青海省河南M_S5.1和玛沁M_S5.0地震后库玛断裂带的地震活动趋势研究          下载免费PDF全文

都昌庭  杨广华 《地震工程学报》2001,(2)

根据地震活动特征、大武地震台尾波持续时间及长宁、湟源和西宁 3个台水氡异常变化 ,讨论了 1 999年河南MS5 .1和玛沁MS5 .0地震发生后库玛断裂带的地震活动趋势 .结果表明 ,河南—玛沁地区的中强地震活动与库玛断裂带上的强震活动有明显的对应关系 ;在库玛断裂带中东段存在一个由ML ≥ 3.0地震围成的空区 ;上述2次地震发生后大武地震台尾波持续时间异常依然存在 ,长宁、湟源和西宁台水氡趋势异常仍然持续 .据此认为库玛断裂带存在发生强震的背景  相似文献   

清水李沟井与礼县石桥井流量异常变化与地震的关系          下载免费PDF全文

陈洁  王建荣 《地震工程学报》2001,23(3):238-242

分析了清水李沟井与礼县石桥井汉量变化与邻近地区发生的中强地震的对应关系。发现在邻近地区发生的部分中强地震前半年左右2口井的流量开始出现上升或波动现象，异常变化的幅度最大可达3．75mL/s，对震级较小，而且距离较远的地震无明显的异常反映。2口井流量异常对5级地震的映震范围为250km，6级地震为350km，7级地震为500km。  相似文献   

Casualties‘ States During Destructive Earthquakes   总被引：1，自引：0，他引：1  

Zhao Zhendong  Zheng Xiangyuan 《中国地震研究》2001,15(2):215-221

The index of casualties is introduced for the trapped that is still alive after a destructive earthquake to indicate his(her)injury degree.In order to describe the injury-developing process controlled by three factors:the initial injury degree,the trap surroundings and the physique of the cornered,a function SFC( State-Function of Casualties) can be naturally constructes.Through parameter analysis from eight pieces of figures,it can be found that the trapped with weaker physique and worse initial injury degree and in adverse trap surroundings deserves sooner rescue.  相似文献   

Analysis on Depth Distribution and Precursor Mechanism of Small and Moderate Earthquakes     

Wang Jian 《中国地震研究》2001,15(4):406-411

ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｓｅａｒｃｈｏｎｅａｒｔｈｑｕａｋｅｆｏｃｕｓｄｅｐｔｈｄｉｓｔｒｉｂｕｔｉｏｎａｎｄｉｔｓｐｈｙｓｉｃａｌｂａｃｋｇｒｏｕｎｄｉｓｏｎｅｏｆｍｏｓｔａｔ ｔｅｎｔｉｖｅｐｒｏｂｌｅｍｓ.Ｐｒｏｆ.ＦｕＺｈｅｎｇｘｉａｎｇ (1 996)ｒｅｓｅａｒｃｈｅｄｔｈｅｒｅｌａｔｉｏｎｓｂｅｔｗｅｅｎｆｏｃｕｓｄｅｐｔｈｄｉｓｔｒｉｂｕ ｔｉｏｎｏｆａｆｔｅｒｓｈｏｃｋｓ ,ｃｒｕｓｔａｌｖｅｌｏｃｉｔｙｌａｙｅｒｓａｎｄｓｕｒｆａｃｅｔｈｅｒｍａｌｆｌｏｗ .Ｒｅｓｅａｒｃｈｏｎｆｏｃｕ…  相似文献   

Post-earthquake investigation on several geosynthetic-reinforced soil retaining walls and slopes during the Ji-Ji earthquake of Taiwan   总被引：1，自引：0，他引：1  

Hoe I. Ling  Dov Leshchinsky  Nelson N. S. Chou 《Soil Dynamics and Earthquake Engineering》2001,21(4):3087

