基于离心机模型试验的甘肃江顶崖古滑坡复活机理研究     

郭长宝  张永双  刘定涛  滑帅  任三绍  李雪  金继军 《工程地质学报》2022,30(1):164-176

位于白龙江断裂带的甘肃舟曲江顶崖古滑坡规模巨大,受断裂活动、降雨入渗与河流侵蚀和人类工程活动等因素影响,多次发生复活-堵塞白龙江灾害事件,造成极大危害。为研究江顶崖古滑坡的复活机理,本文在野外地质调查的基础上,重点开展了滑体在含水率为10%、15%和20%条件下的离心机模型试验。研究表明:在滑体含水率为10%情况下,试验结束后仅在坡体中后部产生少量裂缝,但滑坡体整体还处于稳定状态; 而在滑体含水率为15%和20%情况下,滑坡均发生了破坏,在滑体含水率分别为15%、20%情况下坡体失稳所需离心加速度分别为100g和50g。试验测试分析表明,江顶崖古滑坡为推移式滑坡,其变形先从坡体中后部开始,坡体中后部产生裂缝,随后裂缝逐渐向前缘扩展,最终裂缝贯通造成滑坡滑动破坏。滑坡体的变形过程主要分为3个阶段: ①变形启动阶段(裂缝开始形成阶段); ②变形加速阶段(裂缝加速发展阶段); ③失稳阶段。通过离心模拟试验,结合野外调查分析,认为江顶崖古滑坡复活的因素主要受降雨和孔隙水压力的影响,是受前缘河流侵蚀牵引、降雨入渗造成滑坡中后部推移的耦合滑动。  相似文献   

突变理论在边坡工程应用的研究进展     

Fan Liuming  Geng Pengchao 《地球科学进展》2015,30(11):1268-1277

突变理论是非线性科学领域中的一个重要分支,作为一种数学工具已经在众多领域得到广泛应用,在边坡工程中的应用尤为活跃。首先简述了突变理论的发展概况和基本原理,然后分别从3个方面详细论述了突变理论在边坡工程应用中的研究进展,即基于尖点突变法的边(斜)坡稳定性分析、基于突变级数法的边(斜)坡稳定性评价和基于灰色理论、模糊数学的尖点突变预测模型对滑坡时间预报,重点讨论了相应的理论模型、应用方法和实际效果,最后结合目前存在的问题探讨突变理论在边坡工程的发展趋势。  相似文献   

Investigations and assessment of the landslide hazards of Fengdu county in the reservoir region of the Three Gorges project on the Yangtze River   总被引：12，自引：0，他引：12  

Shuren?WuEmail author  Yimin?Jin  Yongshuang?Zhang  Jusong?Shi  Chen?Dong  Weizhi?Lei  Ling?Shi  Chengxuan?Tan  Daogong?Hu 《Environmental Geology》2004,45(4):560-566

The spatial database of landslides in Fengdu County of the reservoir region of the Three Gorges project (TGP) on the Yangtze River was compiled from a variety of different sources including field investigations on landslides, existing catalogues and archives on landslides, reports of meteorological events and human engineering activities that triggered slope failures. The major factors that are found to have affected the slope stabilities are outlined, and an assessment and zonation of landslide hazards of the region is made using an integrated information model, which is divided into destructive, disastrous, likely disastrous and essentially non-disastrous areas from the assessment of landslide hazards. The destructive and disastrous areas are respectively 1.9 and 13.8% of the total region, mostly being nearby townships, highways along the south bank of the Yangtze River and residential quarters along two flanks of the Yangtze River and its distributaries, that will impose direct impact to highway transportation and residential lives, and may effect to some degree the navigation of the Yangtze River, reservoir banks, and building of cities and towns.  相似文献   

A comparison of the GIS based landslide susceptibility assessment methods: multivariate versus bivariate   总被引：30，自引：0，他引：30  

Mehmet?Lütfi?SüzenEmail author  Vedat?Doyuran 《Environmental Geology》2004,45(5):665-679

