Determination of load-bearing capacity of bored piles based on axial static compression test results in field conditions

Abstract

    Determining the load-bearing capacity of bored piles from axial static compression tests is a reliable method that allows testing of the calculated load-bearing capacity according to theory, thereby selecting the most accurate load-bearing capacity value for the pile. The principle of the experimental method is to load the pile in axial compression gradually, and measure the corresponding settlement of the pile until the ultimate load value of that load level is reached. This method is suitable for the practical working model of the pile and soil, thus providing highly reliable results in evaluating the load-bearing capacity of the pile. However, quantifying the displacement of the pile head corresponding to the ultimate load, which is only a convention; or the axial compression load, Pthu, is specified to be taken as two hundred percent of the design loadbearing capacity, Ptk, while this value depends on the theoretical calculation method of the pile load-bearing capacity, geotechnical conditions, and depth of the pile, resulting in different errors in the obtained results. This article is based on the results of axial static compression tests on bored piles at some construction sites in weak soil areas in Ho Chi Minh City, comparing and evaluating
them with load-bearing capacity values calculated from different theoretical methods in TCVN 10304: 2014