桩基多层框架结构对水平地震荷载的响应

通过对建筑在桩基上的多层框架结构的上部结构、桩基础、地基共同工作时的运动分析,建立结构系统的运动微分方程.采用桩基承台的水平位移及转角为广义坐标,将多自由系统的动力学问题转化为二自由度系统问题求解.在求系统运动微分方程基础上,得到承台的水平位移和转角.从而求得上部结构各层的位移、速度、加速度、惯性力及上部结构对基底的剪力和弯矩.     

地裂缝环境下钢筋混凝土框架结构的地震响应

为了研究地裂缝场地钢筋混凝土（RC）框架结构的地震响应规律,采用ABAQUS有限元分析软件,建立地裂缝场地土与结构体系的三维数值模型. 将计算结果与跨地裂缝结构模型试验结果进行对比,验证了数值模拟方法的可行性. 通过对框架结构位移角、层间剪力、结构总水平地震作用的定量分析,获得地裂缝对框架结构动力响应的影响规律及影响范围. 研究结果表明,地震作用在地裂缝场地表现出的非一致性加重了上部结构的损伤程度,结构中间跨的构件及节点破坏尤其严重,上盘结构的裂缝长度和宽度更大. 框架结构跨越地裂缝是最不利的布置形式,动力响应尤为剧烈,在结构设计时应尽量避免. 近地裂缝场地上盘结构的响应程度大于下盘,表现出“上、下盘效应”,在上盘0~20 m和下盘0~15 m范围内,框架结构破坏严重,在上盘30 m和下盘20 m外,结构反应显著减小.     

框架结构的弹塑性地震响应时程分析

在总结钢筋混凝土框架结构其各种计算模型的基础上，推导了单杆件的弹塑性刚度矩阵，并采用空间协同分析的方法对框架结构在地震作用下的弹塑性响应进行了计算和分析，开发了计算框架结构动力特性，框架结构在地震作用下弹性响应，框架结构在地震作用下弹塑性响应的计算机程序。     

多层框架结构计算的几个问题

对多层框架结构计算中梁端弯矩调幅，地震组合与非地震组合的比较，风荷载作用下柱的剪力和梁的最大弯矩等问题进行了探讨。     

多层框架结构电梯井的设计

本文根据大量工程实践经验和理论研究,综合提出了多层框架结构电梯井的设计方法     

多点输入下球面网壳结构地震响应研究

以某球面尾盖网壳结构为例,对其进行多点输入下的地震响应分析,并与单点输入下的动力时程计算结果进行对比分析,探讨了不同的视波速对于球面网壳表面应力分布的影响、多点输入与单点输入下结构响应的差异以及不同视波速对结构响应及节点位移时程的影响,归纳出多点输入下结构的响应特点,得到行波效应对结构的影响规律.     

多点输入下球面网壳结构地震响应研究

以某球面屋盖网壳结构为例,对其进行多点输入下的地震响应分析,并与单点输入下的动力时程计算结果进行对比分析,探讨了不同的视波速对于球面网壳表面应力分布的影响、多点输入与单点输入下结构响应的差异以及不同视波速对结构响应及节点位移时程的影响,归纳出多点输入下结构的响应特点,得到行波效应对结构的影响规律。     

多层砌体填充墙框架结构的非线性有限元分析

采用ABAQUS软件中非线性分析常用实体单元C3D8R模拟混凝土框架和砌体填充墙,杆单元T3D2模拟钢筋,弹簧单元SPRINGA模拟框架和填充墙体的连接,建立了有限元非线性分析模型。对4榀单跨双层和1榀单跨单层砌体填充墙钢筋混凝土框架结构模型进行了非线性有限元分析,同时将计算值与试验值进行了比较,论证了有限元分析的可行性,进一步分析了砌体填充墙对框架结构性能的影响。     

