二郎山榛子林滑坡动态监测与整治工程

采集滑坡地表裂缝及深部相对位移信息 ,分析其位移 -时间动态变化特征及其影响因素 ,依据位移 -时间信息核定滑坡地质结构 ,预测滑坡发展趋势 ,为整治滑坡设计提供信息。     

滑坡坡面位移特征及其应用

在详细分析滑坡坡面位移特征的基础上,提出根据坡面位移矢量确定滑坡滑动面,预报滑坡发生时间的原理和方法。     

基于深部位移监测的浙江省中林村滑坡变形特征分析

位移监测是获取滑坡范围、滑面位置、滑坡方向等变形特征最直接和最有成效的一种手段,可以为滑坡防治提供较为精准的数据。采取测斜仪和FBG光纤等2种深部位移监测方法,对浙江省中林村滑坡的变形特征与稳定性发展趋势进行了较系统研究分析。监测结果表明:中林村滑坡可分为上部、中下部2个部分,它们均处于蠕滑状态,变形呈缓慢增长趋势。2部分岩土体滑向、滑面埋深、滑动方式等差异明显,斜坡上部具有牵引式滑动特征,活动性不明显,受高陡临空面影响;斜坡中下部具有推移式滑坡特征,活动特征较明显,降雨为主要的诱发因素。     

滑坡坡面位移特征及其应用

在详细分析滑坡坡面位移特征的基础上,提出根据坡面位移矢量确定滑坡滑动面,预报滑坡发生时间的原理和方法。     

钻孔测斜成果曲线在贵州省晴隆滑坡稳定性判识中的应用

结合沪瑞国道主干线贵州境镇胜高速公路十八合同段晴隆滑坡深部位移监测曲线特征,总结归纳了滑坡深部累积位移曲线“V”型、“B”型、“r”型、“钟摆”型及“复合”型等几种,详细论述了常见的曲线特征类型及其研究意义,提出了依据滑坡深部位移监测成果资料判别滑坡动态变形特征及其稳定性的判识方法。     

土质边坡失稳的电阻率响应特征

利用边界积分方程法对土质边坡失稳地球物理模型的视电阻率进行了系统数值计算，研究了土质边坡失稳的电阻率响应特征，揭示了边坡从稳定一失稳演化过程的电阻率变化规律，从而实现了边坡失稳的电阻率响应特征的提取。这些特征信息的获得为利用电法勘探方法探测土质边坡失稳的滑动面或结构面位置提供了依据，同时为实时观测，预测预报土质边坡失稳提供了理论支撑。     

阶跃型位移特征滑坡时间预测预报研究

滑坡时间预测预报目前主要以滑坡最终破坏的时间为目标函数,但对于变形特征为阶跃型的滑坡却难以准确地预测其破坏时间。为此,提出以位移作为此类滑坡时间预报的目标函数。将滑坡位移分解为蠕变位移和波动位移,采用二次移动平均法分别提取,然后采用多项式拟合和灰色GM(1,1)模型分别对蠕变位移和波动位移进行预测,最后将两部分预测位移相加得到滑坡预测的总位移。以典型阶跃型位移特征滑坡——三峡库区八字门滑坡为例,运用其位移监测数据进行验证,并对多模型预测结果进行对比分析,结果表明,该位移预测模型预测精度良好,能较好地预测阶跃型位移特征滑坡位移。     

土质滑坡坡表倾斜变形的室内外试验研究

近年来,滑坡倾斜变形已成为滑坡监测预警的重要指标,但是目前关于坡表倾斜变形与滑坡发育特征的研究尚处于探索阶段。通过开展系列降雨模型试验,并结合现场试验,探究滑坡灾害演进过程中坡表位移与倾斜变形的关系,建立基于坡表倾斜-时程曲线的滑坡预警方法。试验结果表明:滑坡在破坏阶段坡表倾斜变形加速,倾角速率倒数与滑坡残留时间呈线性关系,利用该线性关系可预测滑坡最终破坏时间;滑坡滑动过程中坡表倾斜变形与位移呈线性关系,其斜率与滑动半径一致。根据试验结果首次揭示了坡表变形与滑带几何特征的关系,并为基于坡表变形的滑坡滑带预测方法提供了试验依据。     

基于Midas-GTS的三峡库区金鸡岭滑坡成因机制与稳定性分析

金鸡岭滑坡在暴雨后发生明显变形,通过现场勘察、钻探、物探、深部位移监测以及水平位移监测得出初步结论。为进一步查明该滑坡成因机制,通过解译现有勘察监测资料,结合Midas-GTS软件分析不同工况下滑坡的渗流场、位移场、稳定性计算,综合评价其成因机制。结果如下：（1）物探解译得出金鸡岭滑坡为岩土混合、含水滑坡,滑动面位于T2b1泥灰岩和T2b2泥岩分界线;（2）深部位移监测揭示该滑坡为浅表层土体在发生滑移,滑动面与物探解译得出的滑动面位置一致;（3）水平位移监测表明浅表分布的后梆滑坡和潘家岭滑坡变形速率较快,变形强烈;（4）数值模拟结果显示金鸡岭滑坡在现状工况下处于基本稳定状态;在排干地下水工况下处于基本稳定状态;在暴雨工况下处于欠稳定状态,可能产生整体滑移,其上的潘家岭滑坡及后梆滑坡产生土体次级滑移。（5）金鸡岭滑坡的地形地貌、地质构造、地层岩性、为滑坡的形成和发展提供了物源和场地条件,暴雨和人类工程活动作为诱发因素,进一步加剧滑坡变形。该研究成果将为三峡库区类似滑坡的成因机制与稳定性分析提供理论依据,对后期防治措施具有重要指导意义。     

