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1.
林叔中 《地球科学与环境学报》1989,(4)
本文在分析横山山体地质条件及因地下采空而诱发出的山体变形破坏特征的基础上,对采空区地表山体的变形破坏进行了工程地质力学模拟研究。结果表明,横山山体之下3号煤层的采动坍陷是引起山体变形破坏的直接原因;毗邻山体的电厂区地表隆起变形破坏,是因采空区上覆岩层在坍陷时所产生的向电厂方向的蠕动,致使厂区地基土遭受挤压和变形的结果;随着3号煤层采动的结束及其上覆岩层坍陷过程的完成,电厂区将会恢复到稳定状态。 通过分析,山体岩层倾角增大时有无地下采空影响的山体变形破坏的不同特征,得出了同时具有地表侵蚀临空面和地下采空临空面的山体与仅有地表侵蚀临空面之斜玻的山体变形破坏是不同的。从不同模型材料所得实验结果的一致性,验证了此模拟实验在理论上和实际中都有很好的相似性。 相似文献
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Effect of the inclined weak interlayers on the rainfall response of a bedded rock slope 总被引：1，自引：1，他引：0
Engineering experience shows that outward dipping bedded rock slopes, especially including weak interlayers, are prone to slide under rainfall conditions. To investigate the effect of inclined weak interlayers at various levels of depth below the surface on the variation of displacements and stresses in bedded rock slopes, four geo-mechanical model tests with artificial rainfall have been conducted. Displacements, water content as well as earth pressure in the model were monitored by means of various FBG (Fiber Bragg Grating) sensors. The results showed that the amount of displacement of a slope with a weak interlayer is 2.8 to 6.2 times larger than that of a slope without a weak interlayer during one rainfall event. Furthermore, the position of the weak interlayer in terms of depth below the surface has a significant effect on the zone of deformation in the model. In the slope with a high position weak interlayer, the recorded deformation was larger in the superficial layer of the model and smaller in the frontal portion than in the slope with a low position weak interlayer. The slope with two weak interlayers has the largest deformation at all locations of all test slopes. The slope without a weak interlayer was only saturated in its superficial layer, while the displacement decreased with depth. That was different from all slopes with a weak interlayer in which the largest displacement shifted from the superficial layer to the weak interlayer when rainfall persisted. Plastic deformation of the weak interlayer promoted the formation of cracks which caused more water to flow into the slope, thus causing larger deformation in the slope with weak interlayers. In addition, the slide thrust pressure showed a vibration phenomenon 0.5 to 1 hour ahead of an abrupt increase of the deformation, which was interpreted as a predictor for rainfall-induced failure of bedded rock slopes. 相似文献
3.
采空区地表山体侧向变动,不同于一般天然山坡,也与采空区一般上覆岩层的变形破坏有异;它是二者复合机理的效应。本文在分析考察了毗邻电厂的横山顺倾构造山体、剖析了地下采空情况认为:山体侧向变动中,软弱夹层有决定性作用,变动范围、速率和规模与地下采空有关;并利用地质力学模型试验和数值模拟,探索了采动引起山体应力场及变动规律。结果表明,山体岩层的变形、位移、破坏、由直接顶板向地表发展,采空坍陷诱发了软弱夹层的蠕滑,则产生山体侧向滑移;电厂区地表隆起变形是山体侧向滑移挤压地基土的反映。通过现场实际调研、变形观测资料分析与数值模拟和模型试验的对比研究,提出了“坍落拱梁”的成生效应、挤压蠕滑效应、失稳效应;揭露了顺倾构造山体在采空影响下,具有地表、地下的“复合临空面”的“复合应力场”中“复合变动”的“复合机理”;并提出这种山体侧向变动机理的典型地质模式,借以论证山体稳定性。 相似文献
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以奉节新铺下二台滑坡为例, 基于GPS位移监测数据、裂缝数据、降雨量及库水位等多源数据, 总结分析了大型古滑坡的复活规律, 引入滑坡中长期预报模型, 实现了以季度或月份为时间单位的跨水文年滑坡位移预测, 并通过岩土体蠕变压缩模型, 验证了推移式滑坡后缘裂缝形成机理。结果表明: ①降雨是下二台滑坡变形的主导因素, 滑坡变形使得滑体产生裂缝并成为降雨入渗通道, 加剧了岩体破碎与软弱层软化, 降低了滑坡稳定性, 集中持续降雨可使滑坡失稳破坏; ②通过模型预测值与地表监测数据的比较, 将年降雨量作为滑坡中长期预报模型中的主控因素具有实际可操作性且有助于提高滑坡中长预报精度; ③推移式滑坡后缘裂缝由滑坡推移式位移和岩土体压缩形成, 引入蠕变压缩模型计算的裂缝宽度并和监测数据的比较说明, 蠕变压缩模型非常适合该类边坡, 同时应用岩土体蠕变压缩模型反推得到岩土体平均变形模量, 判断岩体破碎程度, 可以为滑坡稳定性分析及后续工程治理提供参考。 相似文献
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《山地科学学报》2021,(8)
