Study of Tunnelling-Induced Response of Building Frame with Shake Table Test.

This paper intends to investigate the effect of tunnelling on the response of a framed building on different types of foundations with the help of shake table test. For the test, effect of utility tunnel on response of scaled prototype steel building has been determined with the help of accelerometer mounted at different floors. For experimental tests, three types of foundation (isolated foundation, mat foundation, and pile foundation) and two different heights of scaled prototype steel building frame have been considered. The analysis was performed in Heavy Structural Engineering Lab at N.I.T Patna, and soil has been excavated from the campus. To consider the ovalling effect of tunnel, shake table was vibrated perpendicular to the axis of tunnel by taking El Centro N-S as input motion. After the analysis it was found that ovalling effect of circular tunnel mostly affects the displacement of building when the tunnel was situated just below the centre axis of building. Same result was found for all types of foundation. Influence of ovalling effect of circular tunnel diminished as the distance between the building frame and tunnel increases. Response of building, constructed over isolated foundation was found to be the mostly effected as compared to the building constructed over other two types of foundation, while building constructed over pile foundation was the least affected. Shake table results show that high-rise prototype scaled steel building is much affected as compared to low-rise prototype scaled steel building frame. The results help in acknowledging the fact that foundation type should be considered for investigating the effect of tunnels during seismic excitation. [ABSTRACT FROM AUTHOR]