共查询到20条相似文献，搜索用时 218 毫秒
1.
土质边坡常因客观条件和地质因素的改变而失去原有的稳定性.通过对某一工程的红粘土土质边坡的稳定性评价,提出了在治理基坑边坡工作中,抗剪指标参数的取用原则和建议. 相似文献
2.
用改进后的BP神经网络评价黄土质边坡稳定性 总被引：11，自引：0，他引：11
首先介绍了改进BP神经网络性能的几种方法；在此基础上，考虑影响黄土质边坡稳定性分析的各种自然因素，包括坡高，坡比，强度指数，土何内摩擦角，土体容重，空隙水压力系数以及地震烈度统方法的计算结果进行逐一对比，对比结果证明了该方法能够满足一般黄土质边坡稳定性评价的精度要求；另一方面，由于方法的改进大大减少了网络的计算时间，使得黄土质边坡稳定性的评价更为便捷迅速，从而证明该方法具有一定的推广应用价值。 相似文献
3.
边坡稳定性与其影响因素之间存在着复杂的非线性关系。通过分析影响边坡稳定性的主要因素,采用支持向量机建立边坡稳定性和影响因素之间的非线性关系;同时,考虑到支持向量机参数对预测效果的影响,采用连续蚁群算法对其进行优化选择,从而提出边坡稳定性预测的蚁群优化支持向量机模型。锦屏一级右岸拱肩槽部位谷坡为顺向坡,绝大部分基岩裸露,自然边坡为大理岩边坡,现状稳定。结合锦屏一级右岸拱肩槽边坡,采用蚁群优化支持向量机模型对其稳定性进行预测分析,预测结果与实际情况吻合较好,说明蚁群优化支持向量机模型在边坡稳定性分析中具有良好的实际应用价值。 相似文献
4.
《地下水》2021,(1)
采用FLAC~(3D)模拟三维土体、岩体或其他材料力学特性,尤其是达到屈服极限时的塑性流变特性,在边坡稳定性分析中具有重要的应用。FLAC~(3D)已经在土质边坡稳定系数和边坡变形特征研究中被广泛应用。以兰州市某土质边坡为例,基于FLAC~(3D)方法,选取边坡中部两个典型剖面进行计算,分析其天然工况下塑性、剪应力变化、稳定性及变形趋势,并结合实际调查结果,验证计算参数选取的合理性。研究结果可知:在不考虑人为及其它因素影响的情况下,土质边坡在自然工况下基本稳定,但从实际模拟过程来看,模拟计算结果一般偏大。故综合认为,为使土质边坡在自然条件下稳定,边坡坡度应45°。 相似文献
5.
通过对316国道土质边坡及岩质边坡进行振动响应测试,研究交通荷载引起土质及岩质边坡振动加速度大小及其空间变化特征,同时利用FFT方法对振动信号进行频谱分析,得到岩质及土质边坡的振动响应频谱特性。测试及分析结果表明,振动波传播过程中携带了反映介质固有特性的信息,岩质及土质边坡对交通荷载的响应均较为敏感,相同荷载在土质边坡引起的振动加速度及振动幅值大于岩质边坡,其中土质边坡沿坡由下向上振动响应有减弱的趋势,且振动在短距离内衰减较快,而岩质边坡振动响应在短距离内衰减较慢;主频随着振动波的衰减有向低频移动的趋势。测试为分析振动传播途径和研究振动对边坡稳定性的影响提供了宝贵资料,对多因素引起的边坡稳定性评价有重要的实际意义。 相似文献
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水对土质边坡的稳定性影响分析 总被引：1，自引：1，他引：0
首先论述了地下水对边坡稳定性的影响因素,水对土质边坡的影响作用,接着推导出了考虑水作用影响的边坡安全系数计算公式,最后指出应用动态的观点来研究边坡体内的地下水作用. 相似文献
11.
A study of slope stability prediction using neural networks 总被引：5，自引：0，他引：5
The determination of the non-linear behaviour of multivariate dynamic systems often presents a challenging and demanding problem. Slope stability estimation is an engineering problem that involves several parameters. The impact of these parameters on the stability of slopes is investigated through the use of computational tools called neural networks. A number of networks of threshold logic unit were tested, with adjustable weights. The computational method for the training process was a back-propagation learning algorithm. In this paper, the input data for slope stability estimation consist of values of geotechnical and geometrical input parameters. As an output, the network estimates the factor of safety (FS) that can be modelled as a function approximation problem, or the stability status (S) that can be modelled either as a function approximation problem or as a classification model. The performance of the network is measured and the results are compared to those obtained by means of standard analytical methods. Furthermore, the relative importance of the parameters is studied using the method of the partitioning of weights and compared to the results obtained through the use of Index Information Theory. 相似文献
12.
