Research on mechanical feasibility of 200-m ultra-high asphalt concrete core rockfill dams

With the rapid development of asphalt concrete core rockfill dams, the construction of 200 m ultra-high asphalt concrete core rockfill dams(UACCRDs) are inevitable in the future. However, there are neither experience for the construction of UACCRDs, nor corresponding design codes for reference. Based on the Rankine's earth pressure theory, the mechanical feasibility of UACCRDs is analyzed at different periods. The stress states of asphalt concrete core(ACC) are divided detailedly and the algorithm that calculates the stress level of ACC is improved via the passive earth pressure theory. The safety control standard of UACCRDs is determined. And the reasonable material parameters of ACC and transition material for the suitable construction of UACCRDs are back calculated. Besides, the engineering measures that improve the safety of ACC are given. The results show that it is feasible to build 200-m UACCRDs. However, the internal friction angle and cohesion of ACC, and the internal friction angle of transition material are necessarily controlled within the reasonable range: φa≥30.5°, Ca≥0.25 MPa andφt≤43.5°, with the growth gradient adjusted by 0.5%, 1.5% and -0.5%/(25 m). That is, the purpose that builds UACCRDs can be achieved by the engineering measures that increase the internal friction angle, cohesion of ACC and reduce the internal friction angle of transition material. The purpose of this paper is to provide a reference for the construction of 200 m UACCRDs. © 2019, Science Press. All right reserved.