共查询到20条相似文献，搜索用时 31 毫秒
1.
A residual soil slope in Singapore that failed on two occasions, in 1989 and 1991, was reanalysed using two (2D) and three-dimensional (3D) slope stability analyses. The geometry of the slope in 1989 differed from that in 1991. The 2D and 3D slope stability analyses on the slope that failed in 1989 showed that the average shear strength parameters of the residual soils are representative of the slope and the factors of safety obtained from 2D slope stability analyses are not necessarily more conservative than 3D slope stability analyses. The analyses also showed that the slope failed in 1989 due to rising groundwater table. The analyses of the slope in 1991 showed that the slope experienced shallow failure due to the high groundwater table. Analyses of the slope after lowering of groundwater table by horizontal drains showed that the factor of safety of the slope has improved tremendously. The differences in factors of safety for 2D and 3D slope stability analyses are greater for low groundwater table as compared with those for high groundwater table. The results illustrated how 3D slope stability analyses have become less daunting to perform and can be incorporated into routine slope designs. 相似文献
2.
黄土地区公路边坡降雨失稳预报研究 总被引：1，自引：1，他引：0
为了研究黄土地区公路边坡降雨失稳灾害的预测预警方法,通过现场调查和理论分析,研究了黄土地区公路边坡降雨灾害危险性初步判别的标准;在分析公路边坡稳定性主要影响因素(边坡结构、边坡形态和植被特征)的基础上,提出了黄土地区公路边坡标准坡型的模型;以标准边坡坡型为基准,根据边坡失稳资料和降雨数据,建立了公路边坡抗灾能力评分表和评分标准。由此提出了适合于陕北黄土地区(包括砂黄土地区和典型黄土地区)公路边坡降雨灾害预测预警的抗灾雨量法,可以针对某个具体的黄土地区公路边坡的降雨灾害进行工点失稳预报。工程应用表明抗灾雨量法可操作性较好。 相似文献
3.
地形地貌对地震波放大效应数值模拟研究 总被引：2，自引：0，他引：2
采用FLAC3D 软件进行大量数值模拟,研究了地形地貌对地震波放大效应规律。结果表明:对于单面坡模型,斜坡较低时,坡体对天然地震波和简谐波的峰值加速度在竖直向和顺坡面向产生线性放大效应。斜坡较高时,若坡角低,两种波形的加速度等值线近似平行于坡面,天然地震波坡顶正下方极值性不明显,但随坡角增大而明显,坡面正下方可见若干条与坡面相平行具节律性的极小值条带,随坡角增大向一条极值带转化,简谐波在高低坡脚时坡顶面正下方区域内都出现等间距相间分布具节律性的极值条带,坡面正下方的极值带状性不如天然地震波明显,随坡角增大而消失; 若坡角高,两波形加速度放大系数顺坡面呈相间的极值圈分布。双面坡坡顶宽度越小,山脊越单薄,加速度放大效应越强烈,随坡顶宽度增大,坡肩加速度放大系数趋于稳定,双面坡对加速度放大效应强于单面坡。对加速度放大效应,多峰形双峰形单峰形,坡顶越不规则,加速度放大效应越强烈。V形河谷坡面上半部分加速度放大效应要强于U形河谷,U形河谷的谷底中部对地震波动力响应要强于V形谷。坡面局部不规则性只影响到坡面局部范围内的峰值加速度分布,坡高、坡角、坡顶几何特征为整个峰值加速度分布的控制因素。 相似文献
4.
介绍了楔形体与开挖坡体模型之间的关系,提出了确定边坡开挖松动区范围的弹性理论分析方法。阐明在用楔形体理论分析出开挖坡体的应力场的基础上,根据一定的坡体材料强度条件（经过安全储备后的摩尔-库仑强度准则和单轴抗拉强度准则）,且考虑三向应力状态,计算搜索坡体在该稳定系数下的开挖松动区,由此计算出在坡体自上而下分步开挖过程中每一步开挖施工完成之后相应的松动区来。提出了分析计算坡体开挖松动区的主要步骤,说明在分步开挖过程中,计算搜索每一步开挖后的坡体松动区主要需通过讨论上一步开挖后的坡体应力场、本步开挖卸荷量及本步开挖后产生的松动区范围等问题来实现。最后,用算例较为详细地说明了用弹性楔形体理论解析坡体开挖松动区的具体操作过程。 相似文献
5.
