Applied Mechanics and Materials Vols. 353-356

Abstract: Microstructure features have a significant effect on the engineering properties of geomaterials. In the current study, the images of the mudstone samples were obtained using the Scanning Electron Microscopy (SEM) technique. After converted the original images into the grayscale and binary ones, the Canny edge detection technique was utilized to detect the particle edges and compute the characteristic shape parameters of the particles in the SEM images, including the eccentricity, flat circular degree, circular degree, discrete index, radius of inscribe circle. The analysis of correlation between these shape parameters was thereafter performed. All of the above processings was implemented using the MATLAB platform. It shows that some parameters, such as eccentricity and anisotropic rate, had a great correlation; and other parameters, such as perimeter and discrete index, had a good correlation; some parameters, such as anisotropic rate and area, had no correlation. The methods presented herein may be referable in investigating the structural features and deformation/failure mechanism of the mudstones in various scales.

Abstract: The transient electromagnetic method (TEM) has sensitive characteristics of low resistivity of water containing. The equivalent plane method based on whole space theory is used in coal mine goaf water TEM detecting. The mine goaf water was forward simulation. The geoelectric model of mine goaf water was equivalented to low resistivity layer thickness. The geoelectric model was forward calculated, and it was differential imaged. Then it found the apparent longitudinal conductance differential imaging reflect the most sensitive. The field experiment was conducted in two mine goaf water in Xiezhuang coal mine. The central loop device was selected as working device. The launch wire frame is length of 2m and 8 turns. A receiving device is receiving probe and the effective area is 212m². The Water distribution range of goaf water in-300 of the seven mining area in front of retaining wall is large, and the water body is deep.

Abstract: For establishing a prediction model of collapsibility loess for central region of Shanxi Province, 48 groups of loess collapsibility test data have been collected from Taiyuan-Jinzhong area. The mechanism of collapsibility were discussed and based on that the moisture content,void ratio and compressibility were chosen form the test data to be the basic parameter for establishment of prediction model by the method of fuzzy information optimization processing. 40 groups of test data were used to establish the model and 8 groups of test data were used to validate the correctness and applicability of the prediction model. From the validation, the correctness and applicability loess collapsibility prediction model has been confirmed. This method is simple, efficient and practical, which can be applied to evaluate the collapsibility of the loess in Taiyuan-Jinzhong area for future construction engineering.

Abstract: s. The microstructure characteristic of compacted laterite with acid contamination was researched by means of electronic microscope scanning and microstructures image analysis in which the hydrochloric acid was used as pollutant and the acid concentration and curing history of samples were taken into account. It shows that acid pollution significantly influences the microstructure of laterite in which with more acid concentration and longer pollution times, the microstructure images behave lower compaction, blur particle edges, dissolution cement among particles, gluing coatings parceling particles, pores among particles and darker gray color. The corresponding parameters of the microstructure behave different properties in which with longer pollution times of samples, there is a maximum of porosity, girths of particles increase, number of particles decreases, the circularity of particles is not obvious, the directionality and the fractal dimension vary with magnification of the images and with more acid concentration, the girths and porosity increase, the circularity and fractal dimension decrease, the particle number and the directionality vary with the magnification of images. The result shows that the mechanism of the effect of acid contamination on laterites micro structures is that the acid erodes its particles and the cement among particles.

Abstract: The model is too much subjective and rougher in the quantification and weight of factors during the current study on the assessment of ground fissure disasters. This paper uses AHP to analyze the nature of the complex ground fissure disaster, many influence factors and internal relations. It also makes the assessment of the ground fissure disaster mathematical, provides an easy decision method, and assesses the risk of the ground fissures in Yuncheng basin by this method.

Abstract: In this paper, we focus on the problem of how to study ground fissure hazards in 3D way, and establish the 3D model of ground fissure. We mainly solve the expression of spatial distribution characteristics and principle of ground fissure in the digital environment. Projection-Deviation method is adopted to establish the 3D model of an arbitrary ground fissure with an inclination angle according to the actual situation. This method has been verified in Xi'an area, the satisfactory results have been obtained. The research achievement provides a new development tendency for studying ground fissure hazards.

Abstract: The North Yellow Sea basin was located in the middle of the North Yellow Sea. It was possible to find oil and gas reservoirs in this area according to different researches. It was also an oceanic area studied little. In this paper, the engineering geological properties of a drill hole samples collected in the middle of the North Yellow Sea Basin was studied, which could provide basic data for engineering construction and oil and gas exploration and development in this area. In result, stratum of the study area can be divided into 9 units; the mechanical properties of cohesive soil are poor, which have the feature of high compressibility and low shear strength; Granular soil, especially unit 9, has high strength and good engineering property, which is appropriate for use as bearing stratum for drilling platform and other ocean engineering.

Abstract: Based on actual measurement of fractures in south end-slope of Antaibao Coal Mine which adopted open-pit and underground mining, the fractures were grouped by directions, and for each group, distribution functions of direction, length and other geometric parameters and density on the observation window were calculated respectively. The statistic results showed that the fracture orientation followed Fisher distribution and the trace length followed lognormal distribution. According to the fractures number, the mean traces length and standard deviation, as well as one-dimensional density of each group, 3D fracture network was simulated with Monte-Carlo method. Then the block theoretical model was built according to the fracture model, and the block distribution of the south end-slope was analyzed and forecast.

Abstract: On the basis of the analysis of the Mengshan lead-zinc minings geological hazards in Wuzhou City, Guangxi province, the paper forecasts the major types of geological hazards which can be triggered are collapse, landslide as well as the goaf ground subsidence, and studies the causes and the occurrence possibility of them by the improved principle of stereographic projection and calculation method of goaf ground subsidence, which can offer a valuable reference to similar mine construction project in the future prevention of geological hazards.

Abstract: This paper took nuclide U as a research object and focused on nuclide U transport. Three-dimensional conceptual model was established for nuclide U transport in certain a radioactive waste disposal field with weak permeable media. Nuclide U transport in the field was studied by means of three-dimensional numerical simulation. Results show that there is good agreement between numerical simulated and observed groundwater level and that the conceptual model and the numerical simulation are reasonable. Nuclide U transport in the field will form a pollution zone after about 10 years in the mainstream direction and pollute groundwater of the southern area. Prevention measures should be adopted for nuclide U transport in the field. The results can provide evaluation of engineering safety of nuclide U transport in the field with scientific basis.