周至井气压系数的变化特征及其与地震的关系

主要采用周至井水位、气压的时值,通过高阶差分回归拟合水位、气压的相关系数与气压系数。并对采用不同滑动步长、不同差分计算出不同时段内的气压系数进行了分析对比,比较了其异同。同时也探讨了相关系数和气压系数与地震的关系。     

地震作用下曲线梁桥结构响应及敏感性分析

为研究不同设计参数对曲线梁桥地震响应的影响以指导结构抗震设计,对不同支承约束曲线梁桥地震响应及地震需求敏感性进行分析。采用增量动力分析（IDA）方法对比分析了不同支承约束曲线梁桥的结构地震响应变化趋势;采用Tornado图形法对不同结构参数影响程度进行了排序,找出了对结构地震需求影响显著的参数。结果表明:采用板式橡胶支座桥梁因支座易发生滑移而导致上部结构位移较大,但降低了下部结构响应,设置固定墩后,下部结构损伤显著增加;对于采用板式橡胶支座和铅芯橡胶支座的曲线梁桥,墩高及跨径对墩底曲率需求影响较大,而对于固定墩为墩梁固结形式和采用盆式橡胶支座的曲线梁桥,跨径及跨数对墩底曲率需求影响较大;对于采用不同支承约束的曲线梁桥,墩高和曲率半径对桥台位移需求影响较大,仅次于地震动参数PGA。     

黏性阻尼与复阻尼对钢筋混凝土框架结构地震响应影响的分析

本文讨论了利用黏性阻尼和复阻尼模型求解结构动力响应的方法;按相同的阻尼比,分别采用复阻尼模型和黏性阻尼模型计算了两个框架结构在不同地震波作用下的响应,并将结果进行对比,分析了两种不同的阻尼模型对结构动力响应的影响。结果表明,采用不同类型的阻尼对结构响应影响很大。     

西宁地震台数字地震震级对比研究

采用西宁台数字地震仪所确定的地震震级(Ms)与中国地震台网中心确定的震级(Ms)进行对比研究,得出了西宁地震台震级(Ms)的台基校正值,并对不同震级和不同区域地震的震级偏差及原因进行了初步分析.     

山西运城市城区主要桥梁的震害预测

采用经验统计法对山西省运城市的4座主要桥梁进行了震害预测计算,给出了4座桥梁的震害预测结果。认为,4座桥梁的破坏程度不同主要是由于桥主跨长度、桥墩高度、支座形式不同及在计算中采用的系数不同引起的,运城市桥梁的破坏程度较低,在遭遇Ⅷ度地震破坏时,中等以上破坏程度的桥梁占25%。     

青海数字遥测台网地震监测能力评估

青海数字遥测地震台网由30个子台组成,全部采用速度记录方式。用速度震级公式对各子台不同震级所能控制的距离进行了计算,得到台网对不同震级地震的监测范围。     

某大型复杂结构地震响应与控制研究

针对某大型复杂结构的地震响应及控制策略进行了研究。首先,建立该结构的整体有限元模型,采用Ritz向量法对结构进行模态分析,研究该复杂结构的振动特性,基于位能加权平均法求解了该复杂结构等效阻尼比;随后,研究了不同布置型式下粘滞消能支撑的受力特点和计算模型;最后.对该结构进行减振设计,分析了不同消能支撑布置形式下的减振效果。结果表明,采用消能减震装置能有效降低复杂结构的地震响应,且并不改变结构体型;同等减震效果前提下,采用人字形支撑比采用斜撑更为经济。本文工作可供类似的大型复杂结构减震设计参考和借鉴。     

华北块体中等地震活动平静特征

采用累计频度方法,对华北活动地块Ms≥5．5地震前中等地震聚集活动区的地震做了时空扫描,并对平静现象进行了定量分析,结果表明：对各Ⅱ级活动地块采用不同的扫描方法．在强震前都表现出明显的增强、平静过程,平静的时间长短与所给定的构造区域有关。本文给出了华北3个Ⅱ级活动地块的发震模式。对各活动地块分别进行了R值检验,表明3个活动地块采用不同的发震模式均具有较高的预报效能。     