The purpose of this study is to evaluate and to compare the results of multivariate (logical regression) and bivariate (landslide susceptibility) methods in Geographical Information System (GIS) based landslide susceptibility assessment procedures. In order to achieve this goal the Asarsuyu catchment in NW Turkey was selected as a test zone because of its well-known landslide occurrences interfering with the E-5 highway mountain pass.Two methods were applied to the test zone and two separate susceptibility maps were produced. Following this a two-fold comparison scheme was implemented. Both methods were compared by the Seed Cell Area Indexes (SCAI) and by the spatial locations of the resultant susceptibility pixels.It was found that both of the methods converge in 80% of the area; however, the weighting algorithm in the bivariate technique (landslide susceptibility method) had some severe deficiencies, as the resultant hazard classes in overweighed areas did not converge with the factual landslide inventory map. The result of the multivariate technique (logical regression) was more sensitive to the different local features of the test zone and it resulted in more accurate and homogeneous susceptibility maps.  相似文献   

Undrained dynamic-loading ring-shear apparatus and its application to landslide dynamics   总被引：26，自引：17，他引：9  

Kyoji Sassa  Hiroshi Fukuoka  Gonghui Wang  Naohide Ishikawa 《Landslides》2004,1(1):7-19

Landslides are gravitational mass movements of rock, debris or earth. Some move very slowly, thus conforming to the field of statics, but some move rapidly. Study of the initiation and motion of rapid landslides needs to develop Landslide Dynamics involving dynamic loading and dynamic generation/dissipation of excess pore-water pressure. New developments in science can be facilitated by new technological advances. This study aimed to develop a new apparatus that can geotechnically simulate the formation of the shear zone and the following long and rapid shear displacement that occurs in high-velocity landslides. Professor K. Sassa and his colleagues at DPRI (Disaster Prevention Research Institute), Kyoto University, have worked to develop an undrained dynamic-loading ring-shear apparatus for this purpose. A series of different types of apparatus (DPRI-3, 4, 5, 6, 7) have been developed from 1992 to the present. This paper describes the development of this apparatus and its application to the study of earthquake-induced landslides and the latest landslide-triggered debris flow in Japan. Also, tests of the latest version (DPRI-7) with a transparent shear box for direct observation of the shear zone during a rapid shearing are described.  相似文献   

Morphology and geometry of Valles Marineris landslides     

C. Quantin  P. Allemand  C. Delacourt 《Planetary and Space Science》2004,52(11):1011-1022

The walls of the Valles Marineris canyons are affected by about 45 landslides. The study of these landslides provides a test of the hypothesis of processes having affected Martian wallslopes after their formation. The dynamics of Valles Marineris landslides are controversial : either the landslides are interpreted as large debris flows or as dry rock avalanches. Their morphology and their topography are basic parameters to understand their dynamics. From topographic MOLA data and remote sensing images acquired with different spatial resolutions (Viking, THEMIS, MOC), the 3D geometry of 45 landslides of Valles Marineris has been studied. The landslides have been classified in 3 geomorphologic classes from the topography of the landslide deposits: the “chaotic” landslides without well identified structures, the “structured deposit without debris aprons” landslides with tectonic structures and small roughness at the deposit front and the “structured deposit with debris aprons” which display circular normal faults at the back of the deposit and several debris aprons at the front of the landslide. The spatial distribution of the three morphological types is in relation with the confinement of the canyons. The initial volume and the total deposited volume were also measured to compute volume balances. The deposited volumes range from 50 to . All volume balances display a maximum deficit ranging from 5% to 70%. The landslides with the largest deficits take place within an enclosed-canyon (Hebes Chasma). Lacking material exportation, these deficits could be interpreted as reflecting the porosity of the landslide source. This fact is in agreement with the hypothesis of a karstic origin of these enclosed-canyons. The Valles Marineris landslides have large mobilities (length/vertical drop) ranging from 1.8 to 12 implying low coefficients of friction and so fluidization mechanisms. The possible filling up of the porosity by volatile could be compatible with the fluidization patterns of Valles Marineris landslides.  相似文献   

汶川地震重灾区泥石流沟内崩滑物空间分布的RS-GIS定量方法   总被引：1，自引：0，他引：1  

张怀珍  范建容  胡凯衡  郭芬芬  刘飞  陈阳 《山地学报》2012,(1):78-86

汶川地震在山区引发大量崩塌、滑坡,形成大量的固体松散碎屑物质堆积在沟谷内(CLCAR,崩滑碎屑区),使得地震山区泥石流活动性增强。以岷江上游四川省汶川县银杏乡、映秀镇的15条泥石流沟的SPOT遥感影像为基础,利用GIS技术对CLCAR空间分布进行分析。建立CLCAR与流域高程、主沟侧距和沟口纵距的分布函数T(x)、M(x)和G(x),对CLCAR的空间分布特征进行描述;并计算其积分(DT、DM和DG)作为CLCAR空间分布特征的定量化参数。结果表明,函数T(x)、M(x)和G(x)能够较全面描述CLCAR的空间分布特征,DT、DM和DG能够作为CLCAR空间分布特征的定量化参数。泥石流沟谷内CLCAR的空间分布对泥石流的形成及规模具有一定的影响;在对灾区泥石流研究时有必要考虑泥石流沟内CLCAR空间分布特征。  相似文献   

