Advanced Materials Research Vols. 594-597

Abstract: In allusion to the status quo of deficient in evaluation theory and methods on the social risk of dam-break, this paper established 24 index systems for the evaluation of dam-break social risk composed by the dam-break hazard intensity, accident probability, hazard-affected body inherent vulnerability and disaster relief capacity. The quantitative calculation formula has also been put forward for evaluation indexes. In line with the Delphi method, a judgment matrix on the social risk caused by dam-break has been constructed, and has obtained the weight of each index by virtue of analytic hierarchy process. The results show the internal friction angle, the downstream main ditch longitudinal gradient, the current dam height and the monitoring & forecasting capacity are the key indicators that affect the social risks of dam-break. The results of this study help to further enhance and improve the technical level of risk evaluation for the tailings pond.

Abstract: Debris flow is a huge geological disaster，the prediction of the quantity of debris flow is very significant. In this paper, combined with three-dimensional (3D) remote sensing image interpretation, a quantitative method has been proposed to calculate the quantity of debris flow. In the catchment of debris flow, the topography has been divided into zero-time valleys and one-time valleys, and the quantity of debris flow is calculated by two analytical ways of the full amount of portative matter and the amount of portative matter only caused by rainfall. In addition, based on the digital elevation model (DEM) and the amount of portative matter caused by rainfall, the spatial analysis function of the geographic information system (GIS) has been used to calculate the topographic parameters of the cross sectional area and the regional plane area of the catchment of debris flow. Then the relationship of the soil-rock output and the topographic parameters can be discriminated. Furthermore, the influencing range of debris flow can be stimulated. By practices, the analytical results can be used to estimate the dangerous area of potential debris flow.

Abstract: Xinjiang arid area is characterized by low rainfall, strong evaporation capacity, sparse vegetation, intensive tectonic movement, and fragile ecological environment ; the rainfall-type debris flow in the arid area are obviously different from the same type debris flow in humid and subhumid area of China with conditions of rainfall excitation, watershed morphology, motion and deposition processes, material composition, active period and disaster mechanism. Investigations and analyses of characteristics of rainfall-type debris flow in the arid area will reveal the rule of the occurrence and development and explore the evolution trends, to establish reasonable disaster reduction measures. Qiaoquli gully located in Kashgar is a typical arid area rainfall debris flow gully. The 50-year frequency outbreak of debris flow in 2005 destroyed chinapakistan highway . Further investigation to this debris flow gully will contribute to our understanding of this kind of debris flow disaster characteristics and mechanism.

Abstract: The gas seepage characteristics of four kinds of broken rocks of different gradations and the relationship between the capping height and the porosity were studied by means of the simulation experiment and the theoretical analysis. The results show that the air flow in the capping layer composed of broken rocks is in the non-Darcy state which can be described as Forchheimer equation and Ergun equation. Moreover, on the basis of the experimental data, the relational expressions between the permeability, the non-Darcy β factor and the porosity were determined. Through the numerical fitting, the equation of the minimum capping height and the porosity was ultimately derived, which provided the basis and the reference for the determination of capping height and the air leakage control of mine.

Abstract: 3D modeling of city has become a hot research topic in the field of GIS, it has very important significance in terms of urban construction, management and planning. Building model is an important sector of 3D city model, after analyzing the traditional algorithm of building modeling, a combined algorithm based on CSG and SketchUp is proposed in this paper. Using CSG model, the regular buildings are constructed firstly, then using SketchUp software, the irregular buildings are constructed. Finally, all building models are combined into a continuous building. The paper uses parts of the actual data to verify the feasibility of this modeling approach in the paper.

Abstract: Three-dimensional (3D) geological modeling and visualization of landslide is very important for landslide monitoring and stability evaluation. Unfortunately there have not been very efficient methods to realize this modeling and visualization process currently. An implementation of 3D landslide geological modeling and visualization based on a hybrid data structure of TIN and GTP is introduced in this paper. The proposed implementation method includes three sections: pre-processing terrain data for known or history data; 3D modeling of landslide terrain surface, slip surface and geological structure surfaces; construction of 3D landslide geological model and 3D visualization of landslide model through java 3D API. The introduced method contributes to a new approach to landslide research.

Abstract: This paper comprehensively analyses the current condition of highway travel services problems at first, and then introduce the theory and background of an emerging technology------LBS (Location Based Service). It discusses the possible methods of using LBS to solve the existing problems in highway navigation and other travel services. Taking the application of LBS applied in urban transportation for reference, this paper proposes the LBS highway solutions with the consideration of characteristics of LBS and highway. Finally, the key issues of LBS application in traffic Navigation are summarized.

Abstract: 3D data model is an indispensable component to any 3D GIS, and forms the basis of 3D spatial analysis and representation. At present, plenty of representative 3D data models are proposed. However, existing models neglect the display result and the consumption of storage space. Based on the analysis of existing 3D GIS data model, a 3D surface model is proposed for fast visualization in this paper, which is composed of node, segment and triangle. The data structure and formal representation of the proposed 3D surface model is developed to organize and store data of 3D model. Finally, an experiment is made to compare this 3D surface model with other 3D data model, and the result demonstrates that the 3D surface model proposed in this paper is superior to the existing data model in terms of data volume, moreover, it can acquire fast visualization speed.

Abstract: By using imbalance thrust force method, the slope stability factor based on three-dimensional slide block was deduced. According to the borehole data of highway, the TIN data layer and grid data layer for three-dimensional slope stability analysis were carried out by use of ArcMap. The value of each gird cell of different layers are picked up as slide block, it makes convenience in the slope stability analysis. Considering the property of bedding landslide, the three-dimensional slope stability analysis program based on VBA of ArcGIS is put forward in this paper. Taking one of the large rocky landslides as an example, the results of the three-dimensional stability analysis with slope before and after excavation, as well as the different water level conditions are compared. Furthermore, the directive significance of the three-dimensional method in landslide harness engineering was discussed.

Abstract: Automatically identifying and removing above-ground laser points from terrain surface is proved to be a challenging task for complicated and discontinuous scenarios. Eight methods have been developed and contrasted with each other for filtering LiDAR (Light Detection and Ranging) data. Only one approach is difficult to acquire high precisions for various landscapes. This paper presents a method filtering point clouds in which firstly a binary quadric trend surface is used to remove most non-terrain points by a defined height threshold and subsequently a progressive morphological filter further is employed to detect ground measurements. The experimental results demonstrate that this method yields less type I and total errors compared with other eight approaches based on ISPRS sample data sets.