Study On Measurement And Numerical Simulation Of The Influence Of Highly Sensitive Objects In The Area Affected By Blasting

Tunnel excavation is often faced when building roads in mountainous areas and hilly areas,and blasting excavation is a very common method in the process of rock mass tunnel excavation.Blasting produces a great impact in a moment,which can not only crack the rock,but also have a certain impact on the surrounding area,especially on the surface houses,pylons and other highly sensitive buildings.How to accurately calculate,evaluate and analyze the impact of blasting impact on highly sensitive surface structures is of great significance for engineering construction.Based on the technology project of Wenzhou--"Research on blasting control technology based on highly sensitive objects" and with the southern mountain tunnel as the engineering background,a technical study on the impact of tunnel blasting on highly sensitive objects on the surface was carried out in this paper.The main contents are as follows:(1)The dynamic response of tunnel blasting to buildings and pylons is simulated by finite element software.It is verified that the vibration velocity and displacement of the sensitive material depend on the strength of the sensitive structure and the vibration load transfer medium-surrounding rock,and pointed out that two factors should be considered comprehensively in blasting design to avoid the influence of resonance effect on surrounding buildings.(2)The accuracy of seismic wave attenuation in the southern mountain tunnel construction was verified by numerical simulation.On this basis,the influence of blasting vibration on highly sensitive surface structures is emphatically studied,and the relationship between the energy of seismic waves and the propagation rule of blast center distance,the surrounding rock conditions and the vertical vibration velocity peak of the corresponding surface node is obtained.(3)The distribution proportion of the peak vibration velocity of the particle in three directions(radial: tangential: vertical)was studied in the same blasting process through the analysis of a large number of monitoring data.It is found that the key to ensure the safety of highly sensitive materials is to determine and control the vertical peak vibration velocity of particles.(4)Numerical simulation is used to study the vibration response of house pylons and pylons to ground buildings and pylons due to blasting safety allowable distance with buried depth of tunnels,blasting different joint inclinations and multi-explosive points.The allowable distance of blasting safety and the most dangerous joint inclination Angle were obtained from the simulation results.