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1.
Fiorucci M. Iannucci R. Lenti L. Martino S. Paciello A. Prestininzi A. Rivellino S. 《Natural Hazards》2016,86(2):345-362
A monitoring system is operative in the Peschiera Springs slope (Central Apennines, Italy) to mitigate the landslide risk related to the hosted main drainage plant of Rome aqueducts by providing alert warning. Such a strategy allows to avoid out-of-service episodes so reducing extra-costs of water distribution management. The Peschiera Springs slope is involved in a rock mass creep characterized by an average steady strain rate of 1 mm year−1 and responsible for several landforms including sinkholes, subvertical scarps and trenches. Moreover, an average aquifer discharge of 19 m3 s−1 causes an intense limestone dissolution concentrated in correspondence with release bands and discontinuities that dislodge the jointed rock mass. Since 2008, an accelerometric network has been operating within the slope; about 1300 microseismic local events were recorded up to now, distinguished in failures and collapses. A control index, based on frequency of occurrence and cumulative energy of the recorded microseismic events was defined to provide three levels of alert. In 2013, a temporary nanoseismic Seismic Navigation System (SNS) array was installed inside a tunnel of the drainage plant to integrate the pre-existent seismic monitoring system. This array allowed to record 37 microseismic events, which locations are in good agreement with the evolutionary geological model of the ongoing gravitational slope deformation. In 2014, a permanent nanoseismic SNS array was installed in the plant and allowed to record several sequences of underground collapses including more than 500 events. The nanoseismic monitoring system is allowing to: (1) increase the detection level of the monitoring system; (2) locate hypocentres of the events; and (3) detect precursors of the strongest events.
相似文献2.
M. Fiorucci R. Iannucci L. Lenti S. Martino A. Paciello A. Prestininzi S. Rivellino 《Natural Hazards》2017,86(2):345-362
A monitoring system is operative in the Peschiera Springs slope (Central Apennines, Italy) to mitigate the landslide risk related to the hosted main drainage plant of Rome aqueducts by providing alert warning. Such a strategy allows to avoid out-of-service episodes so reducing extra-costs of water distribution management. The Peschiera Springs slope is involved in a rock mass creep characterized by an average steady strain rate of 1 mm year?1 and responsible for several landforms including sinkholes, subvertical scarps and trenches. Moreover, an average aquifer discharge of 19 m3 s?1 causes an intense limestone dissolution concentrated in correspondence with release bands and discontinuities that dislodge the jointed rock mass. Since 2008, an accelerometric network has been operating within the slope; about 1300 microseismic local events were recorded up to now, distinguished in failures and collapses. A control index, based on frequency of occurrence and cumulative energy of the recorded microseismic events was defined to provide three levels of alert. In 2013, a temporary nanoseismic Seismic Navigation System (SNS) array was installed inside a tunnel of the drainage plant to integrate the pre-existent seismic monitoring system. This array allowed to record 37 microseismic events, which locations are in good agreement with the evolutionary geological model of the ongoing gravitational slope deformation. In 2014, a permanent nanoseismic SNS array was installed in the plant and allowed to record several sequences of underground collapses including more than 500 events. The nanoseismic monitoring system is allowing to: (1) increase the detection level of the monitoring system; (2) locate hypocentres of the events; and (3) detect precursors of the strongest events. 相似文献
3.
A numerical analysis of rock creep-induced slide: a case study from Jiweishan Mountain,China 总被引：2，自引：1，他引：1
Tao Xu Qiang Xu Maolin Deng Tianhui Ma Tianhong Yang Chun-an Tang 《Environmental Earth Sciences》2014,72(6):2111-2128
Landslides and slope failures are very common phenomena in hilly regions, Southwestern China. These are hazardous because of the accompanying progressive movement of the slope-forming material. To minimize the landslide effects, slope failure analysis and stabilization require in-depth understanding of the process that governs the behavior of the slope. The present paper first briefly describes a three-dimensional numerical brittle creep model for rock. The model accounts for material heterogeneity, through a stochastic local failure stress field, and local material degradation using an exponential material softening law. Then a case study of the Jiweishan rockslide that occurred in China is numerically investigated considering the effect of the mining activity. Numerical simulations visualize the entire process of the Jiweishan rockslide from the fracture initiation, propagation and coalescence. The distribution and evolution of associated stress and deformation field during the slide are also presented. Numerical simulations show that the underground mining excavations have remarkably negative effect on the stability of the rock slope, which is one of the important triggering factors of the rockslide. Moreover, it is possible to take some precautions for the unstable failure of rock mass by monitoring acoustic emission (AE) events or microseismicities since the occurrence of clusters of AE events prior to the final unstable rockslide. The results are of general interest, because they can be applied to the investigation of time-dependent instability in rock masses, to the mitigation of associated rock hazards in rock engineering, and even to a better understanding of the seismic activities in geological and geophysical phenomena occurring in the earth’s crust. 相似文献
4.
