Functional zoning optimization design of cemented sand and gravel dam based on modified Duncan-Chang nonlinear elastic model

Abstract

Cemented sand and gravel is widely used in water conservancy project construction due to its advantages of low material consumption, strong adaptability and environmental protection. Due to the single design of the dam section, its application scope is limited. Aiming at the design problem of the cemented sand gravel dam section, In this paper, the modified Duncan-Chang nonlinear elastic model is used as the constitutive model of dam material, and the design concept of dam functional zoning is combined with the mechanical properties of Cemented sand and gravel dam material to propose the optimal design scheme of functional zoning in line with the CSG dam. The Tobetsu dam in Japan is used as a prototype for finite element optimization design analysis, and the analysis results are compared with the engineering data. The results show that: (1) The optimized scheme changes the upstream slope to 1:0.34 and the downstream slope to 1:0.77 under the condition of ensuring the safe operation of the dam, which reduces the amount of cementitious admixture per unit dam section by 34.2% and 23.6% respectively, significantly reducing the amount of cementitious materials used, in line with the concept of optimal design; (2) The vertical stress of the dam body is compressive stress during the completion period, but both during the operation period, the location of the dam heel appears; (3)The upstream side of the dam axis should have a large modulus of deformation during the operation period, and the modulus of deformation can be reduced from upstream to downstream in order to ensure that the dam deformation is coordinated after water storage.