Study On Seismic Response Properties And Anti-seismic And Seismic-relieving Measures Of Curved Tunnel

The horizontal alignment of tunnel is generally designed as a straight line, but in recentyears, the curved tunnel is increasingly being adopted. Since seismic damages frequentlyoccur to tunnels, people began to pay high attention to seismic analysis. But at present, theseismic research of tunnel is based on the straight line tunnel mostly, and the seismic researchfor the curved tunnel which is being vulnerable to seismic damage is no more common.The paper started out the features and mechanism of seismic damage for general tunnels.Combined with the geometric properties of curved tunnel, explored the mechanism of seismicdamage of curved tunnel, and study the seismic response properties and anti-seismic andseismic-relieving measures of curved tunnel through numerical analysis method. Specificresearch and the results achieved are as follows:(1)To explore the seismic damage mechanism of curved tunnel, and that the seismicdisaster characteristics of the straight tunnel still apply to the curved tunnel. In addition,seismic disaster characteristics of curved tunnel are relative to the curve radius of curvedtunnel、the turning angle of curved tunnel and the curved portion of tunnel widening and otherfactors.(2)Through numerical simulation software to establish the3D numerical simulationmodel of curved tunnel, the study on seismic response properties of curved tunnel underfactors of the direction of seismic waves, curve radius, steering angle and rock classificationhave been proceed. And compared with the results of the straight line tunnel under the samecondition, derived the key locations of seismic analysis and the law of general seismicresponse of curved tunnel. Under the seismic action, the joint of the curved tunnel and straighttunnel appeared stress concentration obviously. Along the curved tunnel axis direction, eachsection’s displacement, stress and internal force response has a large change; it proved that the law of seismic response of curved tunnel is more complex than the law of seismic response ofstraight tunnel.(3)The question of the measures of the anti-seismic and seismic-relieving for generaltunnel whether or not apply to curved tunnel has been analyzed. The results show that themeasure on the reinforcement of the part of surrounding rock of curved tunnel will notachieve good damping effect, and through changing the lining concrete modulus of elasticityand increasing the lining thickness of curved tunnel properly can avail the anti-seismic andseismic-relieving of curved tunnel.