Investigating the reactivation of historical landslides during the 2022 Luding M_(S)6.8 earthquake

On September 5,2022,a strong earthquake with a magnitude of MS6.8 struck Luding County in Sichuan Province,China,triggering thousands of landslides along the Dadu River in the northwest-southeast(NW-SE)direction.We investigated the reactivation characteristics of historical landslides within the epicentral area of the Luding earthquake to identify the initiation mechanism of earthquake-induced landslides.Records of the two newly triggered and historical landslides were analyzed using manual and threshold methods;the spatial distribution of landslides was assessed in relation to topographical and geological factors using remote sensing images.This study sheds light on the spatial distribution patterns of landslides,especially those that occur above historical landslide areas.Our results revealed a similarity in the spatial distribution trends between historical landslides and new ones induced by earthquakes.These landslides tend to be concentrated within a range of 0.2 km from the river and 2 km from the fault.Notably,both rivers and faults predominantly influenced the reactivation of historical landslides.Remarkably,the reactivated landslides are characterized by their small to medium size and are predominantly situated in historical landslide zones.The number of reactivated landslides surpassed that of previously documented historical landslides within the study area.We provide insights into the critical factors responsible for historical landslides during the 2022 Luding earthquake,thereby enhancing our understanding of the potential implications for future co-seismic hazard assessments and mitigation strategies.

A case study of a giant reactivated landslide based on NPR anchor cable Newton force early warning

In a large ancient landslide,approximately 240,000 m3 of sediments were reactivated,posing a grave threat to the safety of iron ore stopes.To trace the deformation and evolution history of reactivated Landslide,we conducted geological surveys and combined real-time monitoring equipment to analyze the landslide data since 1986 and the deformation status of the reactivated Landslide.A multi-factor comprehensive landslide monitoring method and an Newton force early warning system(NFEWS)were established,focusing on underground stress,surface deformation information and landslide stability.Furthermore,we developed a four-level early warning grading standard,employing surface cracks and changes in underground stress thresholds as early warning indicators.This standard adds expert assessment to avoid false alarms and realize real-time dynamics of mining landslides during excavation and transportation.Through the case study and analysis of Nanfen open-pit mine,the NFEWS system offers valuable insights and solution for early warning of landslides in analogous open-pit mines.Finally,the evaluation index system of landslide hazard susceptibility was established by selecting the Newton force influence factor.A landslide susceptibility zoning map is constructed using the information value model.The rationality and accuracy are assessed from three perspectives:frequency ratio,landslide hazard point density,and receiver operating characteristic(ROC)curve.The improved Newton force landslide early warning system provides a good reference for the analysis and monitoring of the creep landslide evolution process.

Development characteristics and failure modes of reactivated ancient landslides in the Sichuan–Tibet transportation corridor,China

The risk of reactivated ancient landslides in the Sichuan–Tibet transportation corridor in China is significantly increasing,primarily driven by the intensification of engineering activities and the increased frequency of extreme weather events.This escalation has resulted in a considerable number of fatalities and extensive damage to critical engineering infrastructure.However,the factors contributing to the reactivation and modes of destruction of ancient landslides remain unknown.Therefore,it is imperative to systematically analyze the developmental characteristics and failure modes of reactivated ancient landslides to effectively mitigate disaster risks.Based on a combination of data collection,remote sensing interpretation,and field investigations,we delineated the developmental attributes of typical ancient landslides within the study area.These attributes encompass morphological and topographic aspects,material composition,and spatial structure of ancient landslides.Subsequently,we identified the key triggers for the reactivation of ancient landslides,including water infiltration,reservoir hydrodynamics,slope erosion,and excavation,by analyzing representative cases in the study area.Reactivation of ancient landslides is sometimes the result of the cumulative effects of multiple predisposing factors.Furthermore,our investigations revealed that the reactivation of these ancient landslides primarily led to local failures.However,over extended periods of dynamic action,the entire zone may experience gradual creep.We categorized the reactivation modes of ancient landslides into three distinct types based on the reactivation sequences:progressive retreat,backward thrusting,and forward pulling–backward thrusting.This study is of great significance for us to identify ancient landslides,deepen our understanding of the failure modes and risks of reactivated ancient landslides on the eastern margin of the Tibetan Plateau,and formulate effective disaster prevention and mitigation measures.

