ZHANG?Hou-quan , TANG?Chun-an , HE?Yong-nian , HAN?Li-jun , ZHU?Wan-cheng
2006, 28(1):1-5.
Abstract:In this paper, self-organization behavior in rock failure progress is simulated by RFPA^20 code under uniaxial compression test. The results visually present ‘3S’ phenomena (stress buildup, stress transference and stress shadow) in the whole failure progress. Some beneficial discussion on self-organized critical characteristics is made in the subsequent text, which has clarified some concepts such as selforganized criticality phenomena and so on. Through this study, it indicates that self-organization behaviour in rock fracture is one dynamic mechanical process, which occurs not only after self-organized critical point but near it, viz. before or after it, only mechanical behavior is different, it is more remarkable after than before.
CHEN?Gao , WANG?Shu-ming , WANG?Jia-ying , ZHOU?Zong-liang
2006, 28(1):6-10.
Abstract:Topography with great rising and falling could affect the interpretation result of magnetotelluric sounding strongly, and different topographic characteristic could cause different effects. But the effects can be suppressed or eliminated by using certain correction method. In this paper, taking Zhenba area as example, characteristic of the topographic effects is studied, and topography correction is carried out successfully. The interpretation result reveals some main faults and nappe clearly, accord with the tectonic structure of this area well.
2006, 28(1):11-14.
Abstract:A new method is proposed for picking up the seismic first arrival time in this paper. The method ,which makes the original time serial mapping in the phrase space, picks up the seismic first arrival time according to its character of the phrase space. Contrast with traditional methods which spends long time for picking up the first arrivals, the new method improves the calculation speed and strengths the stability of result.
SUN?Yuan , QIU?Bin-huang , WANG?Zan-wen
2006, 28(1):15-19.
Abstract:The weak roadbed in sand soil area is a common problem in the highway construction. Adopting transient surface wave method combining with the test information of some drill holes, the relation model of the interface wave velocity and sandy soil the vertical and horizontal distribution characteristic mechanics parameters is built up in thip paper, and and regulation of the sandy soil mechanics parameters can be predicted in prospecting area. Through the practice checking, the predict result mainly coincides with the variety regulation of the actual sandy soil medium, which indicates that the mathematiced relation model built up in the paper is correcf and has higher practicability. The method will provide an economic viable way for prospecting and the classification evaluation of sandy soil in highway roadbed.
WANG?Ai-guo , YANG?Bin , ZHANG?Xiang-hong , LIU?Yu
2006, 28(1):20-25.
Abstract:The characteristics of present tectonic stress along Zhongwei -Tongxin fault zone are obtained by using the finite-element simulation with an elastic model, and the future earthquake rupture risk areas are predicated using rock rupture risk coefficient (KR) and fault gliding risk coefficient (KF) as criteria in this article. The result shows that the modern stress along the fault zone has a feature of segmentation and can be divided into three segments. The earthquake rupture risk areas is from Hongguanguan to Hongguliang. When earthquake occur, the initial rupture area will locate from south Zhongwei to Jiangou, and quickly expands to two sides. Toward east the rupture stops quickly and toward west it attenuates slowly until it reaches Hongguanguan.
2006, 28(1):26-30.
Abstract:The seismic response time-history of a continuous girder bridge with viscoelastic damper is analyzed. The effect of vibration mitigation of the damper in bridge and the influence of the damper parameters to the absorption effect are discussed. The result shows that the bridge with viscoelastic damper can minimize seismic response, and the damper parameter should be optimized in order to get nicer effect.
LU?Peng-zhen , ZHANG?Jun-ping , LIU?Ai-rong , MEI?Li-biao
2006, 28(1):31-35.
Abstract:The structure of Y-shape Bridge is an effective way for solving the city traffic problem. Based on the grillage theory and using common finite element software SAP2000, the vibration frequency and shaking type of structure of Y-shape Bridge are analyzed, and main structure parameter, impacting on its dynamic characteristics are discussed. The result could be a reference for the design of Y-shape Rridge.
