基础隔震在既有建筑物抗震加固中的应用研究

发布时间：2019-05-31 14:54

【摘要】：基础隔震是一种独特的工程应用技术,其主要目的是通过隔离上部结构与下部结构来降低结构的地震作用。由于地震作用是从下部结构传递到上部结构的,所以用基础隔震的方法来隔离上部结构与基础,减少地震能量的传递是合理的,并且用此方法能够更好的减少地震对结构的不利作用。目前,隔震技术的应用很广泛,它不仅运用于基础上,而且用于上部结构中部的某一层。隔震技术通过改变结构的动力特性,使上部结构在地震作用下近似于平动,以此来更好的保护建筑不被破坏。本文利用SAP2000软件对华亭县某四层砖混办公楼进行隔震加固分析,以提高该砖混结构的抗震性能。本文依据《抗震设计规范》,选择El Centro波、Cholame Shandon波和Delta Artif波(人工波)对该隔震结构进行时程反应分析。通过时程反应分析得出三条地震波计算结果的平均值相差1.90%,表明三条地震波收敛性很好,地震波选择合理。此外,通过结构的反应谱分析得到结构的地震反应,然后比较时程分析的包络值与反应谱的计算结果。为了验证不同隔震支座对隔震效果的影响,本论文选择了两种隔震支座布置方式。第一种隔震支座是铅心隔震支座(LRB 400与LRB 500);第二种隔震支座布置方式是铅心隔震支座(LRB 400与LRB 500)与摩擦隔震支座的混合隔震。然后分别对两种隔震结构进行隔震分析,对比隔震和非隔震结构的地震反应,以及对比铅心隔震支座与运用混合隔震的结构的基本周期。本文对铅心隔震的结构模型,和混合隔震模型进行了隔震分析,并与隔震前的结构反应和基本周期进行了比较,结果表明,隔震后楼层最大加速度包络值减少了65.3%,并且最小加速度包络值减少了67%,但是,反应谱分析结果表明:加速度减少了91.3%。时程分析最大速度包络值减少了34%,最小的速度包络值减少了32.8%,然而,反应谱分析速度减少了57.2%。时程分析最大位移包络值增加了86.8%,最小位移包络值增加了87.4%,然而,反应谱位移值增加了56%。根据第一层的层间位移角结果可知,层间位移角的最大值与最小值都小于规范的极限(1/100),即最大值为1/186,最小值为-1/169。对比运用两种类型的隔震技术的结构在地震作用下的反应,结果表明,在相同的地震作用下,运用铅心隔震支座(LRB 400与LRB 500)与摩擦隔震支座的结合的隔震技术的结构的基本周期比运用铅心隔震支座(LRB 400与LRB 500)的隔震技术的结构的基本周期大14.2%。且前者的基本周期比非隔震结构的基本周期大362%。对比砌体墙的应力值,隔震后砌体墙的应力最大减少了97.3%。在考虑结构屈曲分析时,屈曲反应在隔震后开始发展,但是并不影响结构安全。另外,对于基地剪力,时程分析计算结果表明,x方向的最大值减少了70.1%,而y方向的最大值减少了37.2%;x和y方向的最小值分别减少了70.5%和30.0%。计算表明,隔震技术的运用可以有效的降低楼层的地震力、剪力、扭矩、扭转角和弯矩。本论文也模拟罕遇地震的作用,研究分析了在罕遇地震作用下隔震后结构的层间位移角,结果表明,其最大值为1/283,最小值为-1/205,均小于规范要求的1/100。从本文对砖混办公楼的地震分析看来,用基础隔震技术加固结构可以有效的降低地震反应,并且在隔震结构计算分析时优先使用时程分析,或时程分析与反应谱分析结合使用。
[Abstract]:Base isolation is a unique engineering application technology. The main purpose is to reduce the seismic effect of the structure by isolating the upper structure and the lower structure. Since the seismic effect is transmitted from the lower structure to the upper structure, the upper structure and the foundation are isolated by the method of base isolation, so that the transmission of the seismic energy is reasonable, and the adverse effect of the earthquake on the structure can be better reduced by using the method. At present, the application of the isolation technology is widely used, which is not only applied to the foundation, but also for a certain layer of the middle part of the upper structure. By changing the dynamic characteristics of the structure, the vibration isolation technology makes the upper structure similar to the translation under the action of the earthquake, so as to better protect the building from being damaged. In this paper, the seismic performance of the brick-concrete structure is improved by using the SAP2000 software to analyze the seismic isolation and strengthening of a four-layer brick-and-concrete office building in Huingting County. In this paper, the time-course response analysis of the isolated structure is carried out in accordance with the Code for Seismic Design, the selection of El Centro, the Cholame Shandon and Delta Artif waves. The mean difference of the results of the three seismic waves by the time-history analysis is 1.90%, which shows that the convergence of the three seismic waves is very good and the selection of the seismic wave is reasonable. In addition, the seismic response of the structure is obtained by the reaction spectrum analysis of the structure, and the envelope value of the time-history analysis and the calculation result of the reaction spectrum are compared. In order to verify the effect of different vibration isolation supports on the seismic isolation effect, two kinds of vibration isolation support arrangements are selected in this paper. The