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1.
A rainfall-induced shallow landslide is a major hazard in mountainous terrain, but a time-space based approach is still an unsettled issue for mapping rainfall-induced shallow landslide hazards. Rain induces a rise of the groundwater level and an increase in pore water pressure that results in slope failures. In this study, an integrated infinite slope analysis model has been developed to evaluate the influence of infiltration on surficial stability of slopes by the limit equilibrium method. Based on this new integrated infinite slope analysis model, a time-space based approach has been implemented to map the distributed landslide hazard in a GIS (Geographic Information Systems) and to evaluate the shallow slope failure induced by a particular rainfall event that accounts for the rainfall intensity and duration. The case study results in a comprehensive time-space landslide hazard map that illustrates the change of the safety factor and the depth of the wetting front over time. 相似文献
2.
Rainwater infiltration during typhoons tends to trigger slope instability. This paper presents the results of a study on slope
response to rainwater infiltration during heavy rainfall in a mountain area of Taiwan. The Green-Ampt infiltration model is
adopted here to study the behavior of rainwater infiltration on slopes. The failure mechanism of infinite slope is chosen
to represent the rainfall-induced shallow slope failure. By combining rain infiltration model and infinite slope analysis,
the proposed model can estimate the occurrence time of a slope failure. In general, if a slope failure is to happen on a slope
covered with low permeability soil, failure tends to happen after the occurrence of the maximum rainfall intensity. In contrast,
slope failure tends to occur prior to the occurrence of maximum rainfall intensity if a slope is covered with high-permeability
soil. To predict the potential and timing of a landslide, a method is proposed here based on the normalized rainfall intensity
(NRI) and normalized accumulated rainfall (NAR). If the actual NAR is higher than the NAR calculated by the proposed method,
slope failure is very likely to happen. Otherwise, the slope is unlikely to fail. The applicability of the proposed model
to occurrence time and the NAR–NRI relationship is evaluated using landslide cases obtained from the literature. The results
of the proposed method are close to that of the selected cases. It verifies the applicability of the proposed method to slopes
in different areas of the world.
An erratum to this article can be found at 相似文献
3.
Cheng Qiu Tetsuro Esaki Mowen Xie Yasuhiro Mitani Chunxiang Wang 《Environmental Geology》2007,52(8):1569-1579
A shallow landslide triggered by rainfall can be forecast in real-time by modeling the relationship between rainfall infiltration
and decrease of slope stability. This paper describes a promising approach that combines an improved three-dimensional slope
stability model with an approximate method based on the Green and Ampt model, to estimate the time–space distribution of shallow
landslide hazards. Once a forecast of rainfall intensity and slope stability-related data, e.g., terrain and geology data,
are acquired, this approach is shown to have the ability to estimate the variation of slope stability of a wide natural area
during rainfall and to identify the location of potential failure surfaces. The effectiveness of the estimation procedures
described has been tested by comparison with a one-dimensional method and by application to a landslide-prone area in Japan. 相似文献
4.
降雨条件下浅层滑坡稳定性探讨 总被引：8，自引：0，他引：8
降雨条件下浅层滑坡是一种常见、多发的地质灾害现象,为了解边坡稳定性随降雨入渗过程的变化情况,以Green-Ampt入渗模型为基础,并考虑了动水压力的作用,建立了降雨入渗条件下浅层滑坡的概念模型,分别推导了降雨前有、无地下水位条件下的边坡安全系数与降雨时间的关系表达式。从分析结果中可以看出,对于这两种情况下边坡稳定性发生突变的主要原因归结于：前者为在湿润锋与地下水位面接触的短时间内,滑带处的孔隙水压力迅速增高;后者为滑带在浸水饱和情况下,岩土体的强度迅速降低。在此基础上,根据降雨过程中边坡是否达到饱和,提出边坡饱和临界时间的概念,考虑了初始降雨强度小于土壤入渗能力的情况。这个时间可以作为一个参数指标用于浅层滑坡的预警。 相似文献
5.
