發(fā)布時間：2018-02-13 01:42

  本文關(guān)鍵詞： 黏土層 預(yù)應(yīng)力錨桿(索) 剪應(yīng)力 試驗(yàn) 粘結(jié)強(qiáng)度　出處：《昆明理工大學(xué)》2013年碩士論文　論文類型：學(xué)位論文

【摘要】：預(yù)應(yīng)力錨桿(索)作為一種重要的巖土錨固技術(shù),在工程領(lǐng)域有著廣泛的應(yīng)用。目前在關(guān)于預(yù)應(yīng)力錨桿(索)的各種設(shè)計規(guī)范中,均按照平均粘結(jié)強(qiáng)度進(jìn)行錨桿長度的設(shè)計,其合理性和安全性值得商榷。探究預(yù)應(yīng)力錨桿(索)內(nèi)錨固段的荷載傳遞性狀以及錨桿在服役階段的工作性能等,具有重要的工程應(yīng)用價值和較高的學(xué)術(shù)價值。 本文考慮土層預(yù)應(yīng)力錨桿(索)在受荷過程中,土體和固結(jié)體界面的部分脫粘滑移特性,將錨桿錨固段分為滑移段和彈性段�；贫渭魬�(yīng)力以滑動摩擦力的形式體現(xiàn),呈線性分布。對彈性段的分析,結(jié)合彈性半無限空間內(nèi)一點(diǎn)受集中力的Mindlin位移解,獲得了彈性段剪應(yīng)力分布的微分方程,剪應(yīng)力表現(xiàn)為單峰曲線形式。 通過室內(nèi)試驗(yàn),對多束鋼絞線整體受荷時的工程等效彈性模量進(jìn)行測試分析,為工程錨索的張拉計算提供了真實(shí)可靠的依據(jù)。并對電阻應(yīng)變片偏軸測量鋼絞線應(yīng)變時的修正系數(shù)進(jìn)行測試,為預(yù)應(yīng)力錨索現(xiàn)場試驗(yàn)提供可靠參數(shù)。 依托在施樁錨結(jié)構(gòu)基坑工程,針對特定黏土層中預(yù)應(yīng)力錨桿(索),在張拉受荷過程中,錨固段桿體(鋼絞線)沿錨固段的軸向應(yīng)變進(jìn)行測試,經(jīng)轉(zhuǎn)換得到錨桿錨固段剪應(yīng)力沿桿長的分布變化規(guī)律,實(shí)測數(shù)據(jù)和理論分析具有較好的吻合性,驗(yàn)證了理論分析的合理性。 結(jié)合理論分析和試驗(yàn)結(jié)果,從實(shí)測數(shù)據(jù)出發(fā),對現(xiàn)行規(guī)范中關(guān)于預(yù)應(yīng)力錨桿(索)的設(shè)計取值進(jìn)行一定的系數(shù)修正,使之更真實(shí)的反映土層錨桿的受荷工作狀態(tài)。提出錨固段發(fā)揮系數(shù)ε的概念,找尋不同錨桿在不同工作狀態(tài)下,錨固段發(fā)揮系數(shù)的規(guī)律和取值。同時結(jié)合相關(guān)規(guī)范,對錨桿在驗(yàn)收試驗(yàn)中的驗(yàn)收荷載,驗(yàn)收合格標(biāo)準(zhǔn)和驗(yàn)收荷載下的實(shí)際抗拔安全系數(shù),提出了新的思考。 預(yù)應(yīng)力錨桿(索)在巖土錨固中有著舉足輕重的作用,本文所獲得的研究成果對錨桿的設(shè)計理論和施工、試驗(yàn)提供了一定的參考。
[Abstract]:As an important rock and soil anchoring technology, prestressed anchor rod (cable) is widely used in engineering field. At present, the length of anchor rod is designed according to the average bond strength in various design specifications of prestressed anchor rod (cable). It is worth discussing its rationality and safety. It has important engineering application value and high academic value to explore the load transfer behavior of anchoring section in prestressed anchor rod (cable) and the working performance of anchor rod in service stage. In this paper, the partial debonding and slip characteristics of the interface between soil mass and consolidation body are considered during the loading process of the prestressed anchor (cable) in soil layer. The anchoring section of the anchor is divided into sliding section and elastic section. The shear stress of the slip section is reflected in the form of sliding friction force. The differential equation of shear stress distribution of elastic segment is obtained by combining the Mindlin displacement solution of a point in elastic semi-infinite space with a concentrated force. The shear stress is expressed as a single-peak curve form. Through laboratory tests, the equivalent elastic modulus of multi-beam steel strands subjected to integral loading is measured and analyzed. It provides a real and reliable basis for the calculation of the tension of the engineering anchor cable, and tests the correction coefficient of the deflection axis of the resistance strain gauge for measuring the strain of the steel strand, which provides reliable parameters for the field test of the prestressed anchor cable. Based on the foundation pit engineering of pile and anchor structure, the axial strain of anchor bar (steel strand) along the anchoring section is measured in the course of tension and loading of prestressed anchor rod (cable) in a specific clay layer. The distribution of shear stress along the length of bolt is obtained by conversion. The measured data are in good agreement with the theoretical analysis, which verifies the rationality of the theoretical analysis. Based on the theoretical analysis and test results, the design value of prestressed anchor rod (cable) in the current code is modified from the measured data. The concept of play coefficient 蔚 of anchoring section is put forward to find out the law and value of the performance coefficient of anchor section under different working conditions. A new consideration is put forward on the acceptance load of anchor rod in the acceptance test, the acceptance standard and the actual uplift safety factor under the acceptance load. The prestressed anchor rod (cable) plays an important role in the rock and soil anchoring. The research results obtained in this paper provide a certain reference for the design theory and construction of the anchor rod.
【學(xué)位授予單位】：昆明理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2013
【分類號】：TU476

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