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The influences of the slope composition on both sides of the variable slope point and the opening numbers of the exhaust vent on the smoke diffusion and the smoke and heat exhaust efficiency in V-shaped tunnel were investigated by the numerical method. The results showed that for the asymmetric V-shaped tunnel, increasing the number of exhaust vents on the large slope side can improve the smoke and heat exhaust efficiency, but control the smoke in a smaller rang is relatively difficult. The corresponding smoke exhaust vent opening strategy should be drawn up in accordance with the composition of the slope of the V-shaped tunnel and the goal of the smoke control system in practice.

The frost resistance and abrasion resistance of the fiber mesh reinforced concrete under the simulated treatment of external environment were studied through the frost resistance test and abrasion test. The relative dynamic modulus, the amount of spalling per unit area, the amount of abrasion per unit area and abrasion depth were used as evaluation indexes. The result shows that the frost resistance and abrasion resistance of concrete can be enhanced by fiber mesh. For the frost resistance, enhancement effect of carbon fiber mesh is better than that of basalt fiber mesh, and better than that of aramid fiber mesh. For the abrasion resistance, enhancement effect of aramid fiber mesh is better than that of basalt fiber mesh, and better than that of carbon fiber mesh. On the whole, the frost resistance and abrasion resistance of basalt fiber mesh reinforced concrete are better. Therefore, basalt fiber mesh is recommended to strengthen the frost resistance and abrasion resistance of concrete in engineering practice.

This paper analyzes the difficulties of steel template design. BIM information model was used for reference to set up a three-dimensional model. Structure safety, forming quality and construction convenience were fully considered. This paper takes Nanchang Chaoyang bridge as an example for the work of template design in each stage. By exploring the selection criteria of shaped structural steel template and establishing the corresponding calculation and design method, the implementation quality of the bridge tower was ensured. Research formed a template design system of template calculation and design. This system provided reference for other similar types of special structure template design.

As a high-performance variable frequency control technology, vector control has been widely used in the field of AC speed regulation. However, the cross-coupling potential of the induction motor after the vector transformation still affects the system performance. Therefore, the method is studied in which stator current is decoupled to excitation component and torque component using internal model control, and the internal model decoupling stator current controller is designed based on rotor field orientation. The simulation model of induction motor vector control system based on internal model decoupling is constructed with Matlab/Simulink. The simulation result shows that the internal model controller is superior to the traditional PI controller in disturbance-rejection performance and robustness.