Mechanical deformation characteristics of rockfill and dam body zoning of high concrete face gravel dam

With the height breakthrough of the high concrete face gravel dam, the stress difference between the high stress zone inside the dam body and the low stress zone on the dam slope and top increases. The mechanical properties of gravel and block stone under different stress conditions are quite different, which directly affects the partition and deformation safety of dam body. The triaxial mechanical tests are carried out to study the influences of stress conditions on the mechanical and deformation characteristics of gravel and block materials. On this basis, according to the stress distribution characteristics of the dam body, the zoning criteria for high concrete face gravel dams are studied. The results show that the modulus coefficient of block is greater than that of gravel under low confining pressure. With the increase of the confining pressure to a certain extent, the modulus coefficient of block materials decreases greatly, while that of gravel materials is larger. In order to take advantage of the mechanical properties of the two materials and strengthen the deformation control of the dam body, the zoning criteria and the optimization adjustment method based on the stress distribution characteristics of the dam body are proposed. The high-and low-stress areas of the dam are filled with gravel and block stone, respectively. Finally, a type of partition type of the dam body with block stone and half-clad gravel stone is recommended, which improves the comprehensive safety of the high concrete face gravel dam.