鐵路PC拱形腹板槽形梁受力分析及施工中預應力張拉控制研究
發(fā)布時間:2018-08-01 15:57
【摘要】:在交通基礎設施建設中槽形梁作為一種新型的橋梁結(jié)構形式,以其豎向剛度大的結(jié)構優(yōu)勢,受到了工程人員的青睞,廣泛使用在軌道交通線路中。目前對槽形梁的受力分析研究主要集中在等截面、無橫梁的槽形梁結(jié)構形式上,但對變截面有橫梁的槽形梁研究不多。本文以某在建鐵路建設中的一座變截面預應力混凝土槽形梁為研究對象,對其不同階段的整體受力進行了數(shù)值模擬分析,主要做了以下幾個方面的工作:(1)通過查閱國內(nèi)外的相關文獻,對槽形梁的發(fā)展、工程應用、分析方法和研究現(xiàn)狀進行了綜述。文中采用MIDAS-FEA有限元專業(yè)應用軟件建立了槽形梁的實體分析模型,探索了縱、橫梁設置對主梁內(nèi)力及其變形的影響,證明了縱、橫梁設置可以有效的增強道板床的縱、橫向抗彎剛度,進而減小道板床厚度和主梁自重,同時可以改善道板床的受力和主梁線形。分析表明主梁底板(道板床+橫梁)的豎向變形大于腹板,因此橋下凈空的確定應以橫梁下緣的標高為基本依據(jù)。(2)對于設有縱、橫梁體系的槽形梁結(jié)構,其主梁腹板與道板床、主梁與橫梁、次縱梁與橫梁交匯處也是預應力束交匯處,預應力束密集,應力集中現(xiàn)象明顯,在設計、施工時要多關注這些位置的構造鏈接,保證梁體的安全性和可靠度。在恒載、活載作用下,槽形梁在支座布置有橫向約束一側(cè)的腹板橫向變形大,因此在設計中應該以該側(cè)腹板的內(nèi)力作為腹板配筋設計的依據(jù)。(3)在單線列車運營時,槽形梁會出現(xiàn)偏載效應,主梁表現(xiàn)出明顯的彎扭耦合效應;設有縱、橫梁體系的槽形梁其道板床的“剪力滯”現(xiàn)象不明顯。結(jié)合工程中支座發(fā)生沉降對主梁進行整體受力分析,結(jié)果表明在恒載、活載作用下支座發(fā)生沉降對主梁內(nèi)力的影響不大。(4)在施工階段的預應力束張拉過程中,按照順序依次張拉及間隔張拉腹板束兩種情況進行主梁內(nèi)力和變形的分析比較,確定出后者為合理的張拉方案。(5)通過對槽形梁的主梁腹板、縱、橫梁及道板床預應力束的超欠張拉分析,結(jié)果表明:超張拉對主梁的變形控制有利,但對于結(jié)構會產(chǎn)生附加的超壓、拉應力;欠張拉對于主梁的線形控制不利。因此在結(jié)構設計中,通常要求對預應力束超張拉應該控制在10%以內(nèi),且避免欠張拉。隨著橫向預應力束張拉程度的降低,道板床和主梁腹板的橫向壓應力減小,由于次縱梁的存在,橫向壓應力在道板床橫向呈齒狀變化。
[Abstract]:As a new type of bridge structure in the construction of transportation infrastructure, slot beam is widely used in rail transit lines because of its advantages of large vertical stiffness. At present, the stress analysis of grooved beam is mainly focused on the equal section, the structure form of the groove beam without cross beam, but the research on the groove beam with variable cross section is not much. In this paper, a prestressed concrete slotted beam with variable section in the construction of a railway is studied, and the numerical simulation of the whole force at different stages is carried out. The main works are as follows: (1) the development, engineering application, analysis methods and research status of grooved beam are summarized by consulting the relevant literature at home and abroad. In this paper, the solid analysis model of grooved beam is established by using MIDAS-FEA finite element professional application software, and the influence of longitudinal and transverse beam setting on the internal force and deformation of main beam is explored. It is proved that longitudinal and transverse beam setting can effectively enhance the longitudinal of track slab bed. The transverse bending stiffness can reduce the thickness of the slab bed and the weight of the main beam, and at the same time, it can improve the force of the slab bed and the alignment of the main beam. The analysis shows that the vertical deformation of the bottom slab of the main beam is greater than that of the web plate, so the determination of the clearance under the bridge should be based on the elevation of the lower edge of the beam. (2) for the slotted beam structure with longitudinal and cross beam system, the main beam web plate and the track slab bed should be determined. The intersection of main beam and crossbeam, secondary longitudinal beam and crossbeam is also the intersection of prestressing beam, the prestressing beam is dense, and the phenomenon of stress concentration is obvious. In design and construction, more attention should be paid to the structural link of these positions to ensure the safety and reliability of beam body. Under the action of dead load and live load, the transverse deformation of the web with transverse constraint on the support is large, so the internal force of the side web should be taken as the basis for the design of web reinforcement. (3) in the operation of a single line train, the internal force of the side web should be taken as the basis for the design of web reinforcement. The beam-slabbed with longitudinal and transverse beams has a "shear lag" phenomenon which is not obvious. Combined with the settlement of the bearing in the project, the overall force of the main beam is analyzed. The results show that the settlement of the bearing has little effect on the internal force of the main beam under dead load and live load. (4) in the process of prestressing beam tensioning in the construction stage, The internal force and deformation of the main beam are analyzed and compared according to the sequence of tension and spacer web bundle, and the latter is determined to be a reasonable tensioning scheme. (5) through the analysis and comparison of the main beam web plate of the grooved beam, longitudinal, The results show that the overtensioning is beneficial to the deformation control of the main beam, but it will produce additional overpressure and tensile stress for the structure, and the undertensioning is unfavorable to the linear control of the main beam. Therefore, in the design of the structure, the overtension should be controlled within 10%, and the undertension should be avoided. With the decrease of the tension degree of the transverse prestressing beam, the transverse compressive stress of the track slab bed and the main beam web plate decreases. Due to the existence of the secondary longitudinal beam, the transverse compressive stress changes in the transverse tooth shape of the track slab bed.
