共查询到20条相似文献，搜索用时 765 毫秒
1.
In this paper, an approach is presented to analyze the stability risk of rock slopes based on a new rating system. Three factors are used to estimate the risk level of rock slopes: (1) failure probability, (2) element at risk rating, and (3) vulnerability rating. Element at risk and vulnerability ratings are both given a range from 0 to 10, and the probability of failure is varied between 0 and 1, so the risk rating ranges between 0 and 100. This risk rating can be used to determine both the quantitative and qualitative risk levels of slopes at the same time. The method is tested on the western sector of the slopes facing Songun copper plant phase III, Iran, to clarify its procedures and assess its validity. Deterministic kinematic analyses showed that the slope has a potential for circular failure. Risk assessments revealed that the risk levels of the slope in both static and pseudo-static conditions are “very low” and “high,” respectively.
相似文献2.
How to efficiently assess the system reliability of rock slopes is still challenging. This is because when the probability of failure is low, a large number of deterministic slope stability analyses are required. Based on Subset simulation, this paper proposes an efficient approach for the system reliability analysis of rock slopes. The correlations among multiple potential failure modes are properly accounted for with the aid of the “max” and “min” functions. A benchmark rock slope and a real engineered rock slope with multiple correlated failure modes are used to demonstrate the effectiveness of the proposed approach. 相似文献
3.
Evangelin Ramani Sujatha Thirukumaran V. 《Journal of the Geological Society of India》2018,91(4):489-495
Linear infrastructure networks like roads play a vital role in the socio-economic development of hill towns centered on tourism. Stability of the slopes along the hill roads are therefore a major concern and slope failures lead to disruption of traffic and loss of property/life or both. This study analyses the stability of cut-slopes along the Kodaikkanal – Palani hill road in the Western Ghats, India using rock mass classification systems like rock mass rating (RMR), slope mass rating (SMR) and continuous slope mass rating (CSMR). These geomechanical classifications provide a preliminary assessment of rock quality based on rock strength, discontinuity properties, hydrogeological condition of the slopes and slope stability based on the inherent rock strength parameters, discontinuity orientation and method of excavation. The results showed that both rock quality and discontinuity orientation contribute to type of failure in rock slopes with RMR > 40. SMR results are conservative while CSMR classification is matches more closely to the failures obtained from the field survey. CSMR classification represents continuous slope stability conditions and hence are more suitable for development of spatial database. Cutting of roads, thereby, steepening slopes has a definite influence on the stability of slopes. 相似文献
4.
Abhishek Kumar Chaurasia H. K. Pandey H. C. Nainwal Jitendra Singh S. K. Tiwari 《Journal of the Geological Society of India》2017,89(6):689-696
The rock mass rating (RMR) and slope mass rating (SMR) has been carried out to classify the slope in terms of slope instability. To understand the RMR and SMR various geostructural, geomorphologic and hydrological parameters of the slopes were measured and analyzed. 32 rock slopes/rock cum debris slopes were identified in the study area. The present RMR and SMR study is an outcome of extensive field study along a stretch of about 10 km on road leading from Srinagar to Pauriarea along Alaknanda valley. The technique followed incorporates the relation between discontinuities and slope along with rock mass rating (RMR) and slope mass rating (SMR). The analysis of the 32 studied slopes shows that in the Gangadarshan area out of six rock slope facets, two falls in class II (stable) and four in class IV (unstable). It is significant to note that the slope facets coming under class IV are comprised of active landslide portions. While the slopes under class II show minor failure or old landslide debris. 相似文献
5.