first isolation support is a lead-core shock-isolation support (LRB 400 and LRB 500), and the second type of shock-isolation support is arranged in a hybrid isolation of a lead-core shock-isolation support (LRB 400 and LRB 500) and a friction-isolation support. The seismic response of the isolated and non-isolated structures is compared with the basic period of the structure of the hybrid isolation. In this paper, the structure model of the lead-core vibration isolation and the hybrid isolation model are compared. The results show that the maximum acceleration envelope value is reduced by 65.3%, and the minimum acceleration envelope value is reduced by 67%. However, the results of the analysis show that the acceleration is reduced by 91.3%. The maximum velocity envelope of the time-history analysis is reduced by 34%, and the minimum velocity envelope value is reduced by 32.8%. However, the rate of the response spectrum analysis is reduced by 57.2%. The maximum displacement envelope value of the time-history analysis increased by 86.8% and the minimum displacement envelope value increased by 87.4%. However, the displacement value of the reaction spectrum increased by 56%. According to the inter-layer displacement angle of the first layer, the maximum value and the minimum value of the interlayer displacement angle are smaller than the limit of the specification (1/100), that is, the maximum value is 1/186 and the minimum value is -1/169. The results show that under the same seismic effect, The basic period of the structure of the seismic isolation technique using the combination of the lead-core isolation support (LRB 400 and the LRB 500) and the friction-isolation support is 14.2% larger than the basic period of the structure of the isolation technique using the lead-core isolation support (LRB 400 and the LRB 500). And the basic period of the former is 362% larger than that of the non-isolated structure. The stress value of the masonry wall is compared with that of the masonry wall after the earthquake, and the stress of the masonry wall is reduced by 97.3%. In consideration of the structural buckling analysis, the buckling reaction begins to develop after the earthquake, but does not affect the safety of the structure. In addition, for the base shear, the time-history analysis results show that the maximum value of x-direction is reduced by 70.1%, while the maximum value of y-direction is reduced by 37.2%, and the minimum value in the x and y directions is reduced by 70.5% and 30.0%, respectively. The calculation shows that the application of the seismic isolation technology can effectively reduce the earthquake force, shear force, torque, torsion angle and bending moment of the floor. The paper also simulated the effect of the rare earthquake, and analyzed the inter-layer displacement angle of the post-seismic structure under the effect of the rare earthquake. The results show that the maximum value is 1/283 and the minimum value is-1/205, which is less than 1/100 of the specification. Based on the seismic analysis of the brick-and-concrete office building, the seismic response can be effectively reduced by the base isolation technology, and the time-history analysis is given as a priority in the calculation and analysis of the isolation structure, or the time-history analysis and the response spectrum analysis are used in combination.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU352.12

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