Estimation of engineering geology condition of Baoquan Upper Reservoir gulches

Different scales of gulches were found in Baoquan Upper Reservoir during the excavation. The coverages of the gulches are mainly debris soil of less compressibility, but deformation modulus is only about 0.001 compared to rocky foundation. The main issues of the gulch treatment considering the anti-seepage by using asphalt and concrete for of the upper reservoir bank and avoiding large heterogeneous settlement of the contact zone in soft and hard rock, are analyzed and estimated in detail.