Kripamoy Sarkar Ashok Kumar Singh Anurag Niyogi Prasanta Kumar Behera A. K. Verma T. N. Singh 《Journal of the Geological Society of India》2016,88(3):387-393
The present paper demonstrates the assessment of slope stability analysis between Rampur to Jhakri road section along National Highway (NH-22), Himachal Pradesh, India. The different types of slope failures have affected most part of slopes which causes considerable loss of life and property, inconveniences such as disruption of traffic along highways. The poorly designed rock slopes for road widening or construction purposes may weaken the stability of the slopes. A detail field investigation has been carried out to collect the representative rock samples for determination of physico-mechanical properties of rock and joint data for kinematic analysis. The rocks exposed in the area are highly jointed quartzite and quartz-mica schist of Rampur-Larji Group of Palaeoproterozoic age. The continuous slope mass rating (CSMR) technique has been applied for the assessment of slope stability analysis at five vulnerable locations and the results shows slopes are partially stable to unstable. Kinematic analysis mainly shows wedge type of failure along with few toppling and planar failures. The existing slope required immediate treatment to prevent the failure for its long term stability. 相似文献
6.
Soil-rock mixtures (S-RM) are widely distributed in mountainous regions, and there are different genetic types and scales of S-RM slopes. The stability of these slopes is very important for slope safety during the construction and operation of engineering projects. Since the mechanical properties of an S-RM are mainly dominated by its random component, accurately investigating the structure of an S-RM slope is the fundamental basis for evaluating the mechanism of a landslide. In this paper, in situ direct shear tests are used to obtain the “soil” strength parameters of the S-RM, the microtremor survey method (MSM) is introduced to detect the S-RM slope and the numerical method of FEM is utilised to simulate the failure characteristics and stability of the S-RM slope. Based on the MSM, the strata structure and proportions of solitary rock blocks in the S-RM slope are investigated, and three possible models of the S-RM slope are established. By using the strength reduction method in numerical simulations, the potential failure surface and stability of a slope of homogeneous soil and that with solitary rock blocks are discussed. The study results show that the MSM is an effective method to estimate the proportion of rock blocks in the S-RM slope. The presence of solitary rock blocks makes the slope potential slide surface complicated. The factor of safety of the S-RM slope is higher than that of the homogeneous soil slope, the rock blocks at the toe of the slope are favourable for slope stability and the rock blocks near the surface of the slope squeeze the lower soil and improve the safety factor of the slope. 相似文献
7.
综合黔西地区层状岩质开挖边坡研究成果发现:岩体结构特征是分析评价层状边坡变形失稳模式、机制和稳定性的重要基础。因此,结合该地区层状边坡地质条件的差异性,针对性地划分岩体结构类型对边坡的分析评价尤为重要。考虑地层岩性组合、地质构造、软弱夹层（结构面）因素,系统地将边坡岩体结构类型分为4个大类（近水平-缓倾边坡岩体,倾斜层状边坡岩体,陡倾、直立、倒转层状岩体,地质构造作用强烈或含有溶蚀洞穴、沟壑的边坡岩体）和10个亚类,并针对相应类型的边坡进行工程地质综合评价,分别阐述了失稳模式和机制。以边坡岩体结构类型为基础,甄选影响开挖边坡稳定性的6个定性指标和6个定量指标;对指标组合赋权,用未确知测度理论对边坡进行稳定性预测评价,建立了“岩体结构-指标组合赋权-未确知测度理论”的新评价体系。实例预测结果表明预测结果与实际情况具有较好的一致性,说明该方法是一种可靠性高、科学合理的稳定性预测新方法,可在相关工程领域中应用推广。 相似文献
8.
Enhancement of random finite element method in reliability analysis and risk assessment of soil slopes using Subset Simulation 总被引：4，自引：2，他引：2
Random finite element method (RFEM) provides a rigorous tool to incorporate spatial variability of soil properties into reliability analysis and risk assessment of slope stability. However, it suffers from a common criticism of requiring extensive computational efforts and a lack of efficiency, particularly at small probability levels (e.g., slope failure probability P f ?<?0.001). To address this problem, this study integrates RFEM with an advanced Monte Carlo Simulation (MCS) method called “Subset Simulation (SS)” to develop an efficient RFEM (i.e., SS-based RFEM) for reliability analysis and risk assessment of soil slopes. The proposed SS-based RFEM expresses the overall risk of slope failure as a weighed aggregation of slope failure risk at different probability levels and quantifies the relative contributions of slope failure risk at different probability levels to the overall risk of slope failure. Equations are derived for integrating SS with RFEM to evaluate the probability (P f ) and risk (R) of slope failure. These equations are illustrated using a soil slope example. It is shown that the P f and R are evaluated properly using the proposed approach. Compared with the original RFEM with direct MCS, the SS-based RFEM improves, significantly, the computational efficiency of evaluating P f and R. This enhances the applications of RFEM in the reliability analysis and risk assessment of slope stability. With the aid of improved computational efficiency, a sensitivity study is also performed to explore effects of vertical spatial variability of soil properties on R. It is found that the vertical spatial variability affects the slope failure risk significantly. 相似文献
9.
