SHAKING TABLE MODEL TESTS ON FAILURE OF TUNNEL PORTAL SECTION OF DIFFERENT INCLINATIONS UNDER STRONG EARTHQUAKE

摘要

Portal section of mountainous tunnel is one of the most easily damaged parts during strong earthquake.Failures of this part may block roads, which greatly influences the transportation of the local area after earthquake.Shaking table model tests on failure of tunnel portal section of different inclinations are carried out.A rigid testing box is adopted in the tests.A new similarity material with a main component of fly ash has been successfully made to simulate the surrounding highly jointed rock in a homogeneous, isotropic manner.Tests with a model scale of 1:50 are designed.Slope angles are set to 25°, 35° and 45° in order to study the mechanism of structure and slope failure under different slope inclinations.By the testing results, the rule of tunnel portal failure under the conditions is studied.The results can be references for other similar projects and for seismic damping measure design.