COLANY computes the load-settlement response of a rigid raft supported by a layer of clay which has been stabilised with a large number of stone columns. The results of an analytic solution for the settlement, assuming no yield in the clay or column, is calculated. The program then computes the load-settlement response of the stabilised clay. These analyses were published by Balaam and Booker (1981,1985). Finally, the solution is computed for the settlement response of the stabilised clay when the column is fully plastic. These solutions enable the settlement to be predicted for all load levels.
In these analyses of the behaviour of a clay stabilised by a large number of stone columns a "unit cell" is considered. This "unit cell" consists of a stone column and the surrounding soil within the column's zone of influence. A number of plausible assumptions are then made. The validity of these assumptions have been checked by performing elasto-plastic finite element analyses and the agreement is very good. However, the computational effort required for the finite element analyses is many orders of magnitude greater than for this analysis.