Evaluating the failure probability of a slope under the seismic condition during a given exposure time is important for performance-based assessment of slope stability. In this paper, a two-stage method is suggested to study the seismic stability of a slope during a given exposure time. In the first stage, the exceedance probability of the horizontal pseudo-static acceleration is evaluated. In the second stage, the vulnerability curve of the slope, which shows the relationship between the horizontal pseudo-static acceleration and the failure probability of the slope, is established. The failure probability of the slope during a given exposure time is then assessed by combining the exceedance probability curve of the horizontal pseudo-static acceleration and the vulnerability curve of the slope. Examples investigated show that the reliability of a slope under the seismic condition is controlled by multiple slip surfaces. A slope may have different failure probabilities during the same exposure time when it is at different locations because of different levels of ground shaking. Event at the same site, different slopes may have different failure probability because of the difference in factors like slope geometries and geological conditions. The method suggested in this paper can be used to quantify the effect of the above factors on the reliability of a slope. 相似文献
10.
Satish Kumar Kishor Kumar N. N. Dogra 《Journal of the Geological Society of India》2017,89(4):407-412
Rock slopes require geo-engineering evaluation to assess the instability of critical slopes leading to landslides particularly in Himalayan terrain where rocks are highly jointed, fractured and weathering prone. Interplay of discontinuities in the rocks coupled with other parameters is one of the prime causes of failure of slopes. Engineering rock mass classification, such as, rock mass rating (RMR) and slope mass rating (SMR) along with geological strength index (GSI) have widely been used for stability assessment of rock slopes above tunnel portals, and these classifications are employed here for assessment of stability of slopes of critical nature along Rampur-Powari highway in Himachal Pradesh. In the present study, out of 154 numbers of slopes, a total of 29 have been selected for assessment of their criticality by employing RMR, SMR and GSI. 相似文献
11.
以往研究中倾倒变形研究在反倾边坡较多而在顺倾边坡中很少,对两种不同结构的边坡形成倾倒体的异同点更是存在较多空白。在总结大量倾倒体实例基础上,对层状反倾和顺倾边坡倾倒变形形成条件及发育规模特征进行了详细研究。结果表明,顺倾边坡若发生倾倒,通常表现为坡高 100 m,边坡坡角 35°,岩层倾角 60°,岩性为薄层或薄层与中层互层的软岩、软硬相间的岩石;反倾边坡当坡角 30°及岩层倾角 30°就可能发生倾倒,其岩性为薄层～中厚层状的软岩、硬岩及具有似层状结构的坚硬岩石均可;提出层状岩质边坡“倾倒临界倾角 ”的概念,对于顺倾边坡, 60°,当 时边坡将可能产生倾倒破坏,当 时边坡通常产生顺层面的“滑移-弯曲”或“滑移-拉裂”型破坏;反倾边坡 30°,当 时边坡才可能演化成明显倾倒变形,当 时边坡不会倾倒或倾倒不明显;对于地质条件基本相同而坡体结构不同的两种边坡,反倾边坡形成的倾倒体无论是发育分布面积还是倾倒深度通常是大于顺倾边坡的,而且一旦形成倾倒体,二者的规模通常是深层的、大型或特大型的;倾倒体的分布面积和倾倒深度均呈现一种随坡高的增加而增加的趋势,坡高 250 m时其分布面积和倾倒深度表现为陡然增加,并且反倾边坡增加幅度大于顺倾边坡。 相似文献
12.
