。 (2)研究了单自由度体系在含有速度脉冲的近断层地震动作用下的响应,对比分析了矩形地下结构在脉冲型近断层地震动和无脉冲远场地震动作用下的剪切变形。首先运用小波分析的方法将含有速度脉冲的近断层地震动分解为高频波和脉冲波两部分,分别分析其对单自由度体系动力响应的影响,论述了仅用脉冲模型模拟近断层地震动的局限性；其次,建立不同截面形状的地下结构模型,计算不同柔度系数时,地下结构在远场地震动和脉冲型近断层地震动作用下的剪切变形系数,研究脉冲型近断层地震动对地下结构地震响应的影响,以及随柔度系数变化的规律。 (3)分析了地表建筑结构常用的简化模型,研究了高阶振型对地表结构层间位移谱、以及对层间位移沿结构无量纲高度分布的影响；以地铁车站为研究算例,重点分析当地铁车站埋置于不同类型场地中时,地下结构的存在对地表临近建筑能够产生影响的地表区域范围。根据现行规范对场地类型的规定,选取软土、中软土和硬土三种类型的均质场地做为研究基准,以纯弯曲、纯剪切和弯剪组合三种类型的结构作为研究对象,给出了有、无地铁车站时,三种场地中所选结构层间位移角的变化趋势；将地铁车站水平宽度作为地下结构与地表建筑相对距离的衡量基准,分析地下结构的尺寸与其所能影响到的地表建筑所处位置的关系,总结地下结构的影响范围随场地条件变化的规律,并分析对不同类型地表结构的影响程度；研究不同场地条件下,地下结构的存在对场地设计地震动的影响。 (4)地铁车站属于大型地下空间结构,以两层双柱三跨式地铁车站为例,着重从场地土体刚度、加速度峰值以及地表建筑变形类型三个方面进行分析,研究地下结构对地表临近建筑地震响应的影响。首先在有限元软件中分别建立无车站的自由场模型和土体-地铁车站相互作用模型,基于广义层间位移谱分析地铁车站的存在对地表临近建筑结构地震响应的影响；其次,研究了地表结构自震特性和距车站水平距离两个因素对地表结构层间位移角、及其沿结构无量纲高度分布的影响规律,同时分析了场地土体与地下结构相对刚度,以及输入地震动峰值加速度的变化对所得结果的影响；最后,分析了不同自振周期的地表结构所受地下结构影响的变形类型。 (5)以成层土体中浅埋地铁区间隧道为研究对象,分析隧道对不同类型地表建筑地震响应的影响以及所能影响到的地表区域范围。首先根据有、无隧道存在的情况下地表结构层间位移的计算结果,分析隧道的影响随地表建筑与隧道之间的相对位置发生变化的规律；其次,针对隧道可能贯穿建筑下方的情况,重点分析了隧道对位于其上方的地表结构层间位移角的影响,给出了不同自振周期地表结构的层间位移角在有、无隧道影响下沿结构高度的分布,并分析地表建筑的变形类型。
[Abstract]:With the rapid growth of the economy, the process of urbanization in China is accelerating, and the population and material wealth are gradually concentrated in the city. The development of underground space and the establishment of underground transportation system based on the subway are the quickest and most effective way to alleviate urban traffic. The rapid development of urban underground space and its earthquake resistance are becoming more and more important. Safety will inevitably become an important part of the earthquake resistance and disaster prevention and mitigation in urban areas. The population of large underground structures is concentrated, space limited, and evacuate slowly. Once the earthquake is damaged, the loss of life and property directly caused by the earthquake will be more serious than the ground structure, and the restoration of the underground structure is relatively difficult. The indirect economic loss is also huge. Most of the subway traffic engineering is run through the interior of the city. The buildings are usually built near the surface of the city, or the construction of a new commercial area and a residential area near the subway engineering for the convenience of traffic. The existence of the underground space structure will change to the foundation conditions of the buildings and change the seismic waves. The propagation path will further affect the seismic response of surface buildings.
