The starting mechanism and movement process of the coseismic rockslide: A case study of the Laoyingyan rockslide induced by the “5.12” Wenchuan earthquake     

LIU Bo  HU Xie-wen  HE Kun  HE Shu-heng  SHI Hong-bin  LIU Ding-yi 《山地科学学报》2020,17(5):1188-1205

The"5.12"Wenchuan earthquake in 2008 triggered a large number of co-seismic landslides.The rear boundary or cracks of co-seismic landslide are generally located at the steep free surface of thin or thick mountains.Dynamic process of this kind of landslides could be divided into two parts:the seismic dynamic response of the slope and the movement process of rock mass.Taking the Laoyingyan rockslide as an example,the amplification effect was studied by single-degree-of-freedom system analysis method.Besides,the dynamic process of landslide under seismic loading was simulated by the finite difference method(FDM)and discrete element method(DEM).The amplification coefficient of the rockslide to seismic wave is 1.25.The results show that the critical sliding surface of the Laoyingyan rockslide was formed at the 23 th seconds under the action of seismic wave.At the same time,tension failure occurred at the rear edge of the sliding mass and shear failure occurred at the front edge.The maximum displacement was 0.81 m and the initial velocity was 2.78 m/s.During the initiation process of the rockslide,the rock mass firstly broke down along the joints which are along the dip of the rock stratum,and then collapsed bodily along the secondary structural planes.In the process of movement,the maximum velocity of rock mass was 38.24 m/s.After that,the rock mass underwent multiple collisions,including contact,deceleration to 0 and speed recovery after rebound.Finally,due to the constant loss of energy,the rocks stopped and accumulated loosely at the foot of the slope.The longest distance of movement was about 494 m.Besides,the smaller the damping ratio,the farther the rock mass moved.Compared with the results without considering the amplification factor,the movement distance of landslide by considering the amplification factor was more accurate.The study of the Laoyingyan rockslide is helpful to strengthen our field identification of potential co-seismic rockslides.At the same time,understanding its movement and accumulation process can help us better predict the hazard scope of the co-seismic rockslides,and provide a reference for the design of treatment projects.  相似文献   

Research on the ShakeMap System with Consideration of Site Effects     

Chen Kun  Yu Yanxiang  Gao Mengtan 《中国地震研究》2010,24(2):211-221

In accordance with the principle of similarity in geology and topography,the V3S0(the average shear-velocity down to a 30m depth below the surface) approximation of sites is acquired by correlation between V3S0 and slopes after calculating the maximum slope of topography using the 30-sec Chinese Mainland DEM(Digital Elevation Model) data set.Site-amplification factors are then quantified with V3S0 and applied to the ShakeMap system developed by this study to revise ground-motion amplitudes on bedrock estimated from empirical relationships.Finally,the distribution of ground motion parameters on the surface is obtained.This article also introduces the calculation process,calculation models of the ShakeMap systems and related software systems.In conclusion,certain examples indicate that the ShakeMap system is feasible in the Chinese Mainland.  相似文献   

Shaking Intensity Distribution of the April 14,2010 Yushu,China Earthquake     

Chen Kun  Yu Yanxiang  Gao Mengtan 《中国地震研究》2010,24(3):394-397

Two hours after the 2010 Yushu Earthquake, the shaking intensity distribution was obtained using the ShakeMap Rapid Generation System Based on Site Effects,developed by the author,which integrates the information of tectonic settings,the strike and scale of causative faults, focal mechanism solutions, fault rupture process and attenuation relationship in Western China,as well as local site effects. The results are as follows: ① The major axis of shaking intensity distribution is directed NW-SE,parallel to the Yushu fault; ② The meizoseismal area reaches an intensity Ⅸ and covers 300km2; ③ The intensity Ⅸ area is mainly distributed in the area 40km southeast and 15km northwest of the epicenter along the causative fault; ④ Due to local soil conditions,the northwestern part of the area with intensity Ⅸ on bedrock shows an intensity Ⅷ when converting from the bedrock to the soil; ⑤ Areas with intensity Ⅷ,Ⅶ,Ⅵ measure 3,000km2,8,000km2,and 24,000km2, respectively.  相似文献   

Satellite Monitoring of the Surface Water and Energy Budget in the Central Tibetan Plateau   总被引：1，自引：0，他引：1  

YANG Kun  Toshio KOIKE 《大气科学进展》2008,25(6):974-985

The water and energy cycle in the Tibetan Plateau is an important component of Monsoon Asia and the global energy and water cycle. Using data at a CEOP （Coordinated Enhanced Observing Period）-Tibet site, this study presents a first-order evaluation on the skill of weather forecasting from GCMs and satellites in producing precipitation and radiation estimates. The satellite data, together with the satellite leaf area index, are then integrated into a land data assimilation system （LDAS-UT） to estimate the soil moisture and surface energy budget on the Plateau. The system directly assimilates the satellite microwave brightness temperature, which is strongly affected by soil moisture but not by cloud layers, into a simple biosphere model. A major feature of this system is a dual-pass assimilation technique, which can auto-calibrate model parameters in one pass and estimate the soil moisture and energy budget in the other pass. The system outputs, including soil moisture, surface temperature, surface energy partition, and the Bowen ratio, are compared with observations, land surface models, the Global Land Data Assimilation System, and four general circulation models. The results show that this satellite data-based system has a high potential for a reliable estimation of the regional surface energy budget on the Plateau.  相似文献   

