The effect of soil mechanical parameter variations on seismic response of urban tunnels in semi-statically analysis



Underground structures, depending on their geometrical shape, depth of replacement and different geotechnical and seismic parameters, behave in different manners when earthquake occurs. The buried structures faced significant damages in recent large earthquakes. Buried tunnels with circular cross section, such as urban undergrounds are very popular in transportation engineering. Such these tunnels are usually constructed, using Tunnel Boring Machine (TBM). The seismic behavior of such buried structures during operation is of importance. When designing such structure under earthquake conditions, seismic parameters and physical and mechanical properties if soil play important role. The response of a lining of buried circular tunnel against the earthquake is a function of the compressibility and flexibility ratios of the structure, the in-situ overburden pressure and at-rest coefficient earth pressure, K0, of soil. The trust, bending moment and deformations can be calculated using closed form solution.