Obstacles of triangular shape are a good approximation to submerged barriers used to control the sediment depositing in reservoirs. The interaction between a Boussinesq constant-flux compositional gravity current and a submerged barrier of triangular shape is studied numerically based on results of 3-D Large Eddy Simulations (LES). The paper discusses the structure of the two-layer flow during the quasi-steady regime observed starting some time after the current passed the obstacle and ending some time after the reflected bore at the obstacle reached the submerged part of the rear end wall upstream of the obstacle. The paper analyzes the changes in the temporal variation of the flux of heavier fluid advected over the bottom barrier, the speed of the reflected hydraulic jump and its characteristics, the depth of the reflected flow and that of the current downstream of the obstacle. The mean flow, turbulence structure and the potential of the current to induce scour over the barrier and downstream of it during the quasi-steady regime are investigated.