边坡治理中的植物固坡法 总被引：11，自引：2，他引：11
植物固坡法是近年来国际上越来越流行的一种边坡治理方法。本文阐述了植物固坡法的基本原理和作用机理，介绍了当前国内外植物固坡工程的一般施工流程，对镇江市的边坡治理提出了建议，最后对植物固坡法的应用前景作了分析。 相似文献
6.
We examine slope profile types and variations in slope gradient and slope relief with depth for both passive and active margins in the northern most South China Sea.The passive South China margin is characterized by an exponential slope profile,mainly assodated with clustered slope-confined canyons.The active Taiwan margin shows a linear-like shape with great variations along the lower slope.Fewer eanyom occur on the Taiwau margin,and hence the influence of canyon incision on slope morphology is relatively less significant.Quantitative analyses of slope curvature,slope gradleut and square root of relief variance are useful statistical parameters to explain characteristics and variability of morphology of the slope of the South China margin,but not for the Kaoping slope on the Talwan side.On the active Taiwan margin,tectonic activities are dominant over sediment deposition and surface erosion,producing a slope profile quite different from those of passive margins of the Middle Atlantic,KwaZulu-Natal,South Africa where failure on slope and accompanying canyon incision are the dominant processes shaping the slope morphology. 相似文献
7.
随着海州露天矿的闭坑,岩体结构越来越弱化,围岩的支承能力越来越小,露天矿边坡处于不稳定状态,具有发生大规模滑坡的潜在危险。根据海州露天矿工程地质条件,边坡形态,稳定状态及监测目的,研发海州露天矿边坡预应力锚索远程监测系统。系统应用GPRS远距离无线传输技术远程主动监测边坡岩体内部应力变化来获取岩体变形特征和滑移信息,实现边坡锚索应力全天候连续自动监测,其采用太阳能进行供电,适用于边坡中、长期监测。通过对海州露天矿边坡监测与边坡稳定性分析的现场应用实践证明,该系统可以对边坡稳态进行实时监测,对边坡滑坡灾害防治具有重要意义。 相似文献
8.
土工格栅加筋土边坡是一种新型的边坡支护结构,对于提高边坡稳定性、节约工程用地、保护生态环境意义重大。为了对机场加筋高填方边坡加固方案进行优化设计,本文以某机场跑道西北角的6#高填方边坡为例,首先基于边坡的地质条件和高填方边坡的实际情况,提出3种不同边坡坡率的加筋土边坡设计方案;其次采用简化Bishop法、Spencer楔形体法以及Morgenstern-Price法分别计算在天然、暴雨以及地震工况下的边坡稳定系数;最后利用有限元法分析3种加固方案下的加筋土边坡在天然工况下的变形特征以及筋材轴力分布规律。结果表明:3种设计方案在天然、暴雨以及地震工况下均能满足边坡稳定性要求,贴坡填筑的多级加筋土边坡的筋材轴力分布规律沿着竖向呈现锯齿状分布,最大筋材轴力在每级边坡的坡脚处突变增大。与加筋土缓坡（坡率1∶1.5）设计方案相比,加筋土挡墙（坡率1∶0.25）在坡高、筋材使用量、护坡面积以及挖填方量等方面均有明显减小。综合考虑稳定性、工程造价以及施工周期,采用加筋土挡墙的设计方案更合理。 相似文献
9.
