Study on Optimization of Double Sidewall Heading Method and Deformation Control
Based on the background of an ultra-shallow buried expressway tunnel in soft soil under-crossing expressway project in Guangdong Province,in order to address the challenges of excessive tunnel and surface settlement,traffic control difficulty,and high construction and operation safety risk that associated with traditional double sidewall heading construction method,on the basis of which this study proposed an optimized construction method to improve the working procedure,shorten the step distance and strengthen the tunnel face. The optimized construction method is studied by means of numerical simulation,monitoring and measurement to control the deformation. The results show that,compared to the traditional construction method,the optimized method can reduce the amount of temporary support installation and demolition by nearly half,shorten the working time and reduce the cost. It can greatly shorten the step distance,accelerate the construction progress,and improve the safety of tunnel excavation,support operations,and surface traffic. The reinforcement of the tunnel face can significantly reduce the surface and tunnel settlement deformation and improve the stability of the tunnel face. The optimized construction method can control the surface settlement and deformation of surrounding rock and support,ensuring the safety of tunnel construction and the operation of the highway above.
under-crossing expresswaydouble sidewall heading methodoptimization on the construction methoddeformation controlsafe construction