2010, 32(2):105-111,138.
Abstract:Using the velocity field result of horizontal movement observed by GPS in the periods of 1999-2001,2001-2004 and 2004-2007,based on the inversion of aseismic negative dislocation,strain accumulation of the main boundary faults and their time-space evolution features are researched.Possible influences of the MS8.1 earthquake at west the pass of Kunlun Mountains on Nov.14,2001 and the Sumatera MS8.7(Mw9.0) earthquake on Dec.26,2004 are analyzed,together with the strain accumulation background related to the Wenchuan MS8.0 and the Panzhihua-Huili MS6.1 earthquakes in 2008.
LUO?Guang-cai , DING?Hai-ping , WANG?Shao-bo
2010, 32(2):112-116.
Abstract:Taking three component peak ground accelerations from 13 earthquakes recorded by 486 stations,provided by Pacific Ocean Seismic Engineering Research Center (PEER) and Consortium of Organizations for Strong Motion Observation Systems (COSMOS) as the basis of study,peak ground accelerations are classified according to the magnitudes and the epicentral distances.The relations between the PGV/PGA,PGD/PGA and magnitude,epicentral distance are obtained.The result indicates that the ratio of peak value increases along with the magnitude and epicentral distance increasing.At last,attenuation relationship between the ratio of peak value and magnitude epicentral distance is presented which could be referenced in aseismic design.
ZHANG?Xue-dong , YAN?Zhi-xin , ZHANG?Sen
2010, 32(2):117-121.
Abstract:On the basis of dynamics finite elements theory,rocky slopes with different height and gradiant are computed in the process of modol analysis and time-dependent analysis of seismic acceleration by ANSYS software.Some new dynamic response laws and phenomena are found through the research.The modol analysis shows that the natural vibration frequency of slope dropped as rising of slope height;while the changes of slope angle acts contrary to the natural vibration frequency.Time-dependent analysis of seismic acceleration also indicates that the displacement,speed and acceleration of slope response in the similar way.The amplitude of time-dependent curve of slope crest displacement evidently increase as the increasing of the slope height,nevertheless,the slope crest displacement changes slightly when the slope height reaches a certain degree(about 200 m),meanwhile,the ground motion responsed at the slope crest has a obvious hysteresis comparing to the slope foot.Furthermore,the slope crest displacement has a linear upward trend with the increasing in slope gradiant,besides,the attenuation effect of seismic wave and the amplification effect of slope exists at the same time.The results would have a great reference value to aseismic design of slope.
SU?He-jun , ZHANG?Hui , SHI?Jie
2010, 32(2):122-128.
Abstract:Qilianshan fault zone is one of the stronge seismicity regions in weatern China.In this paper,the typers,cycle depth and speed of groundwater in the faults zone are discussed through calculated the saturation index SI,the isotope ratio of Hydrogen-Oxygen and 3He/4He ratio by Aquachem 5.1 and Phreeqc software.The results show that all of the groundwater samples in the zone have the characteristics of atmosphere causes,small cycle depth,short residence time,and weak water-rock reaction.This research conclusion provides the basis date for earthquake prediction in future.
LU?Ming-yong , FAN?Xue-fang , ZHOU?Wei , FANG?Zong-fei , ZHAO?Li-kui
2010, 32(2):129-138.
Abstract:The long-time trend change shape and evolutionary characteristics of subsurface fluid in North China before MS≥6.0 earthquakes since 1976 are analysed.The results show that the begin time of long-time trend change of subsurface fluid is earlier,and the range is wider,with the characteristics of compatibility,repetition and migration etc.The migrate direction along major tectonic belt is from wide outer regions to epicenter area,or from epicenter area to wide outer region.The shape of changes show trend turn change,damage annual variation and accelerating variation etc,among them the trend turn change is majority shape.Study on level of underground water shows that the majority variation shapes of long-time trend change on level of underground water are slow elevation or descending diminution.Then long-time trend change of subsurface fluid and crustal deformation before strong earthquakes are comparatively studied.The results discover that the begin time of crustal deformation is earlier than it of subsurface fluid,the tensor-pressure variation of crustal deformation is more closely related with the level variation of underground water,namely if change of crustal deformation shows mostly slow pressure or tensor diminution,the change of underground water level shows slow elevation or descending diminution.Finally,the mechanism on long-time trend change of subsurface fluid before strong earthquake is discussed.Slow incremental tectonic stress make crack of rock closure and crust deform,the crust deformation changes porosity,pore pressure and permeability,causes the long-time trend abnormal change of subsurface fluid in the early stage of preparation earthquake.The tectonic stress slowly enhancing and congregating to future seismic center cause the change to migrate into future seismic center.The continuously upwelling of deep material and increment influencing range make the change migrate from future seismic center to outlying zone.
HE?Rui , YANG?Jian-si , ZHANG?Yi
2010, 32(2):139-143,149.
