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Consecutive combined response spectrum

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earthquake Engineering and Engineering Vibration 2014年第4期13卷 623-636页

作者： Xu Longjun Zhao Guochen Liu Qingyang Xie Yujian Xie Lili Department of Civil Engineering Harbin Institute of Technology at Weihai Institute of Engineering Mechanics China Earthquake Administration

Appropriate estimates of earthquake response spectrum are essential for design of new structures, or seismic safety evaluation of existing structures. This paper presents an alternative procedure to construct design spectrum from a combined normalized response spectrum （NRSc） which is obtained from pseudo-velocity spectrum with the ordinate scaled by different peak ground amplitudes （PGA, PGV, PGD） in different period regions. And a consecutive function./（/） used to normalize the ordinates is defined. Based on a comprehensive study of 220 strong ground motions recorded during recent eleven large worldwide earthquakes, the features of the NRSc are discussed and compared with the traditional normalized acceleration, velocity and displacement response spectra （NRSA, NRSv, NRSD）. And the relationships between ground amplitudes are evaluated by using a weighted mean method instead of the arithmetic mean. Then the NRSc is used to define the design spectrum with given peak ground amplitudes. At last, the smooth spectrum is compared with those derived by the former approaches, and the accuracy of the proposed spectrum is tested through an analysis of the dispersion of ground motion response spectra.

关键词： ground motion response spectrum normalized response spectrum consecutive combined response spectrum design spectrum

3-D velocity structure in the central-eastern part of Qilianshan

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Acta Seismologica Sinica(English Edition) 2004年第3期17卷 272-281页

作者： ZHANG Yuan-sheng(张元生) ZHOU Min-du(周民都) RONG Dai-lu(荣代潞) ZHANG Li-guang(张立光) XU Zhong-qiu(许中秋) Lanzhou Institute of Seismology China Earthquake Administration Lanzhou 730000 China Lanzhou Institute of Seismology China Earthquake Administration Lanzhou 730000 China Lanzhou Institute of Seismology China Earthquake Administration Lanzhou 730000 China Lanzhou Institute of Seismology China Earthquake Administration Lanzhou 730000 China Earthquake Administration of Lanzhou City Lanzhou 730000 China

The 3-D velocity tomography image of the central-eastern part of Qilianshan is obtained by the joint inversion of 3-D velocity structure and focal parameters based on the S-P data of micro-earthquakes recorded by the digital seismic network set up for a Sino-French cooperation program since 1996. The inversed velocity structure does primarily reflect some important features of the deep structure in the region and provide the scientific background for the further study of active tectonic structure and the calculation of earthquake parameters.

关键词： central-eastern Qilianshan micro-earthquake observation 3-D velocity structure focal pa-rameters joint inversion

Abnormal Phenomena of Volume Strain before Large earthquakes

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earthquake Research in China 2015年第3期29卷 373-385页

作者： Wu Lijun Chen Zhengwei Li Hangu Xu Lei An Bayaer Xu Shunqiang Institute of earthquake Science China Earthquake Administration Key Laboratory of earthquake Prediction Institute of Earthquake ScienceCEA Wudi Dashan Seismic Station Earthquake Administration of Shandong Province Seismological Bureau of weihai city Geophysical Exploration Center CEA

This paper studies the imminent anomalies observed by the Sacks volume strainmeter in Erzhangying station and Tiantanghe station before 80 earthquakes with Ms≥ 7. 0 which took place from January 2011 to April 2014 all over the world. Then, preconditions for anomaly identification are put forward for complex earthquake cases. Statistical results show that volume strain observation has a better earthquake reflecting ability for earthquakes with magnitudes larger than 7. 0 and epicentral distance within 8000kin. In addition, these results also reflect that the volume strain observation can better reflect precursory anomalies of such earthquakes. Based on categorization and description of those anomalies, we divide the anomalies into three types, that is, earth tide distortion type, abrupt change type and slow earthquake type. Furthermore, the paper makes a statistical analysis of these types and preliminarily discusses their mechanical properties as well. According to research, volume strain anomaly has an indicative significance to future strong earthquakes in the world.

