Development and characteristic research on new thermal insulation and anti-permeability grouting material for tunnels in cold regions.

The surrounding rock of tunnels in cold regions are susceptible to the freeze-thaw cycle resulting from the combination of low temperatures and moisture during tunnel service. The phenomenon will not only lead to the expansion of pores and fissures in the surrounding rock of the initial tunnel, but also destroy the integrity of the rock. This destruction will have a serious impact on tunnel structure and rail transit operation safety.

Numerical simulation and theoretical study on the impact of wind-sand flow of high-speed trains in long tunnel space.

When high-speed trains (HST) run in enclosed spaces such as long tunnels, the thermal accumulation of their suspension devices is continuous and cannot be effectively dissipated. In addition, previous experiments or simulations for the heat dissipation of HST in tunnel spaces did not consider the impact of sand. To clarify the impact of HWS-LT on the heat accumulation of HST equipment cabin, this study used the CFD method to numerically simulate the impact of different wind-sand flow concentrations or no-sand wind on the cooling of equipment in the long tunnel space.

Finite element analysis and optimization of tractor gearbox body under various kinds of working conditions.

As the main component of the tractor gearbox, the box has the functions of shifting operation and carrying the cab, it also carries part of the framework function. If the strength, stiffness, or vibration characteristics of the box do not meet the allowable requirements, large vibration and noise may occur, and even there is the possibility of fracture in some limiting conditions. To solve this problem, according to the structural parameters of a gearbox, the three-dimensional model of the box was established by using the three-dimensional modeling software Creo.

Safety evaluation of rail transit vehicle system based on improved AHP-GA.

The rail transit vehicle system is an important subsystem with the most frequent operation accidents and the most direct impact on passengers. Based on the particularity of the vehicle system and the complexity of the system, the hierarchical analysis method (AHP) is used to evaluate its safety. High-order judgment matrix often has inconsistency, and the judgment matrix consistency guarantee is the key to the hierarchical analysis method applied.

A virtual simulation experiment platform of subway emergency ventilation system and study on its teaching effect.

For safety engineering majors, it is very important to cultivate the practical ability of professional talents. Due to the difficulty of conducting experiments in dangerous environments, a virtual simulation experiment teaching platform was established. The platform allowed students to understand the structure of the subway ventilation room, and master the control requirements of the ventilation system in the event of sudden fire, blockage, and failure in the subway.

A new water quality assessment model based on projection pursuit technique.

A new water quality assessment model was built based on projection pursuit technique. A great quantity of sample data was applied to increase the model's precision. A new genetic algorithm combined with conditional optimization method was proposed and applied to the model optimization, which could deal with global optimization problem with various restrictions effectively.