Geohazard Caused by Groundwater in Urban Underground Excavation

Figure 8

Change of pore pressure distribution at various depths and locations at different phases of launching of a shield in longitudinal direction. (a) Initial phase. (b) Main excavation. (c) Launching of the shield. Note: legend means points at various distance from the retaining wall and “-” in pore pressure distribution contour is positive pore pressure. “Pwater” means pore pressure.