共查询到20条相似文献，搜索用时 171 毫秒
1.
Introduction
The Tanlu fault zone lies in the eastern China, which is an important huge active fault with a long history. It has experienced a complex generation and evolution process and affects significantly the regional structure, paleogeography, magma activity, minerogenesis and earthquake activity in the area. With a length of 2 400 km, the fault zone consists of 2-4 or more parallel faults of 10-40 km in width, cutting through different geotectonic elements in the eastern China （FANG et al, 1986）. On July 25 in 1668, an extraordinarily large earthquake of M=8.5 occurred on the Changyi-Dadian fault （F1） that is an embranchment of Tanlu fault zone, resulting in a surface rupture with a total length of 130 km （LI et al, 1994; CHAO et al, 1995）. The paleoseismic study reveals that 3 events with a magnitude equal to 8 occurred on the Changyi-Dadian fault. The recent event occurred 3 500 a ago and the reoccurrence interval is about 3 500 a （LIN and GAO, 1987）. During the Tancheng earthquake （on July 25, 1668）, the Anqiu-Juxian fault was not ruptured, which was a Late Pleistocene active fault （ZHENG et al, 1988; GAO et al, 1988; CHAO et al, 1994） and was doubted as the seismogenic fault of the M=7.0 Anqiu earthquake occurred in 70 BC by certain geologists （CHAO et al, 1994）. 相似文献
2.
Introduction The Tanlu fault zone, the largest active structure in the eastern region of China, is character-ized by right lateral strike-slip movement with dip-slip component in the Quaternary; it shows great significance for the modern seismicity (FANG et al, 1976; Institute of Geophysics, China Earthquake Administration, 1987; GAO et al, 1980; MA, 1987; LI, 1989; CHAO et al, 1995). The Tanlu fault zone is the boundary between the Jiaoliao block and the North China Plain block of … 相似文献
3.
Fractal research of fault gouge 总被引：1，自引：0，他引：1
ＦｒａｃｔａｌｒｅｓｅａｒｃｈｏｆｆａｕｌｔｇｏｕｇｅＳＨＵＮ－ＭＥＩＳＨＡＯ（邵顺妹）ａｎｄＪＩＮ－ＣＨＡＮＧＺＯＵ（邹瑾敞）ＥａｒｔｈｑｕａｋｅＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＬａｎｚｈｏｕ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａ... 相似文献
4.
The coseismic Coulomb stress change caused by fault interaction and its influences on the triggering and delaying of earthquake are briefly discussed.The Xianshuihe fault belt consists of Luhuo,Daofu,Kangding,Qianning and Ganzi fault.Luohuo(Ms=7.6,1973)-Kangding(Ms=6.2,1975)-Daofu(Ms=6.9,1981)-Ms=6.0,1982)earthquake is a seismic sequence continuous on the time axis with magnitude greater than6.0.They occurred on the Luhuo.Kangding,Daofu and Ganzi fault,respectively.The coseismic Coulomb stress changes caused by each earthquake on its surrounding major faults and microcracks are calculated,and their effects on the triggering and delaying of the next earthquake and aftershocks are analyzed.It is shown that each earthquake of the sequence occurred on the fault segment with coseismic Coulomb stress increases caused by its predecessors,and most after-shocks are distributed along the microcracks with relatively larger coseismic Coulomb stress increases resulted from the main shock.With the fault interaction considered,the seismic potential of each segment along Xianshuihe fault belt is reassessed,and contrasted with those predicted results ignoring coseismic Coulomb stress change,the significance of fault interaction and its effect on triggering and delaying of earthquake are emphasized.It is con-cluded that fault interaction plays a very important role on seismic potential of Xianshuihe fault belt,and the maximal change of future earthquake probability on fault segment is up to 30.5%. 相似文献
5.
Unstable fault deformation and information synthesis 总被引：2，自引：0，他引：2
ＵｎｓｔａｂｌｅｆａｕｌｔｄｅｆｏｒｍａｔｉｏｎａｎｄｉｎｆｏｒｍａｔｉｏｎｓｙｎｔｈｅｓｉｓＷＡＮ－ＪＵＢＯ（薄万举），ＪＵＥ－ＭＩＮＸＩＥ（谢觉民）ａｎｄＧＵＡＮ－ＳＨＯＵＬＯＵ（楼关寿）ＦｉｒｓｔＣｒｕｓｔａｌＤｅｆｏｒｍａｔｉｏｎＭｏｎｉｔ... 相似文献
6.
ＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｆａｕｌｔｒｏｃｋｓａｎｄｐａｌｅｏｅａｒｔｈｑｕａｋｅｓｏｕｒｃｅａｌｏｎｇｔｈｅＫｏｋｔｏｋａｙＥｒｔａｉｆａｕｌｔｚｏｎｅ，Ｘｉｎｊｉａｎｇ，ＣｈｉｎａＬＡＮＢＩＮＳＨＩ１）（史兰斌）ＣＨＵＡＮＹＯＮ... 相似文献
7.
吴忠良 《地震学报(英文版)》2004,17(5):542-548
IntroductionInearthquakeandengineeringseismology,fortheexplanationofthehigh-frequencycontentsinearthquakegroundmotion,itisoftenassumedthatalargeearthquakeiscomposedofmanysmallereventswithavarietyofsizes(Frankel,1991).Thesesmalleventscomefromtheruptureoftheasperitiesalongtheearthquakefault,showingthecharacteristicsoffractals(Aki,1981).Thisworkingassumptioncanexplainsomeoftheimportantpropertiesofseismicsourcesuchasthehigh-frequencyfall-offofsourcespectra.Ontheotherhand,however,beinglimitedbyobs… 相似文献
8.
I. Anastasopoulos A. Callerio M. F. Bransby M. C. R. Davies A. El Nahas E. Faccioli G. Gazetas A. Masella R. Paolucci A. Pecker E. Rossignol 《Bulletin of Earthquake Engineering》2008,6(4):645-675
Field evidence from recent earthquakes has shown that structures can be designed to survive major surface dislocations. This
paper: (i) Describes three different finite element (FE) methods of analysis, that were developed to simulate dip slip fault
rupture propagation through soil and its interaction with foundation–structure systems; (ii) Validates the developed FE methodologies
against centrifuge model tests that were conducted at the University of Dundee, Scotland; and (iii) Utilises one of these
analysis methods to conduct a short parametric study on the interaction of idealised 2- and 5-story residential structures
lying on slab foundations subjected to normal fault rupture. The comparison between numerical and centrifuge model test results
shows that reliable predictions can be achieved with reasonably sophisticated constitutive soil models that take account of
soil softening after failure. A prerequisite is an adequately refined FE mesh, combined with interface elements with tension
cut-off between the soil and the structure. The results of the parametric study reveal that the increase of the surcharge
load q of the structure leads to larger fault rupture diversion and “smoothing” of the settlement profile, allowing reduction of
its stressing. Soil compliance is shown to be beneficial to the stressing of a structure. For a given soil depth H and imposed dislocation h, the rotation Δθ of the structure is shown to be a function of: (a) its location relative to the fault rupture; (b) the surcharge load q; and (c) soil compliance. 相似文献
9.
Introduction Like the longitudinal migration (DING, et al, 1993) of fault activity, the lateral migration is a common phenomenon in the fault development and evolvement, especially in the piedmont and the margin of lake basin. As a large inland basin beside the northeast margin of Qinghai-Xizang block (DENG, YOU, 1985; Research Group of Active Fault System around Ordos Massif, 1988; Bureau of Geology and Mineral Resources of Shaanxi Province, 1989; PENG, et al, 1992), the lateral m… 相似文献
10.
M. F. Bransby M. C. R. Davies A. El Nahas S. Nagaoka 《Bulletin of Earthquake Engineering》2008,6(4):607-628
The propagation of reverse faults through soil to the ground surface has been observed to cause damage to surface infrastructure.
However, the interaction between a fault propagating through a sand layer and a shallow foundation can be beneficial for heavily
loaded foundations by causing deviation of the fault away from the foundation. This was studied in a series of centrifuge
model tests in which reverse faults of dip angle 60° (at bedrock level) were initiated through a sand layer, close to shallow
foundations. The tests revealed subtle interaction between the fault and the shallow foundation so that the foundation and
soil response depend on the foundation loading, position, breadth and flexibility. Heavily loaded rigid foundations appeared
best able to deviate fault rupture away from the foundation but this deviation could be associated with significant foundation
rotations. However, a lightly loaded foundation was unable to deviate a reverse fault and the fault emerged beneath the foundation.