关键词： Large earthquakes Volume strain The earth tide distortion Abruptchange Slow earthquakes earthquake case study

Lateral migration of fault activity in Weihe basin

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Acta Seismologica Sinica(English Edition) 2004年第2期17卷 190-199页

作者： FENG Xi-jie(冯希杰) DAI Wang-qiang(戴王强) earthquake administration of Shaanxi Province Xi''an 710068 China Earthquake Administration of Shaanxi Province Xi''an 710068 China

Lateral migration of fault activity in Weihe basin is a popular phenomenon and its characteristics are also typical. Taking the activity migrations of Wangshun Mountain piedmont fault toward Lishan piedmont fault and Weinan platform front fault, Dabaopi-Niujiaojian fault toward Shenyusi-Xiaojiazhai fault, among a serial of NE-trending faults from Baoji city to Jingyang County as examples, their migration time and process are analyzed and discussed in the present paper. It is useful for further understanding the structure development and physiognomy evolution history of Weihe basin.

关键词： lateral migration fault activity Weihe basin

Crustal thicknesses and Poisson's ratios beneath the Chuxiong-Simao Basin in the Southeast Margin of the Tibetan Plateau

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Earth and Planetary Physics 2019年第1期3卷 69-84页

作者： ZiQi Zhang Yuan Gao Key Laboratory of earthquake Prediction Institute of Earthquake ForecastingChina Earthquake Administration Institute of earthquake Forecasting China Earthquake Administration

In the Southeast Margin of the Tibetan Plateau, low-velocity sedimentary layers that would significantly affect the accuracy of the H-κ stacking of receiver functions are widely *** this study, we use teleseismic waveform data of 475 events from 97 temporary broadband seismometers deployed by ChinArray Phase I to obtain crustal thicknesses and Poisson's ratios within the Chuxiong-Simao Basin and adjacent area, employing an improved method in which the receiver functions are processed through a resonance-removal filter, and the H-κ stacking is *** show that the crustal thickness ranges from 30 to 55 km in the study area, reaching its thickest value in the northwest and thinning toward southwest, southeast and *** apparent variation of crustal thickness around the Red River Fault supports the view of southeastern escape of the Tibetan *** thin crustal thickness in the zone between Chuxiong city and the Red River Fault indicates possible uplift of mantle in this *** positive correlation between crustal thickness and Poisson's ratio is likely to be related to lower crust *** of results obtained from different methods shows that the improved method used in our study can effectively remove the reverberation effect of sedimentary layers.

关键词： receiver functions sedimentary layer southeast margin of the Tibetan Plateau crustal thickness Poisson's ratio Chuxiong-Simao Basin

Study on the characteristics of earthquake's impact on cities

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Acta Seismologica Sinica(English Edition) 2004年第2期17卷 222-229页

作者： PAN Hua(潘华) ZHAO Feng-xin(赵凤新) GAO Meng-tan(高孟潭) Institute of Geophysics China Earthquake Administration Beijing 100081 China Institute of Geophysics China Earthquake Administration Beijing 100081 China Institute of Geophysics China Earthquake Administration Beijing 100081 China

Firstly, the impact of historical earthquakes on 34 China province-level capital cities is evaluated by using historical earthquake catalog. The distribution of affected intensity shows, about 53% of cities have even not been affected by earthquake intensity VI, and 44% of cities have been hit by earthquake intensity VII to IX. For most of the cities, occurrence frequency of affected intensity VI is usually higher than that of affected intensity larger than VI, and the value of affected intensity with maximal occurrence frequency may be very different among cities. So both the maximal affected intensity and the affected intensity with maximal occurrence frequency should be taken into account when the prevention seismic intensity needs to be determined. Secondly, considering the incompleteness of records of historical earthquakes, a method of earthquake catalog computer simulation is introduced to study the features of affected intensity of big cities. 69 county-level cities of Fujian Province are selected to be statistical objects. The statistical result shows, for different risk levels the seismic intensity changes greatly among cities, the seismic intensity of 2% probability of exceedance in 50 years can be regarded as the characteristic affected intensity of city, and can be the basis of determining the city special earthquake prevention level and a proper indicator of future earthquakes impact on cities.

