Study on Airflow Migration and Rock Dust Pollution Behavior in TBM Construction Tunnel
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RESEARCH ARTICLE-CIVIL ENGINEERING
Study on Airflow Migration and Rock Dust Pollution Behavior in TBM Construction Tunnel Qiang Liu1,2 · Wen Nie1,2 · Yun Hua1,2 · Cunhou Wei1,2 · He Ma1,2 · Changqi Liu1,2 · Wenjie Zhou1,2 Received: 24 September 2019 / Accepted: 10 August 2020 © King Fahd University of Petroleum & Minerals 2020
Abstract When tunnel boring machines (TBMs) are used to construct tunnels, large quantities of rock dust are produced, affecting the working environment of construction personnel. To explore ways to improve the air quality in tunnels, this study employed a numerical simulation to investigate controlling rock dust via tunnel ventilation systems. The results showed that when the secondary compressed airflow rate (Q2) was set to 4–11 m3/s, the rock dust produced could be controlled within a range of 77.2 m from the tunnel face. When Q2 = 8 m3/s, the rock dust diffusion distance (LD) reached a minimum of 42.7 m, and the rock dust concentration around the operating region (CW) was approximately 30.1 mg/m3. To explore the further enhancement of dust suppression performance in a tunnel, a numerical simulation was conducted on rock dust diffusion in the tunnel when Q2 was fixed but the exhaust airflow rate (QC) was set to different values. According to the numerical simulation results, when QC = 15 m3/s, the rock dust produced could be effectively controlled at the front of the tunnel with a length of 14.6 m, i.e., the rock dust could be most effectively suppressed. Keywords Ventilation system · Rock dust · TBM-excavated tunnel · Numerical simulation
1 Introduction Currently, tunnel boring machines (TBMs) are extensively used to construct tunnels. Compared with traditional drilling blasting methods, TBMs exhibit more favorable accuracy and safety while also accelerating the tunnel construction process [1–3]. Due to the characteristics of the TBM construction method, tunneling and supporting are always performed simultaneously [4–8]. A TBM generally uses a unique cutter head to cut and crush rock when tunneling. During the construction process, large quantities of rock dust are inevitably produced, significantly polluting the operators’ construction environment and seriously affecting
* Wen Nie [email protected] 1
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, China
State Key Laboratory of Mining Disaster Prevention and Control Co‑Found By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao 266590, China
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miners’ physical health [9–12]. The ventilation system in a TBM excavated tunnel conveys fresh air to the tunnel and discharges rock dust and exhaust gas from the tunnel. However, the production of dust around the tunnel face is difficult to investigate through model tests and field measurements. In contrast, simulation results based on computational fluid dynamics (CFD) can accurately represent the actual conditions. Such models can not only directly d
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