تحليل لرزه اي تونلها و مقايسه با شرايط استاتيكي

Comparison between seismic and static analyses of tunnels

The use of underground structures such as tunnels for subways, highways, material storage, and sewage and water transport is increasing in developed countries. Analyzing of underground structures was static because of decreasing in inertial force for the reason of confining these underground structures with huge mass of surrounding ground. Nevertheless, some underground structures have experienced significant damage in recent earthquake, seismic design of underground structures became more important. Seismic design loads for underground structures are characterized in terms of the deformations and strains imposed on the structure by the surrounding ground. In this paper, effect of earthquake on tunnels and current state of seismic analysis for underground structures will be described briefly first, and then a comparison between seismic and static analyses will be made for a tunnel with specific structural and geotechnical parameters. These analyses show that dynamic forces are much more than static forces so that underground structures must be designed for dynamic forces.