千将坪滑坡三维极限平衡分析

千将坪滑坡位于长江南岸支流青干河左岸,是三峡水库蓄水一个月后发生的水库新生型滑坡。通过千将坪滑坡恢复到原貌,采用三维极限平衡法对滑坡的整体稳定性和失稳下滑的触发因素进行了分析,探讨了水库蓄水和连续降雨对滑坡稳定性的影响。计算分析成果表明,水库蓄水后的浸泡软化作用使滑坡体稳定条件急剧恶化,蓄水和强降雨的联合作用最终导致千将坪滑坡产生大规模深层滑动。     

千将坪滑坡动力学过程仿真模拟

滑坡体的失稳破坏是一个动态过程,动力学行为起着非常重要的作用。采用DDA方法对长江三峡库区千将坪滑坡的运动全过程进行了数值模拟研究。模拟方案充分依据该滑坡的地质、地形特征,按不同岩土体和地质结构面类型进行块体单元划分,模拟了滑坡发生、发展的渐进破坏过程以及滑坡触发后的运动情况。模拟结果表明,千将坪滑坡是以斜坡坡脚的局部破坏为其运动的开始阶段,并进一步牵引上部滑体,在地下水压力作用下最终产生整体滑动。     

长江三峡工程库区千将坪滑坡地质特征及成因分析

千将坪滑坡体位于三峡库区长江支流青干河的左岸,距三峡工程坝址44km。2003年7月13日零时20分,三峡库区秭归县千将坪村发生了山体基岩滑坡,造成15人死亡、9人失踪,4家乡镇企业被摧毁。文章通过对滑后详细地质调查,阐述了千将坪滑坡区地质条件,描述了滑坡发生的前兆现象以及滑坡发生滑动的过程,仔细分析了千将坪滑坡各要素的特征。根据滑坡体物质组成和结构的差异,把滑体物质自滑坡后缘至前缘分为块石堆积区、基岩裂解区、土夹块石区、漂砾卵石区。同时,文中研究了滑带土的物理力学性质,分析了滑坡体的成因机制,从地形地貌、岩性组合、构造条件详细论述了斜坡失稳的内因,认为导致斜坡失稳的外部因素有集中降雨、农田灌溉以及三峡蓄水3个方面的影响。     

三峡库区千将坪滑坡地质力学模型研究

三峡水库初次蓄水不久,千将坪即发生了特大型滑坡。通过对千将坪滑坡滑动区与影响区的勘察试验及对比研究,查明了千将坪滑坡的物质组成、结构及滑坡边界条件,分析了滑坡影响因素及其机制,建立了千将坪滑坡的地质力学模型。分析表明,千将坪滑坡为三峡水库水位上升与降雨联合诱发的水库新生型深层岩质滑坡,水库蓄水起主要和关键作用。     

牵引式滑坡推力计算方法研究

三峡工程运行期间引发大量库区滑坡地质灾害,由于库区水位及降雨等联合影响,使得牵引式滑坡在库区滑坡中占有相当的比例。通过对库区牵引式滑坡形成机制研究,根据变形破坏模式,把牵引式滑坡分为牵引区（初始滑动区）和被牵引区,分析牵引式滑坡在演化过程中牵引区滑体与被牵引区滑体之间的相互依存关系,针对其相互作用力学特征建立合理的物理和数学力学计算模型,初步推导牵引式滑坡推力计算公式,为抗滑桩设计提供合理的设计推力。以三峡库区朱家店牵引式滑坡为例,在确定被牵引区滑体对牵引区滑体存在推力作用情况下,通过推力计算表明,推导出的公式计算得到牵引区滑体的设计推力比单独计算牵引区滑体设计推力更大,相比将牵引区滑体和被牵引区滑体视为整体计算设计推力更小,说明此方法计算的推力用于抗滑结构设计可以达到既安全又经济的效果,为牵引式滑坡治理设计提供新的思路。     

