预应力混凝土开口管桩的极限承载力分析

预应力混凝土开口管桩在沉桩过程中存在土塞作用,因此其受力机理比闭口管桩更加复杂。根据现行规范中的经验公式以及修正公式计算单桩极限承载力时,开口管桩的计算值常常低于或高于载荷试验的结果。根据西安一高层建筑预应力开口管桩的设计和桩基检测结果,对单桩极限承载力计算公式的取值进行分析,阐述了"土塞效应"对单桩竖向极限承载力的影响,对计算公式中的侧阻力及端阻力进行修正,所得到的承载力计算值与试桩结果较为吻合。通过研究,建立了基于土塞效应下根据土的物理指标与承载力参数计算管桩承载力的修正公式。

Analysis on ultimate bearing capacity of single pipe pile of open-end prestressed concrete pipe pile

Owing to the action of the soil plug in the process of driving pile,the open-end prestressed concrete pipe pile.When the ultimate bearing capacity of single pipe is calculated according to the empirical formula and modified formula in present code,the calculated value of open-end pipe pile is always more or less than the result of static loading test.Based on the design of an open-end prestressed concrete pipe pile of a high-rise building in xi’an and pipe pile test,analysised for the formula for calculating the values of the single pile ultimate bearing capacity.Described "Soil Plug effect" affecting the vertical ultimate bearing capacity of single pile.Corrected the formula of side resistance and tip resistance,the resulting calculated capacity is more consistent with the results of the test pile.Through this study,established the correction parameter based on soil plug under the effect of the physical indicators and soil bearing capacity of the bearing capacity.