关键词: 桩端压浆, 钻孔灌注桩, 砂层, 自平衡试验

Abstract: The pile tip grouting is a common method to improve the bearing capacity of bored piles. To study the application effect of pile tip grouting method for the bored pile in sand layers, the installation and test of the test pile were performed in a municipal bridge pile installation project. The pile tip grouting adopts the open grouting method, the maximum grouting pressure in the process of the grouting is 3 MPa, and the total grouting is 2.4 cubic meters. The static loading test of using the selfbalanced method was conducted before and after the trial pile tip grouting to measure the displacement under each load increment and the pile strain at different elevations in the test process. The pile side friction in different range of pile length and pile tip resistance were derived. The test results reveal that, the bearing capacity of the trial pile TP1 increases 31%, pile shaft bearing capacity increases 28%, pile tip bearing capacity increases 46%. The pile tip grouting method can effectively improve the bearing capacity and deformation capacity of bored piles.

Key words: ile Tip Grouting, Bored Piles, Sand Layer, Static Loading Test of Self-Balanced Method