TRIAXIAL TEST RESULTS FOR NONLINEAR STRESS-STRAIN RELATIONSHIP OF COMPACTED SILT

Based on the CU triaxial tests on compacted silt from the Beijing to Kowloon railway subgrade,the stress-strain relationship analysis is made on the silt under different cell pressures,water contents and degrees of compaction.It is found that the compacted silt exhibits a work hardening character under high cell pressure,exhibits a work softening character under low cell pressure,and exists a yield stress.The effects of water content and compaction on soil strength and stress-strain curves are distinct.The common softening formulation of soils is adopted to describe the softening curves under low cell pressure which is less than the yield stress.For the hardening curves,the Duncan-Chang model is used.Combining the stimulation methods mentioned above,the stress-strain relationship of the compacted silt is depicted well.