三峡水库区千将坪滑坡活动性质及运动特征

2003年7月13目三峡水库区秭93县千将坪村发生大规模滑坡。依据遥感解译航片显示的“7．13”滑坡前地貌形态、古滑坡遗迹调查及滑坡发育的地质环境条件分析，认为千将坪原为一整体呈簸箕形的古滑坡。实地调查表明该滑歧的范围在古滑坡的西侧堆积垅和东部沟“7”之间的部分，活动性质为千将坪古滑坡的大规模复活。“7．13”滑坡的东、西侧壁及后壁特征清楚。后壁加滑体斜长1050m，平均宽525m，滑坡总破坏投影面积约0．5km^2；堆积体总体形态与古滑坡相似。据不同的堆积特征，大致可分为4个部分：后缘、滑体后部、中前部及滑坡坝。由各要素特征及其上的地物状态分析，滑坡的中部、前部为深层推移武高速整体滑动，滑坡前缘以反翘姿态飞速冲向对岸，堵断青干河；滑坡的两测，滑体高速下滑时与东西侧壁问作高速剪切运动；滑坡堆积后部，受其下中前部滑体快速滑动而产生的强大牵引力影响，沿古滑面下滑并倾倒、崩落。通过现场调查及综合分析实际资料，认为三峡库区第一期蓄水是触发该滑坡的主要厚因，雨季强降水为辅助因素。另外，根据现场公路断开两点GPS测量估算出公路被切断后下滑了235．91m，估算该滑坡在主滑方向的滑距约为250m，滑坡总体积约为2400万m^3。总体而言，“7．13”千将坪滑坡活动释放能量比较充争，目前整体稳定。但滑体上局部调整活动暂时不会停止。边界以外的古滑体堆积受到严重干扰，会不断发生牵引及塌滑。     

千将坪滑坡滑带地质演化过程研究

千将坪滑坡是三峡水库蓄水后发生的第一个大型基岩滑坡,引起了社会各方面极大的关注。千将坪滑坡的类型、成因演化等问题也成为学术界研究的重点和热点。本文在千将坪滑坡滑带宏观结构分析的基础上,使用层间剪切带应力历史分析方法,结合地质体铀系测年结果,得出千将坪滑坡属于新生滑坡的结论。文章研究了千将坪滑坡滑带的形成过程,分析了形成机制,指出千将坪滑带形成的地质历史成因是内外动力耦合作用的结果,建议三峡库区滑坡防治工作中要重视水库新生滑坡,特别是重视层间剪切带的研究。     

基于PFC3D的鱼鳅坡滑坡运动过程分析

以贵州省开阳县鱼鳅坡滑坡为研究对象,采用颗粒流离散元（PFC3D）对其破坏运动过程进行数值模拟。采用Ball-Wall建模方法建立滑坡模型,对滑坡不同关键部位颗粒进行位移、速度监测,阐明其破坏运动特征。结果表明,降雨为鱼鳅坡滑坡的直接诱发因素。该滑坡在破坏初始阶段以蠕滑变形为主,随着变形量的增加,滑坡体不断挤压坡脚,滑坡岩土体到达应力平衡极限,坡脚产生剪切破坏,并向上牵引发展,滑坡发生整体滑动,斜坡变形破坏模式为蠕滑-拉裂,按照力学条件为牵引式破坏。滑坡滑动最高时速12.4 m/s,最大滑移80 m,滑动阶段持续50 s。研究成果可为对该类滑坡影响范围预测,以及工程措施的制定具有一定的参考意义。     

贵州省德江县香树坪滑坡特征及形成机制研究

香树坪滑坡位于贵州省铜仁地区德江县大坪村齐心组,为大型古滑坡。滑坡边界及前缘坡下发育多条拉陷槽,滑动方向为310～335。基于滑坡区工程地质条件和滑坡变形破坏特征,建立了滑坡形成机制概念模型:在河谷形成及演化过程中,香树坪斜坡以滑移-弯曲演化。滑坡前缘拉槽LC6#和LC3#依次形成,其卸荷和临空效应导致上部坡体进一步变形。滑坡坡脚区因上部坡体进一步滑移变形而应力集中,坡体稳定性整体降低。当坡脚区失稳时滑坡发生。数值分析很好地再现了滑坡演化过程及机理。研究成果可对西部山区类似类滑坡发育条件及识别研究提供参考。     

二密滑坡形成机制

二密滑坡原是稳定的古滑坡体。由于不合理的人为开挖路基、降雨和地下水等因素,诱使古滑坡体重新滑动,影响高速公路的正常施工和人们的安全。通过现场调查、钻探、物探等勘察手段,查明了滑坡区的地形地貌、地层岩性和物质结构;根据所得地质资料确定了滑动面所在位置,计算其稳定性,重点分析该滑坡的形成机制。经过数值分析得出,在古滑坡体下部开挖路基是此滑坡形成的主要原因。目前此滑坡处于挤压-初滑阶段,需及时采取有效的综合措施进行治理。     

