Properties of Expansive Clay Soils. Report 2. A Numerical Procedure for Predicting Heave with Time,

摘要

A relatively economical and expedient numerical procedure and computer code based on the finite difference method were developed for predicting heave with time for heterogeneous expansive soils beneath structures idealized as two-dimensional. The computer code will also compute the potential heave assuming saturation of the foundation soils based on McDowell's swell data. The heave with time estimates should be useful for structures near which penetration of rainwater from the ground surface is permitted, provided that ponding of surface water and external water from leaking water and sewer lines does not occur. The potential heave should be useful if the foundation soils become saturated from excessive watering, poor surface drainage, and leaking water and sewer lines. The required input data include the structural load, specific gravity, liquid and plastic limits, initial dry density and water content, coefficient of vertical permeability, ratio of the horizontal to the vertical coefficient of permeability, and swell and suction relationships of the foundation soils.