Landslides are mainly triggered by decrease in the matric suction with deepening the wetting band by rainfall infiltrations. This paper reports rainfall-induced landslides in partially saturated soil slopes through a field study. A comprehensive analysis on Umyeonsan (Mt.) landslides in 2011 was highlighted. The incident involves the collapse of unsaturated soil slopes under extreme-rainfall event. Fundamental studies on the mechanism and the cause of landslides were carried out. A number of technical findings are of interest, including the failure mechanism of a depth of soil and effect of groundwater flow, the downward movement of wetting band and the increase of groundwater level. Based on this, an integrated analysis methodology for a rainfall-induced landslide is proposed in this paper that incorporates the field matric suction for obtaining hydraulic parameters of unsaturated soil. The field matric suction is shown to govern the rate of change in the water infiltration for the landslide analysis with respect to an antecedent rainfall. Special attention was given to a one-dimensional infiltration model to determine the wetting band depth in the absence of the field matric suction. The results indicate that landslide activities were primarily dependent on rainfall infiltration, soil properties, slope geometries, vegetation, and groundwater table positions. The proposed methodology has clearly demonstrated both shallow and deep-seated landslides and shows good agreement with the results of landslide investigations. 相似文献
6.
台风暴雨型浅层滑坡失稳机理研究 总被引：1，自引：0，他引：1
针对台风暴雨耦合作用下浅层滑坡的失稳机理进行研究。在总结福建台风暴雨型滑坡灾害特征的基础上,提出风荷载对斜坡变形失稳的影响机理是通过植被造成坡体开裂,从而影响坡体的入渗规律。应用GeoStudio软件计算台风暴雨入渗条件下裂隙坡体中暂态非饱和渗流场的变化,以及对斜坡稳定性的影响。计算结果表明:裂隙坡体由于在裂隙处形成集中入渗点,雨水的入渗速度大于无裂隙的坡体,坡体达到饱和状态所需要的时间大为缩短。裂隙深度、间距对滑坡稳定系数的影响较大,裂隙深度越大、间距越小,在相同的降雨条件下滑坡的稳定系数越小,滑坡失稳需要的降雨时长越短。裂隙宽度对滑坡稳定性的影响相对较小。 相似文献
7.
Failure Mechanism of a Shallow Landslide at Tun-Sardon Road Cut Section of Penang Island,Malaysia 总被引：1，自引：1，他引：0
The occurrences of shallow landslides in residual soils of Penang hilly areas are common in rainy days. The failure mechanisms
of a shallow landslide occurred at km 3.9 road in Tun-Sardon area of Penang Island have been simulated using two different
methods of slope stability analysis. The results indicate that the failure was initiated locally inside the slope and then
propagated further to induce total failure. The failure propagation was started from initial local failure zone and was driven
by mobilized shear strength along the shear plane. The slope was marginally stable with an overall factor of safety of 1.32
before it failed to a rainfall event on September 6, 2008. It is found from back calculation that the rain infiltration raised
the temporary water level and reduced the shearing strength of soil to a minimum level with increased pore water pressure
to trigger the failure. This paper suggests further research on shallow landslide of Penang Island considering the direct
rainfall infiltration effect in terms of groundwater pressure-head distribution inside the slope. 相似文献
8.
Rainfall-induced landslides can cause loss of life and damage to property, infrastructure, and the environment. Rainfall patterns affect the pore-water pressure of unsaturated soil slopes, and are related to the slopes’ stability. Four rainfall patterns were chosen to represent natural rainfall patterns for an examination of rainfall infiltration into soil slopes using numerical models incorporating coupled water infiltration and deformation in unsaturated soils. Our analysis showed that rainfall patterns play a significant role in the distribution of the pore-water pressure in soil slopes, and influence the slope stability. The pore-water pressure profile of soil slopes and the factor of safety are affected by the ratio of rainfall intensity and the coefficient of permeability. The depth and shape of the shallow sliding plane of the landslide is closely related to the rainfall pattern; moreover, the results showed a correlation between the factor of safety of the slope and the rainfall intensity. This relationship can be described by a dimensionless rainfall intensity. The nonlinear relationship can be used to estimate the slope stability resulting from rainfall infiltration when the hydro-mechanical coupling in unsaturated soil slopes is considered. 相似文献
9.
