Investigation of the seismic response of high‐rise buildings supported on tension‐resistant elastomeric isolation bearings          下载免费PDF全文

Xilin Lu  Dong Wang  Shanshan Wang 《地震工程与结构动力学》2016,45(13):2207-2228

In many applications of seismic isolation, such as in high‐rise construction, lightweight construction, and structures with large height‐to‐width aspect ratios, significant tension forces can develop in bearings, raising concerns about the possible rupture of elastomeric bearings and the uplift of sliding bearings. In this paper, a novel tension‐resistant lead plug rubber bearing (TLRB) with improved tension‐resisting capabilities is developed and experimentally and numerically assessed. This TLRB consists of a common lead plug rubber bearing (LRB) and several helical springs. After describing the theory underlying the behavior of the TLRB, the mechanical properties of reduced‐scale prototype bearings are investigated through extensive horizontal and vertical loading tests. The test results indicate that TLRBs can improve the shear stiffness and tension resistance capacity even under significant tensile loads. A series of shaking table tests on scaled models of high‐rise buildings with different aspect ratios were conducted to investigate the dynamic performance of the TLRB and the seismic responses of base‐isolated high‐rise buildings. Three different cases were considered in the shaking table tests: a fixed base condition and the use of TLRB and LRB isolation systems. The results of the shaking table test show that (a) base‐isolated systems are effective in reducing the structural responses of high‐rise buildings; (b) an isolated structure's aspect ratio is an important factor influencing its dynamic response; (c) TLRBs can endure large tensile stresses and avoid rupture on rubber bearings under strong earthquakes; and (d) the experimental and numerical results of the responses of the models show good agreement. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Effects of seismic isolation on the seismic response of a California high‐speed rail prototype bridge with soil‐structure and track‐structure interactions          下载免费PDF全文

Yong Li  Joel P. Conte 《地震工程与结构动力学》2016,45(15):2415-2434

With the launch of the high‐speed train project in California, the seismic risk is a crucial concern to the stakeholders. To investigate the seismic behavior of future California High‐Speed Rail (CHSR) bridge structures, a 3D nonlinear finite‐element model of a CHSR prototype bridge is developed. Soil‐structure and track‐structure interactions are accounted for in this comprehensive numerical model used to simulate the seismic response of the bridge and track system. This paper focuses on examining potential benefits and possible drawbacks of the a priori promising application of seismic isolation in CHSR bridges. Nonlinear time history analyses are performed for this prototype bridge subjected to two bidirectional horizontal historical earthquake ground motions each scaled to two different seismic hazard levels. The effect of seismic isolation on the seismic performance of the bridge is investigated through a detailed comparison of the seismic response of the bridge with and without seismic isolation. It is found that seismic isolation significantly reduces the deck acceleration and the force demand in the bridge substructure (i.e., piers and foundations), especially for high‐intensity earthquakes. However, seismic isolation increases the deck displacement (relative to the pile cap) and the stresses in the rails. These findings imply that seismic isolation can be promisingly applied to CHSR bridges with due consideration of balancing its beneficial and detrimental effects through using appropriate isolators design. The optimum seismic isolator properties can be sought by solving a performance‐based optimum seismic design problem using the nonlinear finite‐element model presented herein. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

土工袋技术在市政沟槽回填中的应用研究   总被引：1，自引：0，他引：1  

刘斯宏  高军军  王子健  王柳江  胡晓平 《岩土力学》2014,35(3):765-771

市政工程中管线埋入地下采用的基本流程是先开挖沟槽,将开挖的原土作为渣土处理,待管线在沟槽中安放后再用二灰土石填埋沟槽,经夯实后铺设沥青或混凝土路面。为了有效利用沟槽开挖土、减少二灰土石用量,建议采用土工袋技术处理,即将沟槽开挖土装入土工编织袋后回填至沟槽中。阐述了土工袋技术原理,并依托南京市雨污分流工程,对用土工袋回填的沟槽进行了平板载荷试验、落锤式挠度检测和路面振动测试,评价土工袋沟槽的回填效果。结果表明：土工袋在提高沟槽承载力、减少沉降变形、削弱交通振动干扰等方面具有明显效果。土工袋避免弃土外运,减少了扬尘污染,不失为一种绿色、环保、经济的工程新技术。  相似文献   

基于景观孤岛化分析的传统地域文化景观保护模式——以江苏苏州市甪直镇为例   总被引：1，自引：0，他引：1  

王云才  韩丽莹 《地理研究》2014,33(1):143-156

在城镇化、现代化和商业化快速发展的今天,传统文化景观的破碎化已成为传统地域文化景观的重要空间特征和现象,破碎化直接催生了传统文化景观空间的孤岛化现象,直接影响着传统地域文化景观的整体性,成为传统文化景观整体性保护的重要障碍。本文以苏州市甪直镇为例,在分析区域特征及对当地居民进行问卷调查的基础上,通过构造孤岛化评价指数,评价甪直古镇传统文化景观的格局的综合特征和景观孤岛化现象、特征及形成过程。在传统文化景观孤岛化评价的基础上,通过确定保护圈层、构建文化景观遗产廊道和景观生态网络格局,实现传统文化景观空间的拓展、连接和传统文化景观与缓冲空间的有机复合,成为传统地域文化景观区域性整体保护的空间模式。  相似文献   

