芦山中学框架结构教学楼抗震性能分析
发布时间：2018-09-18 09:47
【摘要】：钢筋混凝土框架结构因其空间布置灵活,自重轻,整体性好,便于工业化施工等优点,在我国广泛应用于学校、医院、住宅、办公楼等人员密集建筑。目前我国结构设计中,规范要求将框架结构填充墙视为非结构构件,建议采用轻质材料,在结构整体受力分析时,不考虑填充墙对其周边框架的影响,仅在计算框架结构自振周期时乘以0.6~0.7的折减系数[4]。近些年我国西南地区几次较大地震中,框架结构因没有合理考虑填充墙而造成结构破坏的案例非常多,由此也造成了较大的人员伤亡和经济损失。因此,框架结构填充墙对结构主体作用的考虑,在规范现有要求的基础上有待进一步完善。另外,研究表明断层附近是地震作用下破坏最为严重区域,受断层破裂方向性效应影响,在破裂传播前方地震动速度和位移时程呈现出高强度脉冲,其为引起近断层结构破坏的一个主要原因[28]。目前大部分学者关于速度脉冲地震动的研究主要集中于分析脉冲周期和峰值与震源参数间的关系以及其对不同类型结构的破坏机理[12][13],然而近断层区域结构抗震分析时速度脉冲地震动强度指标的选取有待进一步研究。目前我国抗震分析和结构设计中采用的地震动强度指标主要为地面峰值加速度PGA[10],但近年来几次大震中结构震害表明近断层区域速度脉冲地震动作用下PGA作为地震动强度指标不太完善。本文主要以芦山中学框架结构教学楼为分析对象,结合该教学楼在2013年4月20日芦山地震中实际震害特点,运用大型非线性有限元软件ABAQUS对其进行数值模拟,主要探讨采用不同密度和刚度填充墙材料的框架结构教学楼在不同强度地震动作用下,填充墙和框架结构主体的震害表现。分析表明,七度抗震设防框架结构教学楼,低烈度地震作用下,填充墙材料为多孔砖的框架结构各楼层位移相比填充墙材料为烧结普通砖的框架结构各楼层位移较大;高烈度地震作用下,填充墙材料为烧结普通砖的框架结构各楼层位移相比填充墙材料为多孔砖的框架结构各楼层位移较大。分析目的主要是指出目前我国结构设计中框架结构填充墙材料的选择不太完善,当框架结构可能遭受地震作用较小时(0.2g及以下),建议采用密度和刚度较大的填充墙材料;当框架结构可能遭受地震作用较大时(0.2g以上),建议采用密度和刚度较小的填充墙材料。本文以芦山中学框架结构教学楼为分析对象,对其进行多组速度脉冲地震动作用下弹性、塑性阶段时程分析,主要探讨多组不同强度速度脉冲地震动作用下框架结构最大地震响应与地震动强度指标间的线性相关性。分析表明,速度脉冲作用下,当框架结构受力处于弹性阶段时,地震动强度指标PGV和PGA与结构最大地震响应相关性较好;当框架结构受力处于塑性阶段时,地震动强度指标PGV和PGD与结构最大地震响应相关性较好。综合考虑时,近断层区域速度脉冲地震动强度指标PGV与框架结构最大地震响应线性相关性较好。分析目的主要是从有限元分析的角度表明目前我国近断层区域抗震分析和结构设计中选用PGA作为地震动强度指标不是很完善,建议选取地面峰值速度PGV作为地震动强度指标。
[Abstract]:Reinforced concrete frame structure is widely used in schools, hospitals, residential buildings, office buildings and other crowded buildings in China because of its flexible spatial arrangement, light weight, good integrity and easy industrialization construction. In the analysis of the whole structure, the influence of infilled wall on the surrounding frame is ignored, and the reduction factor of 0.6-0.7 is only calculated when the natural vibration period of the frame structure is multiplied [4]. In addition, the study shows that the area near the fault is the most severely damaged area under earthquake action, and affected by the directional effect of fault rupture, the velocity and position of ground motion in front of the rupture propagation are affected by the directional effect of fault rupture. At present, most scholars'researches on velocity pulse ground motion mainly focus on analyzing the relationship between pulse period and peak value and source parameters, as well as the failure mechanism of different types of structures [12] [13]. However, near-fault regional junction The selection of velocity pulse ground motion intensity index in structural seismic analysis needs further study. At present, the ground peak acceleration PGA [10] is the main seismic intensity index used in seismic analysis and structural design in China, but in recent years, the damage of structures in several major earthquakes indicates that PGA acts as earthquake under the action of velocity pulse ground motion in near-fault region. The dynamic strength index is not perfect. In this paper, taking the teaching building of Lushan Middle School as the analysis object, combining with the actual damage characteristics of the teaching building in the Lushan earthquake on April 20, 2013, the large-scale nonlinear finite element software ABAQUS is used to simulate the dynamic strength of the building, mainly discussing the frame structure with different density and stiffness filling wall materials. The analysis shows that the displacement of each floor of the frame structure with porous brick as filling wall is larger than that of the frame structure with sintered common brick as filling wall under low intensity earthquake. The main purpose of the analysis is to point out that the selection of filling wall materials for frame structures in China is not perfect at present, and the frame structures may be subjected to earthquakes. When the density and stiffness of the frame structure are small (0.2g or less), it is suggested to adopt filling wall materials with large density and stiffness; when the frame structure is likely to be subjected to large earthquake action (above 0.2g), it is suggested to adopt filling wall materials with small density and stiffness. The time history analysis of elastic and plastic stages mainly discusses the linear correlation between the maximum seismic response and the seismic intensity index of frame structures under pulsed ground motions of different intensity velocities. The correlation between PGV and PGD and the maximum seismic response is good when the frame structure is in plastic stage. The angle shows that PGA is not a perfect seismic strength index in seismic analysis and structural design of near-fault areas in China. It is suggested to select PGV as seismic strength index.