YIN?Ji-yao , XU?Ping , WU?Pei-zhi
2006, 28(1):36-41.
Abstract:As the IGS precise ephemeris which is used in GPS precise positioning (for example, in GAMIT software) can only be available in two weeks later, it is an important condition for using GPS data in the earthquake short-term prediction that taking the IGS rapid ephemeris which can arrives in two days and the IGS ultrarapid ephemeris which can be obtained in 12 hours, both with as nearly same preciseness as the precise ephemeris with, to replace the IGS precise ephemeris. In this paper, based on the observation data of 5 GPS continuous stations in the global positioning integrated application and services system in Beijing in one and half year, the precise located calculation is done by using three IGS satellite ephemeredes. The conclusion is that IGS rapid ephemeris can commonly replace the IGS precise ephemeris in calculation for small network.
XUE?Xin-hua , ZHANG?Wo-hua , LIU?Hong-jun
2006, 28(1):42-45.
Abstract:Considering some defects of BP Neural Network, this paper proposes a GA-BP ( Genetic Neural Network) learning algorithm, which is obtained by using Genetic Algorithm to optimize neural network trained by BP algorithm, and the GA-BP model of sand liquefaction is established. Based on the observation data of sand liquefaction, the computing results of the GA-BP model and the BP model prove that the former is nicer than the later in predicting the sand liquefaction.
ZHOU?Qing-yun , HE?Yong-feng , JING?Ping , LIAO?Gui-sheng
2006, 28(1):46-50.
Abstract:Multiple filter analysis method (MFF) has been proved efficient for computing the dispersion curve of surface wave. In the article ,with the data of earthquake event in Nevada area recorded by single station, MFF is used to derive the dispersion curve of Nevada area, and its characteristic are deeply analyzed. The result shows that the dispersion curves in Nevada area own the character of the dispersion curves of the typical mainland fundamental Rayleigh mode. Furthermore, theoretical dispersion curve of Rayleigh wave is calculated by generalized reflection - transmission method, and the phase velocity curve and group velocity curve of the fundamental Rayleigh mode are compared with that derived from the synthetic seismogram calculated by the modal sunnation method with MFF. Two results coincide better in the interested frequency range, showing MFF is reliable.
ZHANG?Quan-sheng , WANG?Jia-ying , YANG?Sheng , ZHU?Chun-sheng
2006, 28(1):51-55.
Abstract:Using Tianshan region the Far Reference in Xinjiang Uygur and Robust methods, the magnetotelluric sounding data of Northern Autonomous Region are processed and the geological interpretation is given. The region is divided into 4 main tectonical units: Sikeshu depression, the frontal edge fault-fold belt, the nappe belt of northern Tianshan and the middle Tianshan upheaval. The surface of the nappe belt is covered by Carboniferous System bedrock. Under the nappe fault, the abnormal body of low resistivity in middle-shallow layers is discovered, which is deduced as Jurassic and Cretaceous Systems, and it is thought as the main promising oil and gas survey area.
GUO?An-ning , CHEN?Jia-chao , GUO?Zen-jian
2006, 28(1):56-58.
Abstract:In this paper it is consided that the great Indonesia M,,9 earthquake in 2004 is caused by new extension of Indonesia deep trench. The prediction for occurrence year and date of the great earthquake are also discussed by using the law of 35 years.
KANG?Chun-li , LIU?De-fu , CHEN?Yan , ZHOU?Xiao-cheng
2006, 28(1):59-63.
Abstract:Based on the information of OLR ( Outgoing-Longwave-Radiation ) of the satellite telemetry, the spatial distribution and its variation characteristics of the OLR information field in North China are analyzed, and the method for the determination indexes of moderate-strong earthquakes in short-term prediction by combining with seismic activity features is discussed. The result shows that this method may give a specific estimation whether there will be earthquakes with M≥5 in the near future in North China, with good test effectiveness in practice of one year. The method has a practicality for monitoring and forecasting short-term seismic situation in the near future in North China.