Formation and reactivation mechanisms of large-scale ancient landslides in the Longwu River basin in the northeast Tibetan Plateau, China

The northeastern Tibetan Plateau exhibits steep topography and strong internal or external dynamic geological effect and is frequently subjected to strong earthquakes and heavy rainfall. The geological evolution has resulted in a wide distribution of ancient landslides, which has become a hotspot for studying ancient landslide formation and reactivation. In recent decades, several ancient landslides on both banks of the Longwu River, Qinghai Province, China were reactivated, causing serious economic losses and casualties. This study conducted remote sensing interpretation and ground surveys on these ancient landslides. Totally 59 ancient landslides were identified, and the formation mechanism, evolution process, and resurrection mechanism of the Longwu Xishan No.2 ancient landslide were analyzed by means of a detailed field geological survey, drilling, and series of experimental tests such as the particle size distribution test, the Xray diffraction test and the mechanical properties test. The results show that the formation of these ancient landslides is closely associated with the uplift of the Tibetan Plateau and the erosion of the Longwu River. Firstly, the intermittent uplift of the Tibetan Plateau lead to the diversion and downcutting of the Longwu River basin, which forms the alternate slope topography with steep and slow slopes, thereby providing favourable topography and slope structure conditions for the formation of landslides. Secondly, 34.5% clay-mineral content in the Neoproterozoic mudstone with 32.7% particle size less than 0.005 mm, and the corrosion and softening effects of the Neogene mudstone with high clay mineral content under the erosion of water provides favourable material conditions for the formation of landslides. Thirdly, rainfall and human activities are the primary triggering factors for the revival of this ancient landslide group. It is revealed that the evolution process of the ancient landslides on both banks of the Longwu River can be divided into five stages namely tectonic rapid uplift slope formation, river erosion creep-sliding deformation, slope instability critical status, landslide failure-movement-accumulation, and slope reactivation under rainfall erosion and engineering excavation.

Reservoir-induced landslides and risk control in Three Gorges Project on Yangtze River,China

The Three Gorges region in China was basically a geohazard-prone area prior to construction of the Three Gorges Reservoir （TGR）. After construction of the TGR, the water level was raised from 70 m to 175 m above sea level （ASL）, and annual reservoir regulation has caused a 30-m water level difference after impoundment of the TGR since September 2008. This paper first presents the spatiotemporal distribution of landslides in six periods of 175 m ASL trial impoundments from 2008 to 2014. The results show that the number of landslides sharply decreased from 273 at the initial stage to less than ten at the second stage of impoundment. Based on this, the reservoir-induced landslides in the TGR region can be roughly classified into five failure patterns, i.e. accumulation landslide, dip-slope landslide, reversed bedding landslide, rockfall, and karst breccia landslide. The accumulation landslides and dip-slope landslides account for more than 90%. Taking the Shuping accumulation landslide （a sliding mass volume of 20.7 × 106 m^3） in Zigui County and the Outang dip-slope landslide （a sliding mass volume of about 90 × 106 m^3） in Fengjie County as two typical cases, the mechanisms of reactivation of the two landslides are analyzed. The monitoring data and factor of safety （FOS） calculation show that the accumulation landslide is dominated by water level variation in the reservoir as most part of the mass body is under 175 m ASL, and the dip-slope landslide is controlled by the coupling effect of reservoir water level variation and precipitation as an extensive recharge area of rainfall from the rear and the front mass is below 175 m ASL. The characteristics of landslide-induced impulsive wave hazards after and before reservoir impoundment are studied, and the probability of occurrence of a landslide-induced impulsive wave hazard has increased in the reservoir region. Simulation results of the Ganjingzi landslide in Wushan County indicate the strong relationship between landslide-induced surge and water variation with high potential risk to shipping and residential areas. Regarding reservoir regulation in TGR when using a single index, i.e. 1-d water level variation, water resources are not well utilized, and there is also potential risk of disasters since 2008. In addition, various indices such as 1-d, 5-d, and 10-d water level variations are proposed for reservoir regulation. Finally, taking reservoir-induced landslides in June 2015 for example, the feasibility of the optimizing indices of water level variations is verified.

