近断层框架结构群地震响应分析

发布时间：2018-01-08 01:10

本文关键词：近断层框架结构群地震响应分析　出处：《大连理工大学》2015年博士论文　论文类型：学位论文

【摘要】：北岭地震(1994)、阪神地震(1995)、集集地震(1999)和汶川地震(2008)表明,近断层地震对其周围的城市会造成严重的震害。近断层城市结构群的地震响应是造成近断层城市严重震害的重要原因之一,因此,研究近断层城市结构群的地震响应有其现实意义。实际的近断层城市结构群地震响应是由于地震震源产生的地震波在地球介质和建筑结构群中传播的结果,而波动数值方法可以再现这种地震过程中的近断层建筑结构群响应,进而能够透彻地解释城市建筑震害现象,因此,进一步深入开展能够将结构群、地球介质和发震断层同时考虑到同一个计算模型中的近断层结构群地震响应的波动数值方法研究是一项有意义的工作。本论文主要从以下几方面开展研究工作： (1)简单回顾了震源的点源模型和有限断层模型以及粘弹性地球介质模型。重点回顾了地震波传播模拟的解析方法和数值方法以及近断层建筑结构群地震响应的研究现状。最后给出了本文研究目的和主要研究内容。 (2)详细介绍了用于实现断层破裂过程的有限断层震源模型和用于实现地球介质对地震波衰减的广义Zener体(GZB)模型。给出了平面应变问题的矩张量源,整理了涉及有限断层震源参数的经验公式。首次推导并给出了两机制微分型GZB模型的粘弹性参数与积分型松驰时间的关系。通过退化的方式给出了平面应变问题的两机制微分型、L机制记忆变量型和L机制历史变量型GZB模型。本章整理和给出的内容将用于本文以下的研究。 (3)基于两机制微分型、L机制记忆变量型和L机制历史变量型GZB粘弹性模型,分别提出了三种用于模拟地球介质中粘弹性波传播的被研究块体方法。针对本章提出的每一种方法,都采用以下三个算例验证其正确性和有效性。首先,模拟了无限域粘弹性介质中的波动传播,并与解析解对比。其次,模拟了断层破裂引起的近场地面运动,并与离散波数法计算结果对比。最后,模拟了单力引起的不规则起伏自由表面上的地表响应,并与有限元计算结果对比。对比结果验证了本章提出的三种粘弹性波传播的被研究块体方法在计算粘弹性波传播、模拟断层破裂引起的近断层地面运动和处理不规则地表起伏的波动问题方面的正确性和有效性。对比结果同时表明,本章提出的方法具有良好的数值计算精度。 (4)应用第3章提出的基于两机制微分型GZB模型和有限断层震源模型的粘弹性地震波传播的被研究块体方法研究了映秀-北川断层破裂引起的北川近断层地面运动,数值模拟中考虑了汶川地震的断层破裂过程、地球介质的粘弹性衰减、地球介质的非均匀性以及实际的地表起伏。研究结果表明,上盘的地震动明显强于下盘的地震动,上下盘效应明显：上盘和下盘不同空间点处的PGA值随空间变化出现明显的“波动”现象；北川下方地球介质的粘弹性和北川周边地表起伏对北川县城地面运动有很大影响；模拟的北川县城地面运动PGA空间分布规律和频率特性都与北川县城实际震害具有一致性。本文方法提供了一种可以有效模拟近断层地震地面运动的实用工具。 (5)提出了一种同时考虑框架结构群、粘弹性地球介质和发震断层的一体化模型。基于一体化模型,提出一种实现断层破裂产生的地震波在粘弹性地球介质和框架结构群中传播的集成模拟方法。与第4章采用的两机制微分型GZB模型不同,本集成模拟方法中,地球介质中粘弹性波传播的方法采用的是L机制记忆变量型GZB粘弹性模型。为了实现框架结构中弯曲波的传播,建立了框架结构中的被研究块体的控制方程并给出了框架结构中弯曲波传播方法的时域递推过程；为了实现地球介质中的体波与框架结构中的弯曲波的双向传播,建立了一种新的连接土体与结构的被研究块体的控制方程并给出土体与结构连接处波动双向传播的时域递推过程。通过算例,验证了本文提出的框架结构中弯曲波传播方法的有效性。利用本文提出的集成模拟方法研究了Mw6.0级逆断层型假想地震期间近断层框架结构群的地震响应。研究结果表明,对于同一结构群中的不同结构,当不同结构所处位置的PGA值差别不大时,结构与场地之间的共振会造成共振结构的地震响应明显比未共振结构的地震响应大。近断层的地球表面和框架结构群存在最终的非零位移。模拟结果的结构变形图可清晰反映出弯曲波在框架结构群各梁柱构件中传播的过程。当迎着断层走向看时,处于震中和破裂前方之间的结构群整体沿逆时针方向运动。本集成模拟方法为计算断层破裂引起的近断层结构群中结构的位移和构件内力提供了一种有效工具。 (6)基于一体化模型提出一种实现断层破裂产生的地震波在粘弹性地球介质和框架结构群中传播的集成模拟方法。不同于第4章所采用的两机制微分型GZB模型和第5章所采用的L机制记忆变量型GZB模型,本章采用L机制历史变量型GZB粘弹性模型实现地球介质对地震波的衰减。计算框架结构中的弯曲波传播以及实现地球介质中的体波与框架结构中的弯曲波的双向传播的方法与第5章相同。利用本章提出的集成模拟方法模拟了一个Mw6.2级逆断层型假想地震期间山区城市近断层框架结构群的地震响应。模拟结果表明,发震断层的倾角对处于山区城市中不同位置的结构群中十二层结构的地震响应影响显著。当迎着断层走向看时,处于震中和破裂前方之间的结构群整体沿逆时针方向运动。四组框架结构群中,出现最大梁端弯矩峰值的三层结构的位置位于小山山顶,出现最大梁端弯矩峰值的十二层结构的位置位于山体山腰。本章所提出方法能够用于建筑场地的选址并能给出近断层地震引起的框架结构群中各结构的危险位置。 (7)总结全文,并展望进一步的研究内容和工作。
[Abstract]:The Northridge earthquake (1994), Hanshin Earthquake (1995), Chi Chi earthquake (1999) and Wenchuan earthquake (2008) show that the city of the near fault earthquake will cause serious damage to the surrounding city. Near fault structure group seismic response is caused by near fault city one of the important reasons for the serious damage, therefore, study near fault seismic response of the structure of the city group has its practical significance. Near fault earthquake response of the actual structure of the city group is due to earthquake generated seismic wave propagation in the earth medium and the structure of group results, and the numerical method can present this fluctuation in the process of earthquake near fault structure group response, and be thorough explain the city building damage phenomenon, therefore, further to the structure group, earth medium and seismogenic fault considering the same calculation model in near fault earthquake response of structure group number fluctuation Value method is a meaningful work. This paper mainly carry out the research work from the following aspects:
(1) a brief review of the point source model and finite fault source model and viscoelastic earth medium model. Focus on reviewing the research status of analytical method and numerical method of seismic wave propagation simulation and near fault seismic response of building structure group. Finally, the research purpose and main contents of the research are given.
