Papers by Keyword: Tunnel Structure

Abstract: In order to solve the influence of fire and smoke on personnel in highway tunnel for subtended traffic, analysis of measures against the fire in tunnel from structure was conducted. When the tunnel is on fire, smoke hazards lie in high temperature gas and smoke will choke people to cause deaths, fire hazards mainly lie in high temperature which will burn people to cause deaths. The separation pattern of people and smoke, and the separation pattern of people and fire are put forward. Analysis results show that unilateral closed repair road widened to 100cm is a new and feasible solution. Applying the means of setting up symmetrical emergency parking strips in the single tunnel for subtended traffic can help vehicle escape in the tunnel on fire. Setting rail car on the unilateral repair road in the single tunnel for subtended traffic can realize the separation model of people and fire. The results are significant for safety measures against fire in tunnels, and can provide reference for the subtended traffic design.

Abstract: Analyze the role of tunnel lining structure calculation for the elastic resistance, and point out the influence of assuming elastic resistance of Budd-chiarieva method on calculation result and its shortages. Then put forward a new calculation method — Iterative method which can accurately determine elastic resistance distribution law of curved wall tunnel, and introduce basic idea, influencing factor of elastic resistance distribution law, practical method of Iterative method, and the method of improving iterative speed, and the process for calculating internal force of structure is given using Iterative method; contract the calculation results of internal force of structure by Iterative method and Budd-chiari eva method and point out the differences by practical calculation examples. Finally, the application scope of iterative method and necessity for further study are suggested.

Abstract: Single phase specimen of K_0.12TiO₂ with hollandite-type structure was successfully synthesized by the solid-state reaction under Ar/H₂ atomosphere. K⁺ ions were partially extracted from the parent K_0.12TiO₂ specimen by the HCl treatment. The K⁺-extracted K_0.08TiO₂ specimen worked as a rechargeable electrode material. An initial capacity of 92 mAh/g (cut-off voltage: 1.0 V) could be achieved, which approximately correspond to the composition Li_0.28TiO₂. A reversible capacity after 50 cycles was about 50 mAh/g.

Abstract: Through the survey about the durability of existing railway and road tunnels, it is found that there are different kinds of defects in most tunnels concerning poor durability. This phenomenon exists for a number of reasons among which the main ones are geological conditions , hydrological conditions, types of concrete structures, poor grading, larger second lining thickness, excessive larger stiffness and the poor quality construction. Solutions of these problems are provided in this paper. Specific measures are using multiple composite cementitious materials (the cocktailtreatment), providing composite cementitious materials with mixing station mode, using effective superplasticizer with low water-cement ratio and small water usage, adding appropriate amount of cellulose fibers in concrete, emphasizing the initial support and belittling the secondary lining, using reasonable maintaining technology, using new technology of Waterproof Plate. These measures may serve as reference for tunnels’ design and construction.

Abstract: In this paper a 3D FEM model is established to simulate the dayuliang tunnel which is located in the gob area. The vertical and horizontal surface displacements of gob area are obtained in different simulation condition. By these calculated results the character and key region of gob surface subsidence is analyzed. The warning line of subsidence basin is determined. In order to control tunnel structural’s stability its deformation and stress character are also researched to determine stress concentration and important supporting position. These analysis results provide a scientific basis and technical guidance for the tunnel construction in gob area.