Slope Stability Analyses of Outang Landslide Based on the Peak and Residual Shear Strength Behavior

Most of the natural and compacted fine-grained soil slopes that are in saturated or unsaturated condition undergo a large deformation prior to reaching failure conditions.Such slopes should be designed taking account of their strain-softening behavior using the residual shear strength (RSS) parameters.In this paper,the slope stability of a recently reactivated Outang landslide near the Three Gorges Dam in China is analyzed based on the RSS parameters of unsaturated soils.In addition,comparisons are provided in the FOS values of slope using both the peak shear strength (PSS) and RSS parameters.Firstly,a series of site investigations of the hydrologic and geologic conditions,ground surface displacements and cracks were described.The PSS and RSS behaviors of the sliding soils derived from a series of direct shear test results performed on saturated and unsaturated soil specimens are summarized.Secondly,a series of slope stability analysis were conducted considering the precipitation and Yangtze River water level variation within a representative period of 7 months,based on the PSS and the RSS properties.In this study,three different scenarios were considered,which include: i) considering only the precipitation with a constant water level;ii) considering only the decrease in water level without rainfall;iii) considering the combination of precipitation and decrease in water level.In each scenario,four steps were included to calculate the values of factor of safety (FOS) at different times.1) A steady-state seepage analysis was conducted with a constant total head at 525 m on the left boundary and 175 m on the slope surface below the Yangtze River water level.The initial pore water pressures were simulated in the slope under no precipitation and variation of water level.2) A specific boundary condition was applied on the slope surface to model the precipitation and Yangtze River water level variation.A transient seepage analysis was conducted to calculate pore water pressures at different times based on the initial pore water pressures.3) The FOS values at different times were calculated by the Morgenstern-Price method taking account of the variation of pore water pressures at different times,using the peak shear strength (PSS) parameters.4) The last step was repeated replacing PSS parameters with RSS parameters.The RSS parameters were lower than the peak values from laboratory’s direct shear test results for the soils in the sliding zones.The reduction in shear strength from peak to residual state under unsaturated soil condition was greater than that for a saturated soil.The FOS decreased almost linearly with time for the scenario in which only the influence of rainfall infiltration was considered.However,the total reduction in the FOS was relatively small.The FOS decreased rapidly at a linear rate with respect to time with a decrease in water level for the scenario in which Yangtze River water level decrease was considered.The FOS reached to a relatively constant value after Yangtze River water level reached the lowest value.The decrease in Yangtze River water level was the dominant factor that contributed to a reduction in the FOS.The FOS was strongly dependent on the development of the phreatic line after the Yangtze River water level reached the lowest value.The FOS calculated by RSS (i.e.FOSR) is less than unity;they were approximately 16% lower in comparison to that calculated by PSS (FOSP).If PSS parameters were used,the slope would still be stable even under the combined influence of precipitation and Yangtze River water level decrease.These results are inconsistent with the field observations.For this reason,the RSS parameters should be taken into account to evaluate reliably the slope stability of the Outang landslide.

三峡库区三门洞滑坡复活机理及韧性变形研究

三峡库区蓄水诱发大量库岸古滑坡复活变形,引入“韧性变形”概念可很好地解释古滑坡在相似影响因素下的差异性变形响应情况。以三峡库区三门洞滑坡为例,通过现场地质调查及17 a的监测数据,分析古滑坡复活过程中的变形特征及“韧性变形”机制。结果表明:①三峡库区三门洞滑坡为平缓堆积层古滑坡,自三峡水库蓄水后复活变形,前、中、后部变形主要为塌岸、拉张裂缝或坍滑和拉张剪切裂缝;②在库水位下降期间,滑坡的变形对库水位的快速下降响应敏感,库水在低水位运行和上升期间,滑坡变形主要诱发因素是降雨,尤其是连续性强降雨,可引发滑坡持续性变形;③滑坡发生“韧性变形”时,滑体内部经历一次密实过程,使得土体的密度增大,内聚力增强,提高了土体的抗剪能力,在一段时间内拥有抵抗下次变形的力量。研究成果可为三峡库区滑坡监测预警工作提供参考。

工程扰动诱发川西杜米滑坡复活变形特征及机理分析

人类工程活动是诱发滑坡复活并导致滑坡整体或局部失稳破坏的重要因素之一。本文以川西雅江县杜米滑坡为例,通过地质调查、Insar监测、工程钻探、数值分析、稳定性计算等技术方法,在查清滑坡特征的基础上,总结滑坡变形破坏特征并进行分区评价,剖析滑坡复活变形成因机理,探讨滑坡前缘坡脚开挖程度与滑体稳定性之间的关系。研究结果表明,杜米滑坡一共发育3个滑面,分别对应强烈变形区、中等变形区和轻微变形区。前缘坡脚开挖是诱发杜米滑坡复活的主要原因,降雨入渗导致滑带土强度劣化是助推因素。前缘坡脚开挖水平深度超过10 m,暴雨工况滑体将出现明显变形下滑破坏。研究成果对避免类似杜米滑坡导致的“小灾大损”具有较强的参考和借鉴意义。

