預(yù)應(yīng)力混凝土小箱梁受力特性試驗研究
王素娟，周正茂
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王素娟，周正茂（上海同豪土木工程咨詢有限公司，上海 200092）［摘要］為檢驗小箱梁設(shè)計的合理性，對一根長約30m的預(yù)應(yīng)力混凝土小箱梁進行了單梁足尺試驗。試驗采用預(yù)制混凝土塊和部分砝碼進行加載，測量了試驗梁跨中底面和側(cè)面的混凝土應(yīng)變及底面部分鋼筋的應(yīng)變。研究結(jié)果表明：試驗梁的受力變形過程分為彈性變形階段、開裂過程階段和完全開裂階段；通過布置連續(xù)應(yīng)變片可以找出初始開裂的位置，預(yù)應(yīng)力混凝土梁在加載彎矩作用下的開裂是一個過程；在設(shè)計承載力作用下，試驗梁遠未達到破壞，裂縫最大寬度為0.20mm，卸載后裂縫基本閉合。［關(guān)鍵詞］橋梁工程；小箱梁；足尺試驗；應(yīng)變；裂縫；安全系數(shù)中圖分類號：TU317-2，U446-1文獻標識碼：A文章編號：1002-848X(2012)07-0068-05Experimental study on the mechanical characteristics of a pre-stressed small concrete box girderWang Sujuan, Zhou Zhengmao(Shanghai Tonghao Civil Engineering Consulting Co., Ltd., Shanghai 200092, China)Abstract: In order to examine the rationality of the design of small concrete box girder, the full-scale experiment was conducted on an about 30m length pre-stressed small concrete box girder. Pre-cast concrete blocks and some small weights were used in the loading, the concrete strain on the bottom and sides as well as the bottom steel strain were measured. The results indicate that the deformation procedure of the specimen can be divied into elastic deformation stage, crack procedure stage and fully cracked stage. The position of crack can be found by continuously-arranged strain gauges. The cracking of pre-srtressed concrete girder under loading moment is a process. The specimen is far away from destruction under the designed bearing capacity with the maximum width of crack being about 0.20mm, which can be closed when unloaded.Keywords: bridge engineering; small box girder; full-scale experiment; strain; crack; safety factor作者簡介：王素娟，碩士，Email：g_sjwang@126.com。參考文獻［1］張志空心板鉸縫破壞機理及防治措施研究［J］山西建筑，2009,35(2)：318-320［2］金偉良，呂清芳，潘仁泉東南沿海公路橋梁耐久性現(xiàn)狀［J］江蘇大學學報：自然科學版，2007,28(3)：254-257.［3］鄒俊勇.城市大型橋梁橋型選擇分析［J］.交通標準化，2008(4)：204-207.［4］賀恩懷.槽形梁在城市軌道交通工程中的應(yīng)用形式［J］.城市軌道交通研究，2003(3)：68-70,75.［5］黎立新，何智勇，尚峰.山區(qū)高速公路常規(guī)橋梁選型設(shè)計［J］.公路，2005(8)：46-52.［6］李旭光，蔣勁松，張安國，等.“先簡支后連續(xù)”橋型調(diào)研考察報告［J］.西南公路，2004(2)：38-44.［7］郭守儆.中小跨度帶翼小箱梁的特點及應(yīng)用現(xiàn)狀［J］.四川建筑，2007(4)：122-123,127.［8］陳勇，房貞政. 既有預(yù)應(yīng)力混凝土梁現(xiàn)存預(yù)應(yīng)力和極限荷載確定［J］. 建筑結(jié)構(gòu)，2009，39(4)：103-105,68.［9］JTG D62—2004 公路鋼筋混凝土及預(yù)應(yīng)力混凝土橋涵設(shè)計規(guī)范 ［S］.北京：人民交通出版社，2004.［10］周正茂，王素娟.預(yù)應(yīng)力混凝土梁的消壓彎矩試驗研究［J］.建筑結(jié)構(gòu)，2012,42（7）：64-67.［11］王傳志，滕智明.鋼筋混凝土結(jié)構(gòu)理論［M］.北京：中國建筑工業(yè)出版社，1985.