Rainfall infiltration on a soil slope is usually an unsaturated seepage process that can be described by a water-air two-phase flow model. The effect of pore air pressure on rainfall infiltration has been widely recognized and validated by means of numerical simulations and laboratory experiments. However, whether a slope can actually seal pore air continues to be debated by researchers. In this study, a water-air two-phase flow model is used to simulate the rainfall infiltration process on a soil slope, and a field experiment is conducted to realistically test the sealing conditions of a slope. According to the numerical simulation, the areas of water and air flow in and out on the slope surface are relatively stable and can be classified as the "inhalation zone" and "overflow zone", respectively. Intermittent rainfall on the soil slope has an amplifying effect on pore air pressure because rainfall intensity is usually at the millimeter level, and it causes pore air pressure to reach the cm level. A field experiment was performed to determine whether a slope can realistically seal pore air and subsequently verify the regularity of rainfall infiltration. Air pressure sensors were buried in the slope to monitor the pore air pressures during the rainfall process. The monitoring results show that the pore air pressure in the slope changed, which indicates that the slope can seal air. Moreover, the amplification effects of intermittent rainfall on pore air pressure were observed for natural rainfall, which agrees well with the numerical simulation results. 相似文献
7.
论述了BDS/GPS双系统组合下的单频单历元阻尼LAMBDA算法原理,并基于该算法实现一种实时远程变形监测系统。以理县某边坡变形监测应用为例,比较了GPS、BDS及其组合系统下的观测条件和阻尼LAMBDA算法定位效果：BDS的观测卫星数多于GPS,PDOP值相较于GPS也更加稳定;BDS单历元解标准差在N、E、U方向上分别为0.40 cm、0.31 cm、1.00 cm,优于GPS的0.61 cm、0.40 cm、1.74 cm。长期实验结果表明,在我国南部边坡监测中,BDS相比GPS具有一定优势。理县边坡23个月内位移量显著,3个监测站平均位移在N、E、U方向上分别达到8.70 cm、43.63 cm、18.03 cm。强降雨是引起土质山体滑坡的主要因素,使用累积降雨量和累积位移量建立线型回归模型,线性相关系数在0.98以上。在边坡监测中,可将实时的位移数据和降雨数据作为滑坡预警的重要依据。 相似文献
8.
Centrifugal model tests are playing an increasingly important role in investigating slope characteristics under rainfall conditions. However, conventional electronic transducers usually fail during centrifugal model tests because of the impacts of limited test space, high centrifugal force, and presence of water, with the result that limited valid data is obtained. In this study, Fiber Bragg Grating (FBG) sensing technology is employed in the design and development of displacement gauge, an anchor force gauge and an anti-slide pile moment gauge for use on centrifugal model slopes with and without a retaining structure. The two model slopes were installed and monitored at a centrifugal acceleration of 100 g. The test results show that the sensors developed succeed in capturing the deformation and retaining structure mechanical response of the model slopes during and after rainfall. The deformation curve for the slope without retaining structure shows a steep response that turns gradual for the slope with retaining structure. Importantly, for the slope with the retaining structure, results suggest that more attention be paid to increase of anchor force and anti-slide pile moment during rainfall. This study verifies the effectiveness of FBG sensing technology in centrifuge research and presents a new and innovative method for slope model testing under rainfall conditions. 相似文献
9.
