- 摘 要
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（同濟(jì)大學(xué)建筑設(shè)計研究院(集團(tuán))有限公司， 上海 200092）
［摘要］某景觀人行橋為跨度165 m的三跨連續(xù)懸索橋，主跨加勁梁豎曲線為圓弧，空間曲線主纜與索塔均朝橫橋向外側(cè)傾斜。根據(jù)橋梁的景觀要求、幾何形態(tài)與尺度、輕載特征及場地條件，設(shè)計了搖擺索塔的自錨式懸索橋結(jié)構(gòu)系統(tǒng)。搖擺索塔由傾斜的桅桿與背索組成，纜索、桅桿及加勁梁共同形成了穩(wěn)定的空間整體張拉結(jié)構(gòu)系統(tǒng)。采用了桅桿-背索-加勁梁的整體式支座橋墩，在橫橋向形成自平衡系統(tǒng)，抵消了桅桿的地基壓載并避免了設(shè)置背索的重力錨碇。加勁梁重量輕，纜索的重力剛度很小，需要施加額外的預(yù)應(yīng)力。為此通過初始預(yù)應(yīng)力態(tài)設(shè)計來確定結(jié)構(gòu)的預(yù)應(yīng)力度，以外傾的平面懸鏈線為初始幾何構(gòu)形，根據(jù)索桿節(jié)點靜力平衡條件計算主纜的初始預(yù)應(yīng)力態(tài)空間線形與內(nèi)力，按不動點原則和桅桿頂點的靜力平衡條件確定桅桿-背索的受力平面方位。分別采用加勁梁的魚骨式與殼單元有限元模型，計算了整體結(jié)構(gòu)的靜力與動力性能。計算結(jié)果表明：預(yù)應(yīng)力增加了索桿系統(tǒng)的剛度與穩(wěn)定性，減小了加勁梁的撓度； 整體結(jié)構(gòu)具有合理的剛度、穩(wěn)定性與承載能力； 相關(guān)結(jié)構(gòu)性能指標(biāo)符合設(shè)計規(guī)范的要求。
［關(guān)鍵詞］自錨式懸索橋； 搖擺式索塔； 整體張拉結(jié)構(gòu)； 初始預(yù)應(yīng)力態(tài)； 主纜空間線形； 剛度； 穩(wěn)定性
中圖分類號：TU394文獻(xiàn)標(biāo)識碼：A文章編號：1002-848X(2020)22-0119-06
Structural design and analysis of a spatial integral tension suspension bridge
YANG Huizhu, WU Shuigen, DAI Chongmin
(Tongji Architectural Design (Group) Co., Ltd., Shanghai 200092, China)
Abstract:A landscape pedestrian bridge is a three-span continuous suspension bridge with a span of 165m. The vertical curve of the main span stiffening beam is a circular arc, and the spatial curve of main cable and the cable tower are inclined to the outside of the horizontal bridge. According to the bridge′s landscape requirements, geometry and scale, light load characteristics and site conditions, a self-anchored suspension bridge structure system with swinging towers was designed. The swinging tower was composed of inclined masts and back cables. The cables, masts and stiffening beams together formed a stable spatial integral tension structural system. The monolithic supporting pier with mast, back cable and stiffening beam was adopted to form a self-balancing system in the transverse direction, which offset the foundation ballast of the mast and avoided the setting of the gravity anchorage of the back cable. The stiffening beam was light in weight, the gravity stiffness of the cable was very small, and additional prestress was required. For this reason, the initial prestress state design was used to determine the prestress degree of the structure. The cambered plane catenary was the initial geometric configuration. According to the static balance condition of the cable-rod node, the initial pre-stressed space line shape and internal force of the main cable were calculated, and the force plane orientation of the mast and back cable was determined according to the fixed point principle and the static balance condition of the mast vertex. The fish-bone and shell element finite element models of the stiffening beam were used to calculate the static and dynamic performance of the overall structure. The calculation results show that the prestress increases the stiffness and stability of the cable-rod system, and reduces the deflection of the stiffening beam; the overall structure has reasonable stiffness, stability and bearing capacity; the relevant structural performance indicators meet the requirements of the design code.
Keywords:self-anchored suspension bridge; swing cable tower; integral tension structure; initial prestressed state; spatial curve of main cable; stiffness; stability
*新形態(tài)大跨度柔性景觀人行橋設(shè)計的關(guān)鍵技術(shù)(2020J-JG02)。
作者簡介：楊暉柱，博士，高級工程師，一級注冊結(jié)構(gòu)工程師，Email: YangHuiZhu@163.com； 通信作者：吳水根，碩士，教授級高級工程師，一級注冊結(jié)構(gòu)工程師，Email: shuigen111@#edu.cn。
