COMPARISON BETWEEN UNCONSOLIDATED UNDRAINED SIMPLE AND DIRECT SHEAR TESTS ON COMPACTED SOIL

The purpose of this investigation is to ascertain the proper strength parameter(UU) of compacted soil of Wushan high embankment and is to calculate the stability of the compacted soil reasonably.Some findings in simple and direct shear tests are analyzed to summarize the drawbacks and strongpoints of the simple and direct shear devices.By utilization of a simple equipment like NGI simple shear device,unconsolidated undrained simple and direct shear tests are conducted to determine and compare the strength properties of the compacted soil of Wushan high embankment.The shear test samples are made to simulate the real compacted soil of embankment.The optimum water content is 12% and the coefficient of compaction is not less than 0.95.The results of the simple and direct shear are compared.The results show that the cohesion of the simple shear test is lower than that of the direct test by up to 20.3%;and the internal friction angel of the simple shear is 5 ° lower than that of the direct shear.Based on the predecessors′ achievementst,he differences of the results obtained are analyzed in detail.