随机振动功率谱复现迭代算法的研究

采用功率谱复现迭代算法,依据系统的频率特性,对驱动信号进行迭代补偿,使得系统的响应谱能够高精度地复现期望谱。基于对影响随机振动功率谱复现精度因素的分析,提出在不同频段采用不同迭代步长的驱动谱迭代算法,给出了算法的程序框图,并通过试验验证了算法的有效性。     

近场地震波最大反应到时的统计性研究

本文通过对地震反应谱的数值计算,以各种不同频率的最大反应到时为样本进行概率统计,给出了近场地震波不同频率的最大反应到时谱。为采用时程分析法进行结构抗震计算时持续时间的选取提供了依据。     

立式储液罐地震破坏快速评估方法

本文采用大型有限元程序ANSYS对立式储液罐的地震反应进行了非线性数值分析,考虑了罐体和内部液体的相互作用,得到了3个不同容积的储罐,在不同峰值的地震动时程输入下的反应结果。结合地震灾害中立式储罐的地震破坏现象和特点,以及现有的立式储罐地震破坏预测方法,提出了立式储罐的地震破坏快速评估方法。     

Seismic fragility of base-isolated water storage tanks under non-stationary earthquakes

Seismic fragility curves for fixed-base and base-isolated liquid storage tanks are developed under non-stationary earthquakes, and their seismic performance are compared. The correlation between different earthquake intensity measure (IM) parameters and peak response quantities of the base-isolated liquid storage tanks are investigated. The failure criteria are chosen based on (1) the elastic buckling strength of the tank wall, which is defined in terms of critical base shear and critical overturning moment, and (2) in terms of the critical isolation displacement. The uncertainty involved is considered in the earthquake characteristics. Non-stationary earthquake ground motions are generated using Monte Carlo (MC) simulation. Influence of the isolator characteristic parameters and modeling approaches on the seismic fragility of the base-isolated liquid storage tanks is also investigated. Peak ground acceleration is found to be the well correlated IM parameter with the peak response quantities of the base-isolated liquid storage tanks. Substantial decrease in the seismic fragility of the base-isolated liquid storage tanks is observed as compared to the fixed-base tanks. Significant influence of the isolator characteristic parameters on the seismic fragility of the base-isolated liquid storage tanks are reported in the present study.     

大型储液罐摩擦摆基底隔震控制分析

针对弹性钢制圆柱储液罐,基于Haroun-Housner模型,将连续流体质量等效为3种集中质量,分别为:对流质量、脉冲质量和刚性质量,与这些集中质量连接的相应刚度取值依赖于储罐壁和流体质量.在水平地震激励下,在储罐底部加摩擦单摆支座,给出了简化的液体 - 储罐-隔震支座的力学分析模型,建立了摩擦摆支座基底隔震体系的振动控制方程,并利用Newmark逐步积分法对控制方程进行了数值求解,研究了摩擦摆支座基底隔震的储液罐地震反应,验证了FPB隔震的有效性.     

地下储液罐抗爆炸地冲击作用的流固耦合有限元分析

储液罐的抗震性能虽然得到了较为深入的研究,但对其抗爆炸产生的地冲击作用的研究还十分罕见。本文通过建立流固耦合的数值分析模型,研究爆炸地冲击作用下地下立式储液罐的动力特性,包括储液晃动波高、罐壁的应力和应变、底板的提离和浮放储液罐的“象足”变形产生原因及破坏机理等。研究结果表明,储液罐在爆炸地冲击荷载和地震荷载作用下的动力响应有明显区别,地震荷载作用下的储液罐抗震验算方法不适用于爆炸地冲击荷载。     

储液罐地震安全问题研究综述

储液罐的地震安全问题主要涉及到抗震设防水准的确定和储液罐本身的抗震设计.本文简要介绍了储液罐的震害现象及机理,对比分析了中国、美国、欧洲等国家有关储液罐抗震设防水准,并阐述了国内外学者在储液罐抗震计算方面所做的工作及获得的成果,同时还指出了存在的问题和今后研究工作的发展趋势.     