层间隔震框架结构地震反应动力分析

地震给人们带来的生命安全以及财产的损失是不可估量的。想要减少这种损失,需要发展抗震结构的建筑,减地震发生时带来的损失。而层间隔震框架结构就是最新发展起来的一种隔震结构。它和普通的抗震结构比起来减震性能比较好,有着较大的优越性。本文通过建立模型,利用ANSYS建立起普通的抗震结构以及层间隔离结构然后进行动力特性以及地震相应的分析,通过比较了解层间隔震框架结构相对于普通隔震体系的优异性。     

考虑河谷地形影响的多层框架结构地震易损性

针对杭嘉湖地区冲淤河谷地形分布广泛的特殊情况,结合当地土体工程特性和抗震设防区划设置现状,基于动力时程分析以及概率统计方法,给出适用于杭嘉湖地区多层框架结构的地震易损性曲线,对比不考虑地基、均质地基和河谷地基条件下多层框架结构的动力分析结果. 研究土-结动力相互作用以及局部河谷地形对结构动力响应和易损性的影响,考察房屋结构位于河谷不同位置处的差异. 结果表明,土-结动力相互作用对结构的动力分析结果有显著影响,不考虑土-结动力相互作用将低估房屋结构变形,易损性性能水平超越概率偏低,偏差可达7.9%,结果偏于危险;局部河谷地形对地震波独特的聚焦效应会增大结构变形,地震易损性超越概率与均质地基相比增幅可达12.1%,且河谷不同位置处的聚焦效果不同,在选取的地震波输入下表现为房屋结构距河谷中心越近,结构变形越大、地震易损性超越概率越大.     

Performance-based seismic financial risk assessment of reinforced concrete frame structures

Engineering facilities subjected to natural hazards (such as winds and earthquakes) will result in risk when any designed system (i.e. capacity) will not be able to meet the performance required (i.e. demand). Risk might be expressed either as a likelihood of damage or potential financial loss. Engineers tend to make use of the former (i.e. damage). Nevertheless, other non-technical stakeholders cannot get useful information from damage. However, if financial risk is expressed on the basis of probable monetary loss, it will be easily understood by all. Therefore, it is necessary to develop methodologies which communicate the system capacity and demand to financial risk. Incremental dynamic analysis (IDA) was applied in a performance-based earthquake engineering context to do hazard analysis, structural analysis, damage analysis and loss analysis of a reinforced concrete (RC) frame structure. And the financial implications of risk were expressed by expected annual loss (EAL). The quantitative risk analysis proposed is applicable to any engineering facilities and any natural hazards. It is shown that the results from the IDA can be used to assess the overall financial risk exposure to earthquake hazard for a given constructed facility. The computational IDA-EAL method will enable engineers to take into account the long-term financial implications in addition to the construction cost. Consequently, it will help stakeholders make decisions.     

框架复合隔震结构地震响应分析

以某六层框架复合隔震结构为例,运用有限元分析程序,对一般抗震结构、纯夹层橡胶隔震结构和复合隔震结构三种方案进行了地震作用下的动力响应分析,从分析结果得出纯橡胶隔震结构和复合隔震结构有明显的隔震、减震效果。复合隔震结构从结构的造价和抗震安全度更能体现其优越性,这对复合隔震结构的设计和分析有一定的意义。     

Nonlinear seismic response analysis of reinforced concrete tube in tube structure

Super-highly reinforced concrete tube in tube structure is a developing structure system of high-rise building. The more reasonable derivation process of the multi-vertical-line-element model stiffness matrix is given. On the premise of pointing out the problems of present multi-spring element model, combined with present multivertical-line-element model for analyzing on shear wall, the model is expanded to spatial one, and the stiffness matrix of which is derived. Combined with hysteretic axial model and hysteretic shear model, it is suitable for columns, wall limbs and beams with all kinds of section form. Some examples are calculated and compared with test results, which shows that the models have relatively good accuracy. On the base of the experimental phenomenon and failure mechanism for tube in tube structure specimen, nonlinear seismic responses analysis program on the basis of the advantaged element model for tube in tube structure is developed. Calculation results are in good agreement with those of the pseudo-dynamic tests and the failure mechanism can be well reflected. Foundation item: Project supported by the National Doctorate Program Found of State Education Ministry of China     