本文从工程地质条件和岩石力学两方面对古洞室群围岩的变形破坏规律，特别是支顶岩柱拉裂和剪裂破坏及顶板掉块等进行了研究，对洞室群的稳定性做出了初步评价。在此基础上，提出了以防止地表水沿裂隙入渗和建立一个高效监测系统为主要手段的建议。 相似文献
5.
Climate change is presently a major global challenge. As the world??s largest developing country, China is particularly vulnerable to global warming, especially in the rapidly developing coastal regions in the southeast of the country. This paper provides an overview of the impacts of climate change on the nature of geological disasters in the coastal regions of southeastern China. In the context of climate change, processes with the potential for causing geological disasters in this region, including sea-level rise, land subsidence, storm surges, and slope failures, which already have a substantial occurrence history, are all aggravated. All these processes have their own characteristics and relevance to climate change. Sea-level rise together with land subsidence reduces the function of dikes and flood prevention infrastructure in the study areas and makes the region more vulnerable to typhoons, storm surges, floods, and astronomical tidal effects. Storm surges have caused great losses in the study areas and also have contributed to increases in rainstorms. As a result, numerous rainfall-induced slope failures, characterized by focused time concentration, high frequencies, strong ??burstiness,?? and substantial damage, occur in the study areas. To prevent and mitigate such disasters that are accelerated by climate change, and to reduce losses, a series of measures is proposed that may help to achieve sustainable development in coastal southeastern China. 相似文献
6.
There exists a transition between rockfalls, large rock mass failures, and rock avalanches. The magnitude and frequency relations (M/F) of the slope failure are increasingly used to assess the hazard level. The management of the rockfall risk requires the knowledge of the frequency of the events but also defining the worst case scenario, which is the one associated to the maximum expected (credible) rockfall event. The analysis of the volume distribution of the historical rockfall events in the slopes of the Solà d’Andorra during the last 50 years shows that they can be fitted to a power law. We argue that the extrapolation of the F-M relations far beyond the historical data is not appropriate in this case. Neither geomorphological evidences of past events nor the size of the potentially unstable rock masses identified in the slope support the occurrence of the large rockfall/rock avalanche volumes predicted by the power law. We have observed that the stability of the slope at the Solà is controlled by the presence of two sets of unfavorably dipping joints (F3, F5) that act as basal sliding planes of the detachable rock masses. The area of the basal sliding planes outcropping at the rockfall scars was measured with a terrestrial laser scanner. The distribution of the areas of the basal planes may be also fitted to a power law that shows a truncation for values bigger than 50 m2 and a maximum exposed surface of 200 m2. The analysis of the geological structure of the rock mass at the Solà d’Andorra makes us conclude that the size of the failures is controlled by the fracture pattern and that the maximum size of the failure is constrained. Two sets of steeply dipping faults (F1 and F7) interrupt the other joint sets and prevent the formation of continuous failure surfaces (F3 and F5). We conclude that due to the structural control, large slope failures in Andorra are not randomly distributed thus confirming the findings in other mountain ranges. 相似文献
7.
On June 27, 1998, a moderate earthquake measuring 5.9 on the Richter scale struck the alluvial plains of Cukurova in the Adana-Ceyhan region of Turkey. The earthquake resulted in 145 deaths, about a thousand injuries and significant damage to more than ten thousand structures. The coincidence of the projected location of the release of energy along the earthquake fault with a very vulnerable geological surface formation (the thick alluvial deposits of Ceyhan River containing loose sand layers) resulted in liquefied sediments of substantial thickness and extensive areal distribution. Liquefaction associated ground deformations such as lateral spreading, flow failures, ground fissures and subsidence, sand boils, and slope failures were observed. This paper presents and analyses the geotechnical aspects of this earthquake with the main emphasis on the observed liquefaction and associated ground deformations, together with the earthquake characteristics. The observed liquefaction mechanisms provide valuable information on the seismic response of the alluvial soils covering most of the Cukurova plains, an area of industrial and agricultural importance with more than 2 million inhabitants. The observations from this earthquake also provide us with an opportunity to further improve our understanding of the observed phenomena and their effects that can be expected during other future earthquake events around the world. 相似文献
8.
