Numerical analysis the calcium leaching effect in concrete and concrete-rock interface on concrete gravity dam anti-sliding stability

Decomposition of concrete calcium compounds in the leaching process constantly changed the concrete gravity dam's sliding and resisting forces, which endangered project safety. Nonetheless, the calcium leaching effect on dam sliding stability has not been studied previously, and the dam factor of safety(FOS) evolution remained unknown. This research numerically investigated the impact of calcium leaching on concrete gravity dam stability. A relation between bonded cohesion of concrete-rock interface and CaO/SiO2 ratio of CSH is presented to investigate the shear strength deterioration in the leaching process. The evolution of dam FOS, sliding and resisting forces in a hundred years is obtained. The results showed that the calcium leaching reduced dam stability. Parameter sensitivity analysis showed that the grout curtain hydraulic conductivity and rock foundation type significantly affect the dam FOS. We can improve dam stability in the leaching process by reducing the initial hydraulic conductivity of the grout curtain.

Automated summary

This study numerically investigates the impact of calcium leaching on the stability of concrete gravity dams and presents a relationship between the bonded cohesion of the concrete-rock interface and the CaO/SiO2 ratio of CSH. The results show that calcium leaching reduces dam stability, and the hydraulic conductivity of the grout curtain and the rock foundation type significantly affect the dam factor of safety. Improving dam stability in the leaching process can be achieved by reducing the initial hydraulic conductivity of the grout curtain.