Numerical modeling of water infiltration in slopes under rainfall conditions, especially under rainstorm conditions, is a fundamental problem for slope stability assessment. To obtain representative results, surface water–groundwater flow models are incorporated in the simulation. Based on finite element representation of Richards’ equation and of kinematic wave equations, an integrated 2D numerical model (IMCR2D) of the surface water–groundwater system was established. The model has a symmetrical matrix that modifies the flux boundary according to the runoff solution on the slope. IMCR2D was verified using two laboratory experiments, and it showed good agreement with numerical and experimental results. Additional numerical examples were used to study the effect of flux supply from runoff on infiltration. In comparison with SimMd (an existing method), IMCR2D displayed advantages in cases where surface runoff develops in an upper low-permeability section of the slope and flows down into a high-permeability section of the slope. To illustrate the advantages of the new method, the seepage field and stability condition of a case study in the Three Gorges Hydroelectric Reservoir were analyzed using IMCR2D and SimMd. The deformation of a landslide in part reflects its stability, and therefore, we also used displacement monitoring data to estimate the variation of stability conditions from that aspect. Comparison of the two numerical models indicated that flux supply greatly affects the seepage field, and that rainfall plays an important role in landslide stability evaluation, but only when considering flux supply from upper slope surface runoff. 相似文献
10.
Modeling landslide recurrence in Seattle, Washington, USA 总被引：5，自引：0，他引：5
Diana Salciarini Jonathan W. Godt William Z. Savage Rex L. Baum Pietro Conversini 《Engineering Geology》2008,102(3-4):227
To manage the hazard associated with shallow landslides, decision makers need an understanding of where and when landslides may occur. A variety of approaches have been used to estimate the hazard from shallow, rainfall-triggered landslides, such as empirical rainfall threshold methods or probabilistic methods based on historical records. The wide availability of Geographic Information Systems (GIS) and digital topographic data has led to the development of analytic methods for landslide hazard estimation that couple steady-state hydrological models with slope stability calculations. Because these methods typically neglect the transient effects of infiltration on slope stability, results cannot be linked with historical or forecasted rainfall sequences. Estimates of the frequency of conditions likely to cause landslides are critical for quantitative risk and hazard assessments. We present results to demonstrate how a transient infiltration model coupled with an infinite slope stability calculation may be used to assess shallow landslide frequency in the City of Seattle, Washington, USA. A module called CRF (Critical RainFall) for estimating deterministic rainfall thresholds has been integrated in the TRIGRS (Transient Rainfall Infiltration and Grid-based Slope-Stability) model that combines a transient, one-dimensional analytic solution for pore-pressure response to rainfall infiltration with an infinite slope stability calculation. Input data for the extended model include topographic slope, colluvial thickness, initial water-table depth, material properties, and rainfall durations. This approach is combined with a statistical treatment of rainfall using a GEV (General Extreme Value) probabilistic distribution to produce maps showing the shallow landslide recurrence induced, on a spatially distributed basis, as a function of rainfall duration and hillslope characteristics. 相似文献
11.
强降雨作用下堆积层滑坡稳定性分析 总被引：2，自引：0，他引：2
强降雨作用易造成堆积层滑坡发生,带来严重的生命财产损失。基于Green-Ampt（GA）模型,同时考虑湿润锋以上饱和带渗流作用,推导了一种新的滑坡降雨入渗函数,弥补了GA模型只适用于无限长坡的不足。为考虑降雨入渗对土体条块强度的影响,采用整体抗剪强度准则评价滑坡稳定性,并在受力分析时考虑了湿润锋以上饱和带渗透力作用,建立了滑坡稳定性系数表达式。研究结果表明：滑坡降雨入渗的尺寸效应非常明显,湿润锋扩展速率随着坡长的增大而增大,当滑坡无限长时新降雨入渗模型与GA模型计算结果相同,说明GA模型是新模型的一个特例。此外,降雨初期,滑坡稳定性下降较快;随着降雨的持续,稳定性下降速率逐渐放缓。与模型试验结果对比表明,提出的降雨入渗模型和评价方法计算结果与试验揭示的现象一致,证明了该方法的可靠性。 相似文献
12.