边坡稳定性一直是边坡安全的重点研究对象,针对边坡评价中常见的不确定性因素,可靠度分析是值得利用的方法。为评价某节理发育的岩质岸坡稳定性,通过有限元计算软件,结合现场勘探测绘数据,建立以边坡节理强度参数c、φ为输入变量,安全系数为输出变量的点估计（PEM）计算概率模型,计算结果表明:节理发育对该边坡变形具有明显控制作用;边坡整体可靠性较好,破坏概率极低。最后,通过蒙托卡罗法对可靠度结果进行验证,结果表明两种方法的计算结果不存在显著性差异。研究结果表明节理对岩质边坡稳定具有良好的敏感性,基于节理不确定性的点估计法分析边坡可靠度是一种有效的方法。 相似文献
13.
In the present study, cut slope stability assessment along ghat road section of Kolli hills was carried out by using various geotechnical parameters of rock and soil slope sections and structural kinematics of major discontinuities is presented. The rock slope (RS) stability assessment was carried out using Rock Mass Rating basic (RMRbasic) and Slope Mass Rating (SMR) classification systems. The type of failure and their Factor of Safety (FOS) for individual RS was calculated using Hoek and Bray method. In the case of soil slopes (SS), the FOS was calculated using Circular Failure Chart (CFC) and Limit Equilibrium (LE) methods. The input data for the slope stability analyses were collected through extensive field work followed by stereonet plotting and laboratory test. There are six rock slope sections, and five soil slope sections were taken into consideration for the cut slope stability analyses. The area depicts class II (RS-1, 2, & 6) and class III (RS-3, 4, & 5) of RMR classes. The SMR result depicts for RS-1, RS-2, and RS-6 are 64.40, 60.02, and 60.70, respectively, and falls in class II stable condition. The SMR values of RS-3 and RS-5 were 44.33 and 57, respectively, and come under the class III partially stable condition. The RS-4 with SMR value of 17.33 falls under the class I completely unstable condition. The FOS of planar failure case indicates that RS-3 (FOS = 0.22) is more unstable, while all other sections are having greater than 1 FOS. The calculated FOS values using CFC method reveals that the FOS is very close to 1 for all the SS sections that fall under completely saturated condition which indicates that these slope sections may fail during heavy rainfall. In LE method, the sections SS-3 and SS-4 are unsafe under partially and completely saturated (natural slope) condition. In average slope condition, all the SS sections are unsafe under partially or completely saturated conditions. The facets 2, 3, 4, and 5 required mitigation measures, to improve the stability of slopes. Site-specific mitigation measures were suggested for partially or completely unstable rock and soil cut slopes. 相似文献
14.
Development of a model for analysis of slope stability for circular mode failure using genetic algorithm 总被引：3，自引：1，他引：2
Amin Manouchehrian Javad Gholamnejad Mostafa Sharifzadeh 《Environmental Earth Sciences》2014,71(3):1267-1277
Slope stability estimation is an engineering problem that involves several parameters. The interactions between factors that affect slope instability are complex and multi-factorial, so often it is difficult to describe the slope stability mathematically. This paper, proposes the use of a genetic algorithm (GA) as a heuristic search method to find a regression model for analyzing the slope stability. For this purpose, an evolutionary algorithm based on GA was used to develop a regression model for prediction of factor of safety (FS) for circular mode failure. The proposed GA uses the root mean squared error as the fitness function and searches among a large number of possible regression models to choose the best for estimation of FS from six geotechnical and geometrical parameters. For validation of the model and checking its efficiency, a validation dataset was used to evaluate FS using the proposed model and a previously developed mathematical GA based model in the literature. Results have shown that the presented model in this study was capable of evaluating FS at a higher level of confidence regarding the other model (R = 0.89 for presented model in this study comparing R = 0.78 for the other model) and can be efficient enough to be used as a simple mathematical tool for evaluation of factor of safety for circular mode failure especially in preliminary stages of the designing phase. 相似文献
15.
