含软弱夹层库岸滑坡滑带发育特征研究

本文分析了巴东新城区巴东组第3段岩体中软弱夹层的分布特征、滑坡滑带的发育特征,结果表明巴东组第3段岩体中发育的滑坡滑带可与原岩中的软弱夹层对应,软弱夹层受构造剪切和地下水泥化作用发育成以碎石夹泥或黏土夹碎石为主的滑带.分析认为黄土坡滑坡、赵树岭滑坡的深层变形与巴东组第3段次级褶皱发育、层间劈理密集导致岩体破碎有关,而两滑坡滑体结构差异主要原因是原岩中夹层发育密度差异所致.     

伊犁谷地地形地貌对滑坡的影响

伊犁谷地多山地的地貌特征使其成为滑坡灾害发生的重点地区之一,通过研究地形地貌与滑坡的关系可以看出,地形坡度在22°-34°之间,地面高程在1500-2500m之间,坡向向东,发生滑坡的概率最大,认为伊犁谷地滑坡的形成主要受地形地貌、地质构造、水以及人类工程活动等方面的影响。     

基于深部监测的滑坡动态特征分析

滑坡监测的目的是获取滑坡变形特征和演变过程.对于一些重要场地,判断其是否存在潜在滑坡时,深部位移监测是最直接和最有成效一种手段.通过在某厂房后坡两个监测断面设置5个深部位移监测孔,根据监测结果对滑坡体的范围、整体活动性、滑动方向、滑动面进行以及滑坡类型进行探讨和分析.监测结果表明:厂房后坡具有牵引式滑动特征,活动性明显;坡体位移速度较大,雨季有加速变形的特征;坡体前缘滑面已局部贯通,中、后部滑带也处于蠕动变形状态.     

新疆特克斯达坂矿山滑坡特征及影响因素分析

特克斯达坂滑矿山坡体形成机制包括滑坡的内因和外因两个方面,其中内因方面的地质因素包括:构造因素、岩性因素、水文地质因素、地形地貌因素等,外因方面持续强降雨融雪作用和人类活动。特克斯达坂滑坡的形成是由于长期矿山开采及降雨融雪下易失稳造成由泥岩层与上层粉土层构成的软弱结构面应力集中导致破坏。     

碎石土滑坡综合治理及评价决策方法

碎石土滑坡是一类由降雨激发失稳而产生滑动破坏的滑坡类型,要实现对其综合治理和评价决策,滑坡治理稳定性分析及效果评价就不容忽视.基于官家滑坡实际地质条件和变形破坏情况进行变形破坏机制研究和稳定性影响因素分析,在此基础上实施滑坡工程治理规划处置和治理稳定性分析,然后再参照降雨及滑坡变形情况构建加卸载响应比模型来实现滑坡稳定状态反馈和工程治理效果评价.研究表明:降雨作用及地下水变化是碎石土滑坡变形破坏最主要的动力因素,滑坡工程治理依据排水及抗滑原则确定综合处置措施,经治理稳定性分析,其稳定系数可大幅提高,完全满足不低于1.25的规范要求;并且基于加卸载响应比模型分析滑坡经综合治理后处于安全稳定状态,工程治理措施实施科学合理,工程治理效果显著,综合作用下滑坡稳定性好、安全可靠.     

基于固有振动频率的滑坡安全评价新方法

运用模型实验,在保持下滑力不变的情况下,通过固有振动频率对滑坡内部的黏结力、摩擦力等抗滑力指标进行分析.通过在弱稳定阶段中实际静摩擦力是否达到最大静摩擦力的方法,科学地判识滑体的稳定情况.结果表明:计算的摩擦力可以有效分析滑坡在弱稳定阶段期间的安全性,并证明固有振动频率监测比位移监测更加敏感.同时,固有振动频率的监测可对滑坡损伤做出定量判断,并可以评估滑坡静摩擦力指标,从而实现扰动后滑坡的安全评价.      

永泰县城峰镇旗山小区后山滑坡现场应急调查及处置分析

2010年5月20日,受连续降雨影响,福建省永泰县城峰镇旗山小区后山发现有滑坡地质灾害隐患,后山中下部产生多条35～80m长拉裂缝,坡脚崩塌不断,潜在滑坡规模约8×104m3,存在继续下滑的危险,情况十分危急,威胁坡脚居民2565人的生命和约5.38亿元财产.本文在对灾害现场进行详细地质调查的基础上,结合现场测绘、监测等手段,对该滑坡体的基本特征进行了较深入的调查研究,对滑坡发生及成灾原因进行了初步分析.结果表明,滑坡区地形条件及岩土体特征是滑坡发生的基本条件,连续降雨的饱水加载作用以及雨水沿节理裂隙结构面的下渗软化作用是诱发滑坡发生的直接原因.同时,根据滑坡险情特征,提出了应处置建议及应急卸载措施.最后,根据监测结果信息化指导应急卸载工作,确保了施工安全及受灾群众的生命财产安全.本次成功排险,对指导福建海沿地区地质灾害应急处置工作提供了科学依据.     

