DISCUSSION ON THE POTENTIAL CAUSE OF GROUND FRACTURES THAT APPEARED IN THE 2015 GORKHA EARTHQUAKE, NEPAL DIAGONALLY ACROSS ONE HIGHWAY SECTION CROSSING A SHALLOW VALLEY

Abstract

 The Mw7.8 Gorkha earthquake struck the central region of Nepal on April 25th, 2015 and caused a large number of slope failures, soil liquefactions, extensive damage to buildings and earthen structures etc. in mountains and urban areas. One section of the Araniko Highway that connects Kathmandu to China crosses a small valley at Kausaltar with an embankment. This section has sunken during the earthquake. To elucidate the cause of this ground deformation, shallow soil profiles are explored using the surface wave tomography, standard penetration tests, dynamic cone penetration tests and radiocarbon dating. The deduced soil profile suggests the presence of two weak soil layers that spread beneath the cap surface soil.