摘要
构造了抗拔桩上限分析机构,对饱和黏土中闭口桩与开口管桩抗拔承载力进行了上限计算,通过与弹塑性有限元、下限法及API方法进行对比说明了其合理性,并与实测资料对比验证了此方法的可靠性。研究了长径比、桩壁粗糙程度、土体强度非均匀性和土塞高度对抗拔承载力的影响,拟合出了闭口桩的抗拔净承载力预测公式。主要结果表明:对于闭口桩,归一化的抗拔净承载系数和单桩长径比之间近似呈线性关系。对于开口管桩,开口管桩抗拔净承载力系数与闭口桩抗拔净承载力系数的比值随长径比的增大有增大的趋势;管桩抗拔净承载力系数随着土塞高度的增加而增加,土塞对管桩的抗拔承载力有不可忽略的影响。
A new mechanism is established and applied to the upper bound analysis of uplift piles in saturated clay.Upper bound solutions of uplift capacities of closed and open-ended piles are analyzed.The new mechanism is verified by comparing with elastoplastic finite-element,existing lower bound and API solutions.Its reliability is assessed through case studies including one centrifuge test and two field tests.The effects of the pile length-diameter ratio,pile surface roughness,non-uniformity of undrained soil strength and length of soil plug on the uplift bearing capacity are considered.A formulation predicting the net bearing capacity of closed-ended uplift piles in clay is proposed.The results show that an approximately linear relationship can be established between the normalized net bearing capacity coefficient and the pile length-diameter ratio for closed-ended piles.As for open-ended pipe piles,the ratio of the net bearing capacity coefficient of open-ended pipe piles to that of closed-end piles tends to increase with the increase of the pile length-diameter ratio.The increase in the length of soil plug leads to an increase in the net bearing capacity coefficient of open-ended pipe piles.Therefore,the effect of soil plug should not be ignored.
作者
朱克文
俞剑
黄茂松
ZHU Ke-wen;YU Jian;HUANG Mao-song(Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第7期1995-2004,2027,共11页
Rock and Soil Mechanics
基金
上海市科委自然科学基金项目(No.23ZR1468500)
国家自然科学基金项目(No.51579177)。
关键词
抗拔桩
极限分析法
非均质黏土
土塞
uplift pile
limit analysis method
nonhomogeneous clay
soil plug
