Abstract:

Collapses, even water ingressions or mud inflows may occur to the softflow plastic ground, due to its extremely poor selfsupporting capability. Furthermore, there exist great difficulties in the consolidation of the softflow plastic ground. On basis of successful project cases, the author expounds the design and construction technology for urban Metro running tunnels in softflow plastic ground, including the comparison and selection of such assistant construction methods as grouting inside tunnel, installing advance invert in soft ground section, horizontal jet grouting consolidation and freezing consolidation. Moreover, the author studies on the principle, feasibility, consolidation scope and diffusion radius, pressure, quantity, mortar material and mixing ratio and effects of splitting grouting in softflow plastic silty clay. The paper can provide reference for similar projects in the future.