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位于河北省宽城县某拟建铁路将穿越一老滑坡体,体积约77×104 m3,并在滑坡前缘以路堑方式穿过,因开挖施工导致老滑坡复活.在现场地质调查基础上,阐明了滑坡所在的地质环境条件和发育特征,系统分析了老滑坡的形成原因和复活机理,即老滑坡是受附近断层影响,岩体完整性较差,而前缘河流冲刷和回漩旁蚀降低了边坡的整体稳定性,在暴雨或地震诱发下形成,而修建铁路的路堑开挖则是导致前缘抗滑段失效而复活的主要原因.在现场试验和室内试验成果基础上,分别对沿现滑面和古滑面在不同工况下的稳定性进行计算,并系统分析了铁路路堑边坡开挖对滑坡稳定性的影响程度,并对滑坡治理提出了措施建议. 相似文献
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鬼招手滑坡位于“5·12”汶川地震极重灾区彭州市内,是地震4a后暴雨诱发的高速滑坡.剖析了主滑体和堆积区Ⅰ、Ⅱ、Ⅲ的特征;分析了影响该边坡稳定性并诱发滑坡的6大因素,包括地层岩性、河流及泥石流冲刷掏蚀坡脚、暴雨及雨水下渗、断裂及“5.12”汶川地震、地貌、人类工程活动,其中持续暴雨是滑坡主要诱发因素;计算了主滑体抛射初速度为40.41 m/s,运动距离为137m,定义了主滑体的破坏模式为滑移-抛射模式;总结了滑坡的破坏过程,分为坡体累积破坏、坡体启动、坡体运动、坡体堆积稳定4个阶段;对比分析了暴雨和地震诱发的高速滑坡的不同之处,对于地震灾区的防灾减灾工作具有一定参考价值. 相似文献
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库岸边坡是一个复杂的地质综合体,库岸滑坡是威胁库区安全的地质隐患。多数传统滑坡预测模型为静态模型,未将滑坡变形特征与位移预测二者结合考虑,不能实际反映滑坡演化过程中的动态特性。本文基于溪洛渡库区58处涉水滑坡变形监测结果,归纳了库岸滑坡变形规律,采用机器学习方法实现了不同特征滑坡变形趋势的短期预测。研究结果显示：(1)研究区年平均地表形变速率处于-116.841～265mm·yr-1,负值代表目标地物远离卫星方向位移,正值代表目标地物靠近卫星方向移动,其中存在缓慢变形滑坡13处,根据其累计位移曲线特征划分为：阶跃型、振荡型和持续增长型三类。(2)阶跃型滑坡滑面多为弧线型,其变形主要受库水位周期性变动影响;振荡型滑坡滑面多为折线型,其变形多受库水位和降雨共同作用;持续增长型滑坡滑面多为直线型,其变形主要受自身地质条件控制。(3)针对不同变形特征滑坡,采用长短时记忆(LSTM)神经网络模型考虑多因素耦合和滑坡演化状态建立了滑坡变形动态预测模型,通过评价结果验证,该模型具有较高预测精度及良好的适用性。研究结果可以为溪洛渡库区滑坡系统研究与防治提供依据,为库区不同变形特征... 相似文献
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从滑坡的地质环境入手,通过地质调研及测绘,分析曾家包包大型基岩滑坡的特征、控制因素及成因机制,并运用sama法及不平衡推理法、毕肖普法对滑坡稳定性极限平衡进行计算分析。在此基础上,对在现今应力场作用下滑坡的稳定性采用了有限元模拟,并对模拟的结果进行分析,得出在天然条件下曾家包包滑坡曾处于稳定状态,岩体中的软弱夹层经长期持续的地下水浸润软化逐渐泥化形成倾角上陡下缓的贯通性滑移面,在雨季降雨异常集中期,岩体排水不畅形成较高的空隙水压力,斜坡岩体就会沿滑移面发生顺层滑移,从而形成大型基岩滑坡。 相似文献
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深层倾倒是雅砻江上游层状斜坡变形破坏的主要模式。利用基于演化过程的工程地质研究方法,分析深层倾倒体工程地质特性和内部变形破坏-力学机制,进行工程地质分区评价,并从变形过程和演化阶段上定性认识斜坡的整体稳定性。研究表明:区内深层倾倒体发育规模巨大、变形程度剧烈,且具有明显的分区性,为典型的互层倾倒;软硬相间的岩性组合、陡倾的岸坡结构,加之垂直层面密集节理的切割是深层倾倒体形成的控制性因素。在叠加有残余构造应力的自重应力场中,互层倾倒是受节理面和层面控制的复合倾倒模式,即:硬岩发生块状-弯曲倾倒,而软岩发生弯曲倾倒;受河谷演化控制,深层倾倒体主要经历4个演化阶段:卸荷回弹陡倾面拉裂阶段,初始变形阶段,板梁根部折断、剪切面贯通阶段以及破坏阶段,并最终转化为蠕滑-拉裂模式形成滑坡;变形破坏模式的转化是深层倾倒体进入累进性破坏阶段的重要标志,该滑动面受倾向坡外结构面控制,主要发生在强变形岩体中,而并非沿最大弯折带发育。 相似文献
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张溪滑坡--台风诱发滑坡成因分析 总被引：6，自引：1，他引：5
14号台风“云娜”造成我国东部沿海地区发生多处滑坡地质灾害,张溪滑坡便是其中个案。通过对张溪滑坡成因进行分析,得出了张溪滑坡是在一定厚度覆盖层、特定地形条件、植被条件下,台风风力加载作用及暴雨的淘蚀、软化、增重等一系列过程共同作用下滑动失稳的滑坡。它与暴雨型滑坡的形成机理有显著不同,这一分析成果对类似滑坡的研究和防治具有一定的意义。 相似文献
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AHMET EVREN ERG&#;NAL MURAT TÜRKE&#; T. AHMET ERTEK ALPER BABA C&#;HAN BAYRAKDAR 《Geografiska Annaler: Series A, Physical Geography》2008,90(2):109-123
This paper discusses the occurrence and development of the excavation‐induce deep‐seated landslide, which took place near Dündar village, located west of Orhaneli town in northwestern Turkey. The event occurred in the Bursa‐Orhaneli lignite field, which has been actively operating since 1979. Due to undermining of a gently inclined slope (10°) to extract a coal seam, primary tension cracks, which were precursors of the movement, were first observed in the northern head area in mid‐ to late October 2003. This