有粘结强度桩复合地基中单桩与自由单桩受力性状对比分析

Comparison analysis on bearing behaviors of single pile in composite ground and free single pile

当有粘结强度桩复合地基施工完成后,需进行静载荷试验和低应变检测,以确定处理后的复合地基承载力是否满足设计要求和桩身的完整性。目前不少工程检测时,虽然复合地基载荷试验满足设计要求,但单桩承载力不满足设计要求(尤其是搅拌桩),地基处理因此被评为不合格。针对目前实际工程中存在的这个问题,笔者结合算例,分别对自由单桩和复合地基中单桩的受力性状进行对比分析,以期揭示自由单桩与复合地基中单桩的承载力和桩体强度之间的差异,为如何处理类似的工程问题和开展模拟桩在复合地基中的实际受力状态的研究以及进行单桩静载荷试验方法的研究提供理论依据。

Static loading test and low strain integrity testing must be performed after construction of friction pile formed composite ground in order to verify the ground bearing capacity and the pile shaft integrality. Although the static loading test of composite ground satisfies the requirement of design, the static loading test of singe piles can not satisfies the requirement （especially the soil-cement mixing pile）. Therefore, the ground treatment works is considered unqualified which occurs in many projects presently. As to the current practical problem, based on calculation, the bearing behaviors of single pile in composite ground and free single pile are compared to reveal the differences of bearing capacity and shaft strength of these two types of piles. The analysis results could be a theoretical reference for the similar engineering problems and simulation of the stress state of the piles in the composite ground.