Experimental Study Of Single Pile Bearing Of Expansive Soil Areas

The test study of the bored pile bearing capacity in the expansive soil foundation is a very significant issue. In this paper, using five pressure of bored to single pile compressive static load test. According to the test pile field trials, the expansion of the land base in the hole pile bearing properties and deformation mechanism. This paper tries to expansive soil single pile bearing characteristics theory applied to practice, to provide a theoretical basis for engineering design, especially pile foundation program selection, the determination of the single pile bearing capacity to provide new ideas and effective methods.1Under normal circumstances, the expansion of single pile in the land-based performance status of single pile carrying capacity traits and general clay clay consistent; expansion of land-based water, the presence of negative skin friction of the pile side single pile bearing capacity the status of single pile different traits whit general clay.2Expansion of land-based single pile Q～S curve showed a slow deformation under maximum load were not the true sense of the pile-soil destruction, and therefore in the expansion of land area to determine the ultimate bearing capacity of single pile, in addition to the Q-S curve and S～lgt curve combined with external, but also comprehensive settlement of the top of the pile, the expansion of the land area of the single pile bored pile load-settlement characteristics showing the typical end-bearing piles traits.3Load transfer behavior of the general expansion of the land area of single pile to play before the end of the resistance, as the side of the resistance that both asynchronous and rely mainly on the side of the resistance in the work load to play to provide the bearing capacity, high loads, not to wear through the weathered argillaceous sandstone bored pile tip piercing the destruction may occur.4Consistent with the trend of the load-settlement curve distribution of axial force and pile side friction distribution with the measured results calculated using the finite element method, while there is a gap. The finite element method to calculate load-settlement curve slope than the static load test large; calculated axial force transfer rate faster than the measured; calculated pile friction than the measured value.