Direct Shear Interface Test for Shaft Capacity of Piles in Sand

Abstract For precise estimation of shaft capacity of a pile, it is essential to determine accurately the soil-pile interface friction angle (δ). The apparatus available to measure the value of δ, the miniature pile test apparatus and the soil-pile-slip test apparatus are only available for research purposes. This paper presents the details of an investigation carried out using the conventional direct shear test apparatus to measure the value of δ for soil-pile interface. The direct shear interface tests were conducted using four types of surfaces and two types of sands. The values of δ obtained from these tests are compared with the internal friction angle (φ) of the sand and with the results obtained from soil-pile-slip tests. The interface test results are also used to estimate the shaft capacity of a few model piles embedded in sand.