Applied Mechanics and Materials Vols. 90-93

Abstract: There have some advantages like as Good working conditions, High Security, Guaranteed production capacity and Low loss for Open pit mining, therefore the degree of opencast mining increasing. In this paper numerical simulation and limit equilibrium are used for Stability of west project of side slope which are under the conditions of Normal and Saturation. Draw slope stability results under the two conditions in order to take appropriate measures to provide appropriate post- mining safety protection.

Abstract: Saturated and unsaturated seepage analysises are given for the neonatal landslide——Qianjiangping Landslide applied Three Gorges Reservoir water level and rainfall which happened after the first sluice in Three Gorges Reservoir, the conclusions are discussed from the two aspects: Three Gorges Reservoir sluice and heavy rainfall.

Abstract: A numerical simulation method of the rock bolts non-destructive testing based on ANSYS is presented. ANSYS/ LS-DYNA which is a kind of software of rock bolts dynamic finite domain analysis is used to establish a three-dimension model, after sine curve excitation is loaded, the reflection curve of naked rock bolts, or rock bolts with different defects are got, and the relationship curve between elastic modulus and stress wave velocity are got correspondingly. Experiment result proved that the aboved method was satisfied to simulate the stress wave propagation and the reflection situation in the rock bolts.

Abstract: The inclined surface cracks are under the mixed mode I，II，III loading conditions. In order to study the surface crack growth the stress intensity factors of the front of half-circular surface crack are calculated according to fracture analysis code-3D(FRANC3D). And the influences of inclination angle of the surface crack and the orientation angle on I，II，III mode stress intensity factors were analyzed. I mode stress intensity factor increases along the crack front with increasing inclination angle. And I mode stress intensity factor of the same inclination angle is symmetrical with respect to the orientation angle of 90 degree. II，III mode stress intensity factors are the maximum when the inclination angle is equal to 45 degree. And the behavior of II，III mode stress intensity factors along crack front for the inclination angle of 15 and 30 degree is identical with that of inclination angle of 75 and 60 degree, respectively.

Abstract: Crack propagation in quasi-brittle material such as rock and concrete is studied by a new numerical method, lattice cellular automata. Cellular automaton method is an efficient method that simulates the process of self-organization of the complex system by constructing some simple local rules. It is of the advantage of localization and parallelization. Lattice model can transform a complex triaxial problem into a simpler uniaxial problem as well as consider the heterogeneity of the materials. Lattice cellular automata integrate advantages of both cellular automata and lattice model. In this paper the importance of the study of crack propagation, fundamentals and applications of cellular automata are briefly introduced firstly. Then the cellular automata model is presented, and in order to verify lattice cellular automata, the propagation of mode-I crack in homogeneous material is studied. Results of the numerical simulation are in good accordance with the experimental results and theoretical results of classical fracture mechanics. Furthermore, based on lattice cellular automata, the crack propagation of single crack under uniaxial compression was simulated. During the crack growth the wing crack and secondary cracks were found. The simulation results were consistent with the experimental results.

Abstract: Mining activities are usually associated with environmental impacts, particularly that of air pollution by fugitive dust. Malmberget mine is one of the most important iron mines in Sweden and the dust problem has been noticed by the inhabitants for a long time. Dust collectors had been installed to measure the dust fallout around the mining site. In this research the dust fallout recorded during the period August 2006 till July 2010 were analyzed. Generally speaking the amount of dust fallout was decreasing year by year due to some implemented dust control methods. Mining activities produced more dust during summer than winter. The peak value was 265g/100m2/30d appeared in May 2007, and the lowest dust fallout was 25g/100m²/30d happened in August 2009. Dust was determined to be originated from the open pit area and the industrial center area. Truck transportation on the haul roads, wind erosion of stockpiles and exposed areas were the main activities that caused dust generation.

Abstract: A great number of large-scale hydropower stations are to be constructed in southwest China. Many of them feature great depth or high in situ stresses. In this paper, a coupled damage and rheology method is adopted for stability analysis of an underground cavern group with time effect to consider the rock deformation. Meanwhile, a new method considering the crackopening displacement is used for back analysis. The stability of the surrounding rock masses is then evaluated.

Abstract: An analytical method is presented to investigate the torsional dynamic response of an elastic foundation resting on transversely isotropic saturated soil subjected to harmonic loading. The dual integral equations of an elastic foundation are established according to the mixed boundary-value conditions at the interface and the dynamic torsional characterizes, which are further converted into a Fredholm integral equation of the second kind. The torsional dynamic response problem is solved by solving the Fredholm integral equation. By comparing present numerical solution with that of other’s, the correctness of this paper has been verified.

Abstract: The development of urban rail transit plays the more and more important role in the public transit. It’s significant to analyze the urban rail transit network characteristics and its stability. The basic statistics parameters of Beijing metro network are computed in the paper based on the theory of complex networks, and its network characteristic is analyzed through the comparison to characteristic parameters of four typical networks.

Abstract: The purpose of this paper is to summarize the performance of permeable asphalt pavements (PAP) and to recommend future areas of research and development. The development of PAP as an integral part of sustainable drainage systems is reviewed in the context of traditional and modern urban drainage. The difference between the permeable asphalt pavement and the ordinary bituminous concrete pavement is discussed. A description of the seepage calculation model based on the structural characteristics of PAP is presented. And also water level fluctuations of both the water permeable asphalt pavement and the ordinary bituminous concrete pavement are analyzed by comparing their numerical simulation results. Finally the drainage performance of the water permeable asphalt pavement is demonstrated. The long-term effectiveness of permeable pavement as an alternative to traditional impervious asphalt pavement is examined. The simulation results could provide significant guidance for the structure design of water permeable asphalt pavement.