Applied Mechanics and Materials Vols. 368-370

Abstract: High embank culverts have been widely used in railway, highway, municipal works, and other underground engineering. The vertical earth pressure on the culvert top is a key to design culvert structure correctly and guarantee it safety. Comparing three typical earth pressure theories, combined previous studies of experiment and numerical calculation, acted effect on high embank is analysis. Unstable soil arch effect and additional stress causing by differential settlement are presented. The two acted effect play a main role separately in different fill height. So, two-stage earth pressure calculation formula is given with a h₀ limit fill height. The studies can give some reference to high embank culvert structure design.

Abstract: The hydraulic fracturing method is a common method to measure the ground stress. This article describes the principles of the hydraulic fracturing method, studies the distribution and the value of the ground stress in a tunnel area with the hydraulic fracturing method, and predicts rock burst by using the Russenes discriminance and the Turchaninov discriminance. The results show that the maximum horizontal stress is between 4.7MPa and 11.1MPa, and the minimum horizontal stress is between 4.0MPa and 8.0MPa. The maximum horizontal stress direction of the drilling is between N63 °W and N72 °W, and it is not conducive to the stability of the tunnel surrounding rocks because the large angle intersection of the tunnel axis direction and the maximum horizontal stress direction.

Abstract: In the ultimate bearing capacity formulas, the factor N_γ has not been given a definite expression, so the calculation diagrams are not serious and the hypothesis can’t match the reality. Most of the ultimate bearing capacity factors are received from the results of Prandtl theory, but the theoretic models they used are not the same. And most of the ultimate bearing capacity theories are based on Mohr-Coulomb theory, the effects of intermediate principle stress are ignored. To solve these problems, according to ultimate balance theory and unified strength theory, the analytical formulas of ultimate bearing capacity and N_γ are received when foundation is completely smooth. The results show that the ultimate bearing capacity will increase when considering the effects of intermediate principle stress and the formulas from practical experiences can make the ultimate bearing capacity unsteady.

Abstract: Rock stress-strain curve under uniaxial compression is the output of joint action of rock and test system, so it must have certain noise. In order to realize effective denoising processing, the concept of instantaneous deformation modulus has been put forward, and the difference quotient algorithm of instantaneous deformation modulus has been used to enhance noise. After wavelet analysis and wavelet packet analysis of rock stress consequence and instantaneous deformation modulus respectively, the results of different denoising schemes have been statistically analyzed, this analysis shows that the wavelet packet analysis of instantaneous deformation modulus can achieve optimal denoising effect.

Abstract: This paper mainly focus the on application of BIM in construction and obstacles existing in development of BIM. According to the construction difficulties of some project, the authors established the 3D model of the project, derived the 2D construction drawings and calculated the quantities of the materials by softwares based on BIM technology. Finally, the engineering cost had been controlled effectively and construction period had been cut down substantially. In the paper, a construction management system of BIM is put forward and the main obstacles in the development of BIM are obtained through analyzing based on the practices in the project.

Abstract: 3D city models are important in urban planning for sustainable development. Usually and traditionally, urban planners design the future layout of the towns by drawing the maps, using GIS or CAD packages. 3D city models based on these maps are quite effective in understanding what if the plan is realized. However, creating 3D city models is labor intensive, using a 3D modeling software such as 3ds Max or SketchUp. In order to automate laborious steps, we are proposing a GIS and CG integrated system for automatically generating 3D building models with general shaped roofs by straight skeleton computation, based on general shaped building polygons (building footprints) on digital maps.

Abstract: Abstract. In the field of magnetic anomaly detection(MAD) under ocean, oceanic waves produce magnetic noise which cannot be ignored. An AR model is used to describe the noise at first. Then the MAD model is built basing on the magnetic dipole model. Finally, a method for decreasing the noise in MAD basing on wavelet denoising is proposed. According to simulation, the way of wavelet denosing has obvious effect on decreasing the noise and increasing SNR.

Abstract: In order to improve the efficiency of 3D buildings reconstruction, based on the previous related advance technology and theory, It put forward a novel method for detecting building contours in irregularly triangulated point cloud data, On the condition that image resolution and density of the point cloud scale it adopt a new registration method, improve the LIDAR point cloud data with registration accuracy on remote sensing images. which make building reconstruction from these data sources feasible and reliable. It is also meaningful for virtual reality, urban planning, and simulation of disaster scenarios etc. finally the experimental results show that the proposed method can obtain more accurate results in comparison with the previous method.

Abstract: The high-turbidity solid-liquid two-phase problem of the complex flow pattern is of greatest importance for the grit chamber with rotational flow. An Eulerian-Eulerian two-phase model for describing the collision force between particles in sandstone wastewater properly was developed. A bench scale experiment combining with a hydroelectric project was conducted. By analyzing the removal efficiency at different speeds of blade, the optimized rotating speed was obtained. Based on the optimized rotating speed, three-dimensional numerical simulation of the two-phase flow field was studied. The simulation results showed that when the number of blade is four, the optimum removal efficiency can be reached, which was found to be in reasonable agreement with the experimental data.

Abstract: Model making is not only a required course of industrial design major but also a indispensable link to enterprises in developing new products. It represents design conception directly through the rich of materials and processes. To reconstruct shape design of model effectively, we have employed the ISDX module Pro/E software to reconstruct a cartoon crab toy, which explains the reconstruction process based on the model of industrial products and provides design reference for students and practitioners.