本文選題：水下橋墩加固 + 預(yù)制混凝土管片　； 參考：《東南大學(xué)》2015年碩士論文

【摘要】：我國(guó)橋梁在飛速發(fā)展的過(guò)程中,由于其運(yùn)營(yíng)時(shí)間的增長(zhǎng)及交通量與日俱增等原因,各種各樣的病害也相繼出現(xiàn),而橋墩是橋梁結(jié)構(gòu)中唯一的抗側(cè)力構(gòu)件和直接的豎向受力構(gòu)件,在運(yùn)營(yíng)中一旦發(fā)生病害將嚴(yán)重限制橋梁相關(guān)功能的發(fā)揮,甚至由于承載能力不足而導(dǎo)致橋梁結(jié)構(gòu)的倒塌。本文針對(duì)當(dāng)前常被忽視的水下橋墩加固技術(shù)進(jìn)行研究,在總結(jié)相應(yīng)加固技術(shù)研究現(xiàn)狀的基礎(chǔ)上,提出了預(yù)制混凝土管片快速拼裝加固水下橋墩技術(shù)。本文首先對(duì)預(yù)制混凝土管片快速拼裝加固水下橋墩技術(shù)進(jìn)行了室內(nèi)模擬試驗(yàn)研究,通過(guò)對(duì)比分析未加固試件、整澆試件與內(nèi)部無(wú)FRP網(wǎng)格的加固試件和內(nèi)置FRP網(wǎng)格的加固試件的軸壓試驗(yàn)結(jié)果得出：加固試件的破壞模式得到了顯著改善,由脆性破壞變?yōu)檠有云茐�；加固試件的峰值荷載和峰值位移得到了大幅提高,無(wú)FRP網(wǎng)格的加固試件和內(nèi)置FRP網(wǎng)格的加固試件的峰值荷載提高比例為28%和63%,峰值位移提高比例為16%和44%；通過(guò)合理的設(shè)計(jì),可以使加固試件的綜合力學(xué)性能接近甚至優(yōu)于一次性整澆成型的同類(lèi)試件；影響預(yù)制混凝土管片快速拼裝加固水下橋墩技術(shù)加固效果的關(guān)鍵參數(shù)是預(yù)制混凝土管片的環(huán)向連接性能、水下不分散混凝土強(qiáng)度及環(huán)向約束強(qiáng)度。然后,采用ABAQUS有限元分析軟件進(jìn)一步對(duì)上述三個(gè)關(guān)鍵參數(shù)進(jìn)行定性分析得出：預(yù)制混凝土管片環(huán)向連接性能將影響結(jié)構(gòu)應(yīng)力分布和材料強(qiáng)度的發(fā)揮程度；水下不分散混凝土強(qiáng)度和環(huán)向約束強(qiáng)度對(duì)加固結(jié)構(gòu)的峰值荷載影響呈線性相關(guān)的關(guān)系。在試驗(yàn)研究及ABAQUS有限元模擬的基礎(chǔ)上,綜合考慮增大截面法及約束混凝土對(duì)加固效果的影響,提出了預(yù)制混凝土管片快速拼裝加固水下橋墩技術(shù)的理論計(jì)算模型,通過(guò)相關(guān)文獻(xiàn)試驗(yàn)數(shù)據(jù)的驗(yàn)證發(fā)現(xiàn)該模型具有廣泛的適用性。最后,以江西北港湖大橋23-4#樁基為依托,進(jìn)行了預(yù)制混凝土管片快速拼裝加固水下橋墩技術(shù)的試點(diǎn)應(yīng)用研究,取得了良好的加固效果,并在此基礎(chǔ)之上結(jié)合試驗(yàn)研究成果總結(jié)提出了預(yù)制混凝土管片快速拼裝加固水下橋墩技術(shù)的施工工藝流程和質(zhì)量控制措施,形成了一套完整的水下結(jié)構(gòu)加固方法,對(duì)相關(guān)工程的加固設(shè)計(jì)與施工具有重要的指導(dǎo)意義。
[Abstract]:In the process of rapid development of bridges in our country, due to the increase of operation time and traffic volume, a variety of diseases have appeared one after another, and pier is the only anti-lateral force member and the direct vertical force member in the bridge structure. Once the disease occurs in the operation, the bridge function will be restricted seriously, and even the bridge structure will collapse due to the insufficient bearing capacity. In this paper, the reinforcement technology of underwater pier, which is often neglected at present, is studied. On the basis of summarizing the research status of the corresponding reinforcement technology, the technology of fast assembling precast concrete segment to reinforce underwater pier is put forward. In this paper, first of all, the laboratory simulation test is carried out on the technology of quick assembling and strengthening underwater pier with precast concrete segments, and the unreinforced specimens are compared and analyzed. The results of axial compression tests of the cast-in-situ specimens, the strengthened specimens without FRP mesh and the strengthened specimens with built-in FRP mesh show that the failure mode of the strengthened specimens has been significantly improved, from brittle failure to ductile failure. The peak load and the peak displacement of the strengthened specimens have been greatly increased. The proportion of the peak loads of the strengthened specimens without FRP mesh and that of the strengthened specimens with built-in FRP mesh are 28% and 63%, and the proportion of the peak displacement is 16% and 44% respectively. The comprehensive mechanical properties of the strengthened specimens are close to or even superior to those of the one-off cast-in-place specimens. The key parameters affecting the technical strengthening effect of precast concrete segment are the performance of circumferential connection of precast concrete segment, the strength of underwater non-dispersive concrete and the strength of circumferential restraint. Then, the ABAQUS finite element analysis software is used to analyze the above three key parameters qualitatively. It is concluded that the performance of the precast concrete segment in circumferential connection will affect the stress distribution of the structure and the exertion degree of the material strength; The influence of the strength of underwater non-dispersible concrete and the strength of circumferential confinement on the peak load of reinforced structure is linearly correlated. On the basis of experimental research and ABAQUS finite element simulation, considering the influence of increasing cross-section method and confined concrete on reinforcement effect, a theoretical calculation model of rapid assembly of precast concrete segments for strengthening underwater pier is put forward. It is found that the model has wide applicability through the validation of relevant experimental data. Finally, on the basis of 23-鈪，

本文編號(hào)：1923207