Research On Mounted Lining Structure Of Mountain Highway Tunnel By Drilling And Blasting Method

The construction of mountain highway tunnels usually needs to deal with various complex geological conditions.Drilling and blasting construction has become the most commonly used construction method in tunnel construction in China due to its strong adaptability and simple and flexible advantages.It will be difficult for other constructions in the future for a long time.The method is completely replaced.The lining and components of mountain road tunnels are mostly made by traditional cast-in-place methods.The labor-intensive production mode is adopted.The working conditions in the tunnel are poor.The on-site procedures are numerous and interfere with each other.The construction quality and worker safety are difficult to be guaranteed.Quality problems such as cracking of the lining,deterioration of the structure,and water leakage have occurred.Cast-in-place construction is difficult to meet the requirements of modern tunnel construction for mechanization,efficiency,and environmental protection.The contradiction between rough cast-in-place construction and the increasingly stringent domestic construction requirements is becoming increasingly acute,and urgently needs to be resolved technically.The development of prefabricated lining structure of mountain road tunnels can improve the mechanization and assembly level of mountain road tunnel construction,effectively improve and solve the above engineering problems,and have important social and economic benefits.The thesis adopts literature research,data statistics,simulation analysis and other methods to carry out research on the assembly lining structure of the drilling and blasting mountain highway tunnel.The main results are as follows:(1)Investigate the application status of underground prefabricated assembly structures at home and abroad,and organize assembly linings in various countries The design theory and calculation model determine the calculation method suitable for the analysis of the stress of the assembled lining of the mountain highway tunnel.(2)According to the structural design and research results of open-cut tunnels,underground tunnels and shield tunnels at home and abroad,combined with the drilling and blasting construction characteristics,a set of lining structure system suitable for drilling and blasting mountain highway tunnels is proposed,including Tunnel building boundary and inner contour,lining structure form,lining type,joint structure,lining waterproof,component design,assembly method,structural block,etc.(3)Considering the high efficiency and engineering adaptability of the assembled lining transportation assembly,a new type of inverted arch segmentation scheme is proposed in the detailed structural design,which greatly reduces the single block thickness of the prefabricated inverted arch block,and better guarantees the structural reliability.At the same time,a new prefabricated prefabricated unfilled invert arch structure for mountain highway tunnel is proposed.(4)Considering the construction convenience of assembled lining,a new type of lap joints with simple operation and easy construction is proposed.The lap joints and common tenon joints are simulated carefully,the mechanical behavior characteristics of the joints are studied,and the joint structure is revealed.The evolution law of stress and strain has mastered the main factors affecting the joint stress,and optimized the joint design for the assembled lining.(5)Research on the design parameters of assembled lining from various aspects such as safety reliability and construction adaptability.The beam-spring model is used for numerical calculation.From the aspects of structural division,structural thickness and bending stiffness,the stress characteristics and deformation evolution law of the fabricated lining structure are analyzed,and optimized design parameters are proposed.