本文關(guān)鍵詞： 超大跨徑 超高性能混凝土 懸臂拼裝 接縫優(yōu)化設(shè)計　出處：《湖南大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：超大跨徑UHPC連續(xù)箱梁橋是利用UHPC材料優(yōu)良的抗拉、抗壓性能，采用薄壁結(jié)構(gòu)、密集橫隔板箱梁和部分體外預(yù)應(yīng)力相結(jié)合的一種新型連續(xù)梁結(jié)構(gòu)。與傳統(tǒng)連續(xù)梁橋相比，具有跨越能力大，自重輕，穩(wěn)定性強(qiáng)，后期運(yùn)營跨中徐變撓度小，易于維護(hù)檢修等優(yōu)點。針對超大跨徑UHPC連續(xù)箱梁橋，本文提出了懸臂拼裝法施工的牛腿式UHPC節(jié)段間接縫，并對其進(jìn)行參數(shù)優(yōu)化分析，研究簡化的單牛腿接縫的抗剪性能，考察橫隔板對接縫抗剪性能的影響，考察箱梁腹板豎向接縫是否滿足結(jié)構(gòu)受力要求。鑒于此，本文作者主要進(jìn)行了以下研究工作： （1）建立接縫抗剪有限元模型，通過數(shù)值分析，比較常規(guī)混凝土接縫與UHPC接縫的抗剪性能，考察單牛腿接縫與剪力齒塊接縫受力性能，并對UHPC單牛腿接縫的傾角、深高比、齒梁高之比進(jìn)行優(yōu)化設(shè)計。計算結(jié)果表明：UHPC接縫抗剪性能遠(yuǎn)超于常規(guī)混凝土接縫，UHPC單牛腿接縫設(shè)計合理可行，其最優(yōu)水平傾角為0°~45°，深高比≥1/10，齒梁高比為1/3~2/3。 （2）利用優(yōu)化結(jié)果設(shè)計制作UHPC雙懸臂梁接縫模型，對比研究不同橫隔板數(shù)目的懸臂梁段在材料彈性下接縫的抗剪性能，并考察兩種結(jié)構(gòu)剪切破壞的全過程。通過二者試驗結(jié)果的對比考察隔板對結(jié)構(gòu)接縫的抗裂和承載力方面的作用。靜力試驗的結(jié)果表明：薄壁箱梁腹板接縫抗剪性能強(qiáng)，密集橫隔板能提高接縫抗剪承載力，接縫角趾開裂應(yīng)變達(dá)到455με，遠(yuǎn)大于普通混凝土的接縫強(qiáng)度，抗裂安全度可達(dá)1.63。 （3）建立試驗梁的有限元模型，對試驗梁進(jìn)行數(shù)值分析，更加細(xì)致的考察結(jié)構(gòu)各方面的性能，深入分析橫隔板對接縫受力性能的影響，并與試驗結(jié)果相比較。結(jié)合試驗結(jié)果及有限元分析得到：UHPC單牛腿接縫的抗剪性能足夠強(qiáng)，密集橫隔板能夠明顯提高接縫的抗剪性能。 （4）簡單介紹主跨400m的UHPC連續(xù)箱梁橋，并建立全橋MIDAS有限元模型，分析其整體受力情況及收縮徐變性能。分析結(jié)果顯示超大跨徑UHPC連續(xù)箱梁橋的應(yīng)力分布均勻，能夠滿足結(jié)構(gòu)的受力要求，運(yùn)營階段跨中下?lián)系膿隙刃�，可以有效避免成橋后橋梁下�(lián)祥_裂的風(fēng)險。 （5）根據(jù)整體計算模型建立箱梁支座附近梁段的局部有限元模型，分析箱梁在正常使用極限荷載工況下支座附近節(jié)段的受力性能，確定該方案的腹板抗剪及接縫抗剪性能力能否滿足結(jié)構(gòu)受力的要求。分析結(jié)果顯示該結(jié)構(gòu)牛腿接縫保持良好的連接功能，結(jié)構(gòu)的整體性,接縫處及腹板的主拉應(yīng)力水平較低，不會發(fā)生開裂，，能夠適應(yīng)UHPC單向預(yù)應(yīng)力體系超大跨徑梁橋的受力要求。
[Abstract]:Large span UHPC continuous box girder bridge is a new type of continuous beam structure which combines thin wall structure, dense transverse diaphragm box girder and partial external prestressing force by using the excellent tensile and compressive properties of UHPC material. Compared with the traditional continuous girder bridge, the large span UHPC continuous box girder bridge is a new type of continuous beam structure. It has the advantages of large span capacity, light weight, strong stability, small creep deflection in late operation span, easy maintenance and repair, etc. Aiming at large span UHPC continuous box girder bridge, this paper puts forward a new method of cantilever assembling method, which is used to construct the joint between the segments of the UHPC segment, which is constructed by cantilever assembly method, and is easy to be maintained and overhauled. The parameter optimization analysis is carried out to study the shear resistance of the simplified single corbel joint, to investigate the influence of the shear resistance of the transverse diaphragm butt joint, and to investigate whether the vertical joint of the web of the box girder meets the structural stress requirements. The author has carried out the following research work:. 1) the finite element model of joint shear resistance is established. Through numerical analysis, the shear behavior of conventional concrete joint and UHPC joint is compared, the mechanical behavior of single leg joint and shear tooth block joint is investigated, and the angle of inclination and the ratio of depth to height of single leg joint of UHPC are investigated. The calculation results show that the shear resistance of the 1: UHPC joint is much better than that of the conventional concrete joint. The optimum horizontal inclination angle is 0 擄45 擄, the depth to height ratio is 鈮

本文編號：1516546