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(廈門理工學(xué)院， 廈門 361024)

［摘要］提出在樁頂（坑底）位置處設(shè)置鋼筋計(jì)測(cè)試下部樁身抗拔承載力的鋼筋應(yīng)力測(cè)試法試樁，采用有限元軟件ABAQUS對(duì)4類試樁（常規(guī)試樁、鋼筋應(yīng)力測(cè)試法試樁、套管試樁及坑底試樁）開展數(shù)值分析，總結(jié)不同試樁下抗拔樁荷載傳遞規(guī)律及其工作機(jī)理。在此基礎(chǔ)上采用所提出的鋼筋應(yīng)力測(cè)試法試樁在不同有效樁長及開挖深度下進(jìn)行抗拔樁承載性能分析，結(jié)果表明：抗拔樁有效樁長越長，與坑底試樁抗拔樁極限承載力相比，基坑底面處鋼筋拉力的損失比例越?。浑S著開挖深度的加大，與開挖后抗拔樁承載力相比，測(cè)試得到的鋼筋拉力的損失比基本在10%～15%范圍變化。在實(shí)際工程應(yīng)用中，建議可按所提出的鋼筋應(yīng)力測(cè)試法測(cè)試抗拔樁下部樁身承載力，考慮開挖的影響，按10%～15%來折減抗拔樁的極限承載力。

［關(guān)鍵詞］抗拔樁； 超深開挖； 承載力損失比； 有限元法

中圖分類號(hào)：TU3755文獻(xiàn)標(biāo)識(shí)碼：A文章編號(hào)：1002-848X(2015)11-0081-06

Bearing behavior analysis and design method study on uplift pile under deep excavation condition

Wu Yibin

(Xiamen University of Technology, Xiamen 361024, China)

Abstract:A reinforcement stress test method in pile test was presented with reinforcement meter set at the top of the pile (bottom of foundation pit) to test the lower pile uplift bearing capacity. Using the finite element software ABAQUS, numerical analyses of 4 kinds of pile tests were carried out including conventional pile test,  reinforcement stress test method  in pile test, casing pipe pile test and pile test at the  bottom of foundation pit. The load transfer rule and working mechanism of uplift pipe in different pile tests were summarized. On this basis, the proposed reinforcement stress test method in pile test was used in  bearing performance analyses of uplift piles with different effective pile lengths and excavation depths. Results show that the longer is effective length of uplift pile, the smaller is reinforcement tension loss ratio of bottom pile compared with ultimate bearing capacity of uplift pile in pile test at bottom of foundation pit. With the increase of the excavation depth, compared with the  bearing capacity of uplift pile after excavation, obtained reinforcement tension loss ratio changes basically in scope of 10% to 15%. In the actual project application, suggestions were provided that bearing capacity of bottom uplift pile could be tested by the proposed reinforcement stress test method, and the ultimate bearing capacity of uplift pile should be reduced by10% to 15%.

Keywords:uplift pile; deep excavation; loss ratio of bearing capacity; FEM

*上海市青年科技“揚(yáng)帆計(jì)劃”科研課題項(xiàng)目（14YF1414800），上海市人才發(fā)展資金計(jì)劃資助項(xiàng)目（2014031），上海市科研計(jì)劃課題項(xiàng)目(1104H105000)。

作者簡介：吳毅彬，博士，Email: 53686090@qq.com。

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