多层立交隧道节点振动台试验研究

发布时间：2018-05-17 14:37

本文选题：振动台试验 + 浅埋隧道　；参考：《南京工业大学》2015年硕士论文

【摘要】：目前现有的关于地下结构抗震的理论和研究中主要是针对规则结构进行的,对于工程中出现的浅埋和复杂结构的研究则较少。南京市江东北路定淮门大街节点改造工程作为城市地下立交工程,本工程在国内外首次采用了主线双层、匝道双层的交叉设计。本文以工程中出现的双层隧道与双层匝道组成的交叉节点为研究对象,设计并完成的复杂节点的振动台试验,研究浅埋复杂结构在地震过程中的地震反应。首先本文论述了研究地下结构震动响应的研究意义;介绍了地下结构常见的震害类型以及地下结构模型试验研究方法：离心机试验、振动台试验;介绍了模型试验的相似设计理论,根据模型结构和模型土两种不同材料分别推导出不同的相似比例关系。针对振动台试验的方案、准备和设计过程,系统研究了浅埋结构振动台试验技术,包括模型相似比的确定、模型土箱的选择、结构模型制作、模型土的制作、传感器的布置方案及仪器埋设等相关问题。进行振动台试验获得模型试验数据,分别从土体加速度传播规律、结构动力特性、加速度时程、模型结构应变变化、伸缩缝处相对位移等方面进行分析,获得浅埋复杂地下结构在加速度传播、应变变化等方面的规律性认识。得到的主要结论有：(1)地下结构的存在会改变地震波在土体的传播规律,增大结构周围一定范围的土体加速度反应峰值。(2)由于地下连续墙的存在,保证了结构同周围土体的连续运动,在一般地震动作用下,结构顶部和底部的峰值加速同周围土体的峰值加速度差别较小,略小于周围土体的峰值加速度：在700ga1以上的强震作用下,项板由于受到的地连墙的约束作用较小,在跟随周围土体作受迫运动的同时又受自身惯性力的影响,结构顶部的峰值加速度略大于周围土体的峰值加速度。(3)在水平向地震动作用下,地下结构的地震响应是由结构周围土体控制的,结构随着周围土体发生剪切变形,因此,应变主要集中在侧墙与楼板相交处。结构中板是所有构件中刚度最弱处,故结构中板的应变反应明显大于其它部位。在300gal地震作用下该处出现损伤。(4)对于浅埋隧道结构,强震作用下,地下结构有上浮趋势,可能会对地基土上部的道路、房屋等造成破坏,应引起注意。
[Abstract]:At present, the existing theories and researches on earthquake resistance of underground structures are mainly aimed at regular structures, but there are few researches on shallow buried structures and complex structures in engineering. As a city underground interchange project, Nanjing Jiangdong North Road Dinghuai Gate Street Node Reformation Project is the first cross design of main line double layer and ramp double layer in China and abroad. In this paper, the shaking table test of the complex joint is designed and completed to study the seismic response of the shallow buried complex structure in the process of earthquake by taking the cross node of the double-layer tunnel and double-ramp in the engineering as the research object. At first, this paper discusses the significance of studying the vibration response of underground structure, introduces the common types of earthquake damage of underground structure and the research methods of model test of underground structure: centrifuge test, shaking table test; In this paper, the similarity design theory of model test is introduced. According to the model structure and model soil, different similarity ratio relations are deduced. Aiming at the scheme, preparation and design process of shaking table test, the shaking table test technology of shallow buried structure is studied systematically, including the determination of model similarity ratio, the selection of model soil box, the making of structural model and the making of model soil. Sensor layout and instrument installation and other related issues. The model test data were obtained by shaking table test. The acceleration propagation law, structural dynamic characteristics, acceleration time history, strain change of model structure, relative displacement of expansion joint, etc., were analyzed respectively. The laws of acceleration propagation and strain variation of shallow buried complex underground structures are obtained. The main conclusions are: (1) the existence of underground structure will change the law of seismic wave propagation in soil, increase the peak value of soil acceleration response in a certain range around the structure, because of the existence of underground diaphragm wall, The continuous motion of the structure and surrounding soil is ensured. Under the action of general ground motion, the peak acceleration at the top and bottom of the structure is less different from the peak acceleration of the surrounding soil. A little less than the peak acceleration of surrounding soil: under the action of strong earthquake above 700ga1, the item plate is affected by the inertia force while following the surrounding soil to make forced motion because of the restraint of the ground connecting wall. The peak acceleration at the top of the structure is slightly larger than the peak acceleration of the surrounding soil.) under horizontal ground motion, the seismic response of the underground structure is controlled by the soil around the structure, and the shear deformation of the structure occurs with the surrounding soil, so, The strain is mainly concentrated at the intersection of the side wall and the floor. The structure plate is the weakest part of all the members, so the strain response of the plate in the structure is obviously greater than that in other parts. For shallow tunnel structure and strong earthquake, the underground structure has the tendency to rise, which may cause damage to the road and house in the upper part of the foundation and soil, which should be paid attention to.
【学位授予单位】：南京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U456

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