Abstract:A detailed tomographic image of the upper crustal structure in Bachu-Jiashi area,Xinjiang Uygur Autonomous Region,is determined by using P-wave arrival time from the Bachu-Jiashi MS6.8 earthquake in 2003.The inversion results as following:Over 5 km depth in the region,P-velocity imaging shows strongly horizontal heterogeneity,reflecting characteristics of sedimentary cover;Between 5~14 km dpeth,P-velocity imaging suggests that there exist two high and conjugated velocity zone encircled with relative low velocity body,one trending NWW and the other NNE.Combined with tectonic background and focal mechanism solutions,it is holded that the character of earthquakes in this region is similar under the action of double-couple,one of which is along NW-SE right-lateral strike-slip couple,and the other is along NNE-SSW compressive stress.The NWW and NNE zone of heterogeneity provided the fundation for strain energy accumulation and release,and was an important condition for occurence of the Bachu-Jiashi earthquake.Combined the macro damage and isoseismic feature from field investigation and the study on petroleum seismic exploration,it is considered that this earthquake occurred on Bashitupu fults in western tarim basin,which trends along NWW and is north dipping.
LIU?Xiao-feng , LIU?Hong-chun , GAO?Hong-shan , PAN?Bao-tian , LI?Bao-xiong , FAN?Bing
2010, 32(2):144-149.
Abstract:Various evidences of terrace and stratigraphy show that Qinghai-Tibet plateau and its adjacent region experienced an intensive tectonic uplift during the middle Pleistocene,namely the Kunlun-Huanghe Movement.The deepth of 104.5 m loess had been deposited on the 7th terrace of Weihe River in Longxi segment.Through the studing on dating approaches such as palaeomagnetic and grain size,the 7th terrace is estimated to form in about 870 ka before.The height above the river indicates that the uplift amount is at least 205 m from Pleistocene to today,and the move rate is about 0.2 m/ka.The time of this uplift event was same with Kunlun-Huanghe Movement,and was a response to intensive uplift of Qinghai-Tibet plateau.
HOU?Yuan-chao , GUO?Yong , GAO?Song
2010, 32(2):150-153.
Abstract:By briefing the early-warning practice demand of cities for possible future earthquake,a response model establishment of emergency disposal which based on the early-warning regional division is presented.With the application of clustering analysis and statistical methods in early-warning regional division,the basic model which is composed of the layout,the interface and the part of self-control to its fault response is constituted,and realization of the characteristic model is analyzed also.
GE?Wei-peng , YUAN?Dao-yang , HE?Wen-gui , LIU?Xing-wang , ZHENG?Wen-jun
2010, 32(2):154-161.
Abstract:Through the studying on the many surveying methods and process for Lanzhou active fault prospecting project,using the advanced Computer-aided Software/System Engineering theory and Method,the data from the project are analyzed.Meanwhile,some computing database technologies such as MDA (Model Driven Architecture),UML (Unified Modeling Language) and Geodatabase,are introduced and relationship among them are emphasized also.Based on this work,the data integration framework for Lanzhou active fault prospecting project is resulted.
PING?Jian-jun , FENG?Xiang-dong , YANG?Li-ming
2010, 32(2):162-168.
Abstract:Based on the earthquake catalogs,the spatial seismic effect risk degree of a strong earthquake to external areas is calculated.Combined with the regional background spatial seismic effect risk degree and several pre-occurred earthquakes,the synthesis spatial seismic risk degree for the study area is calculated through scanning,which could be used to predicate potential seismic risk area.The seismic risk area predicating demonstrations in North China and Southwest China indicate that this method has a certain effects and may be of practical significance to seismic risk area predicating.
XU?Yong-lin , ZHU?Yuan-qing , ZHOU?Jing-mao , FAN?Yi-yao , QIN?Hao-wen , YUAN?Zhen-ji , GAN?Jin
2010, 32(2):169-172.
Abstract:Jinmao tall building is one of hightest building in China with height of 420.5 m.For diagnosing the building's healthy status,in other words,its safety,the frequencies of vibration types and damping are obtained from the building vibration by the Auto-regressive and Moving Average Model,and the fequencies and damping before and after earthquake or typhoon,or existing for a long peroid are compared.The result shows that this method is well manipulated and used in healthy diagnosis and maintenance for tall buildings and big bridges.
WANG?Gen-long , LIU?Hong-shuai , ZHANG?Jun-hui
2010, 32(2):173-178.
Abstract:MS 8.0 Wenchuan earthquake on May 12,2008 caused Beichuan county massive damage,and resulted in more than ten thousands deaths.The whole Beichuan county town has become ruin.Based on the field seismic investigation,three principal causes of building and road's serious damage as well as personnel heavy casualties are given:the ground surface rupture effect caused by seismo-active fault movement,the secondary geological hazards (collapse and landslide) and the vibration failure effect caused by strong ground motion.Damage of buildings along the main fault and secondary faults were more serious,but destruction in adjacent buildings is relatively not severe.The Wangjiayan landslide and Jingjiashan collapse brought about huge damage to the Beichuan county town and led to more than 2000 people death.The effects of vibration failure were ubiquitous for all buildings,especially horizontal shear movement generated serious constructional damage.
