Uplift pressure in cracks during earthquakes
Several standard specifies that uplift pressures remain unchanged in joints and cracks during an earthquake. These uplift pressures are then equal to the initial pre-seismic values. However, CADAM3D allows the application of other modeling assumptions for sensitivity studies:
CADAM3D allows three options to consider the transient evolution of uplift pressure in joints and cracks during an earthquake (Figure 207): (a) no uplift pressure develops in a crack opened by seismic shaking (USBR 1987, CDSA 1997 for high seismicity region), (b) uplift pressure remains unchanged (USACE 1995, FERC 1991, CDSA 1997 for low seismicity region), (c) full hydrostatic pressure develops in the crack without consideration for the drainage system (ICOLD 1986).