汶川大地震同震滑坡复活变形特征研究

同震滑坡复活具有不确定性、隐蔽性强和区域分布面积广等特点,往往被忽视,容易成为防灾减灾的盲区。该文根据同震滑坡堆积物变形复活所处的坡体位置和主要诱发因素,将复活类型划分为坡脚侵蚀型和坡面降雨型,基于InSAR技术、无人机多期航拍和地面调查数据,分别对青林沟滑坡和沙坝村滑坡变形特征、过程、原因进行分析,坡脚侵蚀型主要以“沟道侵蚀—坡体滑塌—坡体后退”模式变形和复活;坡面降雨型则以“颗粒运移—下渗增强—颗粒粗化—滑面发展”模式变形和复活。将InSAR技术应用于同震滑坡大范围和长时间序列变形监测,不仅是同震滑坡变形和复活研究的有效手段,对于地质灾害评价、预测与防治也具有参考意义。

映秀-北川断裂带北川段唐家湾滑坡活动历史与形成机制

以映秀-北川断裂带北川段唐家湾滑坡为研究对象,基于地形资料、多期遥感与航拍影像,结合14C测年的方法,细分了唐家湾滑坡的活动历史,分析了2016年唐家湾滑坡再次复活的主要控制因素。研究结果表明:(1)唐家湾斜坡历史上至少发生过四期滑动,其中第一期次滑坡发生在全新世以前;第二期次滑坡发生于全新世初期;第三期次滑坡发生在2008年汶川地震时期,系龙门山断裂带活动过程中产生的同震滑坡;第四期次滑坡分别发生在2016年和2018年,属于断裂带滑坡堆积体的再次局部复活;(2)2016年唐家湾滑坡的形成与断裂活动、河流侧蚀和水等因素有关,其中,上覆滑坡堆积体、下伏高陡基岩形成的二元斜坡结构,是唐家湾滑坡发生的决定性条件;断裂活动及其导致的浅地表最大主应力偏转是唐家湾滑坡变形的重要内因;(3)以唐家湾滑坡为例,初步讨论了基于地形条件控制的断裂带滑坡堆积体复活的地质模型,其形成演化表现为断裂带活动和河流侵蚀形成滑坡(或陡峭地形)→先期滑坡后壁(或陡峭地形)接受上部老滑坡堆积→二元斜坡结构控制下的老滑坡复活变形。该滑坡为研究地形控制断裂带滑坡复活提供了独特的案例,研究成果对于理解和评估该类滑坡,开展综合防治等方面具有重要的借鉴价值。

青藏高原东部大渡河流域太平桥乡古滑坡群复活特征多源遥感识别

青藏高原东部大渡河流域是全球古滑坡最为发育的地区之一。由于人类工程活动的增多以及强降雨的频发,大渡河流域的古滑坡复活问题已日趋严重。本文选取大渡河流域太平桥乡古滑坡群的各洛寨村滑坡为例,采用无人机航空遥感(UAV)和Interferometric Synthetic Aperture Radar(InSAR)监测相结合的多源遥感技术手段,对各洛寨村滑坡的复活变形特征以及复活机理进行研究分析。基于无人机航空遥感影像能够有效识别各洛寨村滑坡的变形特征,两组横向贯穿中上部滑坡体的大规模拉张裂缝以及前缘左侧大型次级滑坡表明该滑坡呈现整体复活迹象。依据InSAR时序监测结果证实,2020年5月至6月持续两个月的强降雨是古滑坡复活的主要诱发因素,该滑坡目前仍处于持续变形状态。在强降雨或者地震等条件下,前缘左侧次级滑坡可能进一步下滑,甚至引发各洛寨村滑坡整体失稳滑动。基于多源遥感技术手段的各洛寨村滑坡复活变形特征及机理研究,其成果能够为大渡河流域古滑坡复活的防灾减灾工作提供有效技术支撑。

Reservoir Regulation for Control of an Ancient Landslide Reactivated by Water Level Fluctuations in Heishui River,China

Due to the complex geological processes of Qinghai-Tibet Plateau,numerous deposits,especially the large-scale ancient landslide deposits,are characteristic features of the valleys incised in southwestern China.Intense water level fluctuations since 2011 in Maoergai Reservoir,China,registered the reactivation of Xierguazi ancient landslide,and presented a significant risk to neighboring facilities.Based on detailed field survey and drilling exploration,the landslide was divided into Zone A and Zone B,and other characterizations of landslide were studied as well.To precisely measure the extent of landslide displacement during filling and drawdown stage,surface displacement monitoring system was deployed on the landslide.The monitoring analyses data reveal that reservoir fluctuation is the dominant factor influencing landslide displacement,especially during drawdown stage.Moreover,a future sliding is anticipated in Zone A,while a creep had already existed in Zone B.A reservoir regulation was then established using the lead-lag correlation between reservoir fluctuation and landslide displacement and landslide stability analysis.In the end,the follow-up deformation monitoring demonstrates that the reservoir regulation controlled the landslide effectively.Landslide control by reservoir regulation in Maoergai can serve as a case study for other settlements involved in similar construction activities.

