【摘要】 山区桥梁大体积混凝土承台水化热高，在昼夜温差、风速、海拔等环境因素的影响下，易造成承台内部温度、里表温差过大，易使承台产生温度裂缝，从而对桥梁整体的安全性、抗渗性和耐久性产生不利影响。以贵州山区某高墩连续刚构桥梁为研究对象，建立了有限元模型，计算结果显示：大体积混凝土承台浇注后水化热造成最高温度出现在承台中心层，出现时间约为浇注后第3～4 d。承台中心层、顶层与底层的最高温度分别为67.4,51.6,48.7℃,最大里表温差为29.8℃,里表温差超出了规范要求。由于部分承台计划夏季施工，承台内部温度则会更高。为改善承台整体温度场，避免温度裂缝的产生，对该桥梁大体积混凝土承台进行水化热温度场影响因素分析。承台温度场关键控制指标为承台最高温度和里表温差，这两项关键控制指标影响因素优化。结果表明：承台冷却效果影响程度由高至低依次为混凝土入模温度、冷却水管间距、冷却水入水温度、冷却水管层数、冷却水量(足量后);优化后承台温度场得到有效改善，现场应用效果显著，温度场的有限元计算结果与现场实测温度数据吻合良好；最高温度和里表温差均满足规范要求且浇注后承台表面未发现温度裂缝，表明优化后温控方案实用有效。更多还原

【Abstract】 The mass concrete bearing platform of mountainous bridge has high hydration heat. Under the influence of the environmental factors such as the temperature difference between day and night, wind speed, altitude and so on, it is easy to cause the temperature difference between inside and outside of the pile cap to be too large, and easy to cause the temperature crack of the pile cap, therefore, the safety, impermeability and durability of the bridge as a whole are adversely affected. Taking a high pier continuous rigid frame bridge in Guizhou mountain area as the study object, the finite element model is established, and the calculation result shows that the highest temperature appears in the center layer of the mass concrete cap after hydration heat is poured, and the appearance time is about 3-4 d after pouring. The maximum temperatures of center layer, top layer and bottom layer of pile cap are 67.4, 51.6 and 48.7 ℃ respectively, and the maximum temperature difference between inside and outside is 29.8 ℃, which exceeds the requirements of the specification. As part of the cap is planned for summer construction, the internal temperature of the cap will be higher. In order to improve the overall temperature field of the cap and avoid the occurrence of temperature cracks, the influencing factors of hydration heat temperature field of the mass concrete cap of the bridge are analyzed. The key control indicators of the temperature field of the cap are the highest temperature of the cap and the temperature difference between the inside and outside of the cap. The result shows that(1) the influencing degrees of cooling effect from high to low are concrete formwork temperature, cooling water pipe space, cooling water inlet temperature, cooling water pipe layer number, cooling water quantity(with sufficient quantity);(2) after optimization, the temperature field of the cap is effectively improved and the field application effect is remarkable, and the finite element calculation results of the temperature field are in good agreement with the field measured temperature data;(3) the maximum temperature and the inside-surface temperature difference meet the requirements of the specification, and no temperature cracks are found on the surface of the cast-in-place cap, that indicates that the optimized temperature control scheme is practical and effective.更多还原