隔震结构非平稳随机地震响应与抗倾覆易损性计算方法研究

发布时间：2018-01-24 21:43

本文关键词： 隔震滞迟系统非平稳随机振动等效线性化抗倾覆易损性分析　出处：《大连理工大学》2014年博士论文　论文类型：学位论文

【摘要】：隔震是在强震作用下减小结构发生破坏的最具潜能的技术之一。它不但被广泛应用在公寓、办公楼、医院、学校等新建建筑中,而且在改善现有桥梁、具有历史纪念价值的古建筑的抗震性能方面,也颇具吸引力。1995年阪神地震之后,隔震建筑的数量急剧增加,一些形式复杂的新型隔震结构不断涌现,如高层隔震结构、复合隔震结构、层间隔震结构等,这些都给隔震建筑的设计带来新的挑战。由于地震具有随机性,将随机振动方法应用到工程结构地震响应分析中具有显著的优势。在均匀调制/完全非平稳地震作用下,基于虚拟激励法(PEM)和等效线性化法(ELM)的求解方法,本文提出了几种特殊隔震结构随机地震响应的计算方法,并对高层基础隔震结构的抗倾覆问题做了易损性分析。具体内容如下： 1.基础隔震多自由度滞迟系统非平稳随机地震响应分析基于虚拟激励法和等效线性化技术,计算了基础隔震的多自由度滞迟系统在均匀调制非平稳/完全非平稳随机激励下的地震响应。虚拟激励法把求解非平稳随机振动问题转化为普通的动力响应时间历程分析。对于均匀调制的非平稳随机振动问题,通过构造混合型精细时程积分的格式求解,对于完全非平稳随机振动问题,采用Runge-Kutta法求解。将虚拟激励法计算的结果与Monte Carlo计算的结果相比较,发现吻合较好,从而验证了虚拟激励法求解此类问题的有效性。 2.基于三维有限元模型的基础隔震结构非平稳随机地震响应计算方法对于大型复杂的基础隔震建筑,基于三维有限元模型,推导了求解其非平稳地震响应的运动方程,特别是针对非偏心或轻微偏心的隔震建筑,通过滞迟变量的凝聚和静力校正技术,提出了一种求解其非平稳随机响应的高效算法。由于隔震结构底部筏体的刚度远远大于隔震支座的水平刚度,对于非偏心或轻微偏心的隔震建筑,我们假定相同类型的隔震支座在相同方向上产生的滞迟变量的大小相等,这样使得描述隔震支座滞迟特性的滞迟变量仅与隔震支座的类型相关而与隔震支座的数量没有必然关系,大大减少了等效微分方程组的数量,提高了非平稳随机振动的效率；与此同时,采用静力校正技术,使得既考虑了高阶振型对结构响应的影响,又没有显著增加问题的计算量,达到事半功倍的效果。最后,使用本文所提方法计算了一个简单的基础隔震的框架结构的随机响应,并利用Monte Carlo法验证了本文算法的正确性。 3.层间隔震结构考虑P-△效应地震响应的计算方法通过引入层间隔震结构的几何刚度阵,提出了层间隔震系统考虑P-△效应地震响应的计算方法。隔震层在强震作用下会形成较大的层间变形,在轴向荷载作用下,将在隔震支座两端形成较大的附加弯矩,通过构造水平力偶来代替P-△效应所形成的附加弯矩,从而得到层间隔震系统的几何刚度阵。在层间隔震地震响应计算时,只需要在原来结构刚度矩阵的基础上叠加这个几何刚度矩阵,就可以按照逐步积分法求得考虑P-△效应的层间隔震结构的地震响应,免除P-△效应计算所需要的迭代运算步骤,提高了计算效率。利用虚拟激励法计算了层间隔震结构在均匀调制非平稳激励下的地震响应,讨论了不同场地类别和设计地震分组下,P-△效应对层间隔震结构地震响应的影响；利用时程分析法研究了在近断层地震作用下,P-△效应对层间隔震结构地震响应的影响,研究表明：P-△效应会对隔震系统的下部结构带来巨大的安全隐患,特别是在近断层地震动作用下,显得尤为突出。 4.高层隔震结构抗倾覆易损性计算方法利用首次破坏准则,基于三维有限元模型,建立了高层基础隔震建筑各个隔震支座在地震作用下发生抗倾覆破坏的概率的计算方法。研究了地震波传播方向、隔震后的基本周期、压应力限值、隔震层的附加阻尼比、场地特性和设计地震分组等因素对隔震支座抗倾覆破坏易损性曲线的影响,为高层隔震建筑的设计提供理论支持。
[Abstract]:Isolation is one of the most potential technology to reduce the structural damage under earthquake. It is not only widely used in apartments, office buildings, hospitals, schools and other new buildings, but also in improving the seismic performance of existing bridges, the historic value of ancient architecture, but also attractive in.1995 after the Kobe earthquake. The number of isolated buildings increased dramatically, some new isolation in the complex structure are constantly emerging, such as high-rise buildings, the composite isolation structure, interlayer isolation structure, which gave the design of isolation building brings new challenges.
As a result of the earthquake is random, the random vibration method is applied to the structural seismic response has significant advantages in the analysis. In the uniform modulation / fully nonstationary earthquake, based on pseudo excitation method (PEM) and the method of equivalent linearization (ELM) method, this paper puts forward the calculation method of some special stochastic seismic isolation structure in response, the vulnerability analysis and anti overturning problems of high-rise base isolated structure. The specific contents are as follows:
Non stationary random seismic response analysis of 1. base isolation and multi degree of freedom hysteresis system
The pseudo excitation method and the equivalent linearization technique based on the calculation of the multi degree of freedom system in the late lag of base isolation uniformly modulated non-stationary / completely under non-stationary random excitation. The seismic response of the pseudo excitation method to solve non-stationary random vibration problem is transformed into ordinary dynamic response time history analysis for non-stationary random vibration problem of uniform modulation, by constructing a hybrid scheme for precise time integral, for non-stationary random vibration problems, using the Runge-Kutta method. Compared the calculation results with the virtual excitation method of Carlo Monte, and good agreement was found, which verifies the validity of the pseudo excitation method for solving such problems.