Different models were developed for evaluating the probabilistic three-dimensional (3-D) stability analysis of earth slopes and embankments under earthquake loading. The 3-D slope stability model assumed is that of a simple cylindrical failure surface. The probabilistic models evaluate the probability of failure under seismic loading considering the randomness of earthquake occurrence, and earthquake induced acceleration and uncertainties stemming from the discrepancies between laboratory-measured and in-situ values of shear strength parameters. The models also takes into consideration the spatial variabilities and correlations of soil properties. The probabilistic analysis and design approach is capable of obtaining the 2-D and 3-D static and dynamic safety factors, the probability of slope failure, the earthquake induced acceleration coefficient, the yield acceleration coefficient, the earthquake induced displacement, and the probability of allowable displacement exceedance taking into account the local site effect. The approach is applied to a well known landslide case: Congress Street Landslide in Chicago. A sensitivity analysis was conducted on the different parameters involved in the models by applying those models to the Congress Street landslide considering different levels of seismic hazard. Also, a sensitivity analysis was carried out to study the sensitivity of computed results to input parameters of undrained shear strength, and corrective factors. A comparison was made between the different models of failure. The parametric study revealed that the hypocentral distance and earthquake magnitude have major influence on the earthquake induced displacement, probability of failure and dynamic 2-D and 3-D safety factors. 相似文献
16.
Modeling uncertainty in stability analysis for design of embankment dams on difficult foundations 总被引：2，自引：0，他引：2
A probabilistic 3-D slope stability analysis model (PTDSSAM) is developed to evaluate the stability of embankment dams and their foundations under conditions of staged construction taking into consideration uncertainty, spatial variabilities and correlations of shear strength parameters, as well as the uncertainties in pore water pressure. The model has the following capabilities: (1) conducting undrained shear strength analysis (USA) and effective stress analysis (ESA) slope stability analysis of staged construction, (2) incorporation of field monitored data of pore water pressure, and (3) incorporation of increase of undrained shear strength with depth, effective stress, and pore water pressure dissipation. The PTDSSAM model is incorporated in a computer program that can analyze slopes located in multilayered deposits, considering the total slope width.
The main outputs of the program are the geometric parameters of the most critical sliding surface (i.e., center of rotation/radius of rotation and critical width of failure), mean 2-D safety factor, mean 3-D safety factor, squared coefficient of variation of resisting moment, and the probability of slope failure. The program is applied to a case study, Karameh dam in Jordan. Monitored data of induced pore water pressure in the dam embankment and soft foundation were gathered during dam construction.
The stability of Karameh dam embankment and foundation was evaluated during staged construction using deterministic and probabilistic analysis. Foundation stability was evaluated based on the monitored data of pore water pressure.
The study showed that the mean values of the corrective factors which account for the discrepancies between the in situ and laboratory-measured values of soil properties and for the modeling errors have significant influence on the 2-D safety factor, 3-D safety factor, slope probability of failure, and on the expected failure width.
The degree of spatial correlation associated with shear strength parameters within a soil deposit also influences the probability of slope failure and the expected failure width. This correlation is quantified by scale of fluctuation. It is found that a larger scale of fluctuation gives an increase in the probability of slope failure and a reduction in the critical failure width. 相似文献
17.
Evaluating cut slope failure by numerical analysis—a case study 总被引：3，自引：3，他引：0
Slope failure is very common phenomenon in hilly regions, especially in young techno active mountainous like Himalayas. It
is hazardous because of the accompanying progressive movement of the slope-forming material. In order to minimize the landslide
effects, slope failure analysis and stabilization requires in depth understanding of the process that governs the behavior
of the slope. The present article mainly deals with the analysis of the stability of road cut slopes of Rudraprayag Area,
Uttarakhand, India. The area experiences local as well as regional slides every year. Extensive field study was carried out
along the road cut slopes. Laboratory experiments were conducted to determine the various Physio-mechanical properties of
rock mass. These properties have been used as input parameters for the numerical simulation of slope using FLAC3D (Fast Lagrangian
Analysis of Continua) including geological discontinuities. The computed deformations and the stress distribution along the
failure surface are compared with the field observations. The study indicates that the overall slope is unstable except at
the location E where slope is critically stable. The effects of instability have been thoroughly considered and remedial measures
have been recommended. 相似文献
18.
