CAI?Hui-teng , ZHANG?Ying , CAI?Zong-wen , ZHANG?Jin-fu
2010, 32(4):313-317,338.
Abstract:Four mapping principles are illustrated by means of mathematical language to attain their corresponding mathematical mapping relations.The computing process is designed to facilitate the numerical computation of transformation for ground motion attenuation relation.Taking Western America as the reference area,the horizontal earthquake peak acceleration attenuation relation on bedrock in Yunnan is deduced.The results show that four mathematical mapping relations and the designed numerical computing process are feasible in the course of transformation.Besides,the results of minimal warping mapping principle and minimal warping reversible mapping principle are superior to results of IR mapping principle and IM mapping principle.
HE?Tong-jiang , LIU?Hong-yan , LI?Xiao-fan
2010, 32(4):318-324.
Abstract:Early convolutional differentiators are all based on the Fourier transformation,their precision is a little higher than that of four-order finite difference.For improving the precision and efficiency of seismic modeling,a new modeling approach(Convolutional Forsyte Polynomial Differentiator Method,CFPD)is developed in this paper by using optimized convolutional operators for spatial differentiation and staggered-grid finite-difference for time differentiation in wave equation computation.The solution of this new method is much close to the exact value,and the precision is nearly equal to that of 16-order finite difference.Viscous-elastic wave equation can better explain wave phenomena of the true earth media.This paper applies the CFPD method to model 2-D viscous-elastic seismic wave field for the first time,and further derives the first-order velocity-stress discreate equations for viscous-elastic media.The numerical results show that the algorithm can bring reliable outcomes with high precision and fast speed,and viscous-elastic modeling is much efficient.
QU?Jun-hao , LIU?Xi-qiang , SHI?Yu-yan , WU?Dan-tong , MIAO?Qing-jie
2010, 32(4):325-329.
Abstract:Automatic judgment for seismic event is a vital part of the automatic location system.In this paper,combined with the actual model of digital waveform characteristics,a new method in line with the computerized operating mode is proposed.Waveform is preprocessed using the traditional STA/LTA method combined with waveform continuity and concentration of stations.It effectively ruled out the interference stations and ensure the accuracy of automatic judgment of seismic events.It is well validated in the actual operation process.
WANG?Juan , QIU?Hong-mao , ZHANG?Bo , LIU?Jun-min , WANG?Xiao-ming , WANG?Hong , LU?Yuan-lei , XU?Jin , LI?Jian , CUI?Jia-jia
2010, 32(4):330-333.
Abstract:A method of slowness-azimuth station corrections(SASC)for seismic array which is designed to correct slowness and azimuth in predefined small bins is introduced.The aim of SASC is to remove the systematic bias from observations so that the performance slowness-azimuth for stations can be improved.The slowness-azimuth for HILR and LZDM Verification Seismic Arrays in Comprehensive Nuclear-Test-Ban Treaty(CNBT)Beijing National Data Centre(NDC) is corrected using this method,and the rusults of testing with new correction show improvement of slowness and azimuth estimation.
HUAN?Rui , LI?Ai-yong , ZHU?Chun-sheng , YANG?Sheng
2010, 32(4):334-338.
Abstract:The Magnetotelluric exploration profile of Maqu-Beichuan shows the extent and structure characters of upper crust,lower crust and upper mantle along the sections.First,there exists a large nappe structure from north China block to Longmenshan tectonic belt between the overlying strata of upper crust and basement.Second,the thickness of upper crust,especially the one of crystalline basement,limits the stability of blocks.Third,the relief of low-resistivity layer in the crust and the swell or sag of Moho are close correlative to the stability of blocks.
2010, 32(4):339-342.
Abstract:Dynamic fininte element method and time history analysis are explored to analyze dynamic property of slope during seismic process considering soil dynamic property and seismic characters.The minimum mean safety factor is explored to evaluate slope stability.The result is compared with the one of the pseu-static method.The result from a typical slope in a real case indicates that the method is feasible.
MU Peng , WU Wei-jiang , YANG Tao
2010, 32(4):343-348.
