Excavation faces can sometimes be supported by chemical stabilisation, in which chemical solutions are injected under pressure to bind and harden the soil. The method works only in porous soils. It is listed as one of the other ground support options beside benching, battering, shoring and shields, and whether it suits depends on the soil being porous enough to take the injected solution.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.