Reliability Estimation of Flow Characteristics Obtained in Laboratory Tests

Embankment dams, particularly tailings dams, are nowadays usually placed in swampy areas often dominated by organic soils, such as peats. Structures construction on soft organic soils makes it necessary to calculate subsoil deformations with a special consideration of the water flow. The test results show that the relationship between flow velocity and hydraulic gradient is always nonlinear. The specific behavior of soft subsoil demands determination of the test results reliability. Therefore in the statistical analysis of the test results suitable statistical methods and proper measures in laboratory tests should be used. Several statistical models have been applied to analyse the flow pump test data in order to provide a correct description of water flow velocity in soft subsoil. For practical purposes the simplification of the multiple regression function of many variables, eg.: strain = f (consolidation stress, deviatory stress, mean stress, void ratio, time etc.), has been provided for engineer tasks. The permeability characteristics were determined using statistic and the regression functions.