Described in the paper are the development and application of a simple approach for estimating the response of a swelling soil profile to the percolation of surface water. the approach is made up of two parts: (a) a model for the flow regime, to predict the development of the wetted zone with time--it is used to predict the lateral extent and the vertical penetration of the wetting front for a surfacewetting source of fine extent; and (b) a model for the swelling process under constrained conditions--it is used to predict the surfaceheave of a swelling clay profile as a function of the extent of thewetted zone, and induced lateral and vertical constraints. the approach is illustrated by reference to the prediction of the development of heave with time in a swelling marl profile. the swelling parameters of the marl were obtained from laboratory tests in which radialas well as vertical stresses were measured. it is shown that the effect of confinement and limited extent of surface wetting source, often neglected in standard one-dimensional analysis, may be of major significance in limiting the heave that will develop in the field. this paper appeared in transportation research record no. 1137, soil mechanics considerations in arid and semiarid areas. for covering abstract see irrd no 817740.
Abstract