三峡库区千将坪滑坡高速滑动机制研究

2003年7月13日,三峡水库初期蓄水至135 m高程30 d之际,在三峡库区秭归县发生了三峡库区的第一个水库滑坡,滑坡方量达1 500万m3,最大滑速达16 m/s,最高涌浪达24.5 m。滑坡造成10人死亡,14人失踪,摧毁129间民房以及4个工厂,致1 200人无家可归。千将坪滑坡发生后,为了预测三峡库区及世界其它水库工程可能发生的同类高速滑坡,持续数年研究千将坪滑坡的高速滑动机制,通过理论分析及数值模拟,探索了千将坪滑坡的高速滑动机制,认为千将坪滑坡具有孕育高速滑坡的典型结构特征,滑坡滑带的峰残强降差是滑坡高速启动的根本原因,高陡边坡蕴藏的高势能及滑带液化是滑坡加速高速滑动的主要原因。     

Mechanism and failure process of Qianjiangping landslide in the Three Gorges Reservoir,China

The Qianjiangping landslide is a large planar rock slide which occurred in July 14, 2003 shortly after the water level reached 135 m in the Three Gorges Reservoir, China. The landslide destroyed 4 factories and 129 houses, took 24 lives, and made 1,200 people homeless. Field investigation shows that the contributing factors for the landslide are the geological structure of the slope, the previous surface of rupture, the water level rise, and continuous rainfall. In order to reveal the mechanism and failure process of the landslide, numerical simulation was conducted on Qianjiangping slope before sliding. Based on the characteristics and the engineering conditions of the landslide, the topography and the geological profiles of Qianjiangping slope before sliding is reconstructed. The seepage field of Qianjiangping slope before sliding was simulated with the Geostudio software. The results show that ground water table rises and bends to the slope during the rise of water level, and the slope surface becomes partially saturated within the period of continuous rainfall. Using the ground water table obtained above, the failure process of Qianjiangping slope is simulated with the Flac3D software. The results demonstrate that the shear strain increment, displacement, and shear failure area of the slope increased greatly after the water level rose and continuous rained, and the landslide was triggered by the combined effect both of water level rise and continuous rainfall. The development of shear strain increment, displacement, and shear failure area of the slope shows that the landslide was retrogressive in the lower part of the slope and progressive in the upper part of the slope.     

地震在滑坡体上的响应形式研究:以苦地瓜子滑坡为例

地震滑坡分为三大类,即高度破裂或严重高度破裂滑坡、存在分离剪切面的滑坡以及以流相为主的滑坡。在中国西
南地区,根据地震滑坡特点,按其运动方式划分为：推移式滑坡、牵引式滑坡、溜滑性滑坡和崩塌性滑坡四大类。在四川
省茂县苦地瓜子滑坡特征的调查中,发现了一些较为特殊的地质现象,主要包括以下几点：（1） 滑坡上游边界冲沟中湖相
沉积和滑坡体上分布的湖积物表明苦地瓜子滑坡曾经发生过堵江事件,部分为堵江后的堰塞湖区域,在此区域发生河湖相
沉积,其结果是滑坡此部分被湖积物所覆盖,呈现出了与其他几个区覆盖物截然不同的现象;（2） 苦地瓜子滑坡中下部发
现砂土液化现象及规律性排列的裂缝;（3） 踏勘时在滑坡中下部发现直立错坎,错坎两侧土性不同,在颜色和物质组成上
都有较明显不同。错坎左侧为粉土状物质,而右侧以碎石土为主;（4） 在滑坡的中部以及中偏下部位都发现有平行于滑动
方向的裂缝;（5） 现场调查时在坡体中上部发现有充填楔,充填物颗粒较大、磨圆度较好,与地面盖层的颜色、岩性条件
相同。综合各种现象进行分析,室内试验和数据统计,认为茂县苦地瓜子滑坡为地震诱发的滑坡,并且可以从此滑坡中发
现地震滑坡与普通滑坡明显不同,往往在现场留下自重引起的滑坡不好解释的现象,主要有砂土液化迹象、充填楔、地震陡
坎、平行于滑动方向的裂隙;此外地震滑坡还具有等时性和群发性的特点。     

Landslide hazard zonation by deterministic analysis (Veľká Čausa landslide area, Slovakia)

A practical application of a simple and economical solution to landslide hazard zonation based on slope stability analysis was carried out in the Veľká Čausa landslide, Horná Nitra region, central Slovakia. The region is prone to different types of slope deformation controlled by geological structure, physical and mechanical properties of materials, complicated hydrogeological setting, undulating morphology, and man-made influence. Taking into consideration the cause of the landslide, identified as groundwater change, two scenarios of landslide activity have been investigated. Scenario 1 considers the maximum groundwater level recorded from March 1995 to October 1998, corresponding to the period starting from the most recent landslide activity up to the end of remediation work. Scenario 2 considers the maximum groundwater level recorded from November 1998 to December 2004, after the remediation works, and corresponding to the actual situation of the landslide. It has been found from this study that slope angle has the highest influence on landslide instability in the Veľká Čausa landslide. Therefore, high resolution Digital Elevation Model (DEM) is essential for obtaining reasonable results. In addition, an appropriate selection of the model input parameters (e.g., shear strength) is very important. The validation between the calculated landslide hazard zonation map and results of monitoring survey were examined. The results show moderate to good agreement with the inclinometric and geodetic measurements. It was also verified that the most active part of the landslide is the north-western side.     