香溪河流域白家堡滑坡变形监测初步分析

白家堡滑坡受三峡大坝蓄水及强降雨影响变形较为明显,且仍在变形过程中。利用GDM600S型全站仪及cx-03D型钻孔测斜仪分别对滑坡地表及滑坡深部位移进行监测。监测结果表明:白家堡滑坡体呈"D"型整体运动;滑坡后缘滑动面(带)和中部滑动面(带)分别在地下11m和28.5m左右;滑坡整体滑动方向大致为NE55°,且滑坡变形具有自后缘向前缘递减的趋势。     

中等倾角岩层顺向坡滑坡发育特征及形成机制分析

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。     

基于物理模拟试验的岩质滑坡地表位移分析

三段式岩质滑坡是一种典型的斜坡变形破坏模式,运用二维地质力学加载系统对其变形破坏全过程进行物理模拟试验研究,采用激光位移计对坡顶和坡脚位置进行位移监测。结果表明:位移监测曲线总体上表现为锁固段经历长时间的能量积累与应力调整后的突发脆性破坏;由于软弱夹层具有蠕滑特性,前缘蠕滑阶段呈现出与土质滑坡相似的初始变形→等速变形→加速变形特征;后缘拉裂阶段作为最短暂的变形阶段,其位移监测曲线表现为“减-增-减-增”的“W”型变化趋势;锁固段是三段式岩质边坡维持稳定的关键所在,其受剪变形的顺序为先上后下,损伤变形由端部向中部递进,最终锁固段剪断形成突发脆性破坏,滑坡高速启动。     

Prediction of landslide displacement with step-like behavior based on multialgorithm optimization and a support vector regression model

Landslide prediction is important for mitigating geohazards but is very challenging. In landslide evolution, displacement depends on the local geological conditions and variations in the controlling factors. Such factors have led to the “step-like” deformation of landslides in the Three Gorges Reservoir area of China. Based on displacement monitoring data and the deformation characteristics of the Baishuihe Landslide, an additive time series model was established for landslide displacement prediction. In the model, cumulative displacement was divided into three parts: trend, periodic, and random terms. These terms reflect internal factors (geological environmental, gravity, etc.), external factors (rainfall, reservoir water level, etc.), and random factors (uncertainties). After statistically analyzing the displacement data, a cubic polynomial model was proposed to predict the trend term of displacement. Then, multiple algorithms were used to determine the optimal support vector regression (SVR) model and train and predict the periodic term. The results showed that the landslide displacement values predicted based on data time series and the genetic algorithm (GA-SVR) model are better than those based on grid search (GS-SVR) and particle swarm optimization (PSO-SVR) models. Finally, the random term was accurately predicted by GA-SVR. Therefore, the coupled model based on temporal data series and GA-SVR can be used to predict landslide displacement. Additionally, the GA-SVR model has broad application potential in the prediction of landslide displacement with “step-like” behavior.     

三峡水库区何家湾滑坡监测及防治措施研究

在研究了三峡水库区何家湾滑坡体空间形态、自然地理及地层岩性的基础上,从气象、水文、库区蓄水及水位变动因素入手,分析了滑坡形成的原因。根据库区地质灾害监测预警工程设计,结合何家湾滑坡的结构和变形特征,确定具体监测方法。对该滑坡进行了大地形变监测、地下水位监测、滑体深部位移监测及宏观监测。其中,大地形变监测数据分析表明:何家湾滑坡的最大变形量已超过2cm,且一直呈现增大趋势;地下水位、滑体深部位移均未发现明显异常,宏观监测亦未发现明显的新的变形迹象。通过分析监测资料并考虑到未来三峡水库蓄水,认为何家湾滑坡目前处于潜在不稳定状态。滑坡体在饱水及水库蓄水后,将处于临界蠕滑或失稳状态。结合滑坡体实际情况对滑坡防治进行初步研究,提出了采用回填压脚支档为主、辅以排水的综合治理措施;并建议加强数据远程传输的研究与实践,以解决目前监测效率不高的问题。     

Numerical modeling of seismic triggering,evolution, and deposition of rapid landslides: Application to Higashi–Takezawa (2004)

