LI?Wen , ZHANG?Yuan-sheng , HE?Bin
2009, 31(3):207-210,226.
Abstract:A new seismic location method using seismic arrival-time and P-wave apparent emergence angle is presented.Through actualized theoretical calculation and actual seismic data disposition,it is proved that using this method could improve the resolving power to focal depth.This method is better for seismic location in the digital seismic network,and the results are valuable for studing fault properties and fault spreading.
LIU?Qing-min , YANG?Wu-yang , LI?Shu-ping , HE?Xin
2009, 31(3):211-216.
Abstract:Hilbert-Huang transformation is a newly developed time-frequency analysis method for dealing with the non-linear,non-stationary signals.In this paper,the basic principles and several key technologies of the Hilbert-Huang transform,as well as its strengths are briefly introduced.It s application to the decomposition of seismic signal with random noise included and actual seismic data are discussed also.The original signal can be really reconstructed with this method,and reconstructed signal improves signal-to-noise ratio and resolution of the attributes, so It is a meaningful method for denoising the seismic data.
WANG?En-li , LIU?Jun-ying , HAN?Li-guo , LIU?Qian-kun
2009, 31(3):217-220.
Abstract:As a method of coherence algorithm based on eigenstructure,the core of C3 algorithmitsis suppressing continuity and emphasizing discontinuity of underground media by computing the coherence of time slices,and finally obtains both higher lateral resolution and lower dip resolution.To improve dip resolution,an improved C3 method,with computing covariance matrix by survey line instead of dealing with sliding panels is presented.The results show the new method has better resolution both in horizon and dip direction.
ZHANG?Dong-hui , HE?Zheng-wei , ZHAO?Yin-bing , YANG?Bin
2009, 31(3):221-226.
Abstract:In Wenchuan earthquake and Tangshan earthquake the local lifeline systems were almost totally damaged.To evaluate the "stability" of the local lifeline systems under the condition of near field earthquake,the evaluation parameters of the two road nets are calculated and analyzed based on the theory of earthquake disaster comparatology.Those parameters are Topological Index(TI(G)),Topological Inverse Index(TII(G)) and Node Solitude Index(NSI) etc.The result shows that the "Stabilities" from low to high are Tangshan Before-earthquake (1975), Wenchuan Before-earthquake (2007), Tangshan After-earthquake (2008). It is concluded that five additional roads, Beichuan to Anxian and so on, should be built in case of rehabilitation the existing roads before Wenchuan earthquake with the optimization theory from a purely mathematical point of view, in which the local road nets would be the highest regional dispersion, the smallest node isolation index, and would be most stability.
HU?Ya-xuan , CUI?Du-xin , ZHANG?Xi , WANG?Xiong
2009, 31(3):227-230,253.
Abstract:The active characteristics of Haiyuan fault belt are analyzed using GPS data during 1999-2007 firstly.The surveying data show that the movement rates of those GPS sites become decreasing from south to north,especially the rates on two sides of the NWW and NW diration faults have big difference,and the fault movement is mainly strike-slip.Then the initial parameters of inversion are given based on the information of geology and geophysics.The slipping rates and depths of three subsections of Haiyuan fault belt are inversed with constrains of GPS profiles data. The result show that the rates from west to east are 5.49 mm/a, 5. 97 mm/a and 8. 25 mm/a respectively and the depths are 22.8 km,13.3 km and 11.1 km respectively. Through comprehensive analysis on the GPS data and parameters of the fault it is concluded that the movement rate on Maomaoshan--Laohushan fault segment is faster than that on Haiyuan fault segment. Maomaoshan fault has big rate grads where also is earthquake vacancy(ML〉6. 0), so this region exists risk of strong earthquake.
DENG?Bai-chang , WEI?huan , QU?ye , ZHAO?Yu-an
2009, 31(3):231-236.
Abstract:The generation mechanism of seismic electromagnetic disturbance and the model of electromagnetic wave propagation are studied based on the analysis of the abnormal data before moderate-strong earthquakes in Fanxian,and in Wen an,observed by Shandong Earthquake Precursory Electromagnetic Disturbance Observational Network in 2006.And the conclusion is advanced by analysis with the concept of the electromagnetic disturbance abnormal quantity S.