Ding-Jian Wang Hui-Ming Tang Ya-Hui Zhang Chang-Dong Li Lei Huang 《Environmental Earth Sciences》2017,76(8):321
The paper presents an improved analytical approach for evaluating the time-dependent stability of colluvial landslides during intense rainfall infiltration. The approach comprises two steps: first to simulate rainfall infiltration and then to compute the safety factor. In terms of the irregularity of the natural landslide surface in implementation of the method, the landslide is divided into several soil slices with approximately straight sides. Each single slice is regarded as a finite slope so that the infiltration formula and safety factor can be deduced. The infiltration formula is derived with combination of the Green–Ampt model and mass conservation law considering seepage perpendicular and parallel to slope surface simultaneously. In the modified infiltration model, both size effect and angle effect are vividly observed in the process of rainfall infiltration into the finite slope, while the former of which is not presented in the original Green–Ampt model. The safety factor is computed using the limit equilibrium method, with the influence of infiltrating water on the shear strength, gravity and seepage force of soil slices considered. By case study of the Shuping landslide in Three Gorges, decline in the safety factor and the decrease in the tendency are definite. Specifically under the rainfall intensity of 50 mm/h, the failure of Shuping landslide is most likely to occur at the time of 102 h. In addition, the results highlight shallow failure along the wetting front under intense rainfall. 相似文献
13.
Zuoan Wei Guangzhi Yin J. G. Wang Ling Wan Liping Jin 《Environmental Earth Sciences》2012,67(6):1651-1662
The stability of both natural and cut slopes in mountainous areas is a great challenge to highway constructions and operations. This paper presents a successful case study of stability analyses and protection treatments for high-steep cut soil slopes in an ancient landslide zone which was located at Km12+700 to Km15+000 along the Tehran?CChalus highway. This report has three parts. First, geotechnical investigations of in situ direct shear test, SPT tests and laboratory tests were implemented to get the subsurface profiles and the mechanical properties of the soil mass. Second, finite difference analysis was carried out to evaluate the stability of both the natural and cut slopes. Minimum safety factors and potential failure modes of cut slopes were obtained under both static and dynamic conditions. These results indicated that the ancient landslide could not be reactivated under the present climatic and morphological conditions, but there were some potential shallow failures in some cut soil slopes (failure actually occurred during excavation). Protection treatments and reinforcements were thus necessary. Third, the stability of the cut slopes was re-assessed by simplified Bishop limit equilibrium analysis (using Slide 5.0). Some potential failure zones were designed to be protected by back-anchored concrete retaining wall at the slope toe, rock bolts and frame beams on the slope face and planting grass on the slope face. Numerical analysis indicated that these protection measures could stabilize this remedial slope. These practical experiences may be of benefit for similar highway construction projects. 相似文献
14.
边坡开挖和降雨通常是导致边坡失稳的重要原因。本文以湖南湘西山区某国道扩建开挖边坡为研究对象,基于现场边坡监测结果和数值模拟分析,研究了在边坡开挖和降雨条件下坡体变形位移的过程。结果表明:边坡的破坏是一个渐变的过程,不同的影响因素对边坡的影响不同。开挖切方是浅层坡体失稳的诱发因素,开挖切方破坏了坡体的应力平衡,使坡体的应力重新分布,并在坡体中产生浅层的滑动面。雨水的入渗是坡体深层滑动面的诱发因素,雨水沿着裂缝渗入坡体,使浅部滑动面上下土体的变形差进一步加大,进而产生浅层牵引式滑动破坏。同时雨水的入渗使碎石土和强风化页岩交界附近产生高孔隙水压力,在水-岩土共同作用逐渐形成软化的滑带土,从而形成深层滑动面。 相似文献
15.
