Stability analysis of two parallel closely spaced tunnels based on convergence-confinement principle

Shaofeng, L; Jincai, F; Pinghua, Z and Xiang, L (2018) Stability analysis of two parallel closely spaced tunnels based on convergence-confinement principle. Journal of Construction Engineering and Management, 144(6): 04018041, ISSN 0733-9364

Abstract

Stability analysis and risk assessment are key issues in the design and construction of tunnels; however, these assessments are often hard to conduct accurately because of the complexity of tunnel engineering. In order to improve tunnel construction technology, this paper uses the safety factor as the assessment index. A quantitative analysis method for tunnels is presented by using the convergence-confinement principle and the numerical simulation analysis method. To meet these objectives, based on the actual construction technology, the tunneling method is studied using a detailed numerical model to investigate the effects of different patterns for advancing the tunnel face. A new method for solving the safety factor of the support structure is proposed using a three-dimensional numerical model; the detailed solution process is illustrated through the case of Luoyixi tunnel. The results show that the safety factor of a lagging tunnel is significantly less than that of the leading tunnel, and that in order to ensure the stability of a lagging tunnel, reinforcement measures should be included during the construction process. Moreover, there is also a danger signal for leading tunnels: the direction of the butterfly-shaped wings in the plastic zone began to deflect to the vault at the start of lagging tunnel construction. In order to prevent the possibility of the roof falling, an advanced rockbolt should be applied in time. For designers and builders, the developed quantitative method in the form of safety factors can be used for a comprehensive evaluation of the support design and the rock state. For these reasons, this method is a convenient option for optimization analysis in construction technology.

Item Type: Article
Uncontrolled Keywords: construction technology; convergence-confinement principle; numerical simulation method; parallel tunnels; quantitative analysis method; safety factor
Index terms: roof, option, construction technology, reinforcement, risk assessment, design and construction, plastic, numerical model, designer, numerical simulation, tunnel construction, quantitative analysis, complexity, construction process, safety factor, quantitative method, face, stability, builder, tunnel
Subjects: materials science, practitioner, profession, digital engineering, data analysis and analytics, contractual arrangements, psychology, modelling and simulation, building materials, financial risk, structural engineering, design practice, civil engineering, infrastructure and transport systems, systems engineering, decision analysis, building construction
Topics: Digital Applications, Design Practice, Site Management, Organizational Design, Cost Management, Construction Materials, Engineering Principles, Research Practice, Roles and Professions, Risk Management, Procurement
Descriptive scope: 4 PCTA

N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here