Highway tunnel performance during the 1999 Duzce earthquake

摘要

This paper describes the effects of the M_w 7.2 1999 Duzce earthquake on 18-m-diameter highway tunnels near Bolu, Turkey, which were under construction. It provides a first time-opportunity to evaluate the earthquake performance of tunnels in a variety of ground and support conditions in response to a near-source severe earthquake. Information about the tunneling conditions are summarized, including the geotechnical properties of the rock and soil units and general characteristics of the tunnel support system. The results of geotechnical instrumentation are presented to show that permanent increases in bending moment and compressive hoop stress, equivalent to about 17 percent of the overburden, were induced by ground shaking. Analyses were performed using measured strong ground motions for a damaged cross-section in fault gouge clay and the results are shown to agree favorably with observed performance.