东南亚某水电站古滑坡复活机制研究

针对东南亚某水电站坝址区上游右岸古滑坡,通过钻探、地质调查及长期监测研究了滑坡地层特征、滑带特征及变形特征,并对古滑坡复活机制进行探究。结果表明:(1)坡脚卸载和强降雨是古滑坡复活的主要原因;(2)道路开挖导致应力场发生改变,滑坡沿浅表部第四系坡积物和板岩、砂岩接触面“复活”,向临空面产生蠕变变形;(3)古滑坡变形与降雨呈正相关,雨季高强度降雨期间位移与变形速率急速增大,旱季无降雨时滑坡基本处于稳定状态;(4)深部位移监测数据显示,古滑坡深部未见位移突变,降雨对深部位移基本无影响。

三峡库区藕塘滑坡变形特点及复活机制研究

为深入研究库区古滑坡变形特征及其复活机理,文章以三峡库区藕塘滑坡为研究对象,通过对钻孔、探槽及平硐等现场勘查资料和监测资料的深入分析,并结合数值模拟方法,探讨了藕塘滑坡的时-空变形特点及影响因素,并揭示其复活机制。电子自旋共振试验和现场勘查结果表明藕塘滑坡由三个次级滑体组成。监测数据显示:总体上,地表累计位移-时间曲线呈阶跃状变化,即雨季滑坡变形速率急剧加快,旱季则骤减;在空间上滑坡的变形速率随高程的增加而增加。库水和降雨是导致藕塘滑坡变形破坏的主要因素:滑坡下部区域变形主要受库水影响,而滑坡中、上部区域变形主要受降雨影响。数值模拟结果也进一步揭示了影响滑坡孔隙水压力响应的主控因素随滑坡高程的变化而变化。库水骤降使得坡体前部渗透压增大,同时强降雨使得坡体中部及上部孔隙水压力升高,二者共同作用下导致滑坡复活。此外库水位下降或降雨量增加,均会不同程度降低边坡的稳定性。以上结论对于指导实际工程及深化库区古滑坡的研究具有一定的理论意义,同时加强古滑坡的研究有助于丰富滑坡稳定性评价及预测预报方法,为古滑坡的治理提供一定的理论依据。

甘肃舟曲南峪江顶崖古滑坡发育特征与复活机理

江顶崖古滑坡位于甘肃舟曲白龙江左岸,区内地形地貌和地质构造复杂,多高山峡谷且河流纵坡降大,晚第四纪以来强烈活动的坪定—化马断裂带从区内通过,造成地层岩性极为破碎,古滑坡发育,且复活特征明显。在遥感解译和现场调查的基础上,对江顶崖古滑坡的发育特征和复活机理进行分析,认为江顶崖古滑坡堆积体方量为41×106～49×106m3,为在地质历史上形成的巨型古滑坡,位于坪定—化马断裂带及其次级断裂形成的断裂带内。根据滑坡不同位置和坡体结构特征,将江顶崖古滑坡共划分为古滑坡崩塌区、滑坡岩体变形区、古滑坡堆积区等3个大区,以及4个古滑坡复活区等7个区域,坡体内断错陡坎和拉裂缝极为发育。江顶崖古滑坡的中部复活区是主要变形和破坏区,1991年和2018年的复活区均位于该区域内,2018年复活滑坡体体积为480×104～550×104m3,为缓慢滑动的牵引式滑坡。江顶崖古滑坡复活机理复杂,在断裂活动和地震作用下形成的破碎岩土体和斜坡结构特征为滑坡复活提供了内因,强降雨作用增加了坡体自重并弱化了岩土体的力学强度,在暴雨期形成的强烈河流侵蚀作用进一步切割坡脚,从而诱发滑坡的复活;因此,江顶崖古滑坡是在内外动力耦合作用下形成的典型古滑坡复活案例。目前江顶崖古滑坡区域内的4个滑坡复活区仍处于蠕滑状态,在强降雨和河流侵蚀等作用下极可能再次发生复活,并造成堵江和毁坏国道等灾害事件。