混凝土硫酸盐腐蚀损伤的声波与声发射变化特征及机理

试验模拟干湿循环作用下混凝土受10%(质量分数)硫酸钠溶液侵蚀的腐蚀环境,测试和分析硫酸盐不同侵蚀时期混凝土单轴压缩试验时波速和声发射的变化特征.采用环境扫描电镜和能谱仪进行微观观测并结合X射线衍射测试手段分析受蚀混凝土的损伤机理.结果表明:受侵蚀60 d和80 d的试件加载初期会有较明显的压密阶段,试件受硫酸盐侵蚀和干湿循环作用愈久,加载中波速急剧下降的突变点愈提前;受蚀40 d以上的试件加载中声发射事件活跃区间较集中,在腐蚀产生的缺陷和薄弱位置容易出现应力集中和能量集中释放,声发射事件数量急剧上升的突变点提前.通过数学模型以声发射累积振铃计数为损伤变量建立损伤模型可以表征混凝土中环境腐蚀、荷载及损伤之间的作用关系.腐蚀阶段钙矾石与石膏的膨胀作用和硫酸钠的结晶压在试件内部形成微破损,受蚀混凝土表现出不同宏观性能.      

青海玉树结古寺滑坡性质判定及稳定性分析

在"4.14"玉树地震影响下,诱发了大量的不良地质体并促使原有不良地质发展加剧,其中结古寺所在的斜坡地表产生大量弧形拉张裂缝,滑坡体出现了复活迹象。建于结古寺滑坡顶部的结古寺属青海省省重点保护文物,寺院常住僧侣近百人,坡脚为玉树市主干道,为主要经济人文区,一旦滑坡失稳下滑,将造成重大经济损失以及人员伤亡事故。通过对结古寺滑坡性质判定及稳定性分析,为滑坡防治提供了理论依据,并成功地应用到治理工程中,其成果显著。     

某露天采场滑坡的危害性及可控性浅析

为了确定某露天采场滑坡后是否需要停产进行治理,以某大型露天采场冰水堆积层滑坡为例,根据地质条件和监测结果,从滑坡类型、产生原因、滑坡特点、滑移变化规律和滑体解体破坏机理等方面,宏观分析了滑坡产生和发展的整个过程。结果表明：该类滑坡产生的主要原因是降雨和地下水;滑坡类型为蠕变型,滑体在蠕动滑移过程中已经破碎,在离开滑床之时开始解体,出现瞬时整体大滑坡的可能性极小而发生小规模崩塌的可能性极大。通过对滑体给受害体带来的潜在冲击能进行分析,发现滑体作用于受害体的能量很小,其危害性可控。在此基础上,提出了通过采取调整生产计划、截排雨水与地下水、适当削坡、坡面防护、监测等控制措施,来解决以往矿山在进行滑坡治理时难以精准判断是否需要停产的决策难题。     

Landslide Hazard Evaluation: The Landslide Hazard Curves

This paper presents an innovative, practical methodology to establish priorities for slope monitoring and the planning of stabilization works in large hilly areas. The study is based on the analysis of geological and geomorphological maps, identification of catchment areas, and the division of catchment areas into primary (with main stream) and secondary (without main stream) sub-basins. Attention was focused on secondary sub-basins and their characteristics: lithology; an ad hoc parameter q (related to the average rainfall, the size of the basin, and the width of the toe section), and the average slope inclination i. The technique presented enables the “landslide hazard curve,” unique for a given formation in homogenous areas with similar rainfall conditions and seismicity, to be drawn in a chart which features q and i. All the ascertained and assumed unstable areas represented in the chart are located above the landslide hazard curve.?The study was carried out scientifically by taking into account engineering aspects (geological, geomorphological, hydrological, and geotechnical), which influence slope stability. Groundwater levels, important in mapping out landslide prone areas, were considered in the study by means of the parameter q.     

Knowledge-Based Landslide Susceptibility Zonation System

The landslide susceptibility of a region is important for socioeconomic considerations and engineering applications. Thus, an automated system for mapping of landslide susceptibility could be of significant benefit for society. In this paper, a knowledge-based landslide susceptibility zonation (LSZ) system has been proposed. The system consists of input, understanding, expert, and output modules. The input module accepts thematic images of contributing factors for landslides. The understanding module interprets input images to extract relevant information as required by the expert module. The expert module consists of knowledge base and inference strategy to categorize a region into different landslide intensities. Finally the output module provides a LSZ map. It is a pixel-based system and provides output having the scale same as that of the input maps. The system has been tested to prepare a landslide susceptibility map for the Tehri-Garhwal region in India’s lower Himalayas, and further validated with studies for two other different regions. The proposed system provides output commensurate with that provided by experts. The categories of hazard zones have a discrepancy as little as 6.2% in high hazard zones and near to 1.5% and 4% in moderate and low hazard zones, respectively. The high hazard zones in the LSZ maps from the proposed system are supersets of that obtained by experts (i.e., the proposed system provides safer LSZ map). Thus, it can be concluded that the proposed system can be used for preparation of LSZ maps. In the future, the methodology may be extended for real time assessment and prediction of landslide hazards.     