不同连接构造的预制拼装桥墩地震响应分析

为了研究预制拼装桥墩的连接构造能否形成可靠的传力机制及其抗震性能,基于一组预制拼装桥墩拟静力试验,采用ABAQUS软件建立了试验桥墩的有限元模型并结合试验结果验证其有效性。在此基础上,分析现浇、波纹管浆锚连接和榫头+波纹管连接的预制拼装桥墩的地震动力响应。之后,进一步研究轴压比和配筋率对新型带榫头构造的预制拼装桥墩地震动力响应的影响规律。结果表明：在结构形式和地震作用均相同的条件下预制拼装桥墩和现浇桥墩的动力响应结果基本一致。有榫头构造较平面接缝的预制拼装桥墩的位移响应、残余位移、塑性损伤程度更小,榫头构造提高了预制拼装桥墩的抗震性能。通过参数分析发现,轴压比越大,桥墩的位移响应以及塑性损伤程度越大,剪力响应和地震耗能更大;纵筋配筋率越大,桥墩的位移响应以及塑性损伤程度越小,剪力响应越大,但在1%～2%之间,对地震耗能的影响不显著。     

Nonlinear seismic response analysis of reinforced concrete tube in tube structure

Super-highly reinforced concrete tube in tube structure is a developing structure system of high-rise building. The more reasonable derivation process of the multi-vertical-line-element model stiffness matrix is given.On the premise of pointing out the problems of present multi-spring element model, combined with present multivertical-line-element model for analyzing on shear wall, the model is expanded to spatial one, and the stiffness matrix of which is derived. Combined with hysteretic axial model and hysteretic shear model, it is suitable for columns,wall limbs and beams with all kinds of section form. Some examples are calculated and compared with test results,which shows that the models have relatively good accuracy. On the base of the experimental phenomenon and failure mechanism for tube in tube structure specimen, nonlinear seismic responses analysis program on the basis of the advantaged element model for tube in tube structure is developed. Calculation results are in good agreement with those of the pseudo-dynamic tests and the failure mechanism can be well reflected.     

不同设防烈度下RC框架结构的抗侧向倒塌能力

地震作用下建筑结构的抗侧向倒塌能力是抗震性能评价的基础。选取4个结构整体性能参数作为结构抗侧向倒塌能力评价指标,分别为结构强屈比、超强系数、延性系数和延展系数。按中国现行规范设计了12个RC框架结构,考虑侧向力分布形式和设防烈度的影响,采用Pushover方法对结构进行计算,并根据能力曲线和结构整体性能参数对结构抗侧向倒塌能力进行评价。结果表明：结构整体性能参数能从强度储备和变形能力两个方面对结构抗侧向倒塌能力进行分析;随着设防烈度和结构高度的提高,侧向力分布形式对结构抗侧向倒塌能力的影响增大;设防烈度对结构强屈比和结构延展系数的影响较小,对结构超强系数和结构延性系数的影响较大;随着设防烈度的提高,结构超强系数减小,而结构延性系数增大。     

Influence of seismic input on response of Baihetan arch dam

The dynamic responses of the arch dam including dam-foundation-storage capacity of water system, using two different earthquake input models, i.e. viscous-spring artificial boundary （AB） condition and massless foundation （MF）, were studied and analyzed for the 269 m high Baihetan arch dam under construction in China. By using different input models, the stress and opening of contraction joints （OCJs） of arch dam under strong shock were taken into consideration. The results show that the earthquake input models have slight influence on the responses including earthquake stresses and openings of contraction joints in different extents.