Assessment of karst and suffosion hazard for tunnel designing at the site of a new ring highway in Moscow

摘要

The construction of the fourth ring road of a total length of 75 km was approved by the Moscow Government. The arrangement of tunnels appears to be the most difficult part of work. Karst-suffosion hazard was assessed at the tunnel construction site under the Kolomenskoe museum reserve. Geomorphologically, the designed tunnel route will cross the fluviogalcial plain, the second river terrace, and the floodplain of the Moscow River. The surface of midCarboniferous limestone occurs at a depth of 40100 m. The subsurface tunnel is to be driven in weakly permeable mid- and upper Jurassic clay and in some places, in water-saturated sandy-clayey deposits of MesoCenozoic age. The zoning of the studied area according to karst-suffosion hazard was performed. The nonhazardous and potentially hazardous categories were distinguished along the route of projected tunnel and in the adjacent area. The potentially hazardous category covers about 8% of the total tunnel route.