This led to gapping beneath the foundation as well as significant rotations and may cause severe structural distress. As well
as providing insight into the mechanisms of behaviour, the data from the tests is used to validate finite element analyses
in a separate article. 相似文献
11.
Effect of source parameters on forward-directivity velocity pulse for vertical strike slip fault in half space 总被引：1，自引：0，他引：1
It has been found that the large velocity pulse is one of the most important characteristics of near-fault strong ground motions. Some statistical relationships between pulse period and the moment magnitude for near-fault strong ground motions have been established by Somerville （1998）; Alavi and Krawinkler （2000）; and Mavroeidis and Papageorgiou （2003）, where no variety of rupture velocity, fault depth, and fault distance, etc. were considered. Since near-fault ground motions are significantly influenced by the rupture process and source parameters, the effects of some source parameters on the amplitude and the period ofa forward-directivity velocity pulse in a half space are analyzed by the finite difference method combined with the kinematic source model in this paper. The study shows that the rupture velocity, fault depth, position of the initial rupture point and distribution of asperities are the most important parameters to the velocity pulse. Generally, the pulse period decreases and the pulse amplitude increases as the rupture velocity increases for shallow crustal earthquakes. In a definite region besides the fault trace, the pulse period increases as the fault depth increases. For a uniform strike slip fault, rupture initiating from one end of a fault and propagating to the other always generates a higher pulse amplitude and longer pulse period than in other cases. 相似文献
12.
基于显式有限元方法和运动学震源模型并利用昆明盆地三维地下构造模型,本文研究了震源参数对断层附近长周期地震动的影响.结果表明,断层的破裂方式、埋藏深度、破裂速度以及断层面上位错的不均匀分布对断层附近长周期地震动有重要影响.不同破裂方式下,破裂的方向性强的区域分布不同,由于破裂的方向性效应和复杂场地条件的共同作用,导致不同破裂方式的断层附近地震动分布差别很大.随着破裂速度的增加,方向性效应更加明显,断层附近的长周期地震动也随之增大;对于浅源地震,随着断层埋深的增加,地震动明显下降.对于埋藏深度很浅的断层,当Asperity靠近断层上沿时,会显著增大其在地表投影附近的长周期地震动.能否合理地估计这些基本震源参数,是预测未来发震断层周围地震动场的关键. 相似文献
13.
实际工程场地中的断层通常具有三维尺寸,应进行三维分析。本文考虑均匀弹性半空间内存在不同长度、深度的三维断层,由下向上垂直入射一个脉冲波,主要采用三维时域显式有限元结合透射人工边界的方法及相应编写的三维显示有限元波动程序DSI3,计算断层附近地震地面运动的时程反应,研究含有三维断层场地地面运动的一些特点,并与自由场反应对比,以说明三维竖向断层对地震波传播的特点和对断层附近地面运动的影响。 相似文献
14.
Influence factors on the ground surface rupture zone induced by buried normal fault dislocation* 
下载免费PDF全文
下载免费PDF全文 The seismic disaster presents a zonal distribution along the fault strike. In this paper, rupture zone of ground surface soil caused by the uniform dislocation, inclined dislocation and warped dislocation of buried normal fault are studied by constituting a three-dimensional finite element model in Automatic Dynamic Incremental Nonlinear Analysis (ADINA). According to the critical value of surface rupture, the variational features and influencing factors of width and starting position of the “avoiding zone” in engineering construction are analyzed by using 96 model calculations. The main results are as follows: (1) Since the rupture zone of the ground surface soil from the point of mechanics is different from the “avoidance zone” from the point of engineering safety, the equivalent plastic strain and the total displacement ratio should be considered to evaluate the effect of the seismic ground movement on buildings. (2) During fault dislocation, plastic failure firstly occurred on the ground surface soil of the footwall side, and then the larger deformation gradually moved to the side of the hanging wall of the fault with the increase of fault displacement. (3) When the vertical displacement of buried fault reaches 3 m, the width of “avoiding zone” in engineering construction varies within the range of 10–90 m, which is most affected by the thickness of overlying soil and the dip angle of the fault. 相似文献
15.
