Thesis (M.Eng.) - Asian Institute of Technology, 1983

At hesis s ubmitted in partial f ulfillment ot the requirement for the degree of Master of Engineering.

This investion has critically reviewed the effective stress strength of partiaLly saturated soils bas ed on two existing theories, i.e. Bishop's (1995) and Fredlund's (1978). These two methods give identical results provided the c and {u00A2} ' value in each eguat1 o n is obtained tor tu~l y saturated soil sampl es. HoW'e ver, tne method of: t:estiny used i .n these two approaches are applicabl e only for tnose vttlues of degree o f saturation when a~r and water pores are continuous. Si.nee the met hod ot snear t esting ot partially saturated soils a.re complicated and t:i.1he consu'1ing, an indirect method to determine the effectiv·e str:ess strength J!arameters troru tJO t ests proposed by arsal (1979) has been investigated and checked tor its validi ty. By extension o f Marsals concept, the determina.tion ot effective s tress strength parameters .trom unconfinea compression t est s and s uction ~ asarements is proposed. On t~ e bas i s ot limited test data reported here, and t he analysis of available aata f or partially saturated s oils, the proposed procedure t o e valuat e ffective stress s tre ngth parameters i s shown to be a promising practical approach. In th1.s proced. u.r e. results fro111 UO t est:s under high contining pressure , unconfined compression tests a nd sucti on measurements are needed to estima t e values ot c {u00A2} and {u00A2} for partially saturated soils e ven tor low v·a.lues of i nitial degr ee or saturation.