| In this paper,a total of 58 three-dimensional finite element models are established by using Midas GTS/NX software to study the influence law of the tunnel safety on the tunnel with different positions and different high span ratio elliptical karst caves under the blasting load,and the numerical model of the dynamic response of the surrounding rock under the blasting load of karst area is established.The calculation results of regression analysis combined with the field data of the karst tunnel blasting safety vibration velocity control standard.The main contents of this paper are as follows:1.The influence factors on the displacement field,velocity field and stress field of tunnel and cave surrounding rock are studied when the blasting load is loaded,and the changes of surrounding rock displacement,vibration velocity and maximum main tensile stress are compared in the presence of III and IV surrounding rock,and the ellipse under the action of blasting load is preliminarily obtained.The main factors that influence the safety of tunnel are the karst cave.2.The maximum velocity of rock mass and the maximum tensile stress change of the cave surrounding rock under the 0.1~3.0 of the tunnel side,below and above the tunnel side are studied respectively,and the influence degree of the tunnel on the safety of the tunnel under the different ratio of different height to span is obtained.3.The safety coefficient between caverns and tunnels under 30 operating conditions is calculated by using speed and tensile stress control standards.The maximum velocity and maximum tensile stress of tunnel excavation are studied under 1m,2m and 3m respectively.4.Through the interpretation of the previous geological prediction results and the blasting monitoring data of the karst area in the new Tung Tuling tunnel,the sardowski regression formula of the karst area of the new Tung Tuling tunnel is obtained,and the reliability of the numerical simulation is verified.The theoretical calculation and the regression analysis are made to put forward the blasting safety in the karst area of the new Tung Zhi ling tunnel control standard for full vibration speed. |
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