movement happened simultaneously with precipitation that was significantly above long‐term average measured at a nearby climatology station (Keles). This precipitation amount is characterized statistically by a significant standardized anomaly of 1.6. The majority of the monthly precipitation total in October 2003, which mainly consisted of rain showers and thunderstorms, occurred in the last week of the month. By April 2004, rotational failure continued intermittently. After a relatively wet (rainy and snowy) period from January 2004 to April 2004, the main rotational slump occurred in late April 2004, causing the entire destruction of Dündar village's cemetery. Daily climatic and synoptic meteorological data have proved that heavy showers in late April may had triggered the last slump by producing rain showers of 19.3 mm and 19.9 mm daily total on 27 and 28 April 2004, respectively. Field observations carried out along the main head scarp have shown that the slope failure was facilitated by a pre‐existing normal fault with an east‐ west direction and 80° dip. Grain‐size analysis showed that the failure occurred on clayey silt, which forms 55% of the slip surface material. Based on the evidence from X‐ray fluorescence and energy dispersive X‐ray spectroscopy results, smectite‐type clay ‐ a product of the chemical weathering of tuff ‐ was the main constituent of the slip surface material. The landslide occurred over an area of 600 m × 650 m with a total volume of 8775 000 m3. Approximately 28 hectares of farm land were entirely destroyed and the excavated coal seam was buried. The mining operation was moved to 100 m north of the landslide area near Gümü?p?nar village. From morphological evidence, it is concluded that excavation activities caused the failure to extend in more than one direction as an enlarging sliding mechanism; this produced a high landslide risk for Gümü?p?nar village, where the most significant normal fault with a 75 m vertical displacement in a coal‐bearing sequence is found in the lignite field. 相似文献
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降雨型浅层滑坡的变形预测模型 总被引：1，自引：0，他引：1
滑坡是边坡被某些诱发因素激发失稳产生滑动的一种地质现象。它是地质灾害的主要类型,尤其以降雨滑坡数量最多,其中浅层滑坡分布最广。通过对降雨型浅层滑坡的变形进行分析,建立了基于功能原理的滑坡一维运动方程,并结合太沙基固结原理,研究滑坡运动过程中孔隙水压力的消散,揭示了滑坡从运动-停止的动力演化过程,构建了降雨型浅层滑坡的位移预测模型,并以都江堰塔子坪滑坡为例进行分析,通过mathmatic给出了滑坡运动的速率、位移与降雨量的量化关系式。 相似文献
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Objective landslide detection and surface morphology mapping using high-resolution airborne laser altimetry 总被引：6，自引：0，他引：6