(2) introduces the finite fault source model for fault rupture process and for the implementation of the generalized Zener earth medium attenuation of seismic waves (GZB) model. The moment tensor source plane strain problem was given, finishing the empirical formula involving finite fault source parameters are given for the first time. The relationship between the viscoelastic the parameters and integral differential mechanism two relaxation time GZB model. Through the degradation of the given differential mechanism two plane strain problem, L mechanism and L mechanism of historical memory variable type variable type GZB model. This chapter gives the arrangement and will be used for the following research.
(3) two differential mechanism based on L type, L type and mechanism of memory mechanism history variable type GZB viscoelastic model, are proposed for three is used to simulate the viscoelastic wave propagation in the earth medium is on the block method. For each method proposed in this chapter, the following three examples the correctness and effectiveness. Firstly, the simulation of wave propagation in infinite viscoelastic medium, and comparison with analytic solutions. Secondly, simulate the fault rupture caused by near field ground motion, and comparing with the results calculated by the discrete wavenumber method. Finally, the irregular surface on the free surface fluctuation response simulation of single force the cause, and compared with the results of finite element calculation. The comparison results show that the proposed three kinds of viscoelastic wave propagation are studied to block method in the calculation of viscoelastic wave propagation simulation, fault rupture and near fault ground motion caused by irregular treatment The correctness and effectiveness of the wave of ups and downs. Problems contrast results also show that the proposed method has good numerical accuracy.
(4) two type differential mechanism based on GZB model and finite fault source model proposed the application of the third chapter of the visco elastic seismic wave propagation is of block method of Yingxiu Beichuan fault rupture caused by Beichuan near fault ground motion, numerical simulation considering the fault rupture process of the Wenchuan earthquake, viscoelastic earth the earth medium attenuation, the inhomogeneity and the actual surface. The results show that the upper ground was stronger than the footwall of ground motion, footwall effect is obvious: the hanging wall and footwall different point PGA values change with space appear the "wave" phenomenon; Beichuan below the earth medium viscosity elastic surface and surrounding areas of Beichuan have great influence on the ground motion simulation of Beichuan County; Beichuan county ground motion PGA spatial distribution and frequency characteristics are Beichuan county with the actual earthquake damage Consistency. This method provides a practical tool can effectively simulate the near fault earthquake ground motions.