Topo-stress based probabilistic model for shallow landslide susceptibility zonation in the Nepal Himalaya 总被引：1，自引：1，他引：0
Ranjan Kumar Dahal Netra Prakash Bhandary Shuichi Hasegawa Ryuichi Yatabe 《Environmental Earth Sciences》2014,71(9):3879-3892
While dealing with slope stability issues, determining the state of stress and the relation between driving force and resisting force are the fundamental deterministic steps. Gravitational stresses affect geologic processes and engineering operations in slopes. Considering this fact, a concept of topo-stress evaluation is developed in this research and used to produce a shallow landslide susceptibility map in a model area. The topo-stress introduced in this research refers to the shear stress induced by the gravitational forces on the planes parallel to the ground surface. Weight of the material on a slope and friction angle of the jointed rock mass are the two fundamental parameters that are considered to govern topo-stress in this study. Considering topo-stress as a main factor for initiating shallow landslides, a GIS-based probabilistic model is developed for shallow landslide susceptibility zonation. An ideal terrain in central Nepal is selected as the study area for this purpose. Two event-based shallow landslide inventories are used to predict accuracy of the model, which is found to be more than 78 % for the first event-landslides and more than 76 % for the second event-landslides. It is evident from these prediction rates that the probabilistic topo-stress model proposed in this work is quite acceptable when regional scale shallow landslide susceptibility mapping is practiced, such as in the Himalayan rocky slopes. 相似文献
16.
植被在世界各地被广泛用于防止滑坡,但在我国东南沿海的台风季节,植被覆盖较好的地区受台风暴雨诱发常有大量滑坡发生。为了研究台风暴雨条件下植被对滑坡发育的促进作用,通过风洞物理模拟实验研究了风荷载和植被摇曳对滑坡稳定性的影响。结果表明: 台风通过植被对边坡施加的荷载不容忽视,在超强台风条件下(风速≥17 m/s),风荷载可使潜在滑坡体的下滑力增加10%以上; 由于台风的风荷载,植被会通过根部对土壤施加强大的扭矩,导致土壤出现裂缝,这些裂缝为雨水渗透提供了快速通道,土壤的渗透系数会增加10倍以上。因此在东南沿海地区的台风季节,应注意植被、特别是高大乔木对滑坡稳定性的不利影响。 相似文献
17.
Pipatpongsa Thirapong Fang Kun Leelasukseree Cheowchan Chaiwan Apipat 《Landslides》2022,19(8):1861-1879
A stability analysis of a laterally confined slope model, lying on an inclined bedding plane, was presented to evaluate the lateral shear resistance by considering the loading paths and failure envelopes. Two slope models were prepared on a bedding plane by compaction, one with and one without lateral confinement. The compacted models are related to the geological conditions at shallow depths where brittle deformation can occur and an excavation can induce horizontal field stress that significantly influences the stability of the slope. Three distinct loading paths, controlled by either tilting the angles or increasing the surcharge loads, were applied to achieve the failure of the slope models. Rankine’s passive earth pressure due to compaction was reduced by the shear strength reduction ratio. The shear strength reduction ratio was estimated through the least-squares fitting method based on the results of model tests at failure when the loading paths intersected the failure envelope. Provided that the effect of lateral confinement in a rock mass can be described by the shear strength reduction ratio, the proposed equations will be beneficial for slope stability analyses of laterally confined slopes on bedding planes. A case study of an undercut pit wall in an open-pit mine was demonstrated by showing that the unknown shear strength reduction ratio can be back-analyzed from the rainfall-induced landslide case. Therefore, the design of other undercut slopes with different geometries and groundwater conditions in the rock mass, which have undergone the same geological process as the back-analyzed case, is possible.
相似文献18.
