Study On The Stress Adjustment Of Earth-rock Fill Dam In Consolidation

The earth-rock fill dam was widely used across the world since its low costs.The earth was consisted from three phase of materials, the soil grain, the gas and water. With the gravity, the gas and water would be drained out from the earth and lead to the dam’s consolidation. The consolidation of the dams was the reflection of the changing stress and strain. In a dam’s life period, there was four main stages, construction stage, storage stage, water lowing stage. In the different time stages, the strain and stress of the dam changed.Based on analysis of the LangMao Mountain earth-rock fill dam, with the method of finite element method, in order to find the weakness of the dam, the change of strain and stress of the earth-rock fill dam was studied, especially on different working stagesDuring the construction stage, the stress adverse parts was located in the the dam right and left side where the constrains were settled. With the increasing water pressure, the earth density below the saturation line turn from the bulk density into the flotation density. Under the effect of the gravity and the water pressure, the stress level of the storage stage was lower than the construction stage, which indicate the changing density was the dominate role on the stress level.During the water lowing stage, the stress level was calculated on the two working conditions, lowing water s level to half of the storage water level and to zero. From the stress contour of the MISESn principle stress、middle principle stress and the minor principle stress, the stress level of the zero water level was 10% higher than the half of the storage water level which indicate the lowing water level should be done slowly in case of the landslides.During the rainfall stage, the earth above the saturation line was saturated, leading to the increasing density. Compared to the storage stage, the stress level was increased lightly. According to the investigation and the FEM calculation, the landslide of the Langmao Mountain dam was induced by the rainfall and the poor quality of the dam. The rainfall increased the fracture of the dam and the creep deformation of the earth finally lead to the landslide.