Advanced Materials Research Vols. 889-890

Abstract: In order to make sure the reasonable roadway layout in lower seam of close coal mining group coordination in Lijiahao coal mine, firstly, applying the theoretical analysis and geological radar detection to get the influence depth of mining from the up coal seam 2-2 to the floor is about 20m, the results show that the thickness of complete strata is about 15m, then determining to use the outward alternate entries in lower seam roadway by using theoretical analysis. At last, determining the distance of outward alternate entries is 12-14m by using FLAC3D numerical simulation software to simulate the change of stress and displacement in roof floor and two sides of roadway.

Abstract: The process of system reliability analysis for a conveying system with GO methodology was presented. The reliability criterion for a parallel conveying system was defined, regarding to its specific structure and function. Some new GO operators were defined and their algorithms were derived, considering system reparability. The system GO chart was established based on system diagram. Some important reliability parameters for steady system, such as availability and MTBF can be directly calculated with the GO calculation. The result shows that the proposed process is effective for the reliability analysis of this type conveying system and can provide a theoretical basis for the program decision and repairable system optimum design.

Abstract: Seepage damage has been one of the most important factors that affect the safe operation of embankment dams, So more consideration is taken into the saturated soil more than non-saturated soil. In this paper, we carry on the experiment by using SEEP/W software to take the flow field analysis of unsaturated soil of the core embankment dam. Based on the experiment, we analyzed the normal water level of dam seepage line, checked the flood level lower position, the pressure and the flow hydrodynamic calculations of the dam such as hydraulic slope, analyzed different water seepage under the dam changes, as well as the reason of the causing damage to the dam and the effect on the heart wall seepage is also analyzed. We found that the reason of dam destroyed is due to the hydraulic slope caused by excessive exports, we propose the corresponding seepage control measures. To solve this problem, we conducted the filtration for the seepage export processing.

Abstract: Because of the excavation of deep foundation pit will have an important impact on the surrounding buildings, causing serious safety risks, In this paper, though the deformation monitoring of deep foundation pit engineering in No.1 Hospital of Jilin University, It has an in-depth analysis and research on the deformation law of foundation pit and surrounding buildings at the stage of foundation pit construction. The results show that the deformation monitoring analysis of deep foundation pit engineering can not only realize the construction information of deep foundation pit , correctly guide the engineering construction, prevent engineering accidents, but also help to further improve the theory of foundation pit deformation, provide reliable data for the design.

Abstract: This paper supposes a perforated T-shaped steel dampers uses T-shaped steel for the material. Meanwhile, Perforated T-shaped steel dampers are designed into different limb width, limb height to research the influence to the damper by FEM ABAQUS. The research results indicate that perforated T-shaped steel dampers displacement is smaller and the hysteresis curve of which is full, the initial stiffness, yield strength and yield stiffness of the damper would be different.In addition, the hysteresis curve will also change, but the yield displacement is almost no difference. The finally certification is that the smaller perforation to the T-shaped hysteretic damper the steadier hysteretic performance.

Abstract: The squeezed branch pile is a kind of frictional end bearing pile which is variable cross-section, a new type of pile foundation with characteristics of high bearing capacity and low settlement. In order to explore vertical settlement regularity of the squeezed branch pile, this paper carries out the theoretical analysis and experimental research on the consolidation settlement law of the squeezed branch pile through the numerical method and static load test. The results of numerical analysis and experimental research show that vertical consolidation settlement is reduced along with increase of the squeezed branch pile diameter, and the settlement of the squeezed branch pile is given priority to consolidation.

Abstract: Hypersonic aircrafts are facing increasingly severe aerodynamic heating, noise and so on, which will lead to nonlinear vibration characteristics for thin-walled structures of hypersonic aircrafts. Considering the influence of thermo-acoustic loadings, finite element formulation of simply supported plate under combined thermo-acoustic loadings are founded, and vibration characteristics of simply supported plate under thermal loadings with temperature gradient and random acoustic loadings are investigated. According to finite element numerical method, modal frequencies, critical thermal buckling temperature difference, dynamic stress response of simply supported plates with temperature gradient under combined thermo-acoustic loadings were calculated before and after thermal buckling. The results show that three types of motion: random vibrations around initial equilibrium position in pre-buckling region, snap-through oscillations between two post-buckling equilibrium positions, nonlinear vibrations around one of the two post-buckling equilibrium position, and The RMS of nodes for different locations of the simply plate are obtained in pre-buckling post-buckling region, and it is shown that different interaction of tensile bend stress, compressive stress and compressive thermal stress lead to different RMS trends.

Abstract: By finite element software ANSYS a model of GIS busbar tube was established for investigating the effect of the gas pressure on the shell. The results shows that the stress concentration degree is higher on the shoulder between the main tube and the branch pipes under the internal pressure and the gravity, and the highest value is 44.92MPa which is far lower than the admissible stress. Stress changed along the thickness direction, and its value decreased gradually from the inside out. The distributions of the strain and deformation are similar to that of the stress.

Abstract: Accurate calculation of the vehicle load is the foundation for the middle and small bridge safety. Longitudinal influence line and transverse distribution coefficient are used in traditional calculation method of vehicle load. This method brings a little big error because of the simplification. A new method based on influence surface is offered in this paper. The analysis results show that the new method can meet more accurate demand.

Abstract: Shield tunnel construction cause soil movement to harm the adjacent underground pipelines. This paper, taking Dalian Spring Street subway station as the background, uses the finite difference software to establish 3-D finite element analysis model to simulate the deformation of pipeline with 45* skew angle in the tunnel construction work. The results show: when the left tunnel push towards pipelines, due to the skew of the pipeline and tunnel, vertical displacement of pipelines is a certain shift to the left. When the right tunnel excavation is complete, the pipeline maximum settlement has a return to the center of the two tunnels. The settlement of pipeline is much bigger than horizontal displacement.