Abstract:In this paper,on the basis of the combination pattern,author calculates two models by using the 3-D finite element method. The major conclusions are:(1)The adjustment element fractures firstly before the strong earthquake takes place,variation of strain with time is a quasi-lambda curve.(2)The accumulative element will fracture after the adjustment element fractures,variation of strain with time is a lambda curve.(3)The strain attenuates quickly along the perpendicular direction of fault strike,but slowly along the fault strike.(4)The situations of the clements in a seismic field region are very complex,and their strain changes with time are non-lambda curves. Finally,some seismic events about lambda-pattern are presented,and some precursory phenomena are interpreted by using conclusion(1).

Abstract:This paper established tracing craking fractal model by combining with the principle of fracture mechanics of rock mass and based on analyzing the fracture mechanics feactures of rock mass,probed into the fractal effect of the fracture toughness of discontinuous rock mass, and Verified the model through press-shear test.

Abstract:This paper deals with the application of the thin layer approximation in 3-D MT presented by S. Park,in the interpretation of the repeated measurements in fixed MT points in the boundary area between Gansu and Qinghai Provinces.The results reveal the good prospect of applying the thin layer approximation in MT measurements in the condition of complex structure. The program made on the basis of the theoretical aspect of the approximation with high accuracy is applicable.

Abstract:This paper systematically studies the interference of groundwater station network in Gansu Province,analyses the some characters of groundwater short-impending anomalies,discusses its monitoring ability to mid-strong earthquakes,and suggests some seismic short-impending anomaly in dices for this region.

Abstract:The buried depth of basement magnetism interface in Hetao rift zone and its adjacent area,Inner Mongolia, is calculated by using inversion method for aeromagnetic data and singlemangnetic boundary in the frequency domain. The buried depth of lower boundary of magnetic layer,i.e. Curie surface,is also calculated in terms of inversion theory for 3-D magnetic stratum.Quantitative features of the upper and tower boundaries of the magnetic stratum are analysed and the crustal structure characteristics and seismogenesis of this area are discussed based on the research results for gravity,geotherm and ground deformation.

Abstract:In this paper, the gravity profile survey in the Tianshui area in 1990 is introduced.The surveying results are calculated by direct inversion method of variable densities.In the area,the crustal structure, besides the sedimentary layers near surface,includes three layers,i.e. the up-per,middle and lower crusts with the average densities of 2.61,2.66 and 2.80 g/cm³, respectively.The average bottom depths are 16, 28 and 45 km respectively,and the layers have considerable variations in both lateral and vertical directions.

Abstract:This paper sums up the activities of historical and modern earthquakes in YunnanProvince and suggest that the seismicities in the region are characterized by high frequency,large magnitude,shallow source and strong disruption.The strong earthquakes can be divided into mainshock and mainshock-aftershock sequences. Since the present century,the activities of strong earthquakes tend to migrate in counterclockwise direction. In addition,authors analyze and discuss preliminarily the causes of the seismicities,and put forward some earthquakes prediction countermeasures for Yunnan region based on these seismicity characters.

Abstract:This paper briefly introduces the Corioli's force and then discusses the possibility to predict the magnitudes of strong aftershocks or ensuing great earthquakes after a main shock by using the geologica data and the action of Corioli's force in focal region.Through analysis of earthquakes,it is considered that the method is feasible

Abstract:In this paper,the reasonable mechanics model are established for single pile foundation in layered elastic ground by means of characteristic analysis,Then the torsional vibration analysis of the pile is carried out according to layered elasto-foundation soil model,thus the analytic solutions for the torsional free vibration characteristics and the coercion responses under the action of the torsional seismic loading and torsional vibration loading of the pile are given. The analytic formulas in the paper provide a new analytic method for the torsional seismic response analysis of the pile foundation in layered elastic ground.

Abstract:By using information diffusion method combined with BP neural network,the authors suggest a kind of fuzzy neuron in present paper.The model of relationship between length of aftershock area and magnitude is discussed by the fuzzy neuron. This model has strong adapt-ability and can treat contradictory samples. Comparison of the results of this model with those of statistical method shows the advantage of the model.

Abstract:In this paper the technical indexes,principle,function of a new specialized electrotelluric measuring instrument(Model-ZD9)developed by authors is introduced. This instrument can be used for routine observation of earth electric field at field stations and to detect deep earth resistivity by using the tensor method. It can also be used in other cases where multi-channel data collecting is required. The tests of various performances and long use in earthquake sites show that the instrument can meet the needs of observing the geoelectric field.

Abstract:In this paper,in view of the actual situation of setting ground tiltmeters in our country,we have derived the current formulae which are used to calcutate the ground tilt azimuth and the dip angle by using observations of the tiltmeters installed in two arbitrary directions and the formula which is used to reduce the data to NS and EW directions.For two kinds of tiltmetersof Taian station,the curves of ground tilt tide have presented synchronous changes after the data have been reduced by using the formulae,and the correlativity have increased obviously. Also,the great changes have taken place after the tilt anomaly data before the Datong-Yang-gao M_S=6.1 earthquake have been reduced,In the end of this paper,the concrete opinions about the reduction of ground tilt observations are given.

Abstract:描述前兆异常幅度的归一化方法1问题的提出目前关于地震前兆异常幅度的表示缺少统一的方法,各手段用各自的观测量(有些甚至用仪器读数)的变化作为异常幅度,在地电阻率观测中用视电阻率的相对变化作为异常。

Abstract:武都两水地应力台震前应变短临异常特征1前言甘肃武都地区两水地应力台站建于1971。该站处于多组构造的交汇复合部位,据多年观测发现,该站是地震前兆监测的敏感部位。

Abstract:768遥控装置发送机部分电路的研制与应用1引言768遥控装置由发送机和接收机两大部分组成,主要用于遥控检查和检验地震遥测系统。768遥控装置每天发出的标定指令和野外拾震计的标定响应脉冲,直接反映了地震遥测系统的可靠性与稳定度。

Abstract:地壳板块运动的广义相对论理论板块构造学说问世以来,迅速地为广大地学工作者所接受^[1,2],被J.T.威尔逊宣称为一次"地球科学中的革命"。它是当前最广泛采用的一种大地构造理论。但是,随着板块构造学说的理论研究不断深入,人们也发现和遇到一些新问题。

Abstract:In this paper, the dynamic model of predicting the origin time of carthquakcs is established by using the grey control system and choosing 6.0 < Ms < 7.0 seismic sequences from Jan. 1980 to Dec. 1988 inJapan as samples,and the best model is chosen to predict the occurrence of the moderate and strong carthquakcs in Japan. Moreover, in view of function transformation,the model GM(1.1)is interpreted in a broad sense and the model cstablished for the sequence must take time when the smooth degree is satisfied as the starting point.More calculations indicate the at the fitting and extrapolated precisions of model cstablished "enough small number" of samples are better than that by "large number"of samples. This is analysed from the view of information theory.