关键词: 交通运输工程, 连通小净距隧道, 小净距上叠风道, 数值模拟, 力学效应

Abstract: Based on the construction process of over-lapping wind-duct with small-distance connecting tunnel in a certain interval of Line 4 in Chongqing rail transit, the two dimensional small-distance two-hole tunnel was regarded as an elliptical single-hole tunnel with the plane elastic complex theory, and the pressure of surrounding rock was solved. Comparing the calculated results with two-dimensional numerical simulation, it is proved that the equivalent calculation model is feasible. According to the research results, a three-dimensional construction numerical model was established to calculate the mechanical effect of wind-duct duct. Through the three-dimensional simulation, 4 essential points of the stress and displacement in the construction process were found out and analyzed respectively. The analysis results show that the excavation of the wind-duct has a significant effect on the surrounding rock and soil of the wind-duct, the interval tunnel and ventilating shaft. The deduced two-dimensional simplified calculation model can be used to simplify the calculation of similar connecting small-distance tunnels, especially liaison passage of small-distance tunnels. At the same time, the three-dimensional simulation results of wind-duct excavation can be used to guide the overlapping wind-duct engineering with the same type.

Key words: traffic and transportation engineering, connecting small-distance tunnel, the over wind-duct with small-distance, numerical simulation, mechanical effect