Abstract:A landslide disaster happened at the hill west to Shixiakou district in Jiuzhou,Lanzhou city,on May 16,2009,which caused great life and property lose.A systematic research on the characteristics and forming cause of Shixiakou landslide is achieved in this paper.It is considered that the key factors of the landslide are unreasonable false virescence irrigation,the high and steep topography in landslides region,and poor rock and soil mass engineering geological properties.Based on the cause analysis of Shixiakou landslide,research on Stability of its western neighbouring high slope is done.The safety coefficient and the potential failure surface are evaluated by strength reduction FEM.As a comparison,limit equilibrium method is executed.The calculation results show that the safety factor calculated by the strength reduction FEM is fairly close to the that calculated by the traditional limit equilibrium method,which ensured the reliability of the result.
CHENG Jian-wu , GONG Hui-ling , GUO Xue-lian
2010, 32(4):349-356.
Abstract:The plant spores and pollen are more desirable indicators to the recovery of environmental change.It had great significance using palynological indicators for the Quaternary stratigraphic subdivision and regional paleoclimate contrast.In this paper,theⅠ~Ⅲ terraces profiles of Anning river at Lugu township,Mianning county in western Sichuan province are selected to do chronology measurement and analysis of pollen samples.The results show that the terrace I formed during the Holocene(Q4),climate was wet or light wet.The terrace Ⅱ deposited during the end of Late-pleistocene(Q33)or the early Holocene(Q14),both temperature and humidity were lower than that of terrace Ⅰ,and vegetation and climate had more than two obvious changes and fluctuations.The terrace Ⅲ deposited during the middle Late-pleistocene(Q32),climate was wet or light wet,the temperature and humidity were higher than terrace Ⅱ,lower than terrace Ⅰ.The tectonic and climate change during the formation of Anning river terraces are discussed.According to the speed of river downcutting,it is indicated that the uplift rate of epipleistocene to be bigger than the end of epipleistocene-Holocene.
PAN Zhen-sheng , LUI Hui , GU Mei-ju , LI Xiao-dong , SHEN Qi
2010, 32(4):357-362,410.
Abstract:Using the joint inversion method,we obtain the source spectrums of 53 MS≥3.0 earthquakes in Keping block,Xinjiang Uygur Autonomous Region,form 2006to 2008,calculate the source parameters of 103 MS≥2.5earthquakes such as seismic moments,stress drops,apparent stress,corner frequencies,and discuss the relationships between these parameters and magnitude.Based on this work,the spatial-temporal evolution patterns of stress fall,apparent stress in Keping block and on both sides of Puchang fault are separately analyzed.The possibility for applying the results to earthquake tendency forecast and short-term seismic activity tracing is also discussed with the case of Keping MS5.2earthquake in 2009.
LIAN Yu-ping , ZHANG Ying , CAI Hui-teng , ZHANG Jin-fu , ZHENG Shi-chun , ZHAO Zhi-wei , WEI Fu-quan
2010, 32(4):363-366.
Abstract:Through the resonant column test on 4typical soils as mud,silty clay,silty clay and silty sand interbedded strata,residual soil,the influence of confining pressure and soil property on dynamic shear modulus Gand damping ratioγof the 4typical soils is explored in detail.The average curves of G/Gmaxandλ/λmaxwith the change ofγunder different confining pressures as well as their recommended values of parameters for the 4typical soils in Zhangzhou are presented.Besides,the influence patterns of confining pressure on the average curve parameters are also quantified.The result could be used as reference for practical projects.
QIU Peng-cheng , WANG Yong-gang , YANG Guang-hua , BAI Xiang-ling , ZHAO Sheng-sheng
2010, 32(4):367-375.
