Blasting Vibration Control Of Subway Tunnels Under Brick-Concrete Structures

In recent years,many cities in China have continued to expand in size and population.In order to alleviate traffic pressure,many cities have vigorously developed subway construction.In some cases subject to terrain and geological conditions,the construction of urban subways requires the use of mining methods for construction.The subway is mainly built in densely populated areas,where the surface buildings are often dense and the surface environment is complex.When using the mining method for blasting construction,the surface buildings may be affected by the vibration effects generated by the blasting.This makes the difficulty of blasting construction greatly increased,and higher requirements are imposed on the vibration generated by blasting.Therefore,it is particularly necessary to study the blasting vibration effect of subway tunnels.How to control the impact of blasting vibration on the surface buildings and take effective measures to reduce earthquakes is an important issue in the construction of subways by the mining method.This article takes the subway project of Wuhan Metro Line 27 range from Zhifang Street Station to Metro Town Station as the background.It is subsurface tunnel that the metro section of Wuhan Subway Line 27 range from Zhifang Street Station to Metro Town Station,which is underneath a three-story brick-concrete structure building with a buried depth of 16?26 meters.In order to make the subway tunnel safely underground through the brick-concrete structure,optimize the blasting scheme by reducing the maximum single detonating charge,increasing the detonation sections,encrypting the peripheral holes.The monitoring points are arranged on the surface in the radial direction,and the vibration peak velocity and frequency of the surface particles after the optimization of the blasting scheme are compared with those of the blasting scheme.The results show that the blasting vibration velocity after optimization of the blasting scheme is significantly reduced,and the frequency is significantly increased,making the building more secure.After the blasting scheme is optimized,when the working surface is directly below the outer wall of the building,the blasting vibration velocity is the largest.From the back of the working face to the front of the working face,the blasting vibration velocity of the surface particles increase first and then decrease,and the hollow effect and the stress wave diffraction phenomenon are obvious.When constructing similar projects,the blasting vibration can be controlled from the aspects of the maximum single detonating charge,the number of the detonation sections and the number of peripheral holes,it is also important to monitor the external walls and similar parts,and fully consider the hollow effect and stress wave diffraction.Figure 54 table 11 reference 55...