Geological Characteristics and Zircon U-Pb Ages of the Dahongliutan Metasomatic Granite in the Western Kunlun Orogenic Belt     

DING Kun  LIANG Ting  YANG Xiuqing  DING Liang  LI Cong 《《地质学报》英文版》2019,93(Z2):169-170

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澳门及其邻近地区海陆风的模拟   总被引：11，自引：0，他引：11  

Lin Wenshi  Wang Anyu  Wu Chisheng  Fong Soi Kun  Ku Chimeng 《大气科学进展》2001,18(6):1231-1240

利用宾州／美国国家大气研究中心的ＭＭ５模式来模拟澳门的海陆风和珠江口的三维风场。模式设计为四重套网格,分辨率分别为 １ｋｍ,３ ｋｍ,９ ｋｍ,２７ ｋｍ。使用常规观测资料作为初始场,模拟时间为３０小时。结果表明采用高分辨率（１ｋｍ）模拟能很好地捕捉到澳门的海风和陆风。海风锋和热力内边界层也清楚可见。如果最小分辨率为３ ｋｍ,则只捕捉到海风,陆风却模拟不出来。  相似文献   

3D COMPUTER SIMULATION FOR LIGNIFICATION OF ANCIENT CHINESE TIMBER BUILDINGS     

YANG JieZHU YixuanLI DerenQIN Kun 《地球空间信息科学学报》2001,4(4):56-60

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅａｒｔｏｆａｎｃｉｅｎｔＣｈｉｎｅｓｅａｒｃｈｉｔｅｃｔｕｒｅｉｓｔｈｅｅｓｓｅｎｃｅｏｆｔｈｅＣｈｉｎｅｓｅｃｕｌｔｕｒａｌｈｅｒｉｔａｇｅｓ .Ｉｔｈａｓｉｍ ｐｏｒｔａｎｔｓｉｇｎｉｆｉｃａｎｃｅｆｏｒｓｔｕｄｙｉｎｇａｎｄｌｅａｒｎｉｎｇＣｈｉ ｎｅｓｅｃｕｌｔｕｒｅａｎｄｃｉｖｉｌｉｚａｔｉｏｎ .Ｉｔｉｓｏｆｇｒｅａｔｄｉｆｆｉｃｕｌ ｔｙ ,ｈｏｗｅｖｅｒ,ｔｏｌｅａｒｎｔｈｅｃｏｍｐｌｉｃａｔｅｄｓｔｒｕｃｔｕｒｅｏｆａｎｃｉｅｎｔＣｈｉｎｅｓｅａｒｃｈｉ…  相似文献   

用非线性近似方法反演单多普勒雷达风场(英)   总被引：4，自引：0，他引：4  

ZHAO Kun  LIU Guoqing  GE Wenzhong  DANG Renqing  Takao TAKEDA 《大气科学进展》2003,20(2):195-204

回顾了近年来由单多普勒雷达观测反演风场的各种方法。这些方法大部分基于线性假设,因此风场的非线性变化经常影响反演结果,使得反演的风场误差增大。我们提出一种以非线性近似理论为基础的反演方法,该方法主要考虑了风场分片光滑的特点并充分利用了雷达的径向风场数据。我们把该方法应用到1998年淮河能量与水循环实验的两个个例中。通过同双多普勒雷达观测的结果比较,发现该方法能反演较高分辨率和准确性的水平风场,反演的垂直风场也比较合理。  相似文献   

NUMERICAL SIMULATIONS AND DOPPLER RADAR DATA ANALYSIS OF A HAIL PROCESS IN HUAIHE RIVER BASIN     

LI Bai  XU Xiaofeng  ZHOU Kun 《Acta Meteorologica Sinica》2002,16(3):388-400

A hail process in Huaihe River Basin observed by CINRAD Doppler radar on 12May 2000 hasbeen simulated by using nonhydrostatic mesoscale numerical model MM5.The simulated wind fieldis analyzed and compared with Doppler radar wind data,both of them show that there was ameso-β cyclone around the hail region.Results show that this meso-β cyclone existed below 3 kmin the troposphere and its cyclonic circulation was very obvious below 1 km.The temperature andmoisture fields from the simulation are also analyzed.Furthermore,the storm-relativeenvironmental helicity and CAPE(convective available potential energy)are discussed.  相似文献   

GRAIN SIZE DISTRIBUTION OF SEDIMENT IN THE NORTHERN EAST CHINA SEA AND THE RELATIONSHIP WITH THE SEA CURRENTS     

LEI Kun    YANG Zuosheng  GUO Zhigang Doctoral student  College of marine geosciences  Ocean University of Qingdao    Qingdao  China Assistant prof.  the Chinese Research Acad 《国际泥沙研究》2002,17(2)

1 INTRODUCTION The East China Sea, one of the largest continental marginal seas in the world, receives large amount of suspended sediment from the land annually (Milliman and Meade, 1983; Shen, 1999). Since late Pleistocene, the deposition of the suspended sediment over the relict sandy sediment induces the complicated distribution of surface sediment (Fig. 1). Many studies have been done on the surface sediment distribution, sedimentation rate, concentration and dispersion of suspen…  相似文献