Scoping prediction of re-radiated ground-borne noise and vibration near high speed rail lines with variable soils     

《Soil Dynamics and Earthquake Engineering》2014

This paper outlines a vibration prediction tool, ScopeRail, capable of predicting in-door noise and vibration, within structures in close proximity to high speed railway lines. The tool is designed to rapidly predict vibration levels over large track distances, while using historical soil information to increase accuracy. Model results are compared to an alternative, commonly used, scoping model and it is found that ScopeRail offers higher accuracy predictions. This increased accuracy can potentially reduce the cost of vibration environmental impact assessments for new high speed rail lines.To develop the tool, a three-dimensional finite element model is first outlined capable of simulating vibration generation and propagation from high speed rail lines. A vast array of model permutations are computed to assess the effect of each input parameter on absolute ground vibration levels. These relations are analysed using a machine learning approach, resulting in a model that can instantly predict ground vibration levels in the presence of different train speeds and soil profiles. Then a collection of empirical factors are coupled with the model to allow for the prediction of structural vibration and in-door noise in buildings located near high speed lines. Additional factors are also used to enable the prediction of vibrations in the presence of abatement measures (e.g. ballast mats and floating slab tracks) and additional excitation mechanisms (e.g. wheelflats and switches/crossings).  相似文献   

Direct displacement loss assessment of existing RC buildings pre- and post-seismic retrofitting: A case study     

《Soil Dynamics and Earthquake Engineering》2014

The seismic retrofitting of a high-rise RC building, recently realized in Italy using the seismic isolation technique, is examined in terms of cost of the intervention (compared to the replacement cost of the building), seismic performances and expected benefits (compared to the building in the as-built configuration), expressed in terms of reduction of direct and indirect seismic losses in case of attainment of different limit states.In the paper, the comparison of the building performance before and after seismic retrofitting is performed in terms of Expected Annual Loss (EAL), applying a direct displacement-based loss assessment approach. The results show a considerable reduction of the EAL (approximately of 70%), passing from the as-built to the retrofitted configuration. The time needed to get the balance between costs of the intervention and benefits due to EAL reduction turns out to be of the order of 13 years.  相似文献   

安装粘弹性转角阻尼器的海洋平台—摇摆墙体系抗震性能分析     

张纪刚  江志伟 《地震研究》2014,37(3)

在海洋平台摇摆墙体系基础上,在摇摆墙底部的铰接点处安装一粘弹性转角阻尼器,进行被动消能结构振动控制,利用ANSYS进行地震荷载作用下的抗震性能验算,并对阻尼器的刚度和阻尼参数进行了分析。结果表明,在摇摆墙底部施加的转角阻尼器能显著降低结构的地震反应。  相似文献   

近车站地铁运行引起的环境振动的实验与分析     

屈迪  林皋  李建波  尹训强 《地震学刊》2014,(2):173-179

选取上海地铁交通9号线沿线近车站典型区段为对象,以基于LabVIEW2010开发平台的振动测试系统进行数据采集。根据现场实测数据,分析了地铁运行时隧洞中心线对应的地表处3个方向,以及距中心线不同距离地表处垂直地面方向的振动响应实况和振动特性及传播规律。结果表明,地面振动以垂直地表方向振动为主,振动幅值距离隧洞中心线越远越小,在15m左右存在放大区,且放大的敏感频率为15~25Hz。本次实验地点靠近9号线某车站,实验数值具有一定的典型性和特殊性,可为完善该领域的研究提供借鉴和参考。  相似文献   

非均质土中桩端扩散虚土桩法的桩基纵向振动研究     

杨冬英  丁海平 《岩土力学》2014,35(Z1):311-318

根据桩端土应力扩散的规律,建立了桩端扩散虚土桩模型。基于该模型对非均质土中桩-土纵向耦合振动进行研究。利用复刚度传递多圈层平面应变模型,得到桩与虚土桩桩侧土的剪切复刚度。结合边界条件、初始条件和连续条件,对扩散虚土桩和实体桩动力方程从底层往顶层逐层进行求解,得到桩顶动力响应的频域解析解和时域半解析解。通过对桩端扩散虚土桩扩散角、扩散层厚度、桩侧土非均质性和桩长的影响进行计算分析,得到基于扩散虚土桩法桩-土纵向振动响应特性。研究结论可为桩基础动力设计和动态检测提供理论依据。  相似文献   

小波降噪与粒子群优化综合回归爆破震动参数     

张乐文  王洪波  邱道宏  孙怀凤  孙子正  丁万涛 《岩土力学》2014,35(Z2):338-342

爆破震动测试得到的数据常常具有较大的离散性,采用剔除错误数据和小波降噪对爆破震动检测数据进行预处理,以标准残差平方和作为爆破振动实测数据与萨道夫斯基公式拟合值偏差大小的判断依据,应用小波降噪对实测数据进行处理的方法,优化了粒子群算法对萨道夫斯基公式中的k和 的回归分析。研究结果表明,小波降噪和粒子群优化算法结合使用,能够较真实地反映爆破震动测试的真实情况,从而提高了对爆破震动测试模拟的精度。研究结果对爆破振动测试理论和工程实践具有一定的参考价值。  相似文献