Experimental study on the settlement behavior of soil–rock mixtures under reservoir water level rise and fall

The terrain and landforms in the reservoir area of Baihetan Hydropower Station are complex, with many high mountains and hills. There are many resettlement sites with large scales, and a large amount of soil–rock mixtures are used. The newly filled soil is affected by the periodic rise and fall of the reservoir water level. Therefore, it is of great significance to study the settlement and deformation of high-fill soil–rock mixtures under the action of water level rise and fall. To this end, a device was developed to simulate the settlement of soil–rock mixtures under the action of water level rise and fall in the reservoir area. Large scale physical model experiments were conducted, with model dimensions of 2.8 m × 2.0 m × 2.7 m in length, width, and height. Pore water pressure, soil pressure, and settlement deformation sensors were buried at five different depths of the soil–rock mixtures, and observation windows were set up. The influence of water level rise and fall on the settlement and deformation law of soil and rock filling bodies was studied, and the settlement mechanism was preliminarily revealed (Large pores are filled and compressed due to permeability, while small pores are reduced due to wet dry cycles.).