Optimization of blasting construction and vibration control technology of multi arch tunnels without central partition walls

Abstract

The construction technology for multi arch tunnels without central partition walls is a new design method for multi arch tunnels. The construction technology of multi arch tunnels without central guide tunnels eliminates side and central guide tunnels, which not only accelerates construction progress but also ensures construction quality and safety. The excavation and support of the rear tunnel of a double-arch tunnel without a central partition are crucial to ensuring the overall stability of the tunnel structure. A combination of manual mechanical excavation and blasting excavation in some areas was used in the excavation and construction of the rear tunnel of the Chenjiachong Tunnel on the Chuyao Expressway in Yunnan in addition to damping materials and measures in the lining of the front tunnel, ensuring the safe excavation of the rear tunnel and the prevention of the lining of the front tunnel from cracking because of earthquakes, The on-site vibration monitoring results of the tunnel indicate that this technology has achieved good results. Overall, the optimized construction technology without a central partition greatly shortens the construction period and improves economic benefits. The construction method is simple and feasible and can be flexibly selected according to the surrounding rock conditions. This study can provide a reference for the construction of other highway tunnels in mountainous areas.