LABORATORY CONSOLIDATION TEST（室内固结试验）.pdf

1 Civil Environmental Engineering Department LABORATORY CONSOLIDATION TEST Application Settlement problems are actually two problems in one. Both the magnitude of settlement and time rate at which this process occurs must be estimated on the basis of laboratory tests. This laboratory will focus on the time rate of settlement as it is often the most important aspect of the problem. This lab also focuses on the pressure-settlement relations. For instance, suppose it is proposed to build a highway embankment over soft soils. The embankment places a load on the soil and depending on the thickness of soft soil and size of the loaded area, the total magnitude of settlement computed may take many tens of years to occur. Thus the project must wait for the settlement to occur before construction of pavement sections can take place. There are technologies available that can speed up the rate of consolidation. These are discussed in courses on Ground Modification. Recall that a complete consolidation test involves loading a soil specimen in a series of increments. From these data, a void ratio (e) vs. log pressure curve is developed and estimates of the total magnitude of settlement are made using the parameters C , C and σ ’ . Estimates of the time rate of settlement are made using the c r p Coefficient of Consolidation, C , that is interpreted from plots of dial gage reading v (compression) vs.