Seismic isolation of rigid cylindrical tanks using friction pendulum bearings

Storage tanks are vulnerable to earthquakes, as numerous major earthquakes have demonstrated. The trend of recent revisions to make seismic design criteria for large‐scale industrial storage tanks increasingly stringent has made development of cost‐effective earthquake‐resistant design and retrofit techniques for industrial tanks imperative. This study assesses the feasibility of seismic base isolation for making liquid‐filled storage tanks earthquake resistant. The sliding‐type friction pendulum seismic (FPS) bearings are considered rather than the elastomeric bearings because the dynamic characteristics of an FPS‐isolated tank remain unchanged regardless of the storage level. This work has devised a hybrid structural‐hydrodynamic model and solution algorithm, which would permit simple, accurate and efficient assessment of the seismic response of rigid cylindrical storage tanks in the context of seismic isolation. Extensive numerical simulations confirm the effectiveness of seismic base isolation of rigid cylindrical tanks using FPS bearings. Copyright © 2001 John Wiley & Sons, Ltd.     

立式钢制储罐基于地震损伤性能的抗震设计方法

针对立式钢制储罐在强烈地震作用下会产生不同程度的损伤的特点，遵循抗震设计规范的“小震不坏，中震可修，大震不倒”的抗震设计原则，结合三水准烈度，提出了储罐的地震损伤性能目标，并给出了基于地震损伤性能的抗震设计方法。所提出抗震设计方法，更加准确地考虑了储罐的提离问题。     

Sloshing behaviours of rectangular and cylindrical liquid tanks subjected to harmonic and seismic excitations

A numerical and experimental study on the sloshing behaviours of cylindrical and rectangular liquid tanks is addressed. A three‐dimensional boundary element method for space with the second‐order Taylor series expansion in time is established to simulate the sloshing phenomenon and its related physical quantities inside a liquid tank subjected to horizontal harmonic oscillations or recorded earthquake excitations. The small‐scale model experiments are carried out to verify some results of numerical methods in this study. The comparisons between numerical and experimental results show that the numerical method is reliable for both kinds of ground excitations. Finally, the water wave and the base shear force of a rectangular tank due to harmonic excitation are also presented at different frequencies. A huge cylindrical water tank subjected to a recorded earthquake excitation is used for application and discussion. Copyright © 2007 John Wiley & Sons, Ltd.     

Response of tanks to vertical seismic excitations

A method for analyzing the earthquake response of elastic, cylindrical liquid storage tanks under vertical excitations is presented. The method is based on superposition of the free axisymmetrical vibrational modes obtained numerically by the finite element method. The validity of these modes has been checked analytically and the formulation of the load vector has been confirmed by a static analysis. Two forms of ground excitations have been used: step functions and recorded seismic components. The radial and axial displacements are computed and the corresponding stresses are presented. Both fixed and partly fixed tanks are considered to evaluate the effect of base fixation on tank behaviour. Finally, tank response under the simultaneous action of both vertical and lateral excitations is calculated to evaluate the relative importance of the vertical component of ground acceleration on the overall seismic behaviour of liquid storage tanks.     

必须重视大型石油储罐的抗震问题

地震灾害是各种自然灾害中最大的一种灾害，而大型石油储罐则是石油化工设备中震害最大设备，因此必须重视大型油罐的抗震问题，本文从油罐的几何形状的荷载特征等方面说明了油罐震害之所以特别大的主要原因；指出了油罐的主要震害；并从四个方面说明了油罐的抗震理论是非常复杂的。