Abstract:The data of water surface temperature before and after Wenchuan MS8.0earthquake in 2008from 73wells in the range of 800km from the epicenter are analyzed.According to the given judgment basis for anomaly and indeterminate anomaly,among the all observasing wells,9wells had seismic precursor anomalies,5wells had anomalies but can not be determined to have relation with the earthquake,3wells had typical"no-anomalous change" and others had no anomaly.It is considered that there are three periods in the anomalous appearance,which are early period with slow change,middle period with sudden change and late period with going down change.Meanwhile the dynamic change characteristics of water level,gas radon and other fluid measure items in the same wells,as well as some deformation items(strain in drill hole,tilt in drill hole,strain in tunnel body etc.)in the same stations or nearby stations(≤50km)are compared with the change of water surface temperature.It is found that crustal deformation anomaly is interrelationed with the late period of anomaly in water surface temperature,but anomaly of water level has nearly not relation with the temperature in same wells.
LIU Xu-zhou , ZHANG Yuan-sheng , ZHOU Min-du , MIN Xiang-yi
2010, 32(4):376-380.
Abstract:The Wenchuan MS8.0earthquake in 2008caused shake even in region more than 1 000 km away.Most strong ground motion stations in Lanzhou area,which were built in"tenth 5-years pla"n for rapid reporting of seismic intensity,recorded seismic wave during the event,the maximum peak acceleration of single channel was 40.4cm/s2.In this paper,129records from 43 stations among total 50stations in Lanzhou area during the earthquake are shown.The distribution of peak accelerations in Lanzhou area and relationship between the peak acceleration and soil thickness are analyzed also.
LI Ying-zhen , NIE Xiao-hong , WANG Zai-hua , YANG Xiao-fang , JIANG Jing-xiang , WANG Qiong
2010, 32(4):381-387.
Abstract:The Hejing MS5.6earthquake occurred on Aug.30,2008,located in an annual seismic risk region in Xinjiang Ugyur Autonomous Region.A group formed by authors for tracing and predicting short-term earthquakes in the east wing of South Tianshan had proposed a short-term prediction in middle of June before the earthquake.In this paper,the work thinking,analysis of anomalous precursors and process of short-term prediction before the event are retrospectively analyzed.Some discussion for short-term earthquake tracing and prediction are also presented.
CHEN Liang , LU Hai-tao , XIE Qing-sheng , LIU Shi-jing , YE Feng
2010, 32(4):388-392.
Abstract:Aimed at problems in traditional sand tables,the research on electronic sand table for Anhui provincial seismic monitoring network using 3DGIS and RS is done.The 3Dvisualization terrain by combining the remote sensing image and the digital elevation model(DEM)is realized,all the seismic stations in Anhui provincial seismic monitoring network and nearby landforms can be shown in 3Dscene.
DU Ji-kui , ZHENG Jian-chang , ZHANG Yu-long , WANG Feng , GAO Yu-feng , BAI Chun-hua
2010, 32(4):393-398.
Abstract:Earthquake contingency plan is the foundation and principal step of earthquake emergency works.Exploiting information management system for earthquake contingency plan is very important to the work's digitalization,standardization and computerization.In this paper,a technical review for the developing process of Information Management System for Earthquake Contingency Plans is given,the working idea and technical proposals are introduced.The main function and operating of the system are presented also.
2010, 32(4):399-404.
Abstract:According to actual needs and design requirements of information network platform construction in earthquake prevention and disaster relief center of Xinjiang,the resources such as communication network,transmission channels et al.in the center are integrated designed.After implementation of the system integration,the information transmission became reliable and stable.The optimization in speed,technology,fund and other aspects is realized.The operation of entire information network system in security and stability is improved.
2010, 32(4):405-410.
Abstract:The Finite Element Method(FEM)has been used in the study of tectonic stress field for a long time,and the essence of numerical modeling has been adopted to the well-established numerical methods of multidisciplinary acknowledge including mathematics,physics and mechanics for studing characters of geological tectonics.In the last decade,great advances have been made on the numerical simulation method,not only an integrated theory has been built up,but also some significant results have been born from several typical tectonic belts.So the FEM becomes one of the most important numerical methods in the study of tectonic stress field.In this paper,taking theory of FEM as a springboard,the new progress and methods in this field at home and abroad is summarized and analyzed.Some problems and prospect of the researching on the field is also given.
Sopyright:China Earthquake Engineering Journal