由O-cell试桩结果确定整桩的性能  

Determination of pile behaviors based on O-cell test results of piles

作　　者：郑英杰[1] 张克绪[1] 张尔其[1] 朱占元[1] 

机构地区：[1]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090

出　　处：《岩土工程学报》2008年第9期1416-1422,共7页Chinese Journal of Geotechnical Engineering

摘　　要：提出了一个根据O-cell试桩结果确定整桩性能的途径,包括基本方法、步骤及必须的资料。以某公路大桥的O-cell试桩为例,采用本文所提出的途径确定出了桩阻力参数、相应整桩的荷载沉降曲线及极限承载力。验证了桩侧阻力与接触面两侧切向位移差之间关系可以用双曲线表示。将按本文提出的方法和现有其他四种方法确定的整桩荷载沉降曲线做了比较,并对各种确定整桩荷载沉降曲线方法的可靠性和适用性做了评价。此外,将按本文给出的整桩荷载沉降曲线和按流行公式确定的整桩极限承载力做了比较,指出了流行公式低估了整桩极限承载力,并对流行公式提出了一个修改建议。强调了,只有按某种有根据的方法确定出完整的整桩荷载沉降曲线,才能由O-cell试桩结果可靠地确定出整桩的极限承载力。An approach to determine the pile behaviors was proposed based on the O-cell test results of piles, including the fundamental method, steps and necessary data. For example, the resistance parameters of piles, the load-settlement curves and the ultimate bearing capacity of piles of a highway bridge were determined by use of the proposed approach. It was validated that the relationship between the side resistance of piles and the difference of tangential displacement between two sides of the pile-soil interface could be expressed by hyperbola. The obtained load-settlement curves were compared with those obtained from other four methods, and the reliability and suitability of these methods to determine load-settlement curves of pile based on the O-cell test results were assessed. In addition, the ultimate bearing capacity obtained from the load-settlement curves was compared with that obtained from the popular formulas, and it was pointed out that the ultimate bearing capacity of piles was underestimated by the popular formulas, and a proposal to modify the popular formulas was presented. It was emphasized that the bearing capacity of piles could be determined reliably based on the O-cell test results of piles only when the perfect load-settlement curves of pile was determined appropriately by reasonable methods.

关 键 词：O-cell试桩法 数值模拟分析 桩阻力 荷载沉降曲线 极限荷载 

分 类 号：TU473.1[建筑科学—结构工程]