【作者】 魏陆顺；

【导师】 周福霖；

【作者基本信息】 哈尔滨工业大学 ， 防灾减灾工程及防护工程， 2009， 博士

【摘要】 1994年美国北岭地震、1995年日本阪神地震、1999年土耳其伊兹米特地震、1999年中国台湾集集地震和2008年中国汶川地震,均产生了重大的人员伤亡和结构破坏。隔震是一种代表性的减震技术,在新建工程和旧房改造中已广泛应用。隔震通过延长结构自振周期、增加阻尼而避免与短周期为主的地震发生共振。最近,为减小结构地震响应,隔震技术也在柔性结构中得到应用。至今,在城市地铁和交通运输线旁边建造了许多建筑,列车的轮轨接触产生的噪声和振动通过地基传到附近的建筑,因而降低了居民的生活质量。隔震技术虽然能有效地减小水平地震反应,但无竖向减振功能。为降低结构的地震和振动响应,新型的三维隔震(振)系统有待研究和开发。目前,我国在减振领域进行了丰富的研究工作,大量的论文和文章重点关注理论研究和隔震改良,然而,在隔震设计及应用问题等却缺乏重视。本文对隔震技术应用有关方面进行了研究,包括:(1)推导了隔震结构的谐振响应,研究了系统参数对响应的影响,分析了反应过程; (2)设计了一新型三维隔震(振)支座,对该支座进行了试验验证。对弹性滑板支座进行了试验研究;(3)对5层钢框架模型进行了隔振对比试验、纯滑移隔震和组合隔震的振动台试验研究;(4)采用简化模型对试验结果进行了仿真分析;(5)研究并探讨了近断层隔震结构的地震反应和隔震设计;(6)对隔震设计谱进行了修正,提出了等效线性预测方法;(7)介绍了组合隔震技术、三维隔震(振)技术的工程应用。对于隔震分析,掌握结构最大地震反应规律比了整个反应过程更为重要。出于上述目的,第2章推导了单自由度隔震结构模型稳态反应,对于刚性摩擦滞回模型,在自由振动和稳态反应基础上,探讨了系统的反应整体过程。得出了隔震结构的最大反应与输入的最大速度、隔震结构周期和频比相关的结论。第3章介绍了本文研究的隔震和隔振支座,并进行了试验研究。三维隔震(振)支座包括联接板、竖向隔振体和水平隔震支座。竖向隔振体和水平隔震支座刚度小,可使隔震(振)结构在竖向和水平向的基频远离环境振动和地震的主要频率。对三维支座进行了验证试验。另外,弹性滑板支座是组合隔震技术中重要的隔震支座。本章还对弹性滑板支座进行了压缩试验、压剪试验、压力相关性能试验和频率相关性能试验研究。探讨了新型的聚氨酯橡胶支座在隔震(振)中的应用。纯滑移隔震技术在国内有许多工程应用,而该技术存在罕遇地震中隔震层有很大位移、上部结构产生扭转反应和地震后存在较大的不可恢复位移等缺陷。第4章中,为研究纯滑移隔震性能,进行了一维、二维和三维的地震模拟振动台试验。试验采用5层钢框架模型,两方向高宽比分别为2.5和5,尺寸相似比为1/4,隔震层由4个直径100 mm的弹性滑板支座构成。对试验结果进行了数值模拟对比分析。试验与数值模拟结果证明了纯滑移隔震技术存在的缺陷。试验还表明,虽然模拟地震试验中,单个支座的轴力变化大,水平性能不稳定,但隔震层的竖向荷载变化相对较小,隔震层的整体滞回性能稳定。所以,采用弹性滑板支座和不承压的橡胶支座的组合隔震技术是解决纯滑移隔震技术缺陷的有效方法之一,也为较经济的隔震技术应用提供了选择。第5章对5层钢框架模型进行了组合基础隔震振动台试验研究。隔震系统包括4个低硬度铅芯橡胶隔震支座和2个弹性滑板支座,以不同特点隔震支座组合使用达到降低上部结构反应的目的。振动台试验和时程分析结果表明,组合隔震技术能有效减小上部结构响应,且隔震层变形在安全范围之内。第6章对近断层隔震结构的地震反应进行了理论和试验研究。采用了单周正弦波对速度脉冲记录进行了模拟,并采用第2章的解析法计算了脉冲模型的反应谱。结果表明,大幅值速度脉冲会导致隔震层产生过大的变形。对于近断层隔震结构设计,本文提出了双滑动面的滑板支座和弹性限位滑板支座方案。与国外规范相比,比如美国IBC2003规范,隔震设计时,我国隔震设计规范主要存在以下两方面的不同,一,反应曲线的长周期段定义为直线段,其结果是速度谱是直线上升;二,在相似的场地类型,场地特征周期较国外的短。依据基岩周期相同和真实地震记录反应谱在长周期段速度谱是恒定的事实,在本文第7章中建议采用修正系数1.6对现规范的场地周期进行修正。对于隔震设计,本文建议1阶模态的响应采用恒定的速度谱计算,其余的振型质量响应采用恒定的加速度谱进行计算。第8章介绍了组合隔震技术的工程应用,并对三维隔震(振)技术工程应用进行了现场实测。对比测试结果表明,隔振系统对隔振效果显著。更多还原

【Abstract】 The 1994 Northridge earthquake in the United States, the 1995 Kobe(Hyogo-Ken Nanbu) earthquake in Japan, the 1999 Izmit earthquake in Turkey, the 1999 Chi-Chi earthquake in Taiwan, China and 2008 Wenchuan earthquake in China, all caused significant loss of lives and damage to civil engineering structures. Seismic isolation, as a typical means of response control technology, has been widely used in both new and existing buildings to protect from the devastating effects of earthquakes. The concept of isolation is to prolong natural period and provide higher damping level to traditional structure to avoid resonance with the relatively short period components dominant in earthquake ground motions. Recently, seismic isolation has been utilized in more flexible structures to reduce acceleration or displacement response.Today, many buildings have been constructed near subways or other traffic facilities in inner city areas of the world. Transportation systems generate noise and vibration by the wheel-rail contact of the trains, which is transmitted through the ground and the foundations into the neighboring structures and reduce the quality of life of the people living in. Although seismic isolation systems are effective in reduce the responses of horizontal vibrations such as earthquakes, the systems are typically not effective in control of the vertical vibrations resulted from traffic operations. To reduce building responses towards seism and transportation vibration, a special 