Application of New Steel Strip Material in Lining Structure Reinforcement for Highway Tunnel Engineering

Abstract

The traditional reinforcement method of highway tunnel lining crack is difficulft to constuct and brings about structure damage. The reinforcement method of new steel strip with carbon fiber and crack perfusion not only constructs simply, but also brings less destruction to the lining structure and has well value of practical application and application prospect. The new steel strip is new material of tunnel structure reinforcement and its main material is Q235A, elastic modulus 210GPa, Poisson's ratio 0.3, se vere 76.93N/m 3 . The main physical and mechanical parameters of new steel strip with width 220mm × 2.5mm thickness are as follows: the cross-sectional area is 564.4mm 2 ; yield load is 68.3KN; yield strength is 34317KN; breaking force is 246.7KN. The bending section modulus of new steel strip inc reases 37times comparing with flat steel strip; its stiffness is increased by 70 times; its tensile strength can be increased 12% ~15%. The new steel strip is better to deal with the less stable surrounding rock - support lining structure of tunnel and underground engineering. The new steel strip interacts with anchorage system for forming mesh stent and connects dispersed anchors together through new steel strip to forming a whole bearing structure, and then it increases overall bearing effect significantly. Combining with highway tunnel in Gansu province of China for lining concrete structural cracks, this article elaborats in detail the main performance and characteristics of new steel strip and carries on the finite element analysis to the crack section structure on the safety of tunnel lining thickness with ANSYS 11.0 commercial software. Th en paper has also been more effective comparative analysis of its secondary lining structure reinforcement measures and puts forward the technical measures for engineering of new steel strip structure reinforcement. This paper provides useful reference and examples for future similer engineering construction quality defects of highway tunnel structure reinforcement rectification work. The highway tunnel is a kind of underground engineering and has strong concealment, strong unpredictability, bad construction environment, the limitation of construction conditions, risk factors, more complex geology, timeliness and other characteristics. In the construction of highway tunnel, many non-human reason can cause secondary tunnel lining under thick, crack and other defects. If using rework measures, it may cause the demolition difficult, large disturbance to the surrounding rock structure system and the collapse accidents. In the case of less thick lining, not too serious in the lining cracking, basically meet the design requirements and the use of functional, if taking other remedial reinforcement method, it can save costs, shorten construction time remediation. Combining with highway tunnel in Gansu province of China, this article introduced ( new steel strip with carbon fiber and crack perfusion) reinforcing method of secondary lining tunnels in structural less thickness, cracks and other defects and can be reference to futrue similar projects in special rectification.