During and after the very wet 1991/1992 winter experienced in Jordan, significant slope failures occurred along several sections of the new Irbid-Amman highway in Jordan. The topography over most of the route is hilly, and significant amounts of cut and fill were used to construct the highway. One such slope failure lies at 44+800 km on the highway south of Jerash City at a distance of about 5.0 km from Wadi Zerqa bridge. A landslide occurred downslope of the highway embankment resulting in a collapse of the most of the gabbion wall supporting the embankment. This paper deals with the overall stability of the slope at 44+800 km. It presents the geological and geotechnical studies carried out at this site, identifies the causes and mechanism of instability, and presents appropriate remedial measures. The study concluded that the landslide movement occurred within the colluvium material. It resulted primarily from excess piezometric pressures generated within the slope as a direct consequence of inadequate drainage. It is recommended to reconstruct the entire gabbion wall with its foundation seated on the sandstone that underlies the colluvium and to install a surface drainage system at the site. 相似文献
9.
大跨度采空影响顺倾构造山体侧向变动的复合机理 总被引：1，自引：0，他引：1
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后认为,山体侧向变动中,软弱夹层有决定性作用;变动范围、速率与规模,与地下采空有关。从而又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。通过现场实际调究、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
10.
《Engineering Geology》2001,59(1-2):115-132
Large landslides are common processes during the evolution of volcanoes and individual events can exceed several cubic kilometres in volume. Volcanic slope failures are a significant risk for the neighbouring population due to their huge volumes and great runout distances. Around the Canary archipelago, a total of seventeen deposits of large landslides have been found, and on Tenerife, seven large landslides have affected the subaerial and submarine morphology during the last ∼6 Ma. However, the causes of such mass movements are still poorly understood. This work analyses the events around the Canary Islands and focuses on the ones that occurred on Tenerife in order to obtain new insights into the mechanisms of large volcanic landslides. The study is divided into a first part that includes site investigations examining the general features favouring large-scale failures at volcanoes. The second part describes the laboratory tests used to analyse a residual soil that may be the potential slip surface of the slides on Tenerife. The site investigation revealed that regional tectonics and the climate have a significant influence on the spatial distribution of the landslides. Moreover, morphological and geological features such as deep fluvial canyons, a high coastal cliff and persistent dike intrusion may favour the initiation of slope failure. A typical residual soil sample from the lateral scarp of the La Orotava amphitheatre on Tenerife was studied by carrying out standard laboratory tests. The microstructure was analysed using environmental scanning electron microscopy and a particular bonding was found. This bonding was also detected by the geotechnical tests. Consolidation tests and direct shear tests revealed that the mechanical behaviour of the residual soil changes greatly if the bonding of the soil is broken. The bonded structure generally fails when the effective normal stress surpasses the yield strength of the bonding. In the case of large volcanic landslides with thicknesses up to several hundred meters, the high overburden easily exceeds this yield strength and generates a broken bonding. Therefore, volcanic residual soils, such as the one analysed in this study, are perfect candidates for the potential failure surfaces of large volcanic landslides. Referring to the La Orotava events, we assume that residual soil layers and morphological, geological and climatic features reduced the slope stability to critical conditions, whereas a strong earthquake associated with a caldera collapse episode may have finally triggered the landslide. The results obtained indicate that the residual soils play an important role in affecting the stability of volcano slopes and their destabilising influence significantly favours large-scale sliding. We suggest that the results obtained from this study can be applied to other locations since volcanic residual soils are common in volcanic areas. 相似文献
11.
Detection of water infiltration and deformation of unsaturated soils by elastic wave velocity 总被引：1，自引：1，他引：0
Intense rainfall is the most important landslide trigger. In many mountainous environments of the world, heavy rainfall has caused many landslides and slope failures in a matter of seconds without warning. Therefore, an early warning system can be an effective measure to reduce the damage caused by landslides and slope failures by facilitating the timely evacuation of people from landslide-prone areas. In this study, we propose an idea to correlate soil moisture changes and deformations in slope surface by means of elastic wave propagation in soil. Constant shear stress drained triaxial tests where water was infiltrated from the bottom of specimen until failure, and slope model tests under artificial rainfall were performed to investigate the response of elastic wave velocities during pre-failure phases of rainwater infiltration and deformation. Analysis of the results has established that the elastic wave velocity continuously decreases in response of moisture content and deformation, and there was a distinct surge in the decrease rate of wave velocity when failure was initiated. Possible mechanisms were interpreted based on the test results. It is proposed that a warning be issued at switch of wave velocity decrease rate. This approach can thus serve as the basis of an early warning system for landslides and slope failure considering both moisture content and deformation. 相似文献
12.
