Strain and tilt changes measured during a water injection experiment at the Nojima Fault zone, Japan   总被引：2，自引：0，他引：2  

Kunio Fujimori  Hiroshi Ishii  Atsushi Mukai  Shigeru Nakao  Shigeo Matsumoto  Yasuhiro Hirata 《Island Arc》2001,10(3-4):228-234

Abstract In order to make geophysical and geological investigations of the Nojima Fault on Awaji Island, Japan, three boreholes measuring 1800 m, 800 m and 500 m deep were drilled into the fault zone. The fault is one of the seismic source faults of the 1995 Hyogo-ken Nanbu earthquake of M 7.2. A new multicomponent borehole instrument was installed at the bottom of the 800 m borehole and continuous observations of crustal strain and tilt have been made using this instrument since May 1996. A high-pressure water injection experiment within the 1800 m borehole was done in February and March 1997 to study the geophysical response, behavior, permeability, and other aspects of the fault zone. The injection site was located approximately 140 m horizontally and 800 m vertically from the instrument. Associated with the water injection, contraction of approximately 0.7 × 10⁻⁷ str (almost parallel to the fault) and tilt of approximately 1 × 10^-7 rad in the sense of upheaval toward the injection site were observed. In addition to these controlled experiments, the strainmeter and tiltmeter also recorded daily variations. We interpret strain and tilt changes to be related to groundwater discharge and increased ultra-micro seismicity induced by the injected water.  相似文献   

General characteristics of the recent horizontal crustal movement in Chinese mainland   总被引：5，自引：0，他引：5  

顾国华  申旭辉  王敏  郑贵明  方颖  李鹏 《地震学报(英文版)》2001,14(4):384-393

1 Introduction of GPS observation dataThe Crustal Movement Observation Network of China (CMONOC) is a major scientific project in China organized by China Seismological Bureau and paticipated by the Bureau of Surveying and Mapping of the General Staff, the Chinese Academy of Sciences and the National Bureau of Surveying and Mapping. Based on the observation data of 25 fiducial stations and 56 basic stations in CMONOC (Figure 1 and Table 1), collected from August 26 to September…  相似文献   

Model of rigid and elastic-plastic motion in intraplate blocks and strain status of principal blocks in Chinese mainland   总被引：5，自引：1，他引：5  

李延兴  黄珹  胡新康  帅平  胡小工  张中伏 《地震学报(英文版)》2001,14(6):603-610

Introduction The Chinese mainland is located in the southeastern part of Eurasia plate and encircled by India, Eurasia, Pacific and Philippine Sea plates. It is one of areas with the strongest tectonic de-formation, especially Qingzang (QinghaiXizang) plateau and NS tectonic zone where the tec-tonic activity is more intensive and intricate. The main part of tectonic activity of Chinese mainland includes a series of tectonic zones and active blocks divided by them. Therefore, the research…  相似文献   

Evaluation of response and energy in actively controlled structures     

Kevin K. F. Wong  Rong Yang 《地震工程与结构动力学》2001,30(10):1495-1510

A computational method of energy evaluation is derived to study the elastic responses and energy distribution of actively controlled single‐degree‐of‐freedom (SDOF) structures during earthquakes. Contrary to the common perception that applying active control force pumps energy into the structure, the applied control force can actually reduce the energy in the structure by reducing the input energy from earthquakes to the structure. In addition, applying control force can dissipate a large amount of energy in the structure when this control force is applied in the direction opposite to the displacement and velocity responses. To demonstrate this energy mechanism in active controlled structures, the two most popular control algorithms, optimal linear control (OLC) and instantaneous optimal control (IOC) algorithms, are used to calculate the control response and energy spectra. One‐step time delay is incorporated into the algorithms to take into consideration the practical aspect of active control. The effects of different earthquakes and damping ratios on control energy and response spectra are studied. These studies show that both OLC and IOC are very effective in reducing the structural displacement and velocity responses by reducing the input earthquake energy as well as dissipating a large amount of energy in the structure. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

On the origin of inhomogeneity of anomalous birefringence in mixed crystals: an example of alums     