In view of the above problems, the dynamic deformation characteristics of the underground structure and the influence of the existence of the underground structure on the seismic response of the surface adjacent to the building structure are analyzed. The main contents are as follows:
(1) according to the pseudo static interaction of soil and underground structure, the relation between the shear deformation of underground structure and the wave length of input excitation is analyzed in the soil of drainage and undrained conditions. The calculation principle and applicable conditions of the pseudo static interaction method of soil underground structure are studied, and the finite element model is established, and the input is determined by the size of the cross section of the underground structure. The sine wave of different frequencies is used as the excitation to analyze the relation between the shear deformation and the wave length of the underground structure under the conditions of drainage and undraining, and the applicable conditions for the calculation with static force instead of the dynamic load are given, and the flexibility coefficient and the relative of the soil and the underground structure are also analyzed. The law of the influence of two factors on stiffness.
(2) the response of a single degree of freedom system to the near fault ground motion with a velocity pulse is studied. The shear deformation of a rectangular underground structure under the action of a pulsed near fault ground motion and an impulsive far ground motion is compared and analyzed. First, the wavelet analysis method is used to decompose the near fault ground motion with the velocity pulse to Gao Pinbo. In the two part of the pulse wave, the influence on the dynamic response of the single degree of freedom system is analyzed, and the limitation of the simulation of the near fault ground motion only by the pulse model is discussed. Secondly, the underground structure model with different cross section shapes is established, and the underground structure is subjected to the far ground vibration and the pulse type near fault ground motion when the different flexibility coefficients are calculated. The shear deformation coefficient is used to study the influence of pulse type near fault ground motion on the seismic response of underground structures and the law of compliance with the flexibility coefficient.
(3) the simplified model commonly used in the surface structure is analyzed. The influence of high order modes on the interlayer displacement spectrum of the surface structure and the influence of the interlayer displacement along the structure without dimension is studied. The subway station is taken as an example to analyze the existence of the underground structure to the surface of the ground structure when the subway station is buried in different types of sites. According to the regulation of the site type, three types of homogeneous sites, soft soil, medium soft soil and hard soil, are selected as research benchmarks, and three types of structure of YISHION bending, pure shear and bending shear combination are selected as the research objects, and the selected structures in three kinds of sites without subway stations are given. The change trend of interlayer displacement angle; the horizontal width of subway station as the reference of the relative distance between the underground structure and the surface building, the relationship between the size of the underground structure and the location of the surface buildings that can be affected, and the regularity of the variation of the influence range of the underground structure with the site strip, and the analysis of the different types of ground. The influence degree of the structure of the table is studied, and the influence of underground structure on the design ground motion under different site conditions is studied.
(4) the subway station is a large underground space structure. Taking the two storey double column three span subway station as an example, this paper focuses on the analysis of the soil stiffness, the peak acceleration and the deformation type of the ground building in three aspects, and studies the influence of the underground structure on the seismic response of the surface adjacent to the building. The free field model and the soil subway station interaction model are used to analyze the influence of the existence of the subway station on the seismic response of the surface adjacent to the building structure based on the generalized interlayer displacement spectrum. Secondly, the displacement angle between the surface structure and the horizontal distance from the station to the surface structure is studied, and the dimensionless height of the surface structure is studied along the structure. At the same time, the influence of the relative stiffness of the soil soil and the underground structure and the change of the peak acceleration of the input ground motion on the results are also analyzed. Finally, the deformation types of the surface structure affected by the underground structures with different self vibration periods are analyzed.
(5) taking the shallow buried subway tunnel in the layered soil as the research object, the influence of tunnel on the seismic response of different types of surface buildings and the area of the surface area which can be affected are analyzed. First, the calculation results of the interlayer displacement of the surface structure under the presence of the tunnel without the existence of the tunnel are calculated, and the influence of the tunnel is analyzed between the surface buildings and the tunnel. Secondly, in view of the possibility that the tunnel may run through the underneath of the building, the influence of the tunnel on the interlayer displacement angle of the surface structure above it is emphatically analyzed, and the distribution of the interlayer displacement angle of the surface structure with different self vibration period is given, the height of the structure is distributed under the shadow of the tunnel, and the surface building is analyzed. The type of deformation.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU311.3;TU93

【参考文献】