A note on the useable dynamic range of accelerographs recording translation   总被引：2，自引：0，他引：2  

M. D. Trifunac  M. I. Todorovska 《Soil Dynamics and Earthquake Engineering》2001,21(4)

Since the late 1970s, the dynamic range and resolution of strong motion digital recorders have leaped from 65 to 135 dB, opening new possibilities for advanced data processing and interpretation. One of these new possibilities is the calculation of permanent displacement of the ground or of structures, associated with faulting or with non-linear response. Proposals on how permanent displacements could be recovered from recorded strong motion have been published since 1976. The analysis in this paper concludes that permanent displacements of the ground and of structures in the near-field can be calculated provided all six components of strong motion (three translations and three rotations) have been recorded, and the records are corrected for transducer rotation, misalignment and cross-axis sensitivity.  相似文献   

Evolution of accelerographs, data processing, strong motion arrays and amplitude and spatial resolution in recording strong earthquake motion   总被引：1，自引：0，他引：1  

M. D. Trifunac  M. I. Todorovska 《Soil Dynamics and Earthquake Engineering》2001,21(6)

This paper presents a review of the advances in strong motion recording since the early 1930s, based mostly on the experiences in the United States. A particular emphasis is placed on the amplitude and spatial resolution of recording, which both must be ‘adequate’ to capture the nature of strong earthquake ground motion and response of structures. The first strong motion accelerographs had optical recording system, dynamic range of about 50 dB and useful life longer than 30 years. Digital strong motion accelerographs started to become available in the late 1970s. Their dynamic range has been increasing progressively, and at present is about 135 dB. Most models have had useful life shorter than 5–10 years. One benefit from a high dynamic range is early trigger and anticipated ability to compute permanent displacements. Another benefit is higher sensitivity and hence a possibility to record smaller amplitude motions (aftershocks, smaller local earthquakes and distant large earthquakes), which would augment significantly the strong motion databases. The present trend of upgrading existing and adding new stations with high dynamic range accelerographs has lead to deployment of relatively small number of new stations (the new high dynamic range digital instruments are 2–3 times more expensive than the old analog instruments or new digital instruments with dynamic range of 60 dB or less). Consequently, the spatial resolution of recording, both of ground motion and structural response, has increased only slowly during the past 20 years, by at most a factor of two. A major (and necessary) future increase in the spatial resolution of recording will require orders of magnitude larger funding, for purchase of new instruments, their maintenance, and for data retrieval, processing, management and dissemination. This will become possible only with an order of magnitude cheaper and ‘maintenance-free’ strong motion accelerographs. In view of the rapid growth of computer technology this does not seem to be (and should not be) out of our reach.  相似文献   

Inelastic buildings with tuned mass dampers under moderate ground motions from distant earthquakes     

P. Lukkunaprasit  A. Wanitkorkul 《地震工程与结构动力学》2001,30(4):537-551

The effectiveness of tuned mass dampers (TMD) in vibration control of buildings was investigated under moderate ground shaking caused by long‐distance earthquakes with frequency contents resembling the 1985 Mexico City (SCT) or the 1995 Bangkok ground motion. The elastic–perfectly plastic material behaviour was assumed for the main structure, with linear TMDs employed by virtue of their simplicity and robustness. The accumulated hysteretic energy dissipation affected by TMD was examined, and the ratio of the hysteretic energy absorption in the structure with TMD to that without it is proposed to be used, in conjunction with the peak displacement ratio, as a supplementary TMD performance index since it gives an indication of the accumulated damage induced in the inelastic structures. For the ground motions considered, TMD would be effective in reducing the hysteretic energy absorption demand in the critical storeys for buildings in the 1.8–2.8 s range. The consequence is reduction in damage of the buildings which would otherwise suffer heavy damage in the absence of TMD, resulting in economical restorability in the damage control limit state. This is of practical significance in view of the current trend toward performance‐based design. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Effect of earthquake ground motions on fragility curves of highway bridge piers based on numerical simulation     

