The coefficient of consolidation is the parameter used to describe the rate at which saturated clay or other soil undergoes consolidation, or compaction, when subjected to an increase in pressure. It is measure in square centimetres per second or square inches per minute.
The coefficient of consolidation can be measured in a laboratory. The process involves measuring the change in height of a soil sample as it is loaded in increments. The coefficient of consolidation can be determined by plotting the change in height against the logarithm or square root of time.
The coefficient of consolidation measures one-dimensional consolidation, or consolidation that occurs when soil experiences no lateral strain. This is acceptable for most practical problems, where it is acceptable to assume that seepage and strain occur only in the vertical direction.
The typical value of the coefficient of consolidation for stiff clay is 0.002 in2/min. Fibrous peat soil, on the other hand, has a typical value of 0.1 in2/min.