This page has only limited features, please log in for full access.
The present study compares and analyzes three risk analysis models that are applicable to shield tunnel boring machine (TBM) tunneling, and thus proposes an improved risk matrix model based on the causal networks applicable to sustainable tunnel projects. The advantages and disadvantages of three risk analysis models are compared, and causal networks are structured by analyzing the causal relationship between risk factors and risk events. Based on the comparison and analysis results, the causal network-based risk matrix model (CN-Matrix model), which complements the disadvantages and exploits the advantages of the three existing models, is proposed in this paper. Furthermore, this study suggests a means of modifying the weighting scores in the estimation of the risk score, which permits the CN-Matrix model to determine the risk level more reasonably. Thus, the improved CN-Matrix model is more reliable and robust compared to the three existing models.
Heeyoung Chung; JeongJun Park; Byung-Kyu Kim; Kibeom Kwon; In-Mo Lee; Hangseok Choi. A Causal Network-Based Risk Matrix Model Applicable to Shield TBM Tunneling Projects. Sustainability 2021, 13, 4846 .
AMA StyleHeeyoung Chung, JeongJun Park, Byung-Kyu Kim, Kibeom Kwon, In-Mo Lee, Hangseok Choi. A Causal Network-Based Risk Matrix Model Applicable to Shield TBM Tunneling Projects. Sustainability. 2021; 13 (9):4846.
Chicago/Turabian StyleHeeyoung Chung; JeongJun Park; Byung-Kyu Kim; Kibeom Kwon; In-Mo Lee; Hangseok Choi. 2021. "A Causal Network-Based Risk Matrix Model Applicable to Shield TBM Tunneling Projects." Sustainability 13, no. 9: 4846.
Soil conditioning is a key factor in increasing tunnel face stability and extraction efficiency of excavated soil when excavating tunnels using an earth pressure balance (EPB) shield tunnel boring machine (TBM). Weathered granite soil, which is abundant in the Korean Peninsula (also in Japan, Hong Kong, and Singapore), has different characteristics than sand and clay; it also has particle-crushing characteristics. Conditioning agents were mixed with weathered granite soils of different individual particle-size gradations, and three characteristics (workability, permeability, and compressibility) were evaluated to find an optimal conditioning method. The lower and upper bounds of the water content that are needed for a well-functioning EPB shield TBM were also proposed. Through a trial-and-error experimental analysis, it was confirmed that soil conditioning using foam only was possible when the water content was controlled within the allowable range, that is, between the upper and lower bounds; when water content exceeded the upper bound, soil conditioning with solidification agents was needed along with foam. By taking advantage of the particle-crushing characteristics of the weathered granite soil, it was feasible to adopt the EPB shield TBM even when the soil was extremely coarse and cohesionless by conditioning with polymer slurries along with foam. Finally, the application ranges of EPB shield TBM in weathered granite soil were proposed; the newly proposed ranges are wider and expanded to coarser zones compared with those proposed so far.
Tae-Hwan Kim; In-Mo Lee; Hee-Young Chung; Jeong-Jun Park; Young-Moo Ryu. Application Ranges of EPB Shield TBM in Weathered Granite Soil: A Laboratory Scale Study. Applied Sciences 2021, 11, 2995 .
AMA StyleTae-Hwan Kim, In-Mo Lee, Hee-Young Chung, Jeong-Jun Park, Young-Moo Ryu. Application Ranges of EPB Shield TBM in Weathered Granite Soil: A Laboratory Scale Study. Applied Sciences. 2021; 11 (7):2995.
Chicago/Turabian StyleTae-Hwan Kim; In-Mo Lee; Hee-Young Chung; Jeong-Jun Park; Young-Moo Ryu. 2021. "Application Ranges of EPB Shield TBM in Weathered Granite Soil: A Laboratory Scale Study." Applied Sciences 11, no. 7: 2995.