A. Malarvizhi Achyuthan Hema D. Gobichandhru 《Journal of the Geological Society of India》2016,87(3):317-322
Occurrences of landslide are most common and critical issue in North-East India. The various types of slope failures have been affected most part of slopes and road section between Malidor to Sonapur area (approx 30 Km) along NH-44 within Jaintia hills district, Meghalaya, India. These slope failures causes considerable loss of life and property along with many inconveniences such as disruption of traffic along highways. The unscientific excavations of rock slopes for road widening or construction purposes may weaken the stability of the slopes. The rocks exposed in the area are highly jointed sandstone and shale of Barail Group of Oligocene age. The Sonapur landslide is most dangerous and destructive rock fall-cum debris flow. The present study includes the kinematic analysis of the slope to assess the potential failure directions as the rocks are highly jointed in some parts of road cut sections. The continuous slope mass rating (CSMR) technique has been applied for slope stability analysis at five vulnerable locations. Kinematic analysis indicates mainly wedge type of failure along with few toppling and planar failures. These failure required immediate treatment to prevent the slide and long term stability of the slope. 相似文献
13.
岩性及岩体结构对斜坡地震加速度响应的影响 总被引：1，自引：0，他引：1
斜坡岩体的岩性及岩体结构是斜坡在地震作用下产生变形破坏的主要控制因素。基于振动台模型试验,对4个斜坡模型探讨了这2个因素对斜坡地震动力响应的影响。岩性包括强度相对较高的硬岩和强度相对较低的软岩,对这两种岩性的斜坡又分别考虑了不含结构面的均质斜坡和含水平层状结构面的斜坡。基于传感器采集到的大量数据,以主频相近的天然地震波和10 Hz正弦波加载为分析工况,获得了以下几点认识：（1）4个模型斜坡坡面和坡内的水平向加速度均具有高程放大效应,尤其是软岩斜坡坡顶放大效应最显著;（2）软岩斜坡对水平向加速度的高程放大效应强于硬岩斜坡,尤其是在均质斜坡中表现最显著,均质软岩斜坡的高程放大效应呈现出明显的非线性特征;（3）当加载方向与水平层面平行时,含水平层状结构面的斜坡比均质斜坡产生了更强的高程放大效应,且在软岩斜坡中体现最显著;（4）岩性差异对斜坡水平向加速度高程效应的影响比结构差异的影响更为显著。研究结果为岩质斜坡的抗震设计提供了一定参考。 相似文献
14.
《Engineering Geology》2007,89(1-2):129-143
The objective of this paper is to present a new rock mass classification system which can be appropriate for rock slope stability assessment. In this paper an evaluation model based on combining the Analytic Hierarchy Process (AHP) and the Fuzzy Delphi method (FDM) was presented for assessing slope rock mass quality estimates. This research treats the slope rock mass classification as a group decision problem, and applies the fuzzy logic theory as the criterion to calculate the weighting factors. In addition, several rock slopes of the Southern Cross-Island Highway in Taiwan were selected as the case study examples. After determining the slope rock mass quality estimates for each cases, the Linear Discriminant Analysis (LDA) model was used to classify those that are stable or not, and the discriminant functions which can determine failure probability of rock slopes were carried out by the LDA procedure. Afterward, the results may be compared with slope unstable hazards occurring actually, and then the relation and difference between them were discussed. Results show that the proposed method can be used to assess the stability of rock slopes according to the rock mass classification procedure and the failure probability in the early stage. 相似文献
15.
