Optimization of ventilation scheme for underground caverns construction based on parametric modeling

Abstract

The crisscross layout and parallel crossing excavation method of of underground caverns make it difficult to ventilate and disperse smoke, and the ventilation effect directly affects the construction progress and safety of the project. Taking a ground water-sealed cavern project as the research object, the OpenBuildings Designer modeling software is redeveloped by Addins method, and the BIM model of the groundwater-sealed cavern is parameterized. According to the initial conditions and boundary conditions consistent with the project, the standard turbulence model and the component transport model are used to simulate the distribution of the wind flow field and the migration of harmful gases in the cavern. The result show that the position of the cross section has a greater influence on the ventilation effect in the range of the secondary lining step distance than the distance from the outlet of the air duct to the working face. When the air duct outlet is located in the middle of the vault and 50 m away from the working face, the ventilation effect within the second lining step distance is the best, and only 9.7 min of ventilation time can meet the needs of long-term operation of construction personnel. The harmful gases in the tunnel are concentrated in the main channels such as connecting roadways and construction roadways. It is considered that jet fans can be arranged in an orderly interval in the main channel to improve its ventilation efficiency.

Keywords

underground caverns / construction ventilation / parametric modeling / numerical simulation / ventilation scheme