A map of extant slope failures is the most basic element of any landslide assessment. Without an accurate inventory of slope instability, it is not possible to analyze the controls on the spatial and temporal patterns of mass movement or the environmental, human, or geomorphic consequences of slides. Landslide inventory maps are tedious to compile, difficult to make in vegetated terrain using conventional techniques, and tend to be subjective. In addition, most landslide inventories simply outline landslide boundaries and do not offer information about landslide mechanics as manifested by internal deformation features. In an alternative approach, we constructed accurate, high-resolution DEMs from airborne laser altimetry (LIDAR) data to characterize a large landslide complex and surrounding terrain near Christchurch, New Zealand. One-dimensional, circular (2-D) and spherical (3-D) statistics are used to map the local topographic roughness in the DEMs over a spatial scale of 1.5 to 10 m. The bedrock landslide is rougher than adjacent unfailed terrain and any of the statistics can be employed to automatically detect and map the overall slide complex. Furthermore, statistics that include a measure of the local variability of aspect successfully delineate four kinematic units within the gently sloping lower half of the slide. Features with a minimum size of surface folds that have a wavelength of about 11 to 12 m and amplitude of about 1 m are readily mapped. Two adjacent earthflows within the landslide complex are distinguished by a contrast in median roughness, and texture and continuity of roughness elements. The less active of the earthflows has a surface morphology that presumably has been smoothed by surface processes. The Laplacian operator also accurately maps the kinematic units and the folds and longitudinal levees within and at the margins of the units. Finally, two-dimensional power spectra analyses are used to quantify how roughness varies with length scale. These results indicate that no dominant length scale of roughness exists for smooth, unfailed terrain. In contrast, zones with different styles of landslide deformation exhibit distinctive spectral peaks that correspond to the scale of deformation features, such as the compression folds. The topographic-based analyses described here may be used to objectively delineate landslide features, generate mechanical inferences about landslide behavior, and evaluate relatively the recent activity of slides. 相似文献
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金龙山地区滑坡综合观测方案的设计原则有:阶段性、科学性、综合性和适用性。滑坡综合观测内容含:斜坡应力变化,滑体的运动变形与滑坡的地声,地下水动态,以及影响滑坡发生发展的因素(降水等)。为此在本方案中包含10个滑坡观测项目(1987—1991年已在当地开展了8个,获取3万余个数据),对观测数据由微型计算机加以综合管理。此外对组建减灾防灾组织系统(如成立指挥部和制定群防避灾措施等)在方案中也作了考虑。 相似文献
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不稳定斜坡危险度的判别 总被引：1，自引：0，他引：1
为判别不稳定斜坡的危险度,在斜坡表面的变形迹象、斜坡本身的内部条件及外界的触发因素中,分出12项定性定量判别指标,它们各自有因子判别值Xj(i为判别指标的编号,1—12;j为因子判别值等级编号,1—6)。把各判别指标的因子判别值Xj叠加并予以综合后,便得叠加因子判别值Y=sum from 1 to N(Xj/N)(N为判别指标的数目,至少取6个),再查表13,定出不稳定斜坡危险度D。 相似文献
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斜坡中发育的多种裂面在滑坡形成过程中将组合成多条变形带，随着变形的发展，变形逐渐向最大剪应力处集中，最终形成滑面。斜坡中多变形带稳定性模糊综合评判是采用数理统计的方法，将滑坡发育过程中影响变形带的因素作为不同的评判因子，对其进行模糊综合评判分析，然后确定最不稳定的变形带。文中最后以金龙山滑坡变形带的稳定性分析为例，证明该方法的正确性。 相似文献
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本文运用断裂力学的原理和方法,分析了斜坡破坏过程中后缘开裂、滑动面的形成和结构面连通的机理,以及破坏中所遵循的轨迹。通过模拟实验、数值分析和应用,证明断裂力学方法是一种分析斜坡破坏机理的有效方法。 相似文献