A. G. Shtukenberg  Yu. O. Punin  E. Haegele  H. Klapper 《Physics and Chemistry of Minerals》2001,28(9):665-674

 Optical anomalies (deviations of the symmetry of optical properties from the ideal symmetry of the crystal) occur in many minerals and synthetic compounds and have been under investigation since the last century. An important feature of optically anomalous mixed crystals is a high degree of optical inhomogeneity, whereas the optical patterns of mixed crystals without anomalies are usually rather uniform. This work is devoted to the study of this phenomenon. As a model object we have chosen mixed alum crystals, which were known for their anomalous birefringence and which revealed the following types of optical inhomogeneities: (1) sector zoning; (2) concentric zoning; (3) subsector zoning; (4) stripes normal to growth front. The inhomogeneity of anomalous birefringence of mixed crystals of alums can be explained by superposition of several effects: mismatch strain, strain along dislocations and growth ordering of isomorphous components. Optical inhomogeneities due to the sector zoning of crystals and their dislocation structure arise even under stationary growth conditions and stationary micromorphology of the growing face. Both variable growth conditions and the relief of the growing face strongly intensify the optical inhomogeneity due to three interrelated factors: (1) a significantly inhomogeneous mismatch strain; (2) a variable degree of ordering of isomorphous components due to the compositional inhomogeneities; (3) different degrees of ordering of isomorphous atoms caused by different orientations, heights and velocities of growth steps. These effects lead to the formation of subsector zoning and zoning superimposed on the optical sector zoning. These optical structures are crossed by birefringent stripes arising from dislocations. Received: 29 March 2000 / Accepted: 11 March 2001  相似文献   

Synchrotron X-ray powder diffraction study of natural P2 /n-omphacites at high-pressure conditions     

A. Pavese  V. Diella  D. Levy  M. Hanfland 《Physics and Chemistry of Minerals》2001,28(1):9-16

 Synchrotron X-ray powder diffraction experiments at high pressure conditions (0.0001–13 GPa) were performed at ESRF (Grenoble-F), on the beamline ID9, to investigate the bulk elastic properties of natural P2/n-omphacites, with quasi-ideal composition. The monoclinic cell parameters a, b, c and β were determined as a function of pressure, and their compressibility coefficients are 0.00277(7), 0.00313(8), 0.00292(5) and 0.00116(4) GPa⁻¹, respectively. The third-order Birch-Murnaghan equation of state was used to interpolate the experimental P−V data, obtaining K ₀=116.6(±2.5) GPa and K′₀=6.03(±0.60). K ₀ was also determined by means of the axial and angular compressibilities [122.5(±1.7) GPa], and of the finite Lagrangian strain theory [121.5(±1.0) GPa]. The discrepancies on K ₀ are discussed in the light of a comparison between techniques to determine the bulk modulus of crystalline materials from static compression diffraction data. Received: 22 February 2000 / Accepted: 10 July 2000  相似文献   

体应变观测中的气压干扰机制和排除方法的研究   总被引：7，自引：0，他引：7  

张凌空  何世海  刘北顺 《地震》1996,(2)

建立体应变理论气压干扰模型,通过实际观测资料研究了气压对体应变月变和日变的干扰过程,探讨消除干扰的方法,且和水位资料作了对比分析。  相似文献   

Cyclic strength and deformation of crushable carbonate sand     

Masayuki Hyodo  Noritaka Aramaki  Masayuki Itoh  Adrian F.L. Hyde 《Soil Dynamics and Earthquake Engineering》1996,15(5):331-336

Cyclic triaxial tests have been carried out on a skeletal carbonate sand from the west coast of Eire. Results are presented for undrained cyclic shear tests on samples with 80% of relative density consolidated under both isotropic and anisotropic conditions. Failure was defined as a 5% double amplitude cyclic strain and a 5% peak axial strain for stress-reversal and non-reversal stress conditions, respectively. Using this definition the cyclic strength for isotropically consolidated samples was affected by the confining pressure although the angular platey nature of the sand resulted in higher cyclic strengths than for a comparable silica sand. For anisotropically consolidated samples the cyclic strength increased with increasing initial static shear stress while on the other hand the cyclic strength normalised in the usual way with respect to the initial confining pressure decreased as this pressure increased.  相似文献   

龙门山断裂带测区古构造残余应力随深度分布及带中残余能量   总被引：1，自引：0，他引：1       下载免费PDF全文

安欧  高国宝 《地震地质》1996,18(1):25-29

以岩体正交异性弹性理论为基础，用Ｘ射线法，在龙门山断裂带测区，选取３个小区深钻孔系列的岩心，测量了岩体中宏观残余应力场的水平和铅直三维主分量、水平和铅直最大剪应力，及其应变能密度随深度的分布，分析了它们沿深度的分布规律，估算了该断裂带岩体中储存的宏观残余弹性应变能的量级  相似文献   

Geometrical　textures　of　faults，evolution　of　physical　field　and　instability　characteristics   总被引：9，自引：0，他引：9  

马瑾  马胜利  刘力强  邓志辉  马文涛  刘天昌 《地震学报(英文版)》1996,9(2):261-269

Ｇｅｏｍｅｔｒｉｃａｌｔｅｘｔｕｒｅｓｏｆｆａｕｌｔｓ，ｅｖｏｌｕｔｉｏｎｏｆｐｈｙｓｉｃａｌｆｉｅｌｄａｎｄｉｎｓｔａｂｉｌｉｔｙｃｈａｒａｃｔｅｒｉｓｔｉｃｓＪＩＮＭＡ（马瑾），ＳＨＥＮＧ－ＬＩＭＡ（马胜利），ＬＩ－ＱＩＡＮＧＬＩＵ（刘力强），Ｚ...  相似文献