张家湾滑坡稳定性分析

采用GEO-SLOPE公司开发的二维饱和-非饱和渗流有限元程序计算地下水位,运用传递系数法对张家湾滑坡进行了稳定性计算.结果表明,滑坡最危险的工况为库水位下降工况,计算结果与目前检测情况相符.     

Inclinometer Monitoring of the Castelrotto Landslide in Italy

Over the last decades the real-time displacement monitoring systems have been increasingly used for assessing the risk conditions due to landslide movements and for managing the early-warning systems. Any decision about safety actions is therefore based upon the data provided by the instrumentation. The purpose of this work is to suggest how in-place inclinometers may be combined with periodical measurements by using a mobile probe in order to evaluate the current movement of a landslide and to assess the reliability of data. The monitoring system installed at the landslide of Castelrotto (northern Italy) is described, giving some details on the instrumentation and the data collected so far. A local quadratic trend model is developed to estimate the kinematic characteristics of the movement, and a statistical procedure for comparing real-time data with periodical measures is given to assess the reliability of data. This analysis shows how the direction of the displacement may be used as an indicator of reliability.     

滑坡体远程监测预警系统在南芬露天铁矿下盘边坡滑体监测实践中的成功应用

南芬露天铁矿对其重大危险源点下盘边坡滑体的监测手段多年来一直采用的是传统的变形监测法,该方法由于表面位移和滑面位移的不一致性,预测预报的准确度十分有限。新一代滑坡体远程监测预警系统,提出了下滑力监测法,能够实时、智能、准确的对滑动面上的滑动力进行测量、无线传输、自动处理,并采用位移监测、应力监测、视频监控三位一体的监测模式,有效地控制和预防了次生地质灾害对矿山生产的重大影响,实现了下盘边坡滑体从以往的现象监测到现在的超前准确预报的本质监测飞跃,对南芬露天铁矿的长远和可持续发展具有十分重要的现实意义。     

Effect of Toe Excavation on a Deep Bedrock Landslide

Observations, data, and analyses that were used to investigate the cause of distress to a single-family residence located adjacent to a major highway cutslope are presented herein. The investigation revealed that the distress in the single-family residence was caused by a deep, large excavation-induced landslide. The excavation, which was made to widen an existing highway, helped trigger the landslide by exposing geologic structures on the cutslope and by unloading the toe of the slope. This case history illustrates some of the ramifications of large highway excavations in natural slopes surrounded by urban areas, e.g., exposing significant geologic features such as shear zones, faults, and folds; the importance of investigating and explaining signs of movement at both the top and toe of a slope; the impact of rainfall on the movement of a large slide mass; and that large slide masses can undergo slow, episodic movement instead of sudden, large movement.     

Modeling Landslide Dambreak Flood Magnitudes: Case Study

Landslide dams typically comprise unconsolidated and poorly sorted material and are vulnerable to rapid failure and breaching, resulting in significant and sudden flood risk downstream. Hence they constitute a serious natural hazard, and rapid assessment of the likely peak flow rate is required to enable preparation of adequate mitigation strategies. To determine the relative utility and accuracy of dambreak flood forecasts, field estimates of peak outflow rates from the failure of the Poerua landslide dam in October 1999 were compared with estimates from physical laboratory modeling, empirical methods, and computer modeling. There was reasonable agreement among the field estimates, laboratory modeling, and computer modeling. Some empirical estimates were less reliable. Reasonably reliable estimates of peak outflow can be obtained from computer model routines sufficiently rapidly to be of use in an emergency management situation. The laboratory modeling demonstrated the effect of dam batter slopes and valley bed slope on peak outflow; this information could be used to refine empirical or numerical estimates of peak outflow.     

BP神经网络对滑坡稳定性评价的非线性方法

分析了滑坡稳定性评价方法,确定了影响滑坡稳定性的相关因素,运用BP神经网络建立了滑坡稳定性评价模型.经应用表明,该模型精度很高.将该模型用于预测巴河流域的相关滑坡稳定性,其结果与实际相符.     

张罗公路洞坎河滑坡分析与治理

张罗公路在建设过程中发生滑坡,通过对滑坡场地地质条件及成因机理分析,认为该滑坡属缓倾岩层牵引顺层滑坡。并进一步对滑坡后场地进行稳定性分析,认为还存在失稳可能,并结合现场情况提出了合理的治理方案,使之符合安全要求,并对此类滑坡的防治提出一些意见。