LIU?Wei , WU?Zhi-jian , MA?Hong-wang , WANG?Lan-min , CHEN?Long-zhu
2010, 32(2):179-185.
Abstract:The typical seismic damages of buildings in both rural and urban areas in southern Gansu province during the Wenchuan MS8.0 earthquake in 2008 and the corresponding reasons are summarized.The investigation showed that the seismic damages of rural buildings were very different from that of urban buildings.Generally,the construction of rural buildings does not follow the seismic design code,which leads to serious damage even in low-intensity seismic areas.Urban buildings,on the other hand,generally survived the earthquake with light or moderate damage.It was found that severe damages of urban building were mostly caused by the effect of poor construction quality,improper design and unreasonable reconstruction.The seismic fortification intensities for those investigated regions are all 8 degree,while the real intensities are 6~9 degrees.So the observed seismic damage could be used to demonstrate whether the current design methods could satisfy the Three-Level performance fortification target.The survey result shows that buildings with good seismic design and construction all have a well seismic behavior,and the distributions of building damages have good agreement with the seismic fortification objectives.At last,advices for seismic fortification and post-earthquake rebuilding are given.
LU?Shuang-ling , YU?Qing-min , QU?Bao-an , FENG?Zhi-jun , LI?Jie
2010, 32(2):186-190.
Abstract:Based on the systemic analysis on observation data of borehole volume strainmeter with work logs,the disturbances which caused the undulate short abnormal change in digital borehole volume strainmeter observation are analyzed.The result shows that the short undulate changes of borehole volume strain were caused by mainly air pressure、rainfall、water level change、construction and electrical source.These cannot be absolutely eliminated by correlated analysis,so the quantitative analysis should be combined with qualitative analysis for concrete condition.The disturbance extent of these factors is related to the geological condition of borehole.The influences of air pressure rainfall and water level are bigger commonly at the boreholes in which exist shatter belt.
YANG?Jia-liang , ZHANG?Si-chang , DIAO?Gui-ling , PENG?Yuan-qian , FENG?Xiang-dong , WANG?Xiao-shan
2010, 32(2):191-195.
Abstract:Based on the analysis of earthquakes distribution in Cangzhou area,it is found that there exists a NNE belt of small earthquakes,which is consistent with strike of the Hebei plain seismic belt.In addition,middle and strong earthquakes show obvious NWW-striking distribution,constructing conjugate structure image with the NNE striking belt.Comparing the focal mechanisms of 2 moderate-strong earthquakes,they are similar and have a nearly vertical NNW fault plane doing left-lateral strike-slip movement.The long axis directions of intensity in the meizoseismal area for 3 earthquakes are NWW.The aftershocks distributed in NWW direction within 5 days after the 1967 Hejian M6.3 earthquake.This character coincides with the distribution direction of historical earthquakes with M≥5.Although there is no relevant shallow fault,mutual verification of many kinds of information reflects that there exists a deep buried fault with NWW striking in Cangzhou area.Therefore it can be regarded as the potential seismic source of seismic risk analysis.
LIU?Sheng-guo , JIANG?Chun-hua , GAO?Jing-chun , FENG?Lu-gang , CHANG?Liang , LI?Yong-qing , HU?Bin , WANG?Li-jun , DING?Rui-tong
2010, 32(2):196-200.
Abstract:The core function,the achieving methods and the modules' interfaces of two software modules for earthquake emergency fast triggering and short message transmitting in the rapid trigger system of earthquake emergency response are introduced.Some details such as the main technical methods,principles and achieving flows of each part are also introduced specifically.
LI?Xi-liang , LIU?Xi-qiang , DONG?Xiao-na , XU?Dan
2010, 32(2):201-205.
Abstract:Higher-order statistics is a useful tool for studying non-Gaussian processes,nonlinear systems and non-minimum phase systems.Some problems,which cannot be solved satisfactorily using power spectrum or correlation functions,can be worthy of using higher-order statistics method.In this paper,the main theoretical results about applications of high-order statistics in geophysics are summarized.
WANG?Wei-jun , HAN?Zhao , WANG?Lei , LI?Lin-sheng
2010, 32(2):206-208.
Abstract:The phenomena of earthquake light in nearly 35 years in Linzhou city of Henan province are summarized and described in this paper.It is found that there is a corresponding relationship between the earthquake light anomaly appearances and occurrence of moderate-small earthquakes in Linzhou area or its adjacent area.The forming mechanism of the ligh is analyzed with the geological structure and the distribution of lithology(quartzite) in Linzhou area.The observation of the ligh and how to use it in earthquake prediction are discussed at last.
Sopyright:China Earthquake Engineering Journal