摘要
国内桥梁设计规范仅规定了箱梁的日照温差荷载,但缺乏桥墩的日照温差荷载。为获得混凝土空心墩日照温差荷载并研究混凝土空心墩壁厚对日照温差分布的影响,根据天文学理论光线追踪方法构建了高墩日照分析模型,在模型中考虑了太阳辐射、环境和上部结构遮荫等主要影响因素,并在宜万铁路马水河桥进行了测试验证,同时对混凝土壁厚与日照温差的关系进行了分析。研究结果表明,空心墩壁厚对桥墩的温差分布影响较大,温差的分布模式不是单一的;混凝土中厚壁墩(30~80 cm),日照温差随壁厚的增加而增大,混凝土厚壁墩(>80 cm)桥墩日照温差不随厚度增加而变化,且内部混凝土温度不受日照的影响;在空心墩的日温差荷载验算过程中,混凝土薄壁墩(≤30 cm)直接按《铁路桥规》箱梁日温差荷载取值是合适的,对于中、厚壁(>30 cm)不宜直接采用箱梁的温差荷载。
The domestic bridge design specification only specifies the temperature difference load of the box girder from sunlight,but lacks of the temperature difference on the bridge pier.In order to obtain the temperature difference load of the concrete hollow pier and the effect of concrete hollow pier wall thick ness on the temperature difference distribution,the sunlight analysis model of high pier was constructed according to the astronomical theory light tracking method,where the main factors of the sun radiation,the environment and the upper structure shade are considered.The test validation is performed in the Yi Wan Railway Mashuihe Bridge,and the relationship between the concrete wall thickness and the temperature difference of the sunlight is further analyzed.The results show that the influence of the hollow pier thickness on the temperature difference distribution is large,the distribution mode of the temperature difference is not single.For the concrete pier with the wall thickness of 30~80 cm,the sunlight temperature difference increases with the increase of the wall thickness.When the wall thickness of the concrete pier is above 80 cm,the temperature difference of the pier changed little with the increase in thickness,and the internal concrete temperature is not affected by the sunlight.For the hollow pier daily temperature difference load verification,the concrete hollow pier with the wall thickness less than 30 cm can directly use the value of temperature difference specified in‘Code for Design on Railway Bridge and Culvert’.For the other concrete hollow pier with the wall thickness above 30 cm,the temperature difference should not directly use the values in the code.
作者
胡安庆
任东华
Hu Anqing;Ren Donghua(China Railway Southwest Research Institute,Chengdu 610031,China)
出处
《石家庄铁道大学学报（自然科学版）》
2021年第4期21-27,共7页
Journal of Shijiazhuang Tiedao University(Natural Science Edition)
关键词
混凝土
空心墩
太阳辐射
壁厚
日照温差
concrete
hollow pier
solar radiation
sunlight temperature difference