3D isolation system is necessary to investigate.Number of studies in the fields of response control and seismic isolation have been conducted in China. Many papers and dissertations have shed light on the theory research and development of seismic isolation, however, with less emphasis on the problems of design and application of the technologies in the daily practice of structural engineering. This dissertation represents comprehensive experimental and analytical study of base isolation technology for practical application in civil engineering, including following aspects: (1) Inferring the isolation responses under the sinusoidal wave by closed-analysis method and studying on the influences of system parameters and the entire response process. (2) Designing an innovative 3D isolator, and conducting the verifying tests of the 3D isolator and the routine and dependence tests of elastic sliding bearing. (3) Completing of the shaking table tests of a five-storey steel structure model, including vibration isolation comparison tests, pure sliding isolation tests and combined base isolation tests. (4) Proposing a simplified numerical model and comparing the simulation results and tests results. (5) Studying seismic isolation response under near-fault earthquake and discussing the means of seismic isolation design. (6) Revising the seismic isolation design response spectrum and the site characteristic period and establishing the equivalent linear forecast method. (7) Introducing the engineering application of the combined base isolation and the three-dimensional seismic and vibration isolation techniques and presenting the site test of vibration isolation.For seismic isolation building, it’s more important to master the law of the maximum responses than to understand the process of seismic reactions. For the purpose, in Chapter 2, the steady-state response of single-degree-of-freedom system with isolation devices are derived. Considering the free vibration and steady-state response of rectangular hysteretic model, the entire response process are discussed. Draw the conclusion that the maximum response of isolation building are correlated with the maximum velocity of input wave and the period of isolation layer and the frequency ration of input to isolated building.In Chapter 3, seismic isolation and vibration isolation devices are introduced and tested. The 3D isolator is composed of the connecting plate, vertical rubber pad and horizontal rubber bearing. The vertical rubber pad and horizontal rubber bearing have very low stiffness, and both vertical and horizontal natural frequencies of the isolated building can be designed far from metro train and earthquake main frequency to insulate both environment vibration and seism. The verifying tests of the 3D isolator were carried out. Additionally, the elastic sliding bearing is a key isolator to combined base isolation technique. In this Chapter, compression test, compressive-shear test, compressive force dependence of horizontal properties and frequency dependence of horizontal properties test of elastic sliding bearings were conducted. The polyurethane rubber isolator applied in seismic and vibration isolation was discussed herein.In China, some buildings were isolated by pure sliding isolation technique, thus the large residual displacements, super-structure rotation response and large isolation deformation are the