关键词： city group affected intensity characteristics earthquake probability of exceedance

Probabilistic earthquake early warning times in Fujian Province

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earthquake Science 2013年第1期26卷 33-41页

作者： Hongcai Zhang Xing Jin Fujian earthquake administration Institute of earthquake Mechanic China Earthquake Administration

earthquake early warning （EEW） systems are a new and effective way to mitigate the damage associated with earthquakes. A prototype EEW system is currently being constructed in the Fujian Province, a region along the Southeast coast of China. It is anticipated that the system will be completed in time to be tested at the end of this year （2013）. In order to evaluate how much advanced warning the EEW system will be able to provide different cities in Fujian, we established an EEW information release scheme based on the seismic monitoring stations distributed in the region. Based on this scheme, we selected 71 historical earthquakes. We then obtained the delineation of the region＇s potential seismic source data in order to estimate the highest potential seismic intensities for each city as well as the EEW system warning times. For most of the Fujian Province, EEW alarms would sound several seconds prior to the arrival of the destructive wave. This window of time gives city inhabitants the opportunity to take protective measures before the full intensity of the earthquake strikes.

关键词： earthquake early warning systems Lead time Fujian region

Characteristics of coseismic water level changes at Tangshan well for the Wenchuan MS_8.0 earthquake and its larger aftershocks

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earthquake Science 2009年第2期22卷 149-157页

作者： Baojun Yin Li Ma Huizhong Chen Jianping Huang Chaojun Zhang Wuxing Wang Institute of Geophysics China Earthquake Administration Beijing 100081 China Institute of earthquake Science China Earthquake Administration Beijing 100036 China earthquake administration of Tangshan city Tangshan 063000 China Graduate University of Chinese Academy of Sciences Beijing 100049 China China earthquake Networks Center China Earthquake Administration Beijing 100036 China

Coseismic water level changes which may have been induced by the Wenchuan Ms8.0 earthquake and its 15 larger aftershocks （Ms〉5.4） have been observed at Tangshan well. We analyze the correlation between coseismic parameters （maximum amplitude, duration, coseismic step and the time when the coseismic reach its maximum amplitude） and earthquake parameters （magnitude, well-epicenter distance and depth）, and then compare the time when the coseismic oscillation reaches its maximum amplitude with the seismogram from Douhe seismic station which is about 16.3 km away from Tangshan well. The analysis indicates that magnitude is the main factor influencing the induced coseismic water level changes, and that the well-epicenter distance and depth have less influence. Ms magnitude has the strongest correlation with the coseismic water level changes comparing to Mw and ML magnitudes. There exists strong correlation between the maximum amplitude, step size and the oscillation duration. The water level oscillation and step are both caused by dynamic strain sourcing from seismic waves. Most of the times when the oscillations reach their maximum amplitudes are between S and Rayleigh waves. The coseismic water level changes are due to the co-effect of seismic waves and hydro-geological environments.

关键词： Wenchuan Ms8.0 earthquake Tangshan well coseismic water level variation analog water level record

Complicated phenomena of the Beichuan-Yingxiu surface fracture zone during Wenchuan Ms8.0 earthquake in Sichuan Province,China

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Chinese Science Bulletin 2008年第24期53卷 3891-3896页

作者： DENG ZhiHui YANG ZhuEn SUN ZhaoMin CHEN GuiHua MA WenTao SUN Qian Institute of Geology China Earthquake Administration Beijing 100029 China Shangdong earthquake administration Jinan 250014 China

After Wenchuan Ms8.0 earthquake,the surface fractures have been investigated in Beichuan city and Yingxiu *** was found that the Beichuan-Yingxiu earthquake fracture zone trends northeastward,dipping to *** earthquake fracture zone is mainly characterized by thrust faulting with small amounts of strike-slip movement,and demonstrating various complexities for different *** phenomena related to dextral strike-slip displacement are found in Beichuan city and those related to left-lateral strike-slip movement in Yingxiu *** compressive shortening of the two surface fracture zones in Beichuan city is 2.8―3.9 m and the left-lateral strike-slip displacement of the surface fractures in Yingxiu Town is 0.52 m.

关键词：汶川地震地震断裂带复杂性北川县