SU?He-jun , ZHANG?Hui , SHI?Jie
2009, 31(3):237-241.
Abstract:There were many times the water in 7# well in Qingshui county of Gansu province,changed to blue colour.The well is located in the anomalous hot area,where deep fluid have abnormal activities.In this paper,the geological environment of the well is surveyed,the causes,storage and transport mechanism of underground gas are analyzed using physical and chemical methods.Meanwhile the causes of blue water phenomenon is explained by "The bubble migration mechanism",it would provide an important theoretical basis for analysing the earthquake precursor in future.
2009, 31(3):242-247.
Abstract:The records of quartz tilter in Wushi station during 1998-2003 are processed with classical method of tidal analysis,and the tilt tidal parameters are calculated.The results indicate that the observational precision of semidiurnal tidal parameters is less than 0.001;the long-term stability is prior 2%.The abnormal varieties of γm2 were recorded before ML≥6.0 earthquakes in neighboring region,but the magnitude of abnormality is less than theoretic value.The observational records of water tilter are well consistent with that of quartz tilter, the conforming precision and stability of water tilter is higher than quartz tilter.
2009, 31(3):248-253.
Abstract:The auto-PSD function analytic solutions of interstorey drift and storey shearing force of multi-storey and high building structural storey model are derived on the basis of pseudo-excitation algorithm.The auto-PSD function moments and standard deviation of interstorey drift and storey shearing force are calculated by numerical integral method.Supposed that the number of random dynamic response passing safe limitation is poison process or two states Markov process,the dynamic reliabilities of interstorey drift and storey shearing force are achieved by the computation program made with the Matlab language. The numerical results indicate that the approach is efficient and effective.
GUO?Tao , SONG?Juan , YAO?Ji , WEI?Ye?qing
2009, 31(3):254-258,264.
Abstract:According to the present Code for Seismic Design of Buildings,a time history method of seismic analysis for a 25-story unsymmetrical double-tower connecting structure,is carried out by using FEA software ANSYS.Its dynamic characteristic and seismic responses are analyzed,and compared with the double-tower structure without connection.The results show that the structure has complex torsional modal and its movement and deformation are harmonized when set the connection.
ZHAO?Xiao?-mao , HUANG?Fu-?qiong , WANG?Xin , DAI?Wang-qiang , HAN?Mei-tao
2009, 31(3):259-264.
Abstract:The relationship between rainfall and groundwater level is statistically analyzed from 2001 to 2006 at Fengxiang well in Baoji city of Shaanxi province.The result shows that Concentrated Rainfall obviously affect shallow well level and the both relate with a index within a definite confine.The influences of rainfall to effectively stress of fault are discussed in three ways such as rainfall loaded,filtering into fault surface and groundwater level altered.The effect to regional stress field can trigger moderate-strong earthquakes.
LI?Jie , LU?Shuang-ling , YIN?Hai-tao , JING?Qiang , Fan?Jun
2009, 31(3):265-271.
Abstract:The periodic characteristics of normal and abnormal signals in gravity observation data from Tai an station are analyzed systematically.The relationship among the high-frequency abnormal signals and typhoon,strong earthquake and atmospheric pressure is studied.The results show that the signal period are about 2~4 minutes for normal cases and 2-3 minutes for abnormal cases,the amplitude of signals for abnormal cases are about 5 times than for normal cases.High-frequency abnormal signals are mainly caused by the typhoon which originated on western Pacific Ocean and go to China mainland or near regions, with percentage of 90%, and the signals are positively correlated with the velocity in center of typhoon. The abnormal signals would disappear with typhoon ended. Some abnormal signals are related with trong earthquake, taking number of 17.24% of earthquakes. But the signals have no relation with atmospheric pressure.
LIU?Jing , SHEN?Xu-hui , MENG?Kai , GUAN?Peng
2009, 31(3):272-276,284.