shortcomings of the isolation system. In Chapter 4, one, two and three-dimensional shaking table tests are carried out to investigate the performance of the pure sliding isolation system. A 5-story steel frame model with aspect ratios of 2.5 and 5 had a length scale of 1/4. The isolation layer contents four 100mm-diameter elastic sliding bearings. Dynamic response analysis was conducted to simulate the test results. Test and analysis results proved the shortcomings of the system. Although the single isolator vertical load change large and the horizontal properties is lack of physical stability, the isolation layer axial loads were change small, and the hysteresis loop of isolation system is stable. Therefore, the combined system of elastic sliding bearings uplifting super-structure and rubber bearings without vertical load is considered one of the measures to develop the pure sliding isolation technique. This gives a chance to build the most economical isolated building.Tri-axial earthquake simulator testing of a five-storey steel structure model with combined base isolation system was conducted in Chapter 5. The system includes 4 lower hardness lead rubber bearings and 2 elastic sliding bearings, and the merits of different seismic isolation devices can be applied to reduce seismic reaction of superstructure. Both the shaking table test results and time history analysis results show that the combined base isolation system can effectively reduce the superstructure reaction and the deformation of isolation layer and greatly improve the safety of the structure.In Chapter 6, seismic analysis of base-isolated structures subjected to near-fault ground motions was analytically and experimentally studied. The velocity pulse motions were simulated by one cycle sinusoidal wave, and the response spectra of the pulse model were calculated by analysis method, which studied in Chapter 2. it is illustrated that the large velocity pulse caused very large deformation of isolation layer. The sliding bearing with two sliding plate and Sliding bearing with polyurethane elastomer were presented for seismic isolation design in near-fault region.As for Chinese seismic design code, there are two aspects different from foreign design code for seismic isolation design, such as IBC2003 code. First, the design response spectrum curve in long period portion is defined by straight line and results the spectrum velocity additionally increased. Secondly, at the similar site class, the site characteristic period is much shorter than foreign code. According to periods are identical at the bedrock and the fact that real earthquake spectrum with a uniform velocity portion in the longer-period range, the site characteristic periods have been revised by a coefficient 1.6, as shown in Chapter 7. For seismic isolation design, this dissertation suggested that calculating the 1st mode response by uniform velocity spectrum and the rest mode mass response by uniform acceleration spectrum.In addition, Chapter 8 introduces the application of the combined base isolation technology and 3D isolator. An apartment building employing the isolation technology on a platform of subway is also presented. The in-situ tests of isolated building and non-isolated building were carried out. The comparative test results show that the vibration isolation system is effective in reducing building responses in high frequency domain.更多还原