YANG?You-ling , SUN?Jia-ning , GAO?Guo-ying , WEN?He-ping
2006, 28(1):64-68.
Abstract:Short-term and impending anomalies of ground tilt before some Ms4.0 and Ms5.0 earthquakes in Xinjiang are analyzed by routine methods. The statistical data such as the period between anomaly initial time and earthquake, the anomaly duration time, the period between anomaly ending and event, the anomalous amplitude and the anomalous shape are summarized. Through analyzing the typical cases the short-term anomalous features of groud tilt before moderate-strong earthquake and strong earthquake in a far distance are presented in the paper. In the short-impending period before event, the number and amplitude of anomalies increase quickly, the anomaly initial time and the predominant period for event occurring are different in different magnitude of events.
YE?Xiu-wei , WEN?Ze-gang , KANG?Ying , SUN?Chong-chi
2006, 28(1):69-73.
Abstract:Using some formulea about relations between source parameters and ambient shear stress 70 deduced by Chen Pei-shan, the 7o for 60 earthquakes(ML≥2.5) occurred in South China are calculated, based on the data of Guangdong Digital Telemetry seismic wave with the source parameters : seismic radiated engergy E, comer periodfo, source peak acceleration ap, source peak velocity vp, source peak displacement dr and seismic moment Mo. The analysis results of the relative errors and correlations for estimated To values from different methods shows that the smallest relative error δT0/T0 is (5 - 15 ) % , when using the source peak acceleration ap, and the correlative coefficient is maximum. For the digital data, T0 could be calculated by ap directly, without seismic moment Mo for which calculation is complicated. So the method of calculating the ambient shear stress with source peak acceleration ap is simple and reliable.
SHEN?Hong-hui , FENG?Zhi-sheng , YAN?Ming-zhi , TIAN?Tao , LI?Wei
2006, 28(1):74-77.
Abstract:The earthquake prediction based on the geoelectric field variation is still in period of fumble and discussion. In this paper, using some digital observation data of geoelectric field in Northwest China, the variation before some earthquakes are analyzed. Some views and suggestion for earthquake prediction based on the geoelectric field are presented also.
WANG?Wei , LIN?Ming-zhou , MA?Qin-zhong , ZHAO?Li-fei
2006, 28(1):78-84.
Abstract:Statistical learning theory (SLT) is a small-sample statistics theory. Support vector machine (SVM) is a new machine learning method based on statistical learning theory. It can process the high nonlinear problems with classification and regression, SVM not only can solve some problems, such as small-sampler over-fitting, high-dimension and local minimum, but also has higher generalization (forecasting) ability than that of the artificial neural networks. In this paper, the classification and regression methods of SVM are introduced , the characters of the methods are analyzed , and the application future of SVM in earthquake prediction is discussed also.
2006, 28(1):85-91.
Abstract:The main types of grounds for non-engineering rural buildings in Gansu Province are summarized. The characteristics and safety problems are discussed for each type of ground, some countermeasures for improving the rural building safety, strengthening the ability of seismic resistance are presented. It is considered that promoting rural construction level through education of skilled farmer worker, relevant knowledge promulgating and public codes and incentives on rural building construction management is an urgent need.
GUO?Zeng-jian , LU?ming , LI?Ge-ping , GUO?An-ning
2006, 28(1):92-94.
Abstract:Eight large earthquakes (Ms ≥ 7 ), including a great Ms 8.1 earthquake took place in Qinghai province and its west neighbour region in last century. The time intervals among these events fit to the temporal triplet distribution with period of 25 years. Based on it , we predict a large earthquake(Ms≥7) will occur again in Qinghai province in 2012 ± 2.
Sopyright:China Earthquake Engineering Journal