With the fast development of modern industry, the fact that coal dominates the main energy structure will not change for a long time. While the output of coal gangue has accounted for 15%~20% in that of coal. Therefore, coal gangue has become one of the greatest contributions to industrially discharged solid waste in China currently. Nowadays the comprehensive utilization ratio is less than 20%, so there is so much room for the activity and comprehensive utilization of coal gangue. In this article, coal gangue in Tongchuan stimulated by thermal, mechanical and chemical activation has been used as supplementary gelatinize material in cement. The optimal activated ways and technological parameter have been selected by the test of strength, fluidity, water requirement for normal consistency of cement paste, and stability. Also XRD and SEM are used to discuss the change of microstructure which has taken place in activated coal gangue preliminarily.
The crushing and loosening arised from the characteristics such as single particle, bad gradation, lacking of self-stability, low cohesion, loose structure and shear strength happen frequently in the aeolian sand formation. These characteristics lead to tremendous difficulty for tunnel's design and construction. Loading such as formation pressure must be undertaken by secondary lining. In this paper, relying on Shen-Mu Tunnel of Yu-Shen expressway, the strength of lining section has been checked according to internal force combination through imitating the interaction of rock and lining by applying elastic resistance. The bearing force of secondary lining in aeolian sand tunnel has been discussed through calculation by ANSYS, which plays an important directive role on the construction process and keeps the project going on well.
A simplified seismic calculation model of immersed tunnel is built up, which is applied to the seismic analysis of Hong Kong-Zhu Hai-Macao Bridge Project’s immersed tube tunnel. According to different spring stiffness of foundation and different spring stiffness of joint, the tunnel and joint’s force and deformation conditions are compared. The results show that: the influence of foundation spring stiffness is significant, for engineering design, the foundations of a more flexible approach should be preferred; contrary to joint force, the joint opening increases with the increase of joint stiffness, thus, flexible joint is better for project; the connection parts of floor and wall, the connection parts of roof and wall are the most disadvantageous position during the earthquake, so, these parts’ design strength should be strengthened and deformation control should be taken.
For the disadvantage in modeling at complex areas, advancing-frontal triangulation method was firstly applied in building numerical model of FLAC3D software. Suitable date structure and algorithm based on Fish program language was mainly studied. The position criterion of adjacent edges to current edge is brought in to improve the efficiency of algorithm; equilateral triangle or isosceles triangle mesh is generated to improve elements’ quality; element size is controlled by simple mathematics means so smooth graded triangular mesh is constructed. Through the research, the first independent FLAC3D pre-process is developed successfully, without relying on other modeling software. Application example shows the feasibility of the method.
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