考虑饱和-非饱和渗流的土坡极限分析 总被引：2，自引：1，他引：1
给出了均质土坝的下游坝坡的安全系数的计算方法。均质土坝的下游坝坡有可能会通过滑裂面发生破坏。土坝中的土坡通常处于非饱和状态。非饱和土坡的安全系数计算需要考虑吸力对抗剪强度的贡献以及土坡中的非饱和渗流。给出处于饱和-非饱和渗流状态下的土坡的安全系数,有助于评价均质土坝的安全系数。下游坝坡的安全系数计算方法有：极限平衡法、上限解法和下限解法,该算法适用于非饱和土坡,且是在饱和土坡安全系数的计算方法上修正得到的。算例中非饱和土坡安全系数的计算考虑了吸力对抗剪强度的贡献。考虑非饱和渗流理论的土坡安全系数计算方法通常更加接近现场实际情况,并且对于同一坝坡,考虑非饱和渗流计算出的土坡安全系数要比饱和渗流理论计算出的安全系数大。 相似文献
10.
强度折减法在评价边坡稳定性时不需要假设和搜索临界滑裂面，相对于其它方法具有一定优势，但失稳判据尚无明
确标准。滑移线场理论（SLFT） 可以计算得到的极限状态下的边坡坡面曲线（简称极限坡面曲线），已有研究表明极限坡
面曲线与边坡坡面的相对位置关系可以判断边坡稳定性。基于该结论提出一种边坡强度折减法失稳判据：不同折减系数计
算得到不同的强度参数，因此滑移线场理论计算得到的极限坡面曲线将发生变化，当极限坡面曲线与边坡坡面在坡底相离
时，判断边坡为稳定状态；当极限坡面曲线与边坡坡面相交于坡脚时，判断边坡为极限平衡状态；当极限坡面曲线与边坡
坡面相交时，判断边坡为失稳状态。对标准边坡考题的计算结果表明：提出的失稳判据收敛性较好，安全系数计算结果与
标准答案和已有失稳判据分析结论相差较小；传统失稳判据收敛指标的确定没有明确标准，当位移突变曲线光滑时很难找
到突变点，很难准确计算对应的安全系数，更重要的是传统失稳判据判断边坡极限状态受到人为主观因素的影响，而提出
的失稳判据可以实现失稳判据的客观标准化；确定的临界滑裂面形状以及在边坡中的位置都与标准答案基本一致，提出的
失稳判据适用于强度折减法。 相似文献
11.
基于案例的边坡治理方案选择决策支持系统研究 总被引：1，自引：0，他引：1
边坡治理是边坡工程研究的核心问题,其治理方案的选择直接关系到边坡治理的成功与否。边坡的治理需要很丰富的经验和知识,但知识的获取一直是边坡治理决策的瓶颈问题。长期以来,边坡治理工程实践已积累了大量的工程案例,这些案例中蕴涵了大量的经验和知识,急需挖掘与开发,并应用于边坡治理决策中,进而指导边坡治理工程实践。为此,针对边坡治理决策中的边坡治理方案选择问题,提出了一种基于案例的边坡治理方案选择系统,用以对边坡治理方案选择提供有效的决策支持。该研究具有较好的工程应用价值。 相似文献
12.
基于坡面稳定的黄土路堑高边坡优化设计 总被引：1，自引：0，他引：1
通过室内外黄土边坡的冲刷试验结果发现,随着坡度的增加,坡面上的最大冲沟深度呈先减少、后增大的趋势。黄土边坡坡角值越接近临界坡角,坡面产生破坏的可能性越小。根据坡面流理论,导出黄土路堑高边坡抗冲刷的临界坡角。根据调查发现,当边坡的坡角相同时,单级坡体越高,坡体（即坡长越长）越易形成明显的冲沟。根据坡角、坡面长和坡面冲刷量之间的关系,建立了基于坡面稳定的黄土路堑高边坡优化设计模型。用该模型对典型路堑高边坡进行计算验证,优化结果和实际情况吻合较好。 相似文献
13.
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
14.
公路边坡岩体分级中坡高修正系数的改进 总被引：2，自引：0，他引：2
坡高与边坡稳定性有密切关系。CSMR分级体系在SMR的基础之上针对水电边坡工程引入了坡高修正系数 ,但在公路边坡分级实践中发现 ,该坡高修正系数仍有待于改进。对各类边坡可能失稳形式的力学分析 ,证明坡高修正系数 可近似表示为 =a+b/H 的形式。通过对 1 0 0余个边坡样本统计分析 ,得出两种不同岩层、坡面产状组合形式下坡高修正系数的数学表达式。经检验 ,改进后的CSMR体系能够满足公路边坡稳定性初步评价的要求。 相似文献
15.