Response spectrum of seismic design code for zones lack of near-fault strong earth- quake records 总被引：1，自引：0，他引：1
It was shown from the study on the recently near-fault earthquake ground motions that the near-fault effects were seldom considered in the existing Chinese seismic code. Referring to the UBC97 design concept for near-fault factors, based on the collected world-widely free-site records of near-fault earthquakes ground motions classified by earthquake magnitude and site condition, the attenuation relationship expressions of the acceleration spectrum demand at the key points within the long period and moderate period were established in term of the earthquake magnitude and the site condition. Furthermore, the near-fault factors’ expressions about the earthquake magnitude and the fault distance were deduced for the area lack of near-fault strong earthquake records. Based on the current Chinese Building Seismic Design Code, the near-fault effect factors and the modified design spectral curves, which were valuable for the seismic design, were proposed to analyze the seismic response of structures. 相似文献
16.
Simplified approach for design of raft foundations against fault rupture. Part Ⅰ： free-field 总被引：2，自引：2，他引：0
Over the past few decades, earthquake engineering research mainly focused on the effects of strong seismic shaking. After the 1999 earthquakes in Turkey and Taiwan, and thanks to numerous cases where fault rupture caused substantial damage to structures, the importance of faulting-induced deformation has re-emerged. This paper, along with its companion （Part Ⅱ）, exploits parametric results of finite element analyses and centrifuge model testing in developing a four-step semi-analytical approach for analysis of dip-slip （normal and thrust） fault rupture propagation through sand, its emergence on the ground surface, and its interaction with raft foundations. The present paper （Part Ⅰ） focuses on the effects of faulting in the absence of a structure （i.e., in the free-field）. The semi-analytical approach comprises two-steps： the first deals with the rupture path and the estimation of the location of fault outcropping, and the second with the tectonically- induced displacement profile at the ground surface. In both cases, simple mechanical analogues are used to derive simplified semi-analytical expressions. Centrifuge model test data, in combination with parametric results from nonlinear finite element analyses, are utilized for model calibration. The derived semi-analytical expressions are shown to compare reasonably well with more rigorous experimental and theoretical data, thus providing a useful tool for a first estimation of near-fault seismic hazard. 相似文献
17.
首先基于有限断层破裂下的运动学震源模型,对比验证了三维谱元法对于近场地震动的模拟精度。 进而通过含盆地模型与不含盆地的一维水平成层模型的地震动强度之间和放大系数分布特征之间的对比,详细研究了直下型断层的破裂速度对盆地地震效应的影响。结果表明,盆地的存在会显著改变近断层地震动的分布特征,同时盆地内不同分量强地震动的分布特征变化较大。断层破裂速度对盆地地震效应影响显著,随破裂速度的增大盆地地震动强度逐渐增加,但不同分量上地震动强度的增加速率显著不同,受盆地效应的影响,放大系数表现出与强地震动不同的分布特征。盆地放大系数整体表现出随破裂速度的增加而减小的趋势,但不同分量放大系数所受影响程度差异明显。同时,盆地内地震动强烈放大区域的位置也受破裂速度的显著影响,但其总体上集中在断层两侧区域及垂直于破裂方向的盆地边缘附近。 相似文献
18.
选取161条速度脉冲型近断层地震动记录,采用最小二乘法拟合得到近断层地震动抗震设计Newmark三联谱,研究了震级、场地和断层类型对近断层设计谱的影响。结果表明：大震（级）相比小震（级）的影响较为显著,大震（级）下设计谱具有更宽的加速度敏感区段,中长周期段内的反应谱谱值更高;在3类断层类型中,大震（级）下逆斜断层的反应谱加速度敏感区段最宽,谱值最大。对于近断层区域的结构在大震（级）下应该考虑增大特征周期并提高设计谱谱值,还应充分考虑逆斜断层等断层类型的影响。 相似文献
19.
近断层强地面运动影响场显式有限元数值模拟的示意性算例 总被引：2，自引：1，他引：2
本文通过一个简单的示意性算例，对近断层强地面运动影响场显式有限元数值模拟的主要环节作了概要说明，给出了算例的主要计算结果并对其作了定性和初步的讨论分析。主要观点和结论是：本文的计算结果较好地定性反映和印证了人们对近断层强地面运动特征（如上盘效应、竖向效应、Fling Step效应和速度大脉冲现象）的现有认识水平，验证了采用的计算模型和计算方法的可行性和科学性。本文关于位移峰值场的计算结果对于估算近断层地表破裂带的位置、长度和宽度具有重要参考价值，应进一步深入研究二者之间的相关性。 相似文献