本文選題：港珠澳大橋 + 混凝土結構��； 參考：《清華大學》2014年碩士論文

【摘要】：基于港珠澳大橋混凝土耐久性設計,本文開展了現(xiàn)場混凝土質量檢測研究,在此基礎上完成了港珠澳工程施工階段各個構件耐久性評估與再設計工作,為工程竣工驗收與服役期管理提供了數據支持。本文首先匯總分析了施工現(xiàn)場實驗室測得的抗壓強度和氯離子擴散系數,以及在預制沉管隧道現(xiàn)場實體構件上無損測得的表面透氣性系數、表面電阻率及保護層厚度。分析表明沉管抗壓強度和氯離子擴散系數均滿足控制規(guī)程的質量要求,保護層厚度合格率基本滿足預期。沉管表面透氣性系數普遍較低,尤其是56d齡期數據,表明預制節(jié)段現(xiàn)場混凝土結構致密。表面電阻率符合正態(tài)分布,并隨混凝土齡期增長呈現(xiàn)出穩(wěn)定的增大趨勢。透氣性和電阻率在數值上總體呈負相關,但不足以回歸出定量關系。在現(xiàn)場檢測數據的基礎上,本文對氯鹽侵入過程進行了施工階段的評估。研究回顧了基于氯鹽腐蝕的耐久性評估模型,總結分析了模型各個參數的統(tǒng)計特征,考慮了附加防腐蝕措施對模型的影響,在此基礎上采用Monte-Carlo方法計算結構各個構件的120年失效概率Pf及可靠指標β,提出了結構初步維護方案和不同工況下的工程建議。計算結果表明大氣區(qū)和水下區(qū)構件的可靠指標較高,可120年免維護;浪濺區(qū)構件需要120年耐久性維護預案;收費站暗橋和C匝道橋墩身內部、沉管隧道內部如有海水滲入時,按浪濺區(qū)工況計算所得120失效概率超過10%,在這些構件施工與構造中需要重點監(jiān)測內部海水滲漏過程,并建立相應的耐久性再評估與再設計流程;沉管隧道竣工后如有海水滲入,則需要啟動陰極保護措施,啟動時間可根據海水滲漏面積比例和預定維護水平計算得到。本文最后進行了耐久性再設計過程研究,并以竣工評估后的沉管隧道的耐久性預案研究、DB02收費站暗橋使用期中的維護方案研究為例展示了耐久性再設計方法。通過計算得出了在三個不同維護水平下,沉管陰極保護啟動周期與海水滲入面積比例的關系曲線。并在一組模擬實測暴露數據的基礎上,更新了收費站暗橋120年可靠指標及失效概率時變曲線,運用全壽命周期成本方法,確定了水平-2耐久性維護方案為最優(yōu)方案。
[Abstract]:Based on the concrete durability design of HongKong-Zhuhai-Macao Bridge, this paper carried out the field concrete quality testing research, and completed the durability evaluation and redesign of each component in the construction phase of HongKong-Zhuhai-Macao project. For the completion of the project acceptance and service period management to provide data support. In this paper, the compressive strength and chloride diffusion coefficient measured by the construction site laboratory, the surface permeability coefficient, the surface resistivity and the thickness of the protective layer on the site members of the precast immersed tube tunnel are summarized and analyzed in this paper. The analysis shows that both the compressive strength and the chloride diffusion coefficient of the immersed pipe meet the quality requirements of the control regulations, and the qualified rate of the thickness of the protective layer basically meets the expectation. The permeability coefficient on the surface of the immersed pipe is generally low, especially the 56 d age data, which indicates that the precast segment concrete structure is compact in situ. The surface resistivity obeys the normal distribution and shows a steady increasing trend with the increase of concrete age. There is a negative correlation between permeability and resistivity, but it is not enough to regress the quantitative relationship. Based on the field data, the construction stage of chloride intrusion process is evaluated in this paper. The durability evaluation model based on chloride corrosion is reviewed, the statistical characteristics of each parameter of the model are summarized and analyzed, and the influence of additional corrosion prevention measures on the model is considered. On the basis of this, the 120 year failure probability P f and reliability index 尾 of each component of the structure are calculated by Monte-Carlo method, and the preliminary maintenance scheme of the structure and the engineering suggestions under different working conditions are put forward. The calculation results show that the reliability index of the components in large gas and underwater zones is higher and can be maintained without maintenance for 120 years; the components in the splash zone need 120 years of durability maintenance plans; in the piers of dark bridge and C ramp bridge at toll station, if seawater is infiltrated into the tunnel interior, The failure probability of 120 calculated according to the working condition of the splash area is more than 10. In the construction and construction of these components, it is necessary to monitor the process of internal seawater leakage, and establish the corresponding process of durability re-evaluation and redesign. If seawater seeps into the tunnel after completion, The starting time can be calculated according to the proportion of seawater leakage area and the predetermined maintenance level. At the end of this paper, the durability redesign process is studied, and the durability redesign method is demonstrated by taking the durability plan of the tunnel after completion evaluation as an example. The relation curves between the start-up period of cathodic protection and the proportion of seawater infiltration area were obtained under three different maintenance levels. On the basis of a set of simulated exposure data, the 120 year reliability index and time-varying failure probability curve of hidden bridge in toll station are updated, and the level -2 durability maintenance scheme is determined as the optimal scheme by using the life-cycle cost method.
【學位授予單位】：清華大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U446

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本文編號：1876142