以鲁甸地震诱发的红石岩崩塌滑坡为研究对象,通过大型振动台模型试验和3DEC数值模拟,研究了含软弱岩层的反倾岩质边坡的动力响应和破坏失稳模式.研究结果表明:水平加载下,随频率增大PGA放大系数先减小后增大,在接近坡体自振频率8Hz的波形加载下,坡体动力响应最为剧烈,软弱岩层对不同频率的横波具有放大和吸收作用,对5~10Hz的横波放大效应明显,对15~20Hz的横波则明显吸收;竖向加载下,随加载正弦波频率的增加,PGA放大系数先增大,25Hz时PGA放大系数减小,随后又继续增大,在频率为30Hz时PGA放大系数达到最大,在5~30Hz范围内软弱岩层对纵波均具有一定的放大效果;双向加载下,坡体水平和竖向PGA放大系数分布与单向加载一致,但双向加载下坡体部分位置动力响应加剧,部分位置动力响应则受到抑制.含软弱岩层的反倾岩质边坡破坏过程可以分为6个阶段:坡体内部轻微损伤-软岩挤出、软硬岩交界上方硬岩拉裂-硬岩裂纹向上延展-软弱岩层挤压滑动-层面和纵向节理贯通形成滑面-边坡破坏.在软弱岩层的反倾岩质边坡中,软弱岩层具有对地震波的放大吸收、折射反射作用,影响着边坡的动力响应特征,软弱岩层的挤出破坏导致上部岩体岩结构面松动开裂,是该类岩质边坡破坏发展的主要原因,对该类边坡需应注意对软弱岩层进行加固防护,减小边坡的动力破坏. 相似文献
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Hong-Yue Sun Yu Zhao Yue-Quan Shang Yang Yu Quan-Li Zhao 《Rock Mechanics and Rock Engineering》2012,45(6):1103-1111
Given insufficient geological investigation and inadequate interpretation of geological settings, remedial works for localized cut slope collapses may induce large-scale failures and cause remarkable damage, as well as economical loss. A number of recent reports have addressed individual large-scale failures due to inappropriate cutting, but the systematic classification of failure patterns has received less attention. In this study, a re-profiling triggered landslide is described in detail. The deep slip surface is located by field measurements; then, the stability of the slope before and after cutting is assessed with the limit equilibrium method. Three types of slopes prone to deep-seated failures are introduced: the loose deposits type, the ancient landslide type, and the deep adverse discontinuities type. The mechanism of each failure pattern is illustrated with a case study. The stability analyses indicate that inappropriate slope profiling may greatly reduce the factor of safety (FS) of a slope. Recommendations are given for mitigating the deep-seated landslide induced by inappropriate cutting, and a case history of successful measures is presented. 相似文献
16.
Hong-yue Sun Louis Ngai Yuen Wong Yue-quan Shang Yong-jiang Shen Qing Lü 《Landslides》2010,7(4):445-454
Infiltration of rainfall into hillslopes is often an important factor in triggering landslides. Using underground water drainage works together with anti-slide piles has been an effective method of landslide control, yet their effectiveness is inadequately discussed in the literature. This paper studies the influence of rainfall on the change in the underground water level beneath a slope by real-time and synchronic monitoring of the rainfall, the underground water level in the boreholes, and the flow rate of the underground drainage tunnel. The effectiveness of the underground drainage tunnel in preventing the rise of the underground water level of the slope is discussed. The researchers also study the deformation behavior of the anti-slide piles by monitoring the lateral displacement of the piles and analyzing the thrust that the anti-slide piles bear by numerical inversion techniques. The results indicate that there is an apparent relationship between the lag in the rising of the underground water level caused by a rainfall and that caused by the immediately previous rainfall. When there is a rainfall accumulation before the occurrence of a heavy rain, this particular heavy rainfall will cause a rapid rise of the underground water level beneath the slope. The monitoring data analysis shows that the flow rate of the underground drainage tunnel increases first, and then the underground water level of the slope rises after a rainfall. In other words, the flow rate of the underground drainage tunnel increases at a rate faster than that of the rise of the underground water level. Hence, the underground drainage tunnel can effectively lower the rise of the underground water level induced by a rainfall. Besides, based on the monitoring data of the lateral displacement of the anti-slide piles and subsequent analysis, the working state of the anti-slide piles is justified. It thus indirectly validates the benefits of using underground drainage tunnel in landslide control. 相似文献
17.