A mathematical model is developed for the dynamic analysis of earthquake‐triggered rapid landslides, considering two mechanically coupled systems: (a) the accelerating deformable body of the slide and (b) the rapidly deforming shear band at the base of the slide. The main body of the slide is considered as a one‐phase mixture of Newtonian incompressible fluids and Coulomb solids sliding on a plane of variable inclination. The evolution of the landslide is modeled via a depth‐integrated model of the Savage–Hutter type coupled with: (a) a cyclic hysteretic constitutive model of the Bouc–Wen type and (b) Voellmy's rheology for the deformation of the material within the shear band. The original shallow‐water equations that govern the landslide motion are appropriately reformulated to account for inertial forces due to seismic loading, and to allow for a smooth transition between the active and the passive state. The capability of the developed model is tested against the Higashi–Takezawa landslide. Triggered by the 2004 Niigata‐ken Chuetsu earthquake, the slide produced about 100m displacement of a large wedge from an originally rather mild slope. The mechanism of material softening inside the shear band responsible for the surprisingly large run‐out of the landslide is described by a set of equations for grain crushing‐induced pore‐water pressures. The back‐analysis reveals interesting patterns on the flow dynamics, and the numerical results compare well with field observations. It is shown that the mechanism of material softening is a crucial factor for the initiation and evolution of the landslide, while viscoplastic frictional resistance is a key requirement for successfully reproducing the field data. Copyright © 2009 John Wiley & Sons, Ltd.     

Correlation between incompetent beds and slope deformation at Badong town in the Three Gorges reservoir, China

Badong town is a new immigration area in the Three Gorges reservoir, China, which is built on many giant deep-seated landslides. In this region, the slope deformation is very severe and it is strongly correlated with the incompetent beds, which are distributed widely in the rock mass. In this paper, two giant deep-seated translational rock landslides used as study cases are Huangtupo landslide and Zhaoshuling landslide. Firstly, the composition materials, structures and deformation characteristics of the two landslides are analyzed. Then, the position, structure, mineral composition and the formation mechanism of the incompetent beds are studied in detail. Finally, based on the comparison of the position, mineral and structure between incompetent beds and sliding zones of the landslides, the correlations between incompetent beds and giant landslide are discussed. The results indicate that 13 large incompetent beds exist in the middle Triassic Badong Formation strata, which can be divided into three types as weak interlayers, crushed beds and groundwater corrosion zones. The dominant minerals in the incompetent beds are illite, chlorite, quartz and calcite. The contents of the clay minerals in different positions are quite distinct, and the maximum difference of clay content exceeds 70 %. In addition, it is found that the contents of minerals in incompetent beds are similar to the slide zones of the landslides. The initial deformation of slopes normally developed along the incompetent beds, which induced subsequent shear displacement easily. Under the effect of gravity, the deep slip zones were generated mainly along the incompetent beds and the failure mode evolved from creep to integral slide gradually. The results can provide an important reference for the mechanism analysis and prevention of landslides in Badong town.     

基于点云密度特征的滑坡位移监测方法

激光扫描仪对同一目标两次采集的点并不重合,无法通过点云的直接比较快速确定滑坡位移。考虑到单个点云位置的不确定性和区域点云密度的稳定性,将点云的密度作为滑坡表面变形的表征,提出了基于点云密度特征的滑坡位移监测方法。将离散的三维点云转化为二维的密度图像,再利用粒子图像测速技术分析位移前后两幅点云密度图像的相关性,从而计算栅格图像中各子集的相对位移值;当各子集的位移全部计算完成后,得到目标区域的平面位移场。室内块体移动试验表明该方法的计算精度受变形梯度的影响,在地表变化剧烈处会产生一定程度的误差,且子集相关性系数无法达到1。在黄藏寺滑坡的位移监测中,利用本方法识别出了边坡的变动区域,计算出了滑坡的平面位移场,直观地反映了滑坡表面变形状况,验证了该方法的实用性。     

钻孔倾斜仪监测在塘角村1^#滑坡预警监测中的作用

塘角村1^#滑坡是三峡库区地质灾害防治监测预警工程Ⅲ期专业监测点。监测方法为滑体深部位移监测、地表位移监测,同时开展地表宏观变形调查。2007年4月滑坡开始出现变形;其中滑体深部位移由钻孔倾斜仪监测,最早发现滑体变形,随后地表位移GPS监测滑体出现变形,同时滑体地表出现裂缝,滑体局部产生溜滑现象;文章通过滑体深部位移实测监测数据纵向分析,结合与其它监测方法（GPS）监测数据进行横向对比分析印证,判断钻孔倾斜仪监测数据的有效性、准确性;阐述钻孔倾斜仪监测在塘角村1号滑坡预警监测中的重要作用。     

湖北长阳丹水撇洪渠出口左岸边坡稳定性分析及治理

根据对该边坡的变形破坏特征及形成条件分析，属滑移-拉裂型边坡。经受了诸如自重应力、构造应力、卸荷变形、降雨等内外因素作用，斜坡岩体沿软弱结构面发生滑移变形。随着剪裂面上的拉应力集中而产生拉裂缝，一旦破坏面贯通，将导致边坡破坏。用计算和经验相结合的方法确定了潜在滑面的位置，并通过参数反演，对滑坡的稳定性进行了定量评价。通过技术经济比较，针对边坡的形成机制、边坡各个部位的变形发展特点及其重要性，采取了分区治理措施。既达到了治理效果又节省了人力物力，可供从事类似22程评价和治理的22程人员参考。