A case study of coping strategies and landslides in two villages of Central-Eastern Nepal     

Karen Sudmeier-Rieux  Stephanie Jaquet 《Applied geography (Sevenoaks, England)》2012,32(2):680-690

Landslides are an increasing problem in Nepal’s Middle Hills due to both natural and human phenomena: mainly increasingly intense monsoon rains and a boom in rural road construction. This problem has largely been neglected due to underreporting of losses and the dispersed nature of landslides. Understanding how populations cope with landslides is a first step toward developing more effective landslide risk management programs. The present research focuses on two villages in Central-Eastern Nepal, both affected by active landslides but with different coping strategies. Research methods are interdisciplinary, based on a geological assessment of landslide risk and a socio-economic study of the villages using household questionnaires, focus group discussions and transect walks. Community risk maps are compared with geological landslide risk maps to better understand and communicate community risk perceptions, priorities and coping strategies. A modified typology of coping strategies is presented, based on previous work by Burton, Kates, and White (1993) that is useful for decision-makers for designing more effective programs for landslide mitigation. Main findings underscore that coping strategies, mainly seeking external assistance and outmigration, are closely linked to access to resources, ethnicity/social status and levels of community organization. Conclusions include the importance of investing in organizational skills, while building on local knowledge about landslide mitigation for reducing landslide risk. There is great potential to increase coping strategies by incorporating skills training on landslide mitigation in existing agricultural outreach and community forest user group training.  相似文献   

A test method for analyzing the deformation of landslide model     

《地震研究进展（英文）》2021,1(3):100031

In order to study the overall deformation of geotechnical model conveniently, the worksite of landslide bridge foundation reinforced by the front and rear row anti-slide piles in Chenglan railway was taken as an example. On the basis of shaking tabe test of a 1/40 reduced scale model, the landslide deformation caused by vibration waves was monitored through burying self-made phosphor bronze strips in soil. Combined with the horizontal and vertical coordinates of the bending strain points on the phosphor bronze strips, the digital matrix was converted by applying Renka Cline random matrix generation method, and the two-dimensional contour plots were drawn based on it. The results showed that the two-dimensional contour plots reflected the basic law of landslide deformation reasonably, and it revealed the evolution process of landslide deformation and failure. The research conclusions were consistent with the test phenomenon, which met the basic requirements of overall deformation analysis of landslide model. This proposed method can monitor multiple cross sections and was practical for model test.  相似文献   

The safety distance of a tunnel under-traversing a slope body with a landslide-prone zone     

《地震研究进展（英文）》2021,1(3):100059

At present, substantial scientific research achievements have been made in the research on landslide occurrence, movement mechanism, mitigation measures, and structural stability during tunnel excavation. However, the interaction mechanism of a tunnel under-traversing a slope body with potential landslides is still not well understood. Based on the field data provided by previous investigations in the study area, six sets of 1:100 laboratory experiment model tests were conducted to study the stability of the landslide-prone zone of the slope body with an under-traversing tunnel. The selected distances between the tunnel and the sliding surface are 1.5, 3, and 5 times of the tunnel diameter, respectively. The experiment results show the interaction between the landslide-prone zone and the tunnel, elucidating the effect of potential landslides during the tunnel excavation process and the reaction of the landslide slip on the tunnel structure. Several conclusions are obtained: ① During the process of tunnel excavation, the vertical displacement of the tunnel vault decreases with the increase of the buried depth. ② The vertical displacement of the sliding surface increases with the increase of the buried depth of the tunnel. The horizontal displacement of sliding surface decreases with the increase of the buried depth. ③ After the occurrence of a rainfall-induced landslide, the vertical displacement of the tunnel vault in the 1.5-diameter-distance case is 57.29% greater than that in the 3.0-dismeter-distance case.④ For a two-cave tunnel, it is suggested that the cave farther from the landslide toe should be firstly excavated since it may generate less structural deformation.  相似文献