Three-dimensional slope reliability and risk assessment using auxiliary random finite element method
This paper aims to propose an auxiliary random finite element method (ARFEM) for efficient three-dimensional (3-D) slope reliability analysis and risk assessment considering spatial variability of soil properties. The ARFEM mainly consists of two steps: (1) preliminary analysis using a relatively coarse finite-element model and Subset Simulation, and (2) target analysis using a detailed finite-element model and response conditioning method. The 3-D spatial variability of soil properties is explicitly modeled using the expansion optimal linear estimation approach. A 3-D soil slope example is presented to demonstrate the validity of ARFEM. Finally, a sensitivity study is carried out to explore the effect of horizontal spatial variability. The results indicate that the proposed ARFEM not only provides reasonably accurate estimates of slope failure probability and risk, but also significantly reduces the computational effort at small probability levels. 3-D slope probabilistic analysis (including both 3-D slope stability analysis and 3-D spatial variability modeling) can reflect slope failure mechanism more realistically in terms of the shape, location and length of slip surface. Horizontal spatial variability can significantly influence the failure mode, reliability and risk of 3-D slopes, especially for long slopes with relatively strong horizontal spatial variability. These effects can be properly incorporated into 3-D slope reliability analysis and risk assessment using ARFEM. 相似文献
16.
中等倾角岩层顺向坡,受坡体结构和岩体物理力学性质控制,多存在变形、崩塌、滑坡等工程地质问题,常常会诱发大规模的地质灾害。该类斜坡潜在滑动面不直接出露地表,一般具有变形机制复杂、隐蔽性强和危害大的特点,是滑坡领域关注与研究的重点。拖担水库大坝左岸为一古滑坡,在水库扩建开挖过程中,诱发古滑坡体复活。在分析古滑坡工程地质条件的基础上,结合地质勘察和变形监测结果,研究了其变形特征及形成机制。研究结果表明:①左岸古滑坡具有岩层倾角“上陡下缓”、滑体底部存在反倾坡内的剪切破碎带、滑床岩体产生弧状弯曲的特点;②古滑坡体为一基岩顺层滑坡,滑动模式为“滑移（弯曲）—剪断”型,其变形破坏过程包括三个阶段:弯曲隆起阶段、滑移剪出阶段和扰动变形阶段;③该类斜坡变形破坏后,坡体易沿“上陡下缓”的椅型软弱层面发生二次滑动,滑坡控制关键是对下部变形区的保护。 相似文献
17.
现有上硬下软边坡的研究大都集中在压缩挤出变形的近水平泥岩、页岩基座型边坡变形演化过程,针对倾倒变形的板岩基座型边坡开挖响应研究甚少,本文以西藏玉曲河某水电站厂址边坡为研究对象,根据现场地质调查建立符合坡体实际情况的地质结构模型,采用物理试验的方法模拟原型边坡开挖。通过试验揭示上硬下软反倾边坡在开挖条件下的变形响应特征及破坏模式。研究结果表明:（1）开挖条件下上硬下软型边坡变形破坏过程分为a）下部软岩倾倒弯曲加剧;b）软岩倾倒折断,上部卸荷硬岩沿已有裂隙剪切;c）倾倒软岩滑移,卸荷硬岩剪断岩性分界部位,折断面贯通3个阶段。其变形破坏模式为下部软岩倾倒—上部硬岩剪断组合滑移型破坏;（2）开挖强倾倒区岩体会使下部软岩迅速失稳并促使上部硬岩剪切破坏;开挖引起的反倾上硬下软边坡大变形在短时间内完成,前期变形和能量积累是一个较长的过程;（3）开挖时需避免对坡脚倾倒岩体“大开挖”施工。 相似文献
18.
