Experimental Study On The Load Transfer Mechanism Of Half-screw Pile

As a new variable cross-section pile, half-screw pile has many features includingreliable quality, high bearing capacity，stability，good environmental performance, fastconstruction rate and well adaptation to the soil. But so far the studies on the bearingcapacity and settlement of half-screw pile have been in the preliminary stage and theapplications of half-screw pile in the project have been in the trial stage.Based on previous studies, the vertical bearing capacity of single pile and settlementtheory are analyzed mainly through static load test, shear displacement method, normativemethod of the experience formula, etc. On the framework of the theory and experiment datastatistics, the load transfer mechanism of half-screw pile is given a deep analysis. The mainresearches are made as follows:First, half-screw pile’ characteristics, construction technology and its advantagescompared with conventional pile are analyzed.Second, the paper researches the features of the bearing capacity of single pile, theload transfer mechanism of half-screw pile as well as some factors influencing the sideresistance of the pile in thread section. Besides, the calculation method of vertical ultimatebearing capacity of half-screw pile is concluded.Through the static load test for half-screw pile, its compression settlement is measuredby the steel strain gauge pre-buried in different sections of the pile. Then the distributionfeatures of the pile’s axial force and side friction resistance are drawn. Compared withordinary screw pile, the half-screw pile’s bearing capacity is improved, which provides theevidences for the future optimal designs of half-screw pile.