【摘要】：在橋梁運(yùn)營(yíng)過程中,大量橋梁或多或少存在不同程度的的病害,對(duì)橋梁的安全性和耐久性產(chǎn)生嚴(yán)重的影響,需對(duì)其進(jìn)行加固改造。體外預(yù)應(yīng)力加固方法就是布置在被加固結(jié)構(gòu)體外的預(yù)應(yīng)力筋通過錨固系統(tǒng)和轉(zhuǎn)向系統(tǒng)與被加固結(jié)構(gòu)連接并把一定的預(yù)加力施加其上,抵消部分由外荷載產(chǎn)生的內(nèi)力,從而改善結(jié)構(gòu)的受力狀態(tài),提高結(jié)構(gòu)的承載力、抗裂性和減小變形的方法。本文主要進(jìn)行了以下工作:(1)從設(shè)計(jì)、施工和運(yùn)營(yíng)管理方面分析總結(jié)了在役橋梁產(chǎn)生病害的原因,對(duì)常用加固技術(shù)的優(yōu)勢(shì)及局限性進(jìn)行對(duì)比分析。(2)研究了體外預(yù)應(yīng)力加固的基本原理,結(jié)構(gòu)內(nèi)力和應(yīng)力增量的計(jì)算公式,并對(duì)其進(jìn)行比較。從截面平衡,整體協(xié)調(diào)變形出發(fā),推導(dǎo)了體外預(yù)應(yīng)力筋應(yīng)力增量的計(jì)算公式。(3)以體外預(yù)應(yīng)力簡(jiǎn)支箱梁為研究對(duì)象,利用軟件Midas FEA建立13個(gè)三維有限元模型,在建模時(shí)考慮材料非線性和開裂后加固的幾何非線性,利用施工階段真實(shí)模擬加固全過程進(jìn)行非線性分析。從承載力、撓度、應(yīng)力和裂縫擴(kuò)展情況入手研究分析了高跨比、轉(zhuǎn)向塊布置、綜合配筋率和張拉控制應(yīng)力對(duì)加固后橋梁受力性能的影響。(4)以一座四跨連續(xù)箱梁橋?yàn)楣こ瘫尘?進(jìn)行了體外預(yù)應(yīng)力加固箱梁的設(shè)計(jì)計(jì)算,從承載力、撓度和裂縫擴(kuò)展等多方面對(duì)比分析非線性條件下加固前后橋梁的工作狀態(tài),證明采用體外預(yù)應(yīng)力加固滿足設(shè)計(jì)荷載要求,并為以后同類工程設(shè)計(jì)施工提供一定的經(jīng)驗(yàn)和借鑒。
[Abstract]:In the process of bridge operation, a large number of bridges have more or less different degrees of disease, which has a serious impact on the safety and durability of the bridge, so it needs to be strengthened and reformed. The method of external prestressing reinforcement is that the prestressed tendons arranged outside the strengthened structure are connected to the strengthened structure through the anchor system and steering system and applied certain prestressing forces to counteract some internal forces generated by external loads. In order to improve the stress state of the structure, increase the bearing capacity of the structure, crack resistance and the method of reducing deformation. The main work of this paper is as follows: (1) from the aspects of design, construction and operation management, the causes of existing bridge diseases are analyzed and summarized. The advantages and limitations of common reinforcement techniques are compared and analyzed. (2) the basic principle of external prestressing reinforcement and the calculation formula of internal force and stress increment of structure are studied and compared. In this paper, the calculation formula of stress increment of external prestressed tendons is derived from section balance and overall coordinated deformation. (3) taking external prestressing simply supported box girder as research object, 13 3D finite element models are established by using software Midas FEA. Considering the material nonlinearity and the geometric nonlinearity of post-cracking reinforcement, the nonlinear analysis is carried out by using the real simulation of the whole process of reinforcement in the construction stage. Based on the analysis of bearing capacity, deflection, stress and crack propagation, the effects of high span ratio, steering block arrangement, comprehensive reinforcement ratio and tension control stress on the mechanical performance of strengthened bridge are analyzed. (4) A four-span continuous box girder bridge is used as the engineering background. The design and calculation of the box girder strengthened by external prestressing are carried out, and the working state of the bridge before and after strengthening under nonlinear conditions is compared and analyzed from the aspects of bearing capacity, deflection and crack expansion, and it is proved that the external prestressing reinforcement meets the design load requirements. And for the future similar engineering design and construction to provide certain experience and reference.
【學(xué)位授予單位】：河北工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U445.72

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本文編號(hào)：2187149