An integrated model simulating the initiation and motion of earthquake and rain induced rapid landslides and its application to the 2006 Leyte landslide   总被引：10，自引：7，他引：3  

Kyoji?SassaEmail author  Osamu?Nagai  Renato?Solidum  Yoichi?Yamazaki  Hidemasa?Ohta 《Landslides》2010,7(3):219-236

A gigantic rapid landslide claiming over 1,000 fatalities was triggered by rainfalls and a small nearby earthquake in the Leyte Island, Philippines in 2006. The disaster presented the necessity of a new modeling technology for disaster risk preparedness which simulates initiation and motion. This paper presents a new computer simulation integrating the initiation process triggered by rainfalls and/or earthquakes and the development process to a rapid motion due to strength reduction and the entrainment of deposits in the runout path. This simulation model LS-RAPID was developed from the geotechnical model for the motion of landslides (Sassa 1988) and its improved simulation model (Sassa et al. 2004b) and new knowledge obtained from a new dynamic loading ring shear apparatus (Sassa et al. 2004a). The examination of performance of each process in a simple imaginary slope addressed that the simulation model well simulated the process of progressive failure, and development to a rapid landslide. The initiation process was compared to conventional limit equilibrium stability analyses by changing pore pressure ratio. The simulation model started to move in a smaller pore pressure ratio than the limit equilibrium stability analyses because of progressive failure. However, when a larger shear deformation is set as the threshold for the start of strength reduction, the onset of landslide motion by the simulation agrees with the cases where the factor of safety estimated by the limit equilibrium stability analyses equals to a unity. The field investigation and the undrained dynamic loading ring shear tests on the 2006 Leyte landslide suggested that this landslide was triggered by the combined effect of pore water pressure due to rains and a very small earthquake. The application of this simulation model could well reproduce the initiation and the rapid long runout motion of the Leyte landslide.  相似文献   

初夏热带西太平洋对流云团周期性西北传播与梅雨带的变动   总被引：4，自引：0，他引：4  

王亚非  山崎信雄 《气象学报》2000,58(6):692-703

为了了解来自低纬度的气象因素对梅雨带季节内变化的影响,文中对1985年和1986年6～7月份的个例进行了细致诊断,并针对有关问题用历史资料做了统计和合成.发现(1)梅雨雨带的向北位移与10～15°N/140°E附近的热带对流云团向西移动有连带关系,当热带对流云团向西北移动时副热带高压也向西北扩张,顺次由东向西影响梅雨带北抬.(2)低纬度向西北方向移动的对流云团具有准8,18以及30 d周期.(3)中国江淮梅雨的入梅也与6月份第一次出现这种对流云团周期性(8,18以及30 d)西北移动有密切关系.  相似文献   

南海及其邻近地区夏季风爆发的特征及其机制的初步研究   总被引：35，自引：6，他引：29  

陈隆勋  刘洪庆  王文  王予辉  山崎信雄 《气象学报》1999,57(1):16-29

利用ＯＬＲ和ＴＢＢ资料,提出一个指标,确定了１９７５～１９９３年间南海夏季风爆发日期,发现与风向转变的日期比较一致。在此基础上,讨论了南海夏季风爆发的过程。随后,还讨论了南海夏季风爆发与海温异常、高原热状况和海陆温差变化的关系,发现它与４月份南海、东太平洋赤道以及３０～４０°ＮＳＳＴＡ有关,与海陆温差由冬季的冷陆暖海转变到热陆冷海有关。  相似文献   

Detection of soil liquefaction from strong motion records     

Mladen V. Kostadinov  Fumio Yamazaki 《地震工程与结构动力学》2001,30(2):173-193

During the recent earthquakes in Japan and the U.S.A. a number of records from liquefied‐soil sites have been obtained. The ground motion parameters from these sites were studied and several methods for detection of liquefaction from seismic records were developed. The methods, however, focus mainly on the horizontal ground motion and may interpret as liquefaction‐induced some records from soft‐soil deposits or records with dominant surface waves, at which sites the phenomenon was not observed. Besides, not all of the available records from liquefied sites were processed. In this paper, after examination of the ability of different types of ground motion parameters to indicate alone soil liquefaction we propose a new liquefaction detection method that simultaneously analyses instantaneous frequency content of the horizontal and the vertical ground acceleration. We also compare performance of the proposed method with that of the other liquefaction detection methods. The computations are carried out using a common data set including records from liquefied and non‐liquefied sites. Results show that the frequency‐related parameters and the proposed method detect more efficiently the occurrence of liquefaction from the seismic records. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献