Numerical Simulation Of Earthquake Resistance Of Anchors In Rock Tunnel

With the national economic development and the planning and construction of traffic projects,the number of underground buildings,such as tunnels,is increasing.It will suffer a certain degree of damage when the tunnel is hit by an earthquake.Therefore,it is necessary to adopt economic and reasonable earthquake protection measures.As an economically active reinforcement method,anchor bolts are widely used in the design and construction of underground engineering.It is necessary to study the way of anchor bolts and its effect on tunnels and linings.In this paper,Hanjiashan Tunnel in Taifeng Highway as engineering background,the dynamic response characteristics of lining supporting tunnel and bolt supporting tunnel under earthquake are compared and studied by using 3D simulation software ABAQUS.Conclusions are as follows:(1)When tunnel and lining without anchor bolt support,its dynamic response shows:in the vertical direction under the earthquake with a peak acceleration of 0.15 g,the acceleration,velocity and displacement of the tunnel decrease with the decrease of the buried depth,and the maximum acceleration is 1.19m/s~2,the maximum displacement is 17mm at the inverted arch.the peak value of stress at right arch is 0.404Mpa.The maximum peak stress at right arch is 0.404MPa.(2)Three kinds of anchor bolt support methods are put forward on the premise of controlling the average length of anchor to 3.5 m:3.5m equal length anchor bolt support,combination of 2.5m and 4.5m anchor bolt support,combination of 2.5m,3m,3.5m,4m and4.5m anchor bolt support.Anchor bolt support has great influence on the acceleration of tunnel surrounding rock,and little effect on the displacement.Compared with the non-bolt support,the maximum reduction value of acceleration,stress and displacement are 14.68%,24.75%and 2.44%respectively.(3)The dynamic response of tunnel and lining under different anchor bolt support and non-bolt support are compared,it is considered that the combination of 2.5 m and 4.5 m anchor bolt support has better seismic effect.