Modelling the flexural buckling failure of stratified rock slopes based on the multilayer beam model
The buckling failure of stratified rock slopes intersected by a set of steep discontinuities that are approximately parallel to the slope surface is frequently encountered while constructing railways and roadways in mountainous areas. In this study, an analytical approach based on the energy equilibrium principle is presented to solve the flexural buckling stability of stratified rock slopes within the framework of multilayer beam theory. The generalized HoekBrown failure criterion is introduced to reflect the influences of slope size(scale effects) on the buckling stability. Subsequently, numerical and physical modellings from previous literatures are employed to validate the proposed approach. Furthermore, a practical case of Bawang Mountain landslide is also used for the comparative analysis. The study shows that the present analytical approach is capable to provide a more reasonable assessment for the buckling failure of stratified rock slopes, compared with several existing analytical approaches. Finally, a detailed parametric study is implemented, and the results indicate that the effects of rock strength, rock deformation modulus, geological strength index, layer thickness and disturbance degree of rock mass on the buckling failure of stratified rock slopes are more significant than that of rock type and slope angle. 相似文献
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11.
地下采煤会引起地表沉降、变形,甚至引发山体、河堤滑坡等地质灾害。采动坡体的稳定性研究一直是采矿工程中实际关心的问题。该文首先介绍分析了概率积分法移动变形稳态、动态预测模型以及基于极限平衡理论的单滑面采动坡体稳定性预测模型,提出了使用概率积分法结合Knothe时间函数对采动坡体稳定性进行预测分析的方法,并使用C#及XML Schema语言编制了相关的计算程序。最后,结合一个工程实例对采动坡体稳定性和动态变化过程进行了预测与分析,通过实测数据验证了提出方法的可行性,得出了采动引起的坡体下沉是影响坡体稳定性的主要因素,并提出了在坡体拉伸阶段进行注浆加固的方法。 相似文献
12.
库岸滑坡体分布广泛,在库水位升降和降雨条件下极易失稳。三板溪水电站东岭信滑坡堆积体总方量2 000×104 m3,最大厚度150 m,2006年水电站蓄水后滑坡体开始出现大变形,每年雨季加剧。首先经野外地质勘察和十余年监测数据整理,探明了地质条件和变形规律;其次使用SEEP/W模块对不同库水位升降速率、2019年库水位结合实测降雨条件下的饱和-非饱和流进行模拟,并采用SLOPE/W分别计算不同时刻的稳定系数。分析认为东岭信为超深层滑坡,其变形过程深受库水位升降和降雨影响;滑坡体具有明显的滞水特征,渗流过程复杂;在库水位上升过程中稳定系数不断下降,而在库水位消落过程中稳定性逐渐增强;在库水位上升和强降雨量共同作用下稳定性下降很快,汛后10 d左右达到最低值,此时的稳定性最差。本研究可用于指导库水位升降和降雨条件下大型滑坡体稳定性评价。 相似文献
13.
为高效获取采动区长时间序列形变，监控煤炭开采对矿区铁路的影响，研究一种基于TCP-InSAR(temporarily coherent point interferometric synthetic aperture radar)的采动区铁路形变监测方法。该方法根据时间序列SAR影像间的相干性，选取临时相干点构建Delaunay三角网，并通过离群值探测去除具有相位模糊度的TCP间的弧段，最后采用最小二乘解算得到区域地表变形。实验使用2016-10~2017-04时间段内的15景Sentinel-1A数据，利用TCP-InSAR技术获得某矿区的铁路形变。结果表明，受采动影响，该时间段内铁路最大下沉值为95 mm，最大倾斜坡度为0.37‰。利用TCP-InSAR技术可实现采动区内铁路长时间的动态形变监测。 相似文献
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降雨入渗和人工开挖是诱发黄土滑坡的重要因素, 为了研究在这2种诱因作用下关中地区黄土滑坡失稳过程及其对稳定性的影响, 以陕西省长武县杨厂村老庙滑坡为研究对象, 通过现场调查、地质测绘和钻孔勘探, 查明了该滑坡变形特征, 定性分析了滑坡变形演变过程; 基于滑坡变形前15 d内日降雨量实测值, 采用有限元软件, 对坡脚开挖后连续降雨作用下滑坡形成过程进行了仿真模拟; 基于强度折减法对该滑坡稳定性变化规律进行了研究。结果表明: ①关中地区特殊的地层结构是滑坡变形的内因, 降雨是最主要的诱发因素; ②滑坡失稳演化过程表现为: 坡体处于蠕滑状态, 坡脚开挖后, 坡体前缘失稳, 牵引中后缘坡体向下错动而产生张拉裂缝, 在降雨作用下, 雨水沿裂缝渗入坡体深部, 滑坡中部岩土体浸水后抗剪强度降低, 从而导致黄土层与红黏土层接触面饱水形成贯通滑带, 诱发深层滑坡; ③滑坡开挖后较初始状态, 稳定性系数降幅为0.102, 此后受连续降雨影响, 稳定性系数在前10 d以平均0.010/d的速率缓慢下降, 第10~13 d以0.034/d的速率快速下降至最低, 第13 d以后开始回升。研究结果可以为该类滑坡防治提供有效依据。 相似文献
15.