This paper gives an overview on the application of geosynthetic-reinforced soil structures in Taiwan. Taiwan has an unique topography and geotechnical conditions that rendered a less conservative and more challenging design compared to that of North America, Europe and Japan. The Ji-Ji (Chi-Chi) earthquake of 1999 gave an opportunity to examine the behavior of reinforced soil structures. The performance of several modular-block reinforced soil retaining walls and reinforced slopes at the vicinity of the fault was evaluated. Reinforced structures performed better than unreinforced soil retaining walls. The failure cases were highlighted and the cause of failure was identified. The lack of seismic design consideration could be a major cause of failure. The compound failure mode, the inertia force of the blocks, and the connection stiffness and strength relative to the large dynamic earth pressure, were among major items that would warrant further design consideration.  相似文献   

Effectiveness of structural control based on control energy perspectives     

Kevin K. F. Wong  Rong Yang 《地震工程与结构动力学》2001,30(12):1747-1768

A computational algorithm for maximizing the control efficiency in actively controlling the elastic structural responses during earthquake is proposed. Study of optimal linear control using a single degree of freedom shows that applying active control is very effective in reducing the structural displacement and velocity responses for long‐period structures, but at the same time it has an adverse effect in increasing the absolute acceleration response. The extent of this adverse effect reduces the effectiveness of the control system, and therefore it poses a limit on the maximum control force in order to provide maximum control efficiency. In view of this shortcoming, maximum control energy dissipation is used to define the most effective optimal linear control law. Less displacement and velocity response are expected as larger control force is applied, but there is always a limit that maximum control energy can be dissipated. This study shows that this limit depends on the structural characteristics as well as the input ground motion, and a general trend is that the maximum control energy decreases as damping increases. Finally, application of the proposed algorithm on a six‐storey hospital building is presented to show the effectiveness of using optimal linear control on a multi‐degree‐of‐freedom system from the control energy perspectives. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Probabilistic Seismic Hazard Assessment Along the Southeastern Coast of Vietnam     

Hong Phuong  Nguyen 《Natural Hazards》2001,24(1):53-74

On the basis of the analysis of geological, tectonic characteristics and earthquake manifestation features, a causative relation between geodynamic regime and seismicity has been established for the southeastern coastal zone and continental shelf of Vietnam. The probabilistic methods have been used to evaluate ground shaking effects at Nha Trang city aswell as for the entire study area. Short, intermediate and long term predictions of ground shaking (in the form of peak ground accelerationmaps) show high risks in the coastal zone of central Vietnam and in the southeastern continental shelf of the country.  相似文献   

9403强热带风暴致洪暴雨Tbb特征分析   总被引：2，自引：1，他引：2  

杨金锡  冯志娴 《气象科学》1996,16(4):378-382

本文利用１经纬度间隔Ｔｂｂ资料分析１９９４年６月９－１０日皖、赣致洪暴雨过程的成因。结果指出，登陆北上的９４０３强热带低压同西风带降水系统相互作用造成了这场大暴雨过程。南北低值系统的叠置使降水系统结构发生变化，在两云系统接合处产生强对流云团，导致降雨量陡增。分析还表明这场致洪暴雨的发生与下面三个因素有关；１．南、北两云系统都有相当尺度和强度；２．南来云团来自ＩＴＣＺ和西南地区云系的水源补充；３．不  相似文献   

江苏省夏季持续干旱和雨涝的气候分析以及环流和海温场演变特征   总被引：3，自引：1，他引：3  

施宁  栾建林 《气象科学》1996,(4)

在对我省夏季持续干旱和雨涝进行气候分析的基础上，研究了夏季持续干旱和持续雨涝的环流特征差异、持续干旱的两种不同的环流型以及前期海温场的特征和演变规律。  相似文献   

山东省干旱演变规律及其影响   总被引：2，自引：0，他引：2  

杨志刚  杨洪昌 《气象》1996,22(5):25-29

利用近５００年旱涝资料分析了干旱对山东省农业，工业及环境的危害。利用功率谱和模糊判别函数研究了旱涝的周期性和阶段性，指出旱涝的演变规律可为气候预测提供依据。  相似文献