Location Optimization Of Double Tunnel Based On Blasting Effect

In recent years,the national economy has entered a new period of rapid development.Our existing traffic system faces huge challenge and opportunities.Roads,railways and municipal tunnels have gained vigorous development and reduced the traffic pressure.Drilling and blasting method is widely used in highway tunnel construction.The effects of blasting seismic waves on the vibration of adjacent tunnels and ground buildings are gaining increasing attention.This paper is based on the multi-arch tunnel project of the western extension of Dalian Bin hai Road.3-D numerical model of the tunnel is established by using the LS-DYNA dynamic software.Combined with the field test data,the vibration response of adjacent tunnels and ground buildings under excavation blasting vibration is studied.In order to make the numerical simulation can truly reflect the actual situation,a more accurate method of explosion simulation is adopted in this paper.The equation of state is used to simulate the relationship between pressure and volume in the process of the explosion.In the meantime,the ALE algorithm is used to simulate the relationship between the structure of explosives and the blasting.In ALE algorithm,the explosives are defined into the fluid in order to avoid excessive distortion caused by explosion in the process of grid adversely affecting the result of the calculation.The main work includes several parts as follows:1.The influence of cutting vibration on the dynamic characteristics of adjacent tunnels and ground structures is numerically analyzed.The peak magnitude of the velocity of the adjacent side of the tunnel is several times to ten times that of the back-blowing side.The vibration law of the surrounding rock and the ground building nodes under different tunnel spacing is compared and analyzed,and the optimal spacing of the tunnel is 20 m..2.The variation law of blasting vibration intensity of adjacent tunnel surrounding rock and ground building structure under each excavation is numerically analyzed.The velocity law of each node X,Y and Z is studied.3.The HHT analysis of the blasting vibration signal of tunnel rock and ground building is carried out,and the frequency and frequency distribution of vibration in three directions of X,Y and Z are obtained.The field test is conducted during tunnel excavation.The velocity curve and vibration frequency of the measuring point are collected.The comparison between the field test results and the numerical simulation results shows that the numerical predictions are consistent withthe measured values to a certain extent,and the rationality and feasibility of the numerical model are verified.