Xu Weiya

GIS-based landslide hazard assessment: an overview

In recent years, landslide hazard assessment has played an important role in developing land utilization regulations aimed at minimizing the loss of lives and damage to property. A variety of approaches has been used in landslide assessment and these can be classified into qualitative factor overlay, statistical models, geotechnical process models, etc. However, there is little work on the satisfactory integration of these models with geographic information systems (GIS) to support slope management and landslide hazard mitigation. This paper deals with several aspects of landslide hazard assessment by presenting a focused review of GIS-based landslide hazard assessment: it starts with a framework for GIS-based assessment of landslide hazard; continues with a critical review of the state of the art in using GIS and digital elevation models (DEM) for mapping and modelling landslide hazards; and concludes with a description of an integrated system for effective landslide hazard assessment and zonation incorporating artificial intelligence and data mining technology in a GIS-based framework of knowledge discovery.

The selection of spread and the application in engineering of GRNN

The algorithm of the generalized regression neutral network (GRNN) is introduced. Compares and analysis with superiorities and characteristics between GRNN and BPNN. The effects and choices of spread are discussed. It is very important to confirm the value of spread. Appropriate value of spread is searched out from all specimens based on the LOO across validate method. A simple example is given to prove the accurate value of spread can improve the generalization ability of the network. The method of GRNN is applied to the examples of slope stability evaluation, it is concluded that GRNN modeling is simpler and more accurate than BPNN in prediction and analysis of slope stability. Artificial neural network algorithm has been widely used in engineering, and GRNN will be accepted for engineers more easily as a means of more advanced algorithms. It will play an increasingly important role in the non-linear calculations.

Study on Coupling Influences of Concrete Dam Foundation Seepage, Stress, and Creep on Structure Behaviors of Dam Body

Abstract Accidents of some arch dams show that dam failures are mainly caused by crack or failure of their foundation rocks, which are directly related to water seepage in the rock. This kind of fluid-rock interaction has an important influence on deformation and stress characters of the dam-rock system. In this paper, the stress and flow fields of dams and their foundation rocks are studied as a coupled system, using visco-elastic constitutive models and finite element solution method. The developed models and FEM technique were applied for analysing the continuous displacement of the 13th dam section of the Longyangxia Dam, and the calculated results agree well with the measured ones.