Marco Wunsch Christian Betzler Sebastian Lindhorst Thomas Lüdmann Gregor P. Eberli 《Sedimentology》2017,64(3):631-657
Hydroacoustic and sedimentological data in the Santaren Channel covering both the leeward slope of Great Bahama Bank and the windward slope of Cay Sal Bank allow new insights into carbonate platform slope sedimentation. The data document the interplay between depositional and erosive processes on both slopes through time and provide information on the current regime and its influence on the slope sedimentary processes. This study emphasizes the diversity and complexity of the slope morphology and the sediment distribution of the youngest high‐frequency sequence, which has developed since the last glacial maximum. The processes triggering slope failures and the formation of channels and gullies differ on both slopes. At the leeward slope of the Great Bahama Bank, extensive slope failures occurred primarily during sea‐level lowering following an interglacial. These slope failures created a slope morphology that channelizes the exported platform sediments during the subsequent highstand. At the windward slope of Cay Sal Bank, contour currents and the local tectonic regime are responsible for slope failures. During sea‐level lowstands, downwelling induces turbidity currents. The interaction of turbidity and contour currents leads to the formation of a system of furrows and slope‐parallel sediment ridges. The discovered heterogeneities in slope sedimentation improve the understanding of carbonate slope sedimentation and provide implications for sequence stratigraphic interpretation of carbonate platform slopes. 相似文献
16.
强度折减法在评价边坡稳定性时不需要假设和搜索临界滑裂面,相对于其它方法具有一定优势,但失稳判据尚无明
确标准。滑移线场理论（SLFT） 可以计算得到的极限状态下的边坡坡面曲线（简称极限坡面曲线）,已有研究表明极限坡
面曲线与边坡坡面的相对位置关系可以判断边坡稳定性。基于该结论提出一种边坡强度折减法失稳判据：不同折减系数计
算得到不同的强度参数,因此滑移线场理论计算得到的极限坡面曲线将发生变化,当极限坡面曲线与边坡坡面在坡底相离
时,判断边坡为稳定状态;当极限坡面曲线与边坡坡面相交于坡脚时,判断边坡为极限平衡状态;当极限坡面曲线与边坡
坡面相交时,判断边坡为失稳状态。对标准边坡考题的计算结果表明：提出的失稳判据收敛性较好,安全系数计算结果与
标准答案和已有失稳判据分析结论相差较小;传统失稳判据收敛指标的确定没有明确标准,当位移突变曲线光滑时很难找
到突变点,很难准确计算对应的安全系数,更重要的是传统失稳判据判断边坡极限状态受到人为主观因素的影响,而提出
的失稳判据可以实现失稳判据的客观标准化;确定的临界滑裂面形状以及在边坡中的位置都与标准答案基本一致,提出的
失稳判据适用于强度折减法。 相似文献
17.
基于现场监测资料,对黄土路堑边坡坡面下土体水热变化规律进行分析研究.结果表明,左边坡坡面下土体温度高于右边坡,左边坡冻结期和冻结深度小于右边坡;右边坡含水率变化深度大于左边坡,水分在边坡5 cm以上浅层土体中迁移速度基本相同,在边坡坡面25 cm以下土体渗透性差异较大,左边坡迁移速度低于右坡;冬季左边坡坡面下浅层土体和右边坡观测范围内地温低于0℃,右边坡坡面25 cm以上对应的含水率为零,而左边坡浅层土体和右边坡25 cm以下土体含水率并不为零;干湿循环和冻融循环在左右边坡土体中的显著程度和影响深度不同. 相似文献
18.
