One-dimensional flow of a gas-liquid system with an active gas phase in a channel with elastic walls is investigated. The structure problem is solved, i.e., a stationary solution of the equations of the joint motion of a bubbly liquid and a membrane has been found which connects two different equilibrium states and which contains a shock with an energy release in the front. Since in the obtained solution the pressure decreases in the channel ahead of the shock, it can be used in a qualitative description of a cavitation mechanism of low-velocity detonation in liquid explosive films on an elastic carrier.