隧道变形与坡体灾害相互关系及其预测模式

分析了坡体病害地段隧道变形开裂的特征及二者相互关系 ,给出了隧道变形与坡体病害相互关系的 5种地质结构模型 ,在此基础上提出了用隧道变形规律预测坡体灾害的模式 ,并用地质力学模型试验结果加以验证。

黄土隧道变形与坡体灾害相互关系及预测方法

本文以山西省临离高速公路孙家沟隧道为例,通过进行现场实测与有限元数值模拟,分析了在古滑坡复活情况下,隧道变形表现形式及裂缝产生特征,并总结了根据现场测量数据进行坡体灾害预测的方法。本文的成果对黄土地区建立高速公路隧道智能管理化系统具有重要的参考意义。

地震灾害体不同基质类型坡面植被恢复动态特征

为了解地震灾害体不同类型坡面植被恢复进程与机制,于2010—2019年,调查汶川地震后大熊猫国家公园卧龙片区地震灾害体不同类型坡面(土壤基质坡面、土壤—岩石混合基质坡面、岩石基质坡面、残留植被斑块基质坡面)上恢复植物群落的结构及物种多样性时空动态。结果显示:(1)从恢复植被的物种数来看,经过十余年的恢复,土壤—岩石混合基质坡面植物种数最多,岩石基质坡面与残留植被斑块基质坡面次之,土壤基质坡面最少。(2)土壤基质坡面、土壤—岩石混合基质坡面和岩石基质坡面恢复灌木物种数占比最高,而残留植被斑块基质坡面中草本植物种数占比最高。(3)从植被演替动态来看,土壤基质坡面、土壤—岩石混合基质坡面、岩石基质坡面、残留植被斑块基质坡面的优势物种,在2010年分别为灌木、灌木和乔木、灌木、草本和灌木;在2013年分别为草本和乔木、灌木和乔木、灌木和乔木、草本和灌木;在2016年分别为草本和灌木、灌木和乔木、草本和灌木、灌木和乔木;在2019年分别为草本—灌木—乔木、灌木、草本和灌木、乔木和灌木。(4)2010—2016年研究区不同类型坡面植物群落高度存在显著性差异,2019年无显著性差异。(5)2010—2019年不同类型坡面地震灾害体各植物多样性指数在总体上均呈现上升趋势,Shannon-Wiener指数上升约0.5倍。

Landslide Hazard Zonation Mapping in Ghat Road Section of Kolli Hills, India

Landslides are the most common natural disaster in hilly terrain which causes changes in landscape and damage to life and property. The main objective of the present study was to carry out landslide hazard zonation mapping on 1:50,000 scale along ghat road section of Kolli hills using a Landslide Hazard Evaluation Factor(LHEF) rating scheme. The landslide hazard zonation map has been prepared by overlaying the terrain evaluation maps with facet map of the study area. The terrain evaluation maps include lithology, structure, slope morphometry, relative relief, land use and land cover and hydrogeological condition. The LHEF rating scheme and the Total Estimated Hazard(TEHD) were calculated as per the Bureau of Indian Standard(BIS) guidelines(IS: 14496(Part-2) 1998) for the purpose of preparation of Landslide Hazard Zonation(LHZ) map in mountainous terrains. The correction due to triggering factors such as seismicity, rainfall and anthropogenic activities were also incorporated with Total Estimated Hazard to get final corrected TEHD. The landslide hazard zonation map was classified as the high, moderate and low hazard zones along the ghat road section based on corrected TEHD.

Geometrical feature analysis and disaster assessment of the Xinmo landslide based on remote sensing data

At 5:39 am on June 24, 2017, a landslide occurred in the village of Xinmo in Maoxian County, Aba Tibet and Qiang Autonomous Prefecture(Sichuan Province, Southwest China). On June 25, aerial images were acquired from an unmanned aerial vehicle(UAV), and a digital elevation model(DEM) was processed. Landslide geometrical features were then analyzed. These are the front and rear edge elevation, accumulation area and horizontal sliding distance. Then, the volume and the spatial distribution of the thickness of the deposit were calculated from the difference between the DEM available before the landslide, and the UAV-derived DEM collected after the landslide. Also, the disaster was assessed using high-resolution satellite images acquired before the landslide. These include Quick Bird, Pleiades-1 and GF-2 images with spatial resolutions of 0.65 m, 0.70 m, and 0.80 m, respectively, and the aerial images acquired from the UAV after the landslide with a spatial resolution of 0.1 m. According to the analysis, the area of the landslide was 1.62 km2, and the volume of the landslide was 7.70 ± 1.46 million m3. The average thickness of the landslide accumulation was approximately 8 m. The landslide destroyed a total of 103 buildings. The area of destroyed farmlands was 2.53 ha, and the orchard area was reduced by 28.67 ha. A 2-km section of Songpinggou River was blocked and a 2.1-km section of township road No. 104 was buried. Constrained by the terrain conditions, densely populated and more economically developed areas in the upper reaches of the Minjiang River basin are mainly located in the bottom of the valleys. This is a dangerous area regarding landslide, debris flow and flash flood events Therefore, in mountainous, high-risk disaster areas, it is important to carefully select residential sites to avoid a large number of casualties.

Landslide Hazard Mapping During a Large Scale Earthquake

This paper reports a method to make hazard maps of sediment disasters resulting from an earthquake and following heavy rainfall for the entire region of Gunma prefecture, Japan. Firstly, we identified the slopes in the study area, which are susceptible to large-scale landslides and land failures during an earthquake with a magnitude of seven on the Richter scale. To analyze the sheer volume of the data, we employed a statistical method to evaluate the susceptibility, mainly considering geomorphologic conditions. Secondly, we extracted mudflow and slope failure susceptible areas and potential flooding zones resulting from a damming at a river triggered by the earthquake and heavy rainfall, and we identified the settlements which would be isolated by the road disruption caused by the sediment disasters. As the result, 359 settlements were classified as potential isolation areas. Combining the above-mentioned susceptibility maps, we obtained two types of sediment disaster hazard maps of the study area, depicting the potential hazards which would occur during the earthquake and the disasters which would be caused by heavy rainfall following the quake, respectively. These hazard maps and the disaster information would be useful for the regional disaster prevention planning and countermeasures in the future.

Methodological Proposition of an Integrated System for Urban Floods Control

In the State of Santa Catarina, Brazil, especially in the Itajai valley, there are records of accidents and disasters mainly associated to landslides and floods, which have caused significant damages and losses, including human lives. In order to make the coexistence with such natural disasters possible, most particularly with floods, a integration is required among the technical, political, environmental, and human knowledge. Measures that encompass integrated actions for the entire river basin, with the help from an updated technical cadastre and tools, such as the GIS, allow the development of planning tools that might effectively help the people to live with the water, or else to cope with floods in a more appropriate manner. This paper attempts to propose a methodology for urban flood control, based on the integration among the several public entities involved in the flood control, along with the CTM （Multipurpose Technical Cadastre） and GIS tool. In order to solve or minimize the problems, the model proposed here aims at promoting a balance between the agents involved, and enables to rank the degrees of importance assigned to the different needs, thus allowing to eliminate or to improve those areas and processes that are duplicated or superimposed.