Construction Risk Analysis And Stratum Improvement For Underground Passage Tunneling In Muddy Stratum

Abstract:How to ensure safety of shallow tunneling construction in the muddy stratum is a key problem that should be settled in engineering circles. The construction technology subject for shallow tunneling method in the muddy stratum is described and investigated by adopting methods of theoretical analysis, numerical modeling and practical construction site etc., taking underground passage construction as examples in several urban areas. The optimized construction technology of improved and reinforced method is tested in construction site. The main content of the paper is shown as following:(1) Through document investigation, data collection etc. muddy stratum distribution of cites in our country is summarized. Engineering characteristics of muddy stratum in typical area, and difficulties of construction technology for shallow tunneling method in the muddy stratum are analyzed.(2) Using risk management means, risk assessment model for shallow tunneling construction in the muddy stratum is established to analyse corresponding risk to reveal source of risk. Then, then corresponding risk control measures is put forward.(3) Using finite element upper bound solution with application to stability analysis in geotechnical engineering in different parameters condition, effects of different reinforced circle range and reinforced parameters on stability for cross section of tunnel are studied. It’s obtained that stratum with unstable failure characteristics in shallow tunnel. Through summary of stability of shallow tunneling method in the muddy stratum, failure law and reinforced mechanism, grouting reinforced suggestion for construction cite reference is presented.(4) On the basis of engineering features of muddy stratum and unstable failure characteristics, the current specific features of improved reinforced methods for of stratum is analyzed. The suitable condition for improved reinforced methods of different stratum is clarified.(5) Relying on underground passage with feature of typical muddy stratum construction examples, strata stability, structure deformation, and security of shallow tunnel are investigated by adapting upper bound finite element method and finite difference method numerical methods. Then construction external environmental condition, specific features of muddy stratum, and difficulties of shallow tunneling method is clarified. It’s mainly used WSS grouting method with TSS grouting method and arch pipe shed method as subsidiary and pre-reinforcement stratum method, and its application in construction site was verified.