High resolution UAV image acquisition method and modeling practice for geological outcrop with a large slope 
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下载免费PDF全文 The observation on the outcrop in the field is one of the most direct and efficient methods to obtain the underground formation information, which provides the most direct first-hand geological data for geological science research. However, the traditional outcrop investigation, especially for the outcrop with a large slope and unreachable area, mainly relies on the inspection, measurement of the slope bottom, and photos to record outcrop information, making it difficult to accurately characterize the whole geological body. Consumer unmanned aerial vehicle (UAVs) with the advantages of good mobility, strong adaptability and low cost, can obtain outcrop images from a short distance, multiple perspectives and varying heights. In this paper, the image acquisition method and model construction accuracy without control points available for the geological outcrop with a large slope are discussed. Consumer UAVs is used to capture images through vertical route and then the geological model is set up. The results show that oblique photogrammetry technology combined with consumer UAVs can effectively build a large slope geological outcrop model with millimeter resolution. The model has the characteristics of high resolution, uniform resolution and high measurement accuracy up to millimeter, which can effectively reduce the difficulty of field investigation and the personnel safety risk, thus it accurately reproduces the outcrop situation with large slope in the field, providing a real and reliable data basis for the section interpretation, analysis and measurement of large slope outcrop. 相似文献
18.
川藏铁路作为史上修建难度最大的铁路,沿线具有显著的地形高差、强烈的板块活动、密集的深大断裂、频发的山地灾害等恶劣地质环境特点,工程建设面临着复杂多变的地表和地下重大地质安全风险挑战。为深入综合分析川藏铁路可研阶段沿线地质风险,定量评价其对工程的影响,基于川藏铁路沿线翔实的时空数据集及资料,采用三维结构建模、数值统计建模、动力建模、时空建模等方法,进行了地表、地下重大工程地质灾害综合定量风险分析。地表工程地质灾害综合风险分析结果表明:在宏观上,川藏铁路沿线存在3个地表地质灾害高风险区,分别是鲜水河断裂带、金沙江断裂带和东构造结地区。由于川藏铁路采用以隧道为主的设计方案,地表地质灾害的风险大大降低。分别建立了活动断裂、岩爆和大变形等风险评估的普适性模型及综合风险分析模型,以易贡隧道为例,对典型重要隧道全线不同段落断裂活动性、岩爆、大变形等典型地下工程地质风险以及综合风险进行了定量评价。结果表明:川藏铁路沿线的地质灾害、断裂活动、岩爆和大变形等重大工程地质灾害的总体风险等级较高,影响工程安全;定量评估结果可以进一步指导后续的设计与施工的优化和深化。本研究为川藏铁路可行性研究提供了有力的科学支撑,同时也为国内外类似线性工程地质灾害风险分析提供参考。 相似文献
19.
野外地质露头的观察、研究能够最直接、最有效地获取地下地层信息,为地质科学研究提供最直观、最真实的一手地质资料。然而传统的露头研究,尤其针对大坡度、人员无法到达区域的露头研究,主要依赖坡底部考察、测量和拍照等方式记录露头信息,难以精细、准确地表征整个地质体。消费级无人机具有机动性好、适应性强和成本低等优势,且能够近距离、多视角、变高度地获取露头影像。本研究对无控制点情况下的大坡度地质露头影像采集方法与模型构建精度进行探讨,利用消费级无人机垂向航线采集影像,然后构建模型。结果证明倾斜摄影测量技术结合消费级无人机能够有效地构建具有毫米分辨率精度的大坡度地质露头模型。构建的模型具有分辨率高、分辨率均一、量测精度可达毫米等特点,可有效降低野外考察的工作难度,降低人员安全风险,真实准确地复现野外大坡度露头情况,为大坡度露头剖面解译、分析和量测提供真实可靠的数据基础。 相似文献
20.
A case study of slope stability mapping is presented for the A Luoi district situated in the mountainous western part of Thua Thien-Hue Province in Central Vietnam, where slope failures occur frequently and seriously affect local living conditions. The methodology is based on the infinite slope stability model, which calculates a safety factor as the ratio between shear strength and shear stress. The triggering mechanism for slope instability considered in the analysis is the maximum daily precipitation recorded in a 28-year period (1976–2003) taking into account runoff and infiltration predicted with a hydrological model. All necessary physical parameters are derived from topography, soil texture, and land use, in GIS-raster grid format with pixel size of 30 by 30 m. Results of the analysis are compared with a slope failure inventory map of 2001, showing that more than 86.9 % of the existing slope failures are well predicted by the physically based slope stability model. It can be concluded that the larger part of the study area is prone to landsliding. The resulting slope stability map is useful for further research and land-use planning, but for precise prediction of future slope failures, more effort is needed with respect to spatial variation of causative factors and analysis techniques. 相似文献