Railway rail supporting pad

An object of the invention is to provide a railway rail supporting pad that allows easy operations at a field site. In the invention, there is provided an outer bag made of a synthetic resin sheet housing a first inner bag and a second inner bag, the first inner bag containing a first reaction solution, the second inner bag containing a second reaction solution, the first and the second inner bags being configured to open at least partly due to outer pressure, the outer bag being provided with a separable sub bag in a communicative manner, an inlet of the sub bag as a communication part between the outer bag and the sub bag being closed by an easily debondable sealed portion, an interior of the sub bag being formed with a plurality of partitioning spaces partitioned by another easily debondable sealed portion.