【學位授予單位】:蘭州交通大學
【學位級別】:碩士
【學位授予年份】:2017
【分類號】:U441;U445.4
本文編號:2158083
[Abstract]:As a new type of bridge structure in the construction of transportation infrastructure, slot beam is widely used in rail transit lines because of its advantages of large vertical stiffness. At present, the stress analysis of grooved beam is mainly focused on the equal section, the structure form of the groove beam without cross beam, but the research on the groove beam with variable cross section is not much. In this paper, a prestressed concrete slotted beam with variable section in the construction of a railway is studied, and the numerical simulation of the whole force at different stages is carried out. The main works are as follows: (1) the development, engineering application, analysis methods and research status of grooved beam are summarized by consulting the relevant literature at home and abroad. In this paper, the solid analysis model of grooved beam is established by using MIDAS-FEA finite element professional application software, and the influence of longitudinal and transverse beam setting on the internal force and deformation of main beam is explored. It is proved that longitudinal and transverse beam setting can effectively enhance the longitudinal of track slab bed. The transverse bending stiffness can reduce the thickness of the slab bed and the weight of the main beam, and at the same time, it can improve the force of the slab bed and the alignment of the main beam. The analysis shows that the vertical deformation of the bottom slab of the main beam is greater than that of the web plate, so the determination of the clearance under the bridge should be based on the elevation of the lower edge of the beam. (2) for the slotted beam structure with longitudinal and cross beam system, the main beam web plate and the track slab bed should be determined. The intersection of main beam and crossbeam, secondary longitudinal beam and crossbeam is also the intersection of prestressing beam, the prestressing beam is dense, and the phenomenon of stress concentration is obvious. In design and construction, more attention should be paid to the structural link of these positions to ensure the safety and reliability of beam body. Under the action of dead load and live load, the transverse deformation of the web with transverse constraint on the support is large, so the internal force of the side web should be taken as the basis for the design of web reinforcement. (3) in the operation of a single line train, the internal force of the side web should be taken as the basis for the design of web reinforcement. The beam-slabbed with longitudinal and transverse beams has a "shear lag" phenomenon which is not obvious. Combined with the settlement of the bearing in the project, the overall force of the main beam is analyzed. The results show that the settlement of the bearing has little effect on the internal force of the main beam under dead load and live load. (4) in the process of prestressing beam tensioning in the construction stage, The internal force and deformation of the main beam are analyzed and compared according to the sequence of tension and spacer web bundle, and the latter is determined to be a reasonable tensioning scheme. (5) through the analysis and comparison of the main beam web plate of the grooved beam, longitudinal, The results show that the overtensioning is beneficial to the deformation control of the main beam, but it will produce additional overpressure and tensile stress for the structure, and the undertensioning is unfavorable to the linear control of the main beam. Therefore, in the design of the structure, the overtension should be controlled within 10%, and the undertension should be avoided. With the decrease of the tension degree of the transverse prestressing beam, the transverse compressive stress of the track slab bed and the main beam web plate decreases. Due to the existence of the secondary longitudinal beam, the transverse compressive stress changes in the transverse tooth shape of the track slab bed.
【學位授予單位】:蘭州交通大學
【學位級別】:碩士
【學位授予年份】:2017
【分類號】:U441;U445.4
【參考文獻】
相關期刊論文 前10條
1 王起才;薛彥瑾;張戎令;劉正楠;何志剛;王沖;;高速鐵路無砟軌道簡支槽型梁靜載彎曲試驗研究[J];西安建筑科技大學學報(自然科學版);2016年04期
2 陳卓異;黃僑;楊明;胡世翔;;波形鋼腹板組合槽型梁剪切撓度計算方法與試驗研究[J];工程力學;2014年10期
3 徐勛;肖林;王炎;司秀勇;;預應力混凝土槽形梁靜力行為研究[J];鐵道建筑;2013年01期
4 聶建國;胡紅松;;簡支槽形梁考慮空間受力的理論解[J];工程力學;2012年12期
5 田楊;鄧運清;黃勝前;;雙線鐵路曲線簡支槽形梁的空間分析[J];鐵道工程學報;2012年07期
6 馬瑩;席進;葉見曙;俞博;;基于板理論的公路混凝土槽形梁內(nèi)力計算方法[J];中國公路學報;2012年03期
7 王彬力;蒲黔輝;白光亮;;重慶輕軌30mU型梁疲勞模型試驗與計算分析[J];鐵道建筑;2011年07期
8 繆文輝;何濤;;蘭新二線風區(qū)槽形梁設計分析[J];鐵道標準設計;2010年11期
9 莊嚴;余小華;蒲黔輝;;城市軌道交通U型梁靜載試驗研究[J];西南公路;2010年04期
10 段敬民;錢永久;;槽形截面梁靜力學特性的研究[J];工程力學;2010年09期
相關碩士學位論文 前2條
1 蔡志鋒;預應力筋的超欠張拉對PC連續(xù)箱梁橋應力及線形的影響分析[D];蘭州交通大學;2014年
2 盧巖;預應力混凝土槽形梁力學性能研究[D];北京交通大學;2008年
,本文編號:2158083
本文鏈接:http://www.sikaile.net/kejilunwen/daoluqiaoliang/2158083.html