采用基于网格的瞬态降雨入渗(TRIGRS)模型,以滑坡灾害频发的陕南安康市东部巴山东段白河县为研究区,探讨模型适用性及不同降雨条件下边坡稳定性空间分布规律。根据中国土壤分布图并结合已有研究,选取模拟所需的水土力学参数。将模拟所得研究区稳定性分布图与实际滑坡目录对比分析进行TRIGRS模型精度评估,分别模拟连阴雨和短时间强降雨两种降雨情景,探讨研究区边坡稳定性空间分布规律,结果表明:1)TRIGRS模型在模拟预测降雨诱发型浅层滑坡时,结合受试者特征ROC曲线进行精度评估,曲线下面积为0.752,说明此模型在白河县进行滑坡模拟时具有一定的合理性与准确性,能反应该地区滑坡灾害的空间分布特征;2)连阴雨情景模拟下,极不稳定区域主要集中在北部低山地貌区,以冷水镇和麻虎镇为主,随降雨历时增加向东部和南部增多,西部仓上镇、西营镇和双丰镇的极不稳定区域面积较少,能承受长时间连续性降雨。短时间强降雨对边坡稳定性的影响更为直接,极不稳定区域随降雨强度增大而增加,以冷水镇和麻虎镇为主要防范区域。结合地形分析,极陡峭区域边坡稳定性最差,无法承受持续性降雨和高强度降雨,较陡峭区域更易受到降雨历时和降雨强度的影响,而平缓区域则能承受长时间及高强度的降雨;3)TRIGRS模型根据不同降雨条件预测易发生滑坡灾害的区域,为滑坡实时预报警系统提供了新的可能方法。 相似文献
19.
For the assessment of shallow landslides triggered by rainfall, the physically based model coupling the infinite slope stability
analysis with the hydrological modeling in nearly saturated soil has commonly been used due to its simplicity. However, in
that model the rainfall infiltration in unsaturated soil could not be reliably simulated because a linear diffusion-type Richards’
equation rather than the complete Richards’ equation was used. In addition, the effect of matric suction on the shear strength
of soil was not actually considered. Therefore, except the shallow landslide in saturated soil due to groundwater table rise,
the shallow landslide induced by the loss in unsaturated shear strength due to the dissipation of matric suction could not
be reliably assessed. In this study, a physically based model capable of assessing shallow landslides in variably saturated
soils is developed by adopting the complete Richards’ equation with the effect of slope angle in the rainfall infiltration
modeling and using the extended Mohr–Coulomb failure criterion to describe the unsaturated shear strength in the soil failure
modeling. The influence of rainfall intensity and duration on shallow landslide is investigated using the developed model.
The result shows that the rainfall intensity and duration seem to have similar influence on shallow landslides respectively
triggered by the increase of positive pore water pressure in saturated soil and induced by the dissipation of matric suction
in unsaturated soil. The rainfall duration threshold decreases with the increase in rainfall intensity, but remains constant
for large rainfall intensity. 相似文献
20.
Geological Characteristics and Stability Evaluation of Wanjia Middle School Slope in Wenchuan Earthquake Area 总被引：1，自引：1，他引：0
Tian-shun Hou Xin-gang Wang Sibel Pamukcu 《Geotechnical and Geological Engineering》2016,34(1):237-249
To investigate the formation mechanism and the stability of Wanjia middle school slope in Wenchuan Earthquake Area, the macroscopic geological characteristics and the failure process of the landslide are researched by engineering geology analysis method, limit equilibrium method, and finit element method. The results show that after the Wenchuan Earthquake, retaining walls, houses and other infrastructure on the foot of Wanjia middle school slope were severely destroyed, 10 cm wide tension fracture appeared at the trailing edge of the slope. Wanjia middle school slope is a type of medium-sized soil landslide. The area of the deformation body is about 19,314 m2, the total volume of the deformation body is about 23 × 104 m3. There may be two potential sliding surfaces in the unstable slope: shallow and deep landslide. The analysis results of the limit equilibrium method and the finite element method show that: under dead weight, dead weight + rainstorm, dead weight + earthquake conditions, the plastic zone occurs mainly at the middle part or the trailing edge of the slope, and it doesn’t fully cut through the deep landslide body, so the deep landslide is stable. However, under rainstorm or earthquake conditions, the plastic zone almost completely cut thorough the shallow landslide body, it shows that the shallow landslide is in the understable–basic stable state. It is found that the results of finite element method is concordant with the results of the limit equilibrium method (F s = 1.06–1.29, the shallow landslide is in the basic stable–stable state). The calculation results show that shallow landslides are likely to occur in Wanjia middle school slope during a rainstorm or an earthquake, so monitoring and control of the slope should be strengthened. The shallow landslide should be managed by some measures, such as anti slide pile retaining structures and drainage works, and the dangerous rock bodies on the slope surface should be cleaned up. 相似文献