Kazi R. Karim  Fumio Yamazaki 《地震工程与结构动力学》2001,30(12):1839-1856

Fragility curves express the probability of structural damage due to earthquakes as a function of ground motion indices, e.g., PGA, PGV. Based on the actual damage data of highway bridges from the 1995 Hyogoken‐Nanbu (Kobe) earthquake, a set of empirical fragility curves was constructed. However, the type of structure, structural performance (static and dynamic) and variation of input ground motion were not considered to construct the empirical fragility curves. In this study, an analytical approach was adopted to construct fragility curves for highway bridge piers of specific bridges. A typical bridge structure was considered and its piers were designed according to the seismic design codes in Japan. Using the strong motion records from Japan and the United States, non‐linear dynamic response analyses were performed, and the damage indices for the bridge piers were obtained. Using the damage indices and ground motion indices, fragility curves for the bridge piers were constructed assuming a lognormal distribution. The analytical fragility curves were compared with the empirical ones. The proposed approach may be used in constructing the fragility curves for highway bridge structures. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

秦山核电站厂址地震动加速度时程预测研究     

郑天愉  邵锦英 《地震工程与工程振动》1996,16(2):33-45

本文研究了建立设计地震震源模型和用理论地震学方法预测基岩场地震震加速度的技术途径，预测了四相设计地震事件在秦山核电站厂址的加速度时程和反应谱，文中根据对地质和历史地震资料的研究，确定不同性质的设计地震事件，建立设计地震震源和工作区介质的确定性模型，针对未来地震的不可完全预见性，以及对地球介质和震源性质现有认识的局限性，文中发展了确定性和随机性组合的综合分析方法，在用确定的介质模型和设计震源计算地震  相似文献   

拱坝系统三维非线性地震波动分析   总被引：18，自引：1，他引：18  

杜修力  陈厚群 《地震工程与工程振动》1996,16(3):39-47

本文将显式有限元结合外推人工边界的方法发展应用于三维非线性近场波动问题的研究。首次提出了拱坝－库水－地基系统三维非线性地震反应波动分析方法，并与传统的无质量地基分析方法进行了比较。  相似文献   

逐步带逼近法在热带所旋路径预报中的应用     

毛绍荣 《气象》1996,22(12):27-30

通过对逐步逼近法１９９５年试验情况与国内外预报台的综合预报以及与国内一些客观预报方法的比较分析，总结出该方法对移动路径明显转折的热带气旋有较好的预报能力，４８小时平均误差达到３００ｋｍ以内，特别是当热带气旋的移速发生明显变化时，该方法较之其它客观方法有明显的优越性。  相似文献   

青藏块体北缘跨断层测量资料宏观分析   总被引：1，自引：1，他引：1  

赵振考  陈兵 《中国地震》1996,12(4):358-366

本文在系统整理青藏块体北缘跨断层测量资料的基础上，进行了形变类型的划分，探讨了不同类型形变所反映的断层运动性能。  相似文献   

The effect of local irregular topography on seismic ground motion     

刘晶波 《地震学报(英文版)》1996,9(2):309-315

Ｔｈｅｅｆｆｅｃｔｏｆｌｏｃａｌｉｒｒｅｇｕｌａｒｔｏｐｏｇｒａｐｈｙｏｎｓｅｉｓｍｉｃ　ｇｒｏｕｎｄ　ｍｏｔｉｏｎＪＩＧ－ｈｏＬＩＵ（刘晶波）（ＤｅｐａｒｔｍｅｎｔｏｆＣｉｖｉｌＥｎｇｉｎｅｅｒｉｎｇ，ＴｓｉｎｇｈｕａＵｎｉｖｅｒｓｉｔｙＢｅｉｊｉ...  相似文献   

强震地面运动的解析解     

范家参  费维水 《地震研究》1996,19(1):95-118

本文用具有非线性Ｒａｙｌｅｉｇｈ阻尼的断裂动力学的控制方程组或方程来研究水平强震地面运动或垂直强震地面运动，并得出其解析解，数值计算结果显示，本文得出的结果与任意选择的两个强震记录是很相似的。  相似文献