Liang Qiao Xing-min Meng Guan Chen Yi Zhang Peng Guo Run-qiang Zeng Ya-jun Li 《山地科学学报》2017,14(6):1113-1123
A colluvial landslide in a debris flow valley is a typical phenomena and is easily influenced by rainfall. The direct destructiveness of this kind of landslide is small, however, if failure occurs the resulting blocking of the channel may lead to a series of magnified secondary hazards. For this reason it is important to investigate the potential response of this type of landslide to rainfall. In the present paper, the Goulingping landslide, one of the colluvial landslides in the Goulingping valley in the middle of the Bailong River catchment in Gansu Province, China, was chosen for the study. Electrical Resistivity Tomography (ERT), Terrestrial Laser Scanning (TLS), together with traditional monitoring methods, were used to monitor changes in water content and the deformation of the landslide caused by rainfall. ERT was used to detect changes in soil water content induced by rainfall. The most significant findings were as follows:(1) the water content in the centralupper part (0~41 m) of the landslide was greater than in the central-front part (41~84 m) and (2) there was a relatively high resistivity zone at depth within the sliding zone. The deformation characteristics at the surface of the landslide were monitored by TLS and the results revealed that rainstorms caused three types of deformation and failure: (1) gully erosion at the slope surface; (2) shallow sliding failure; (3) and slope foot erosion. Subsequent monitoring of continuous changes in pore-water pressure, soil pressure and displacement (using traditional methods) indicated that long duration light rainfall (average 2.22 mm/d) caused the entire landslide to enter a state of creeping deformation at the beginning of the rainy season. Shear-induced dilation occurred for the fast sliding (30.09 mm/d) during the critical failure sub-phase (EF). Pore-water pressure in the sliding zone was affected by rainfall. In addition, the sliding L1 parts of the landslide exerted a discontinuous pressure on the L2 part. Through the monitoring and analysis, we conclude that this kind of landslide may have large deformation at the beginning and the late of the rainy season. 相似文献
16.
通过实地踏勘并辅以钻探等技术手段,对枞阳县高峰村同咀崩塌的边坡地形地貌、地层岩性、地质构造、水文地质条件、工程地质条件以及人类工程活动等条件进行调查,并在进行变形位移监测的基础上,对研究区崩塌灾害的发育特征、影响因素以及形成机制进行了分析,并采用极限平衡法对崩塌灾害的稳定性进行了评价。研究结果表明:2处崩塌灾害规模等级均属小型,破坏方式均为滑移式;影响因素主要包括人工切坡,钾长花岗岩强烈风化,构造裂隙、风化裂隙和卸荷裂隙发育和强降雨等; 2处崩塌在天然工况下处于基本稳定状态,在暴雨工况下处于欠稳定状态,需采取相关治理措施。依据分析评价结果对崩塌灾害治理提出了防治方案建议。 相似文献
17.