含软弱夹层岩质边坡在自然环境和工程实践中都比较常见，稳定性差，边坡失稳产生了大量的滑坡灾害，造成大量人员伤亡和经济损失。因此，含软弱夹层岩质边坡稳定性研究一直是工程地质和岩土工程领域的研究重点之一。在收集整理国内外相关资料的基础上，从自重工况、开挖工况、暴雨和蓄水工况、地震工况方面总结了目前含软弱夹层岩质边坡稳定性的研究现状及进展，取得如下主要认识:(1)软弱夹层对岩质边坡稳定性有显著不利影响，含软弱夹层岩质边坡的稳定性比均质岩质边坡、不含软弱夹层的层状岩质边坡都差；(2)含软弱夹层岩质边坡的稳定性系数、变形特征和破坏模式与软弱夹层的含水状态、抗剪强度、倾角、厚度、间距、层数和边坡坡度有关；(3)开挖容易诱发坡体沿软弱夹层滑坡，含软弱夹层岩质边坡开挖后需要及时支护；(4)爆破层裂效应改变了软弱夹层与围岩的接触状态，减小了它们之间的凝聚力和摩擦力，导致边坡稳定性降低；(5)暴雨和蓄水都不利于含软弱夹层岩质边坡稳定；(6)岩质边坡地震动力响应和变形破坏特征受软弱夹层参数(厚度、倾角、含水状态)、地震波特性(地震波的类型、幅值、频率、激振方向)和边坡结构(顺层或反倾)共同影响；(7)在软弱夹层对水平向动力响应的放大或减弱作用及厚层软弱夹层的消能减震作用方面仍然存在不同观点。在此基础上，分析了研究方法的优缺点，指出当前含软弱夹层岩质边坡稳定性研究存在的问题。最后，针对该领域的研究现状，提出了未来的研究重点和方向，主要包括:含多层软弱夹层岩质边坡的渐进性变形破坏过程和稳定性；全面深入研究单因素作用(开挖卸荷、爆破、地震、暴雨、库水位变化、地下水等)对含软弱夹层岩质边坡稳定性的影响机制；多因素耦合作用下含软弱夹层岩质边坡稳定性；支挡结构体系对含多层软弱夹层高陡岩质边坡的加固机制。 相似文献
19.
考虑时间效应的滑坡风险评估和管理 总被引：4，自引：1，他引：3
提出了考虑时间效应的滑坡风险评估和管理方法。以香港地区近20年的16 000个切破的观测资料为基础,从统计学的角度提出了边坡的时变可靠性分析方法。推导了新建边坡在未来服役时间内的年失效概率的计算公式,并对现役边坡在未来服役时间内的年失效概率进行了预测。确定了基于年死亡人数的滑坡风险接受准则,并分析了基于滑坡时变风险的边坡加固时间。结果表明,考虑时间效应的滑坡风险评估和管理方法能够更加真实地反映滑坡随时间变化的特性。新建边坡的年失效概率随边坡服役时间逐渐增大,尤其是当边坡服役超过10年时,每年发生滑坡的概率急剧增大。现役边坡的年失效概率基本与继续服役时间呈线形关系。此外,香港斜坡维修指南规定的边坡加固时间能够有效地将滑坡风险降低到ALARP区或可接受的风险区。 相似文献
20.
GIS-based evaluation of rockfall risk along routes in Greece 总被引：1，自引：0，他引：1
Andreas A. Antoniou 《Environmental Earth Sciences》2013,70(5):2305-2318
This article presents a GIS-based system, designed to assist in the management of rockfall risk along Greek routes. The system was developed in two stages; the field data collection led to the implementation of a rockfall rating system with its fundamental parameters, while the data process concluded to a rockfall data base and a GIS-based interface. The fundamental parameters were derived from the rockfall hazard rating system developed by Pierson et al. at the Oregon State Highway Division and provide a coherent approach to decide the type and the cost of protection measures to be applied in an area affected by rockfalls and presents highest rockfall risk. The system presented in this paper as well as the original system comprises exponential scoring functions that represent the increased hazard and reflected in nine categories forming the classification. The method presented in this paper modified certain categories from the original system which were described qualitatively and may lead to quite subjective estimations. These categories are ditch effectiveness; climate and presence of water on slope as well as rockfall history. Moreover, the original category “Geologic characteristic” was changed to Structural and Discontinuities Index; an index that relates blockiness of rock mass and orientation of joints with their weathering condition and their roughness. This index follows the classification of weathering and joint’s roughness suggested by International Society of Rock Mechanics, while other modifications regarding the categories “decision sight distance” and “roadway width” were applied based on Greek standards. An application of this modified method to a 3 km road which connects Athinios port and Fira, the capital of Santorini island, Greece, a high traffic intensity road where rockfalls periodically cause traffic interruptions is presented. The method was applied in fifteen cross sections of slopes adjacent to the road and the analyses showed increased risk and the need for urgent remedial works. 相似文献