Piping Check according to Chinese Standard
This verification can be used for both phreatic and confined water levels.
Verification is done using safety factor approach and follows formulas:
where: | SFp | - | Safety factor of stability of the soil against piping |
ld | - | Length of the waterproof curtain below the bottom of the pit | |
D1 | - | Depth between the bottom of foundation pit and phreatic water level or top surface of the confined water aquifer | |
γ´ | - | Unit weight of soil under the buoyant force | |
Δh | - | Difference of waterhead between the inside and outside of the foundation pit | |
γw | - | Unit weight of water |