Spatiotemporal migration of dust pollution during the tunnel mucking process and development of dust removal trolley based on computational fluid dynamics technology.

During tunnel construction, the protracted mucking phase poses significant occupational health risks, particularly from dust exposure. This study delves into comprehensive numerical simulations to examine the spatiotemporal dynamics of dust particles during the mucking process. A distinct 'bimodal pattern' was characterized by higher concentrations in the mucking area (0-30 m) and the inverted arch area (60-110 m), where concentrations exceed 30 mg/m3 under all conditions. To address this issue, a novel dust removal system has been developed. Integrating six dust collectors and one air curtain device, a dust removal trolley is strategically positioned at z = 70 m to locally purify the air. The extracted wind speed of the dust collectors ($V_{\mathrm{inlet}1}$) and the air curtain's wind speed ($V_{\mathrm{inlet}2}$) are optimized based on ventilation conditions and dust dispersion characteristics. This system effectively reduces dust mass concentrations to below 4.8 mg/m³ at six worker locations.