Adopting the real concrete mix proportion of Ronggui Bridge in Guangzhou- Zhuhai inter-city express railway, the tested creep coefficient of C60 HPC was compared with creep coefficient calculated in terms of different concrete codes, and the calculation method of creep deformation of structures was determined. Through long term observation and examination, development laws of the long term deformation of pre-stressed simple supported beams, including its influencing factors and control measures were studied. The results show that during 762 d observing period, pre-stressing loss of the test beams is too small to be more than 8.63%, which means the long term deformation of pre-stressed concrete beams is mainly caused by concrete creep. After surface loading, deformation of the test beams occurring during the earlier 185 d is about 75% of the total long term deformation, while only about 25% in the later is over 500 d. Concrete strain also becomes stable 400 d after surface loading. Ambient temperature and humidity, pre-stress tension age and surface loading age of concrete are all demonstrated to be important influencing factors of long term deformation of pre-stressed concrete structures. Therefore, measures such as maintaining concrete with high humidity and at low temperature, extending pre-stress tension time and track laying time appropriately, can be applied in controlling long term deformation of pre-stressed concrete beams with ballastless track effectively.%采用广珠(广州-珠海)城际容桂水道特大桥主桥的实际混凝土配比，对比分析C60高性能混凝土实测徐变系数和按各种规范计算所得徐变系数，确定结构徐变变形计算方法。通过长期试验观测，研究预应力混凝土简支梁的长期变形发展规律及其影响因素和控制措施。研究结果表明：在762 d的观测期内，梁体预应力损失很小，最多不超过8.63％，说明预应力混凝土梁后期变形主要由混凝土徐变引起；堆载后前185 d内梁体变形平均约占总后期变形的75％，之后500 d内的变形仅占25％；混凝土表面应变也在400 d时基本稳定；环境温度和湿度、预应力加载龄期、二期恒载加载龄期等对预应力混凝土结构后期徐变变形有重要影响，在高湿度、低温度的混凝土养护环境中，适当延长预应力张拉龄期和铺轨时间等可有效控制无碴轨道预应力混凝土梁的后期变形。
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