This paper studies the effect of shrinkage and creep of concrete beams when reinforced concrete T-beam bridges on highwaysin mountainous area are widened,analyzes stress and deflection produced due to shrinkage and creep of new beams after splice of new and old T beams by means of analytical method and derives formulae of analytical method for influences of shrinkage and creep of new and old T beams after splice.With 20 m span T-beam as an example,the paper analyzes deflection and stress of new and old T beams caused by the effect of shrinkage and creep by means of analytical procedure compiled by MATLAB software and compares influences of the height and concrete strength of new T beams on deflection and stress of new and old T beams.The results of analysis show that the height of new T beams may cause cracking of bottom edges of old T beam webs under the effect of shrinkage and creep of concrete,and both the height and concrete strength of new T beams exhibit great influences on stress of new and old T beams.%研究山区公路钢筋混凝土T梁桥拓宽时混凝土梁的收缩徐变效应,采用解析法分析新、旧T梁拼接后由于新梁收缩徐变产生的应力和挠度,推导拼接后新、旧T梁收缩徐变影响的解析法公式.以20m跨径T梁为例,采用MATLAB软件编制分析程序,分析由收缩徐变效应引起的新、旧T梁的挠度和应力,比较新T梁的梁高和混凝土强度对新、旧T梁挠度和应力的影响.分析结果表明,在混凝土收缩徐变作用下,新T梁的梁高可能会引起旧T梁腹板底缘开裂,新T梁的高度及混凝土强度对新、旧T梁的受力影响均较大.
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