Highway construction is commonly required in arid regions. soilsin these regions are generally unsaturated and are characterized byhighly negative pore-water pressures. an extension of saturated soil mechanics principles is required to fully understand their behavior and to perform the necessary analyses for engineering purposes. inrecent years there has been a rapid increase in understanding of the behavior of unsaturated soils. conventional equations for shear strength, volume change, and seepage have been extended to embrace unsaturated soils. presented in this paper is a summary of unsaturated soil principles and theories particularly relevant to highway designin arid regions. the application of these theories to highway engineering is outlined. in addition, several techniques commonly used tomeasure soil suction or negative pore-water pressure are discussed.the measurement of soil suction is central to applying unsaturated soil theories. this paper appeared in transportation research recordno. 1137, soil mechanics considerations in arid and semiarid areas.for covering abstract see irrd no 817740.
Abstract