Study On Theory And Method Of Highway Alignment Selection In High Seismic Intensity Canyon Region

With the frequent earthquake in China, strong vibrations on the surface of Earth causedby the energy release from crust lead to serious damage to the roads, bridges and otherinfrastructures in gorge area. On the other hand, Existing selection method lacks considerationthe earthquake risk in high seismic intensity canyon region that intensifies the damage degreeof regional lifeline. Therefore, an essential question has been raised as to discuss spatialdistribution characteristics of earthquake damage in highway corridors, take into account andassess potential seismic risk, establish theoretical system of highway alignment selection forhigh intensity seismic canyon region, which are not only the basic issues, but also the urgentneeds of assigning construction tasks reasonable and realizing harmony with the environment.Sponsored by special funds of ministry of transport “Research on the key technology ofhighway’s anti-seismic and disaster reduction in reconstruction of Wenchuan earthquake” andwestern traffic technology funds “Research on optimization design of Wuguan expresswayanti-seismic and disaster control technology”, This thesis focuses on the highway alignmentselection in high seismic intensity canyon region. Based the theory of risk analysis andmanagement, the theory and method of highway alignment selection in high intensity seismiccanyon region are researched, in order to solve highway alignment selection and designproblems under complex conditions in seismic areas.In response to the limitation of existing theory system and method of highway alignmentselection, the main content is proposed. Using geographic information system, remote sensing,and global positioning system, the earthquake disasters are surveyed along the highwaycorridors in Wenchuan earthquake areas. The major disaster model is summarized and thespatial distribution characteristics are analyzed. Considering the zonal distribution of seismicdamage to highway, from three aspects of conceptual, logical and physical to design thestructure of spatial database, based on GeoDatabase, the heterogeneous spatial database forhighway earthquake disaster is established. Under the technical support of ArcGIS, based onspatial data mining theory, this dissertation presents a attribute correlation method of highwayearthquake data. The data model of attribute correlation between geological disaster andenvironmental factors is established, and the laws of zonal distribution along highwaycorridors are revealed.For the outstanding characteristics of earthquake risk in high intensity seismic canyonregion, the dissertation discusses the selection method for highway corridor risk-oriented andillustrates the specific contents of risk-oriented from the perspective of system engineering.Combining the method of main component analysis and experts surveys, the dissertationscreens out peak acceleration, vegetation coverage, formation lithology and slope asassessment factors that have significant effect on regional earthquake risk. Based on cloudmodel theory, the method of specifying assessment weights is proposed using cloud model and analytical hierarchy process, and the risk assessment model for highway earthquake isestablished, which express potential earthquake risk and improve the quantitative degree ofearthquake risk assessment.Analyzing the key factors influencing the alignment selection in depth, the dissertationestablishes an assessment system with two levels-a criteria level with risk, economy, safe,environment as index, an alternative level with9-single-factor as index. Using ArcGIS andconsidering the need of alignment selection assessment, the calculation method andquantitative model of assessment factor are established. Introducing multiple attributeassessment theory considering the interact requires between decision makers, the dissertationproposes the multiple attribute assessment method with integrated degree and matched degreein high intensity seismic canyon region, establishes approach model for alignment selectionintegrated degree and matched degree, and illustrates specific assessment procedure, which allprovide technological support for reasonable alignment selection.Analyzing the highway alignment design indexes and the relationship between theirvalues with earthquake, the key design indexes for alignment selection in high intensityseismic canyon region are specified, and factors of the reasonable plan, vertical and horizontalalignment layout are proposed. According to the rescue vehicle characteristics and followingthe standards of highway earthquake risk hierarchy, the specific method for rescue highway ismade. Using three-dimensional discrete mathematical modeling, for different seismic waveparameters-frequency, amplitude and duration-and angle of rocks, the influence laws of slopeheight and gradient on dynamic displacement of slope are revealed, and a reasonable regionfor height and gradient in earthquake areas is proposed. From the aspects of bridge, tunnel andretaining projects, a reasonable layout method for highway infrastructures in earthquake issummarized.In the case study of Wuguan expressway, the method, index system, model researchedabove are applied in alignment selection and design, which verifies the feasibility of researchresults.This theory and method for alignment selection combines field surveys, mathematicalmodeling, theory analysis and construction verification, improves the precision of dataanalysis and management, enriches highway alignment selection methods and theory systemin our country. It has an important practical meaning not only for the highway construction inhigh intensity seismic canyon region, but also for harmonious relationship between highwayand environment; and further more, it has an important theoretical meaning for the scientificdevelopment of transportation in our country.