Bhardwaj Pandit G. L. Sivakumar Babu 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2018,12(2):152-168
Traditional reliability-based design methodologies often involve selection of design which is of lowest cost and satisfies safety requirements. But, this design is sensitive to variation in statistics of input parameters (noise parameters) and might become unsatisfactory if an underestimation of coefficient of variation of input parameters is made. A relatively new design methodology known as robust geotechnical design (RGD) is applied for the case of reinforcement of rock slope using end-anchored rock bolts. This ensures selection of a cost-effective and safe design for which probability of failure (Pf) of reinforced rock slope is least sensitive to the noise parameters. Reliability-based RGD approach involves evaluation of Pf for each design with different possible noise parameters. Finding Pf for the complex geotechnical structure is computationally expensive, and thus an augmented radial basis function-based response surface is used as a surrogate to the finite element model of rock slope. This response surface, being very efficient, also performs well for a range of values of noise parameters. Later, minimum distance algorithm is applied to obtain a cost-effective and robust design. Finally, a comparison is made in the costs between two robust designs obtained for different target probability of failure for the same rock slope. 相似文献
19.
Different models were developed for evaluating the probabilistic three-dimensional (3-D) stability analysis of earth slopes
and embankments under earthquake loading using both the safety factor and the displacement criteria of slope failure. In the
3-D analysis, the critical and total slope widths become two new and important parameters. The probabilistic models evaluate
the probability of failure under seismic loading and consider the different sources of uncertainties involved in the problem,
i.e. uncertainties stemming from the discrepancies between laboratory-measured and in situ values of shear strength parameters,
randomness of earthquake occurrence, and earthquake-induced acceleration. The models also take into consideration the spatial
variabilities and correlations of soil properties. The developed models are incorporated in a computer program, PTDDSSA (probabilistic
three-dimensional dynamic slope stability analysis). These developed analysis/design procedures are incorporated within a
code named SARETL (stability analysis and remediation of earthquake-triggered landslides) that was developed in this study
for stability analysis and remediation of earthquake-triggered landslides. In addition to the dynamic inertia forces; the
developed system takes into consideration the local site effects. The code is capable of: 1. Prediction of permanent deformations
that result from landslides under seismic loading using both probabilistic and deterministic approaches. 2. The assessment
of landslide hazard that affects major transportation routes in the event of earthquakes, and the preparation of earthquake-induced
landslide hazard maps (i.e. maps that show expected displacements and probability of slope/embankments failure) for different
earthquakes magnitudes and environmental conditions. 3. Proposing a mitigation strategy against landslides and suggesting
guidelines for remedial measures. The developed expert system is applied to a major highway case study. Design maps are developed
for the highway under seismic loading.
Received: 18 March 1999 · Accepted: 11 October 1999 相似文献
20.
Effect of Surcharge on the Stability of Anchored Rock Slope with Water Filled Tension Crack under Seismic Loading Condition 总被引：1，自引：0，他引：1
S. K. Shukla S. Khandelwal V. N. Verma N. Sivakugan 《Geotechnical and Geological Engineering》2009,27(4):529-538
In this paper, an analytical expression is derived for the factor of safety of the rock slope incorporating most of the practically
occurring destabilizing forces as well as the external stabilizing force through an anchoring system. The slope stability
is analyzed as a two-dimensional problem, considering a slice of unit thickness through the slope and assuming negligible
resistance to sliding at the lateral boundaries of the sliding block. A detailed parametric study is presented to investigate
the effect of surcharge on the stability of the rock slope for practical ranges of governing parameters such as inclination
of the slope face, inclination of the failure plane, depth of tension crack, depth of water in tension crack, shear strength
parameters of the material at the failure plane, unit weight of rock, stabilizing force and its inclination, and seismic load.
For the range of parameters considered in the present study, it is found that the factor of safety of the rock slope decreases
with increase in surcharge; the rate of decrease being relatively higher for lower values of surcharge. It is also observed
that for a specific surcharge, the factor of safety depends significantly on all other parameters, except for unit weight
of rock and higher values of inclination of stabilizing force to the normal at the failure plane. For any combination of these
variables, the surcharge plays a vital role in the stability. A perfectly stable slope at relatively low surcharge can become
unsafe with the increase in surcharge. The deterioration in the stability can be quite rapid, depending on the combination
of the factors under consideration. The analysis and the general expression proposed herein can be used to carry out a quantitative
assessment of the stability of the rock slopes. 相似文献