The July 14, 2003 Qianjiangping landslide,Three Gorges Reservoir,China

The Qianjiangping landslide occurred after the first impoundment of the Three Gorges Reservoir in July 2003. Field investigation revealed that failure occurred when the reservoir reached 135 m, but the stability of the affected slope was already reduced by pre-existing bedding-plane shears, quarrying of mudstone from the landslide toe, and previous heavy rain. A possible explanation of the rapid and long runout mechanism of the landslide is that movement on a bedding-plane shear ruptured the calcite cement and rapidly reduced the sandstone strength to residual shear strength.     

基于InSAR形变监测的四川甲居古滑坡变形特征

位于四川省丹巴县聂呷乡甲居村的甲居古滑坡主要由甲居滑坡(H01)、聂呷坪滑坡(H02)、小巴旺村滑坡(H03)、聂拉村滑坡(H04)和山顶滑坡(H05)等5个次级滑体组成.受区域构造、强降雨、河流侵蚀、地层岩性等因素影响,甲居古滑坡次级滑体持续发生蠕滑变形,对位于滑体上的村庄、道路和前缘大金河等具有较大危害,2020年遭受50年一遇的强降雨后,古滑坡变形速率有进一步增大的趋势.采用SBAS-InSAR技术,结合遥感解译和现场调查,获取了甲居古滑坡2018年6月至2021年8月的地表变形特征,通过二维形变速率转换获取了甲居古滑坡沿斜坡向(slope)和垂直向(vertical)的形变速率.研究认为,甲居古滑坡沿雷达视线方向(V_LOS)形变速率最大达-179 mm/a,沿斜坡方向的形变速率(V_s)最大为-211 mm/a,沿垂直方向的变形速率(V_v)最大为-67 mm/a.甲居滑坡的北侧区域、聂拉村滑坡的南侧区域和山顶滑坡后缘变形较大,总体上位于强变形-极强变形区.甲居古滑坡的变形机制具有一定差异,其中甲居滑坡以牵引式变形为主,聂拉村滑坡以推挤式变形为主.由于古滑坡地质构造复杂、新构造活动强烈,在强降雨和河流侵蚀作用下极易导致滑坡蠕滑速率加快并进一步失稳,形成堵江溃坝等灾害.建议加强次级滑体的地表变形监测,为流域性地质安全风险防灾减灾提供技术支撑和科学依据.      

Stability Analysis of Landslide near Dewal Village along Murree-Muzaffarabad Road,Pakistan

This study presents a detailed geological and geotechnical analysis of Dewal landslide along Murree-Muzaffarabad road, Pakistan. The study area is situated in a tectonically active region of the earth where mass movements like rock fall, rockslides and slumps cause adverse economic loss through disruption of travelling on roads. The study has the main focus on factors responsible for its instability together with stability analysis using limit equilibrium method by use of computer program Slide (version 5.0). The input parameters of rock mass was evaluated by field investigations and laboratory testing. To analyze the net deposit and net slide mass of the landslide area, multi-date point’s data of 2008 and 2012 of the slide area was obtained and their digital elevation models were generated by using Inverse distance weighting (IDW) technique in ArcGIS 9.3. The study has concluded that the present slope instability is the function of a specific deformation pattern in the rock units (leading towards the possibility of a shear plane under the slid mass), surface and subsurface drainage and the engineering behavior of the overburden and underlying rock units. This study recommends several protection parameters for landslide and suggests that detailed investigation of Dewal landslide is required for long term stability.     

Discrete Element Analysis of Huangtupo Landslide

On the basis of the deep geology and the geological structure of Huangtupo landslide,and ancient landslide in the reservoir of the Three Gorges,the geo-environmental model of the landslide is es-tablished to analyze quantitatively the sliding mechanism by using the discrete element method.It is con-cluded that interbedding structure of soft and hard formation consists of the main geological background,which induced the arching of the formation under gravity.Stability analysis of different loadings shows that the ground building weight on the middle slope may restrain the extension of shear sliding zone be-low,but may activate the foot area which will reduce the safety factor of the front.