层状岩质边坡遍布节理模型的三维稳定性分析 总被引：5，自引：1，他引：4
采用遍布节理模型（ubiquitous-joint模型）描述层状岩体的各向异性特征,并探讨ubiquitous-joint准则中安全系数的计算方法,利用FLAC3D分析层理倾角、倾向与边坡稳定性之间的关系,结果表明：（1）对于顺层边坡,当岩层倾向与坡面倾向的夹角 较小时,边坡的安全系数随层理倾角 的增大呈现先减小后增大再减小的趋势; 20°～30°时,安全系数得到最小值, 60°时安全系数得到最大值;不同破坏型式导致安全系数变化规律之间的差异;当 较大时,曲线从先减小后增大的趋势转变为不断增大的趋势;根据 的大小将顺层边坡分为两类：当 45°时,为严格顺层边坡;当45° 90°时,为斜向层状边坡。（2）对于逆层边坡,当 45°时,曲线呈现先增大再减小然后又增大的趋势,各曲线随 的变化程度基本相同;但减小过程中,随着 的增大,曲线的斜率逐渐减小,边坡稳定性的各向异性程度减小;当 45°时,曲线随 的增大呈现非线性单调递增的趋势。（3）安全系数与 之间的关系表明,对于顺层坡,随着 的增大,边坡安全系数逐渐增大;对于逆层坡,当 较小时( 150°),边坡安全系数随 的增大而逐渐减小;随着 的增大( 120°),边坡安全系数与 呈现递增关系。 相似文献
19.
砂黄土高边坡稳定性的数值模拟研究 总被引：5，自引：0，他引：5
基于野外调查和室内试验分析,阐述了黄土高原北部砂黄土边坡破坏的主要形式及其影响因素。结合陕北高等级公路建设,采用弹塑性有限元法模拟了不同工程开挖条件下坡形、降雨和地震作用等因素对砂黄土高边坡稳定性的影响。结果表明,随着坡角或坡高的增大,边坡稳定性不断变差,阶状坡形比一坡到顶的坡形更利于边坡稳定和防护;降雨作用对边坡稳定影响极大,在坡脚积水的情况下,坡脚处塑性应变值比常态增加近20倍;地震作用促使坡脚应力和应变值升高,并且随着地震动峰值加速度的增大而变化显著。模拟分析结果为砂黄土高边坡优化设计和灾害治理提供了科学依据。 相似文献
20.
The Dynamic Evaluation of Rock Slope Stability Considering the Effects of Microseismic Damage 总被引：1，自引：1，他引：0
N. W. Xu F. Dai Z. Z. Liang Z. Zhou C. Sha C. A. Tang 《Rock Mechanics and Rock Engineering》2014,47(2):621-642
A state-of-the-art microseismic monitoring system has been implemented at the left bank slope of the Jinping first stage hydropower station since June 2009. The main objectives are to ensure slope safety under continuous excavation at the left slope, and, very recently, the safety of the concrete arch dam. The safety of the excavated slope is investigated through the development of fast and accurate real-time event location techniques aimed at assessing the evolution and migration of the seismic activity, as well as through the development of prediction capabilities for rock slope instability. Myriads of seismic events at the slope have been recorded by the microseismic monitoring system. Regions of damaged rock mass have been identified and delineated on the basis of the tempo-spatial distribution analysis of microseismic activity during the periods of excavation and consolidation grouting. However, how to effectively utilize the abundant microseismic data in order to quantify the stability of the slope remains a challenge. In this paper, a rock mass damage evolutional model based on microseismic data is proposed, combined with a 3D finite element method (FEM) model for feedback analysis of the left bank slope stability. The model elements with microseismic damage are interrogated and the deteriorated mechanical parameters determined accordingly. The relationship between microseismic activities induced by rock mass damage during slope instability, strength degradation, and dynamic instability of the slope are explored, and the slope stability is quantitatively evaluated. The results indicate that a constitutive relation considering microseismic damage is concordant with the simulation results and the influence of rock mass damage can be allowed for its feedback analysis of 3D slope stability. In addition, the safety coefficient of the rock slope considering microseismic damage is reduced by a value of 0.11, in comparison to the virgin rock slope model. Our results demonstrate that microseismic activity induced by construction disturbance only slightly affects the stability of the slope. The proposed feedback analysis technique provides a novel method for dynamically assessing rock slope stability and can be used to assess the slope stability of other similar rock slopes. 相似文献