Nghiên cứu ảnh hưởng của một số loại phụ gia đến cường độ kháng nén một trục đất bồi lắng lòng hồ chứa ở Hà Tĩnh

Abstract

Deposited sediment in resevoir has a common feature, i.e. frequently located in water under normal condition. Its composition and structure are due to the surface erosion of the catchment or the erosion along the resevoirs. The dredging of sediment deposition in reservoirs, that are heavily deposited as well as the ones had been operated for many years, is necessary to increase their capacity and operating time. However, this kind of sediment deposition has a high content of water hydration, mud and soft soil, thus the problem of transportation, disposal, environmental assurance and economy will face many difficulties.

The survey results at 13 typical small and medium reservoirs in Ha Tinh province show that the sediment deposition in these reservoir belongs to heavy dust mixed with sand and gravel, and flexible. Once combining with additives, it is appropriate to create new materials with mechanical properties to ensure safety of permeability and stability for the application of construction, repair, and upgrading to ensure the safety of the dam according to TCVN 2816: 2018. The paper presents the results of research on the effects of three popular additives, i.e. fly ash, puzzolan and cement, with different concentrations on unconfined compressive strength of the deposited sediment in reservoir. Based on these results, the analysis and selection of the appropriate additive and additive content will be made.