Slope reinforcement for housing in Three Gorges reservoir area 总被引：1，自引：1，他引：0
The Three Gorges Project of the Yangtze River is the largest hydropower-complex project under construction in the world. Under the largescale relocation projects, 2874 engineered slopes are formed along with the construction of new towns. In this paper, the cutting slopes are mainly soil slopes and rock slopes. Soil slopes include residual soil slopes, colluvial accumulation slopes, swelling soil slopes, and artificial earth fill slopes, etc. Rock slopes include blocky structure rock slopes, layer structure rock slopes, and clastic structure rock slopes, etc. Varied protection measures have been used for slope protection in the reservoir area including shotcrete concrete-anchor bars, frame beams, retaining walls, slope stabilizing piles, sheet-pile walls, anchorage anti-shear tunnels, flexible protection grids, and drainage, etc. Besides, slope deformation monitoring systems have been set up to monitor deformation failure and the stability state of slopes. The protection measures have guaranteed slope safety and maintained a harmony with the urban environment and surrounding landscape. 相似文献
18.
金沙江结合带结构破碎,软弱岩层发育,流域性特大高位地质灾害频繁发生。针对该区域开展大范围滑坡调查与监测研究,对减灾防灾具有重要意义。以金沙江结合带巴塘段为试验区,采用堆叠InSAR技术分别利用升轨、降轨Sentinel-1A卫星数据对该区域滑坡隐患开展了调查研究。在此基础上,以中心绒乡滑坡群为重点研究区,利用多维小基线子集技术获取了区域二维形变速率(水平东西向和垂直向)及二维时间序列结果。通过对4处典型滑坡体的形变时间序列结果进行分析,发现在两年时间段内安里克米滑坡、仁娘村滑坡、贡伙村滑坡1和贡伙村滑坡2水平方向累积位移量分别达到44.3、-26.6、65.3和-77.1 mm,垂直向累积位移量分别达到-30.2、-88.3、-80.9和-56.9 mm,且这4处滑坡呈现缓慢蠕滑变形趋势。通过对贡伙村滑坡2的形变监测二维时间序列与降雨数据分析发现,强降雨对滑坡变形有一定短暂影响。由于滑坡群处于地质条件脆弱地区,构造活动强烈,在强降雨条件下极易导致滑坡失稳,建议对其进行持续监测,同时该研究成果对流域内其他区域的滑坡调查与监测研究具有参考意义。 相似文献
19.
Sang-Soo JEON 《山地科学学报》2014,11(2):336-344
Damage assessment for slopes using geographical information system （GIS） has been actively carried out by researchers working on several government organizations and research institutes in Korea. In this study, 596 slope damages were examined to identify the types of damage associated with dip angles, dip directions, and heavy rainfall resulting from typhoons in South Korea. Heavy rainfall of 100 mm to 300 mm resulted in 80% at the investigated slope damages. A GIS database was developed for highways, rainfall, soil or rock geometry, and types of damage. A grid of rainfall intensity was generated from the records of maximum daily rainfall. Contours for slope damages and heavy rainfall using optimal GIS mesh dimensions were generated to visualize damage patterns and show substantially strong correlation of rainfall with slope damages. The combination of remote sensing with the GIS pattern recognition process described in this work are being expanded for a new generation of emergency response and rapid decision support systems. 相似文献
20.
Distributed fiber optic monitoring and stability analysis of a model slope under surcharge loading 总被引：2，自引：1，他引：1
In the discipline of geotechnical engineering, fiber optic sensor based distributed monitoring has played an increasingly important role over the past few decades. Compared with conventional sensors, fiber optic sensors have a variety of exclusive advantages, such as smaller size, higher precision, and better corrosion resistance. These innovative monitoring technologies have been successfully applied for performance monitoring of geo-structures and early warning of potential geo- hazards around the world. In order to investigate their ability to monitor slope stability problems, a medium-sized model of soil nailed slope has been constructed in laboratory. The fully distributed Brillouin optical time-domain analysis （BOTDA） sensing technology was employed to measure the horizontal strain distributions inside the model slope. During model construction, a specially designed strain sensing fiber was buried in the soil mass. Afterward, the surcharge loading was applied on the slope crest in stages using hydraulic jacks and a reaction frame. During testing, an NBX-6o5o BOTDA sensing interrogator was used to collect the fiber optic sensing data. The test results have been analyzed in detail, which shows that the fiber optic sensors can capture the progressive deformation and failure pattern of the model slope. The limit equilibrium analyses were also conducted to obtain the factors ofsafety of the slope under different surface loadings. It is found that the characteristic maximum strains can reflect the stability of the model slope and an empirical relationship was obtained, This study verified the effectiveness of the distributed BOTDA sensing technology in performance monitoring of slope. 相似文献