Abstract:Gulu Basin which extends over 50 km is situated in the middle of Tibet,and belongs to the north segment of Yadong-Dangxiong fault zone.Based on interpretation of remote sensing and geological tracing result,the ages of sedimentary fans are divided into three stages: Mid-Pleistocene,late time of Late-Pleistocene to Holocene and late time of Holocene.The western margin fault of Gulu Basin is a normal fault which has both vertical and right-lateral movement.Through researching the displacements and the sediments dates, it is obtained that the coseismic displacement is about 5.5 m, and the coseismic vertical displacement is 2-5 m in Ms at north of Dangxiong in 1952; the horizontal slip speed is 3. 75 mm/a, and theis 0. 5-1.5 mm/a since 4 ka; the horizontal slip speed is 1.0-5.0 mm/a,and the vertical slip speed is 0. 5-0.85 mm/a since about 10 ka.
XU?Yi--xi , ZHAN?Hui , FANG?Wei , CHEN?Xin-ze , WU?Wei-ri
2009, 31(3):277-284.
Abstract:With the analysis of gravity/geomagnetic observation and cross-fault leveling data in the middle segment of Shaowu-Heyuan fault zone,the characteristic of the gravitational/geomagnetic field and crustal deformation field are discussed.It shows that there is a better correspondence between the geomagnetic field changes and seismological activity,there are gravitational field abnormal gradient in the vicinity of the epicenters.Fault vertical deformation is controlled by the regional fault and the variation differences denote the seismological activities in some areas.
LI?Jun , ZHANG?Bing , XING?Li-li
2009, 31(3):285-289.
Abstract:An embedded GPS,which can be applied to seismic prospecting and field research,is designed and realized.For field work characteristics and the real-time transmission of data,the system is composed by positioning terminals and supplemented by earthquake decision-making experts and monitoring center.With the style of mobile phone message and monitoring center,the real-time transmission and query of positioning data is mobile.
ZHAO?Jie , DU?Xue?bin , HU?Jian-jun , ZHANG?Cai-yan , XU?Yu?hong , DONG?Hai-long
2009, 31(3):290-295.
Abstract:The quality of the observed data of geoelectric field from Jiayuguan station is analyzed and appraised in six aspects,and the basic factors of geoelectric field change are discussed.The result shows that the data of Jiayuguan station have reflected the real change of earth electric field,and the records are accurate.The short-term and imminent precursors in the geoelectric field and telluric data before 4 times moderate and strong earthquakes occurred near Jiayuguan station are studied.It is considered that before moderate-strong earthquake there are some short and imminent anomalies in the geoelectric field data.
LI?Gang , ZHOU?Li-xia , WANG?Xiao-lei , YAO?Hui-qin , LI?En-jian
2009, 31(3):296-301.
Abstract:Based on the high speed regional network environment built in "the tenth five-year plan" in Earthquake Administration of Tianjin,the website system of load balancing has been constructed in the information network center and Jixian seismic station information node.It is composed of 4 WWW servers and 2 databases servers.The database real-time duplication in the region and different backup of the website are realized,and the problem that the website syestem shows unstable well when visit quantity arises suddenly had solved also. The new network application way and the service strategy in the high speed network environment are explored.
2009, 31(3):302-307,310.
Abstract:High precision GPS network,using to monitoring the crustal movement and deformation of large,middle and small scales,are established in Chinese mainland and its surrounding areas,because the precision of spatial geodetic technology,such as GPS,is improving in the past nearly two decades.The relevant theory and methods for studying the crustal movement and deformation with application of GPS technology are reviewed.The methods of calculating horizontal strain are introduced.The math-physical methods of describing crustal deformation field are introduced with special attention. The progress and existing problems of the study on Extraction the sign of crustal movement and deformation from space geodetic measurements are discussed.
LIN?Shu-bing , WANG?Zhi-peng , WANG?Hai-qing , ZHUANG?Ming?yue
2009, 31(3):308-310.
Abstract:According to the interrelated technical basis and standards,using PDA computer as the hardware platform and windowsCE as software support,the electrical recording system for leveling is disigned and the its program is completed in Microsoft eMbedded Visual Basic enviroment.This system can replace the works with manual recording book of Leveling completely.
Sopyright:China Earthquake Engineering Journal