大河坝古滑坡复活变形特征及成因分析

在分析大河坝古滑体变形特征的基础上,对古滑体的复活成因进行了深入分析研究。分析表明,古滑体复活的首要原因是古滑体的变形破坏及其疏松物质组成为滑体复活创造了基础。其次是对古滑体的认识不足,修建移民房时未对古滑体作必要的防治措施,为古滑体的复活埋下隐患。再者是移民房修建加载活动改变了古滑体原有的平衡,加之水对滑体的积极诱发作用,致使滑体产生推压变形破坏,从而激发了古滑体的复活。

再论茅坪滑坡的复活机制与治理可行性

基于对茅坪滑坡体1993～2000年的监测资料分析,初步认为茅坪滑坡体复活是其东侧白岩危岩体中不合理的采煤活动引起的。为了证实上述推论,2004年7月～2005年1月,对滑坡体的变形、水位和降雨量进行补充监测。结合相关监测成果,进一步论述滑坡体的水动力条件变化及其对滑坡体变形的影响:(1)水动力条件演变包括两个方面,其一是采煤活动诱发的白岩危岩体开裂和崩塌以及由此产生的黄沟流水路径的改变;其二是水库蓄水与运行。(2)黄沟流水路径的改变不但抬升滑坡体的地下水位,且使地下水位在较长时间内维持在高水位。(3)黄沟流水完全来源于大气降雨;降雨,特别是强降雨对滑坡体的变形速度影响最大。(4)1999年后,水库蓄泄水对前缘次级滑体的影响减弱。作为隔河岩变形库区规模最大、变形最为严重的滑坡体,茅坪滑坡的失稳问题应该引起相关各方面的关注与重视。建议在治理工程时优先考虑截排来自黄沟流水。

金沙江支流冲江河巨型滑坡及其局部复活机理研究

中国西南三江活动构造带是大型滑坡的高发区。笔者在滇西北金沙江支流冲江河螺丝湾电站一带发现的巨型滑坡——冲江河滑坡,位于区域性活动断裂带的阶区,属于古地震造成的巨型古滑坡或坐落体,体积可达5.8×108m3。该巨型古滑坡在后期演化中经历了趋稳和局部再复活的过程,其内部存在若干次级滑坡,且表现出级序越低、稳定性越差的特点。在野外调查的基础上,对复活次级滑坡的滑带土进行了环剪试验研究,获得了不同部位滑带土在较大剪切位移条件下的抗剪强度变化规律,认为活动构造带斜坡岩体破碎软弱、坡脚处于应力集中区是冲江河巨型滑坡局部复活的重要因素;在剪切作用下,饱和或近饱和的滑带土因超孔隙水压力而发生液化作用,促进了坡体大变形的发生。试验结果很好地解释了公路坡脚部位,即使少量开挖就可以引起缓慢、持续发生的大变形现象。从滑坡复活机理角度,加强坡面排水和坡前采用抗滑桩技术可以有效控制坡体稳定性。

川西松潘上窑沟古滑坡复活特征及危险性预测研究

随着近年来人类活动加剧和极端天气的频繁出现,古滑坡复活问题日益突出,严重威胁着工程设施和城镇安全。以青藏高原东缘松潘县上窑沟古滑坡为例,在剖析古滑坡复活特征的基础上,分析了不同重现期降雨条件下滑坡的破坏范围和失稳概率,并采用DAN^（3D）软件模拟研究了滑坡运动过程和堆积范围,开展了古滑坡复活的危险性预测评价。结果表明：（1）受坡脚浸润侵蚀和强降雨的影响,上窑沟古滑坡前缘局部H1已经复活,呈现出多级序、多期次活动的特点,目前地表宏观变形迹象清晰,存在进一步失稳可能;（2）H1在20 a一遇的10 d连阴雨条件下处于不稳定状态,失稳概率达99.12%,而后部的H2在100 a一遇10 d连阴雨条件下处于不稳定状态,失稳概率达96.36%,可能和前部H1发生连续失稳下滑;（3）仅前缘局部H1失稳时,滑体最远运移距离约350 m,堆积体前缘不会抵达居民区;（4）当后部H2和前部H1连续失稳时,滑体最远运移距离达550 m,沟口居民区的排导槽首端至国道G213间半径约150 m的扇形区遭受滑坡–碎屑流的危险性大。