(5) proposed a frame structure considering group, viscoelastic earth medium and seismogenic fault integration model. Based on the integration model, presents a realization of the fault rupture propagation of seismic wave in viscoelastic medium and the earth frame structure in integrated simulation method. Two differential mechanism used in GZB model and fourth in this chapter, the integrated simulation method, using the method of viscoelastic wave propagation in the earth medium is the L memory mechanism of variable type GZB viscoelastic model. In order to realize the bending wave propagation in frame structure, established in the framework of the governing equations are the research block and presented the time domain method for bending wave propagation in the framework of the recursive process; in order to realize the two-way transmission of flexural wave wave and frame structure of the earth medium, to establish a new connection between soil and structures are studied to block control equation The time domain and gives the structure and the soil at the junction of fluctuations in two-way transmission recursive process. Through an example, verify the effectiveness of the wave propagation method for bending frame structure in this paper. The Mw6.0 level response reverse fault type earthquake scenarios during fault earthquake swarm structure using integrated simulation method proposed in this paper. The results show that for the different structure of the same structure in different structure, when the location of the PGA value is not very different, the resonance between the structure and the site will cause the response significantly resonance structure seismic response to large earthquakes. The resonance structure near the fault of the earth's surface and the frame structure group had the ultimate non zero the process can clearly reflect the displacement. The flexural wave propagation in the frame structure of beam column members in each group. The simulation results of the deformation of the structure when facing the fault to see, in between the epicenter and the rupture front The structure of the whole group along the counter clockwise movement. The integrated simulation method for calculation of fault rupture caused by near fault structure group in the structure displacement and internal force provides an effective tool.
(6) put forward a model to realize the integration of the fault rupture propagation of seismic wave in viscoelastic medium earth and frame structure in integrated simulation method based on L. The mechanism of memory variable type GZB model adopted by the two mechanisms of the differential GZB model and the fifth chapter which is different from the fourth chapter, this chapter uses L the mechanism of the history variable type GZB viscoelastic model to achieve attenuation of seismic waves in the earth medium. The calculation of bending wave propagation in frame structure and the realization method with fifth two-way transmission of flexural wave and body wave structure in the earth medium in the same chapter. Simulated by using the integrated simulation method is proposed in this chapter a class Mw6.2 reverse fault type earthquake scenarios during the mountain city near fault group frame structure seismic response. Simulation results show that the seismogenic fault angle in the twelve layer structure in different positions in the mountain city of group structure The seismic response was significant. When facing the fault to see, in between the epicenter and broken in front of the whole structure along the counter clockwise movement. The four group structure group, three layer structure of the position of the maximum bending moment of beam end is located in the peak hill peak, twelve layer structure of the position of the maximum bending moment of beam end at the peak the mountain hillside. In this chapter the proposed method can be used for the construction site location and dangerous position of the given structure caused by near fault seismic frame structure in the group.
(7) summary of this paper, and the prospect of further research work.

【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU375.4;TU311.3

【参考文献】