2. calculation method for non stationary random seismic response of base isolation structure based on three-dimensional finite element model
For base isolated building complex, three-dimensional finite element model based on the equation of motion is derived for non stationary seismic response, especially for non eccentric or slightly eccentric buildings, by the hysteretic variable condensation and static correction technology, this paper presents an efficient algorithm for solving its non stationary random response due. At the bottom of the isolation structure raft stiffness is far greater than the horizontal stiffness of the isolation bearing for non eccentric or slightly eccentric isolated buildings, we assume that the bearings of the same type in the same direction on the hysteretic variables of equal size, which makes the type description of bearings hysteretic characteristics of hysteretic variables only and bearings the number and the bearings are not necessarily related, greatly reducing the number of equivalent differential equations, improves the efficiency of non-stationary random vibration; at the same time. Using the static correction technique, which not only considers the influence of higher modes on the structural response, and no significant increase in computational complexity, to achieve a multiplier effect. Finally, using the proposed method of random response of frame structure based on a simple isolation was calculated, and verify the correctness of the algorithm by using Monte the method of Carlo.
The calculation method of P- seismic response considering the effect of the 3. interlayer isolation structure
Through the introduction of interlayer isolation structure geometric stiffness matrix, put forward the interlayer seismic isolation system calculation method considering the effect of seismic response of P- Delta. The isolation layer will form a larger interlayer deformation under strong earthquake, under axial load, the formation of additional moment larger in the bearings at both ends of the additional moment instead of P- the effect by constructing the horizontal couple formed, resulting in geometry layer isolation system stiffness matrix. In the seismic response analysis of isolation layer, only need to overlay this geometric stiffness matrix based on the original structure of the stiffness matrix, can be in accordance with the step by step integral method considering the effect of the isolation layer of P- delta the seismic response of the structure, the iterative steps from P- a effects for calculation, the computational efficiency is improved. By using virtual excitation method to calculate the interlayer isolation structure in the uniformly modulated non-stationary excitation seismic response Should be discussed, different site categories and classification of design earthquake, P- delta effect on seismic response; using time history analysis method is studied in the near fault earthquake, P- delta effects showed that the effect on seismic response, the effect of Delta: P- isolation system the lower part of the structure of a huge security risks, especially in the near fault ground motion, it is particularly prominent.
Calculation method of anti overturning and vulnerability of 4. high rise isolating structure
The first criterion based on the 3D finite element model, established the calculation method of high-rise base isolated buildings all bearing probability of anti overturning failure under earthquake. The seismic wave propagation direction, the basic period of isolation, the compressive stress limit value, the additional damping isolation layer, and site characteristics classification of design earthquake damage factors such as overturning fragility curves of resistance on the bearings, to provide theoretical support for the design of high-rise building.

【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU352.12

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