樁錨支護結構錨桿受力機理試驗研究
張蓓1, 2，黃雪峰1, 2，宋楠3，李旭東1, 2
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（1 后勤工程學院軍事土木工程系，重慶 401311； 2 后勤工程學院巖土力學與地質環(huán)境保護重慶市重點實驗室，重慶 401311；3 72681部隊營房科，青島 266000）［摘要］為分析基坑開挖過程中樁錨支護結構的錨桿受力機理，結合西寧火車站綜合改造工程的深基坑支護結構，對不同工況條件下錨桿的受力進行現場綜合動態(tài)試驗與監(jiān)測。結果表明：在未施加預應力階段，隨著基坑的開挖，錨桿的錨固作用逐漸發(fā)揮，錨桿軸力沿錨固長度呈現先增大后減小的變化趨勢，而摩阻力的分布則存在“中性點”；對錨桿進行單循環(huán)加載時，錨頭施加的荷載有所損失，錨桿軸力和摩阻力均沿錨固段長度逐漸減??；在施加預應力之后，錨桿軸力沿錨桿長度逐漸減小，隨開挖深度的增加而逐漸增大，摩阻力沿錨固長度逐漸減小。所得結論可進一步完善錨桿的受力理論，為基坑支護的優(yōu)化設計及施工提供參考性建議。［關鍵詞］樁錨; 支護結構; 錨桿; 內力; 預應力損失; 滑移面; 現場試驗中圖分類號：U455.7+1 文獻標識碼：A 文章編號：1002-848X(2014)22-0090-05Experimental research on stress mechanism of the anchor of pile-anchor supporting structureZhang Bei1, 2, Huang Xuefeng1, 2, Song Nan3, Li Xudong1, 2(1 Department of Military Civil Engineering, Logistical Engineering University, Chongqing 401311, China; 2 Chongqing Key Laboratory of Geomechanics & Geoenvironmental Protection, Logistical Engineering University, Chongqing 401311, China; 3 Barracks Department of PLA 72681, Qingdao 266000, China)Abstract: To study the stress mechanism of anchors of pile-anchor supporting structure in the process of foundation pit excavation, engineering example of supporting structure of deep foundation pit in Xining railway station renovation project was used. Integrated field experiment and monitoring on stress of anchors under different working conditions were carried out. The results show that anchoring effect of the anchor play the role gradually with the pit excavation at the stage with absence of pre-stress, and axial force of the anchor decreases after increase along anchoring length while the neutral point exists on the distribution of frictional resistance. At the stage of single cyclic loading, the applied loading in the anchor head lose, the anchor axial force and frictional resistance decrease along anchoring length. After application of pre-stress, axial force of the anchor gradually decreases along anchoring length and increases with the excavation depth. Frictional resistance decreases along anchoring length and the variation is obvious at the back of the anchoring length. The obtained conclusions can further improve stress theory of the anchor and provide reference for the optimization design and construction of foundation fit supporting.Keywords: piled anchor; supporting structure; anchor; internal force; pre-stress loss; slip surface; field experiment作者簡介：張蓓，博士研究生，Email:zhangbei_qd@163.com。參考文獻［1］中國土木工程學會土力學及巖土工程分會.深基坑支護技術指南［M］.北京:中國建筑工業(yè)出版社,2012.［2］程良奎.巖土錨固的現狀與發(fā)展［J］.土木工程學報，2001，34（3）：7-12.［3］武崇福,李長洪,畢鑫,等.深基坑預應力錨桿軸力分布研究［J］.建筑結構,2011,41(8):134-137.［4］王景春,徐日慶,侯衛(wèi)紅.深基坑支護中錨桿的預應力與摩阻力試驗［J］.江南大學學報:自然科學版,2007,6(5):588-592.［5］周德培,常春.軟巖高邊坡開挖過程中錨桿軸力分析［C］//中國巖石力學與工程學會第五次學術大會論文集.上海，1998.