【学位授予单位】：中国地震局工程力学研究所
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU352.11;TU375.4
本文编号：2247524
[Abstract]:Reinforced concrete frame structure is widely used in schools, hospitals, residential buildings, office buildings and other crowded buildings in China because of its flexible spatial arrangement, light weight, good integrity and easy industrialization construction. In the analysis of the whole structure, the influence of infilled wall on the surrounding frame is ignored, and the reduction factor of 0.6-0.7 is only calculated when the natural vibration period of the frame structure is multiplied [4]. In addition, the study shows that the area near the fault is the most severely damaged area under earthquake action, and affected by the directional effect of fault rupture, the velocity and position of ground motion in front of the rupture propagation are affected by the directional effect of fault rupture. At present, most scholars'researches on velocity pulse ground motion mainly focus on analyzing the relationship between pulse period and peak value and source parameters, as well as the failure mechanism of different types of structures [12] [13]. However, near-fault regional junction The selection of velocity pulse ground motion intensity index in structural seismic analysis needs further study. At present, the ground peak acceleration PGA [10] is the main seismic intensity index used in seismic analysis and structural design in China, but in recent years, the damage of structures in several major earthquakes indicates that PGA acts as earthquake under the action of velocity pulse ground motion in near-fault region. The dynamic strength index is not perfect. In this paper, taking the teaching building of Lushan Middle School as the analysis object, combining with the actual damage characteristics of the teaching building in the Lushan earthquake on April 20, 2013, the large-scale nonlinear finite element software ABAQUS is used to simulate the dynamic strength of the building, mainly discussing the frame structure with different density and stiffness filling wall materials. The analysis shows that the displacement of each floor of the frame structure with porous brick as filling wall is larger than that of the frame structure with sintered common brick as filling wall under low intensity earthquake. The main purpose of the analysis is to point out that the selection of filling wall materials for frame structures in China is not perfect at present, and the frame structures may be subjected to earthquakes. When the density and stiffness of the frame structure are small (0.2g or less), it is suggested to adopt filling wall materials with large density and stiffness; when the frame structure is likely to be subjected to large earthquake action (above 0.2g), it is suggested to adopt filling wall materials with small density and stiffness. The time history analysis of elastic and plastic stages mainly discusses the linear correlation between the maximum seismic response and the seismic intensity index of frame structures under pulsed ground motions of different intensity velocities. The correlation between PGV and PGD and the maximum seismic response is good when the frame structure is in plastic stage. The angle shows that PGA is not a perfect seismic strength index in seismic analysis and structural design of near-fault areas in China. It is suggested to select PGV as seismic strength index.
【学位授予单位】：中国地震局工程力学研究所
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU352.11;TU375.4
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相关期刊论文 前2条
1 刘启方;袁一凡;金星;丁海平;;近断层地震动的基本特征[J];地震工程与工程振动;2006年01期
2 胡聿贤,周锡元;地震工程的跨世纪发展趋势[J];工程抗震;1999年01期
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