中文摘要：

针对在多年冻土地区建设青藏铁路时混凝土桥灌注桩水化放热引起周围冻土温度场变化这一实际工程问题,采用伽辽金法推导出带相变的瞬态温度场问题的有限元公式,在考虑混凝土作为放热边界的条件下综合考虑了气温变化、风速等多种因素,建立了多年冻土区混凝土桥灌注桩水化放热的传热模型,计算了由于混凝土水化放热引起的冻土温度场变化。结果表明：混凝土水化热在浇筑后半年内对多年冻土的温度场影响很大,回冻时间（融化的冻土温度重新回到天然状态的时间）长达2年以上。而用粉煤灰和硅灰取代一定质量的水泥可以减少混凝土水化热对冻土热状况的影响。

英文摘要：

According to the problems in the project that hydration heat of concrete compresol piles cause changes of temperature field around them when Qingzang railway is built in the zone of permafrost,finite element formulation of the issue of transient temperature field with phase change is obtained by Galerkin＇s method.Taking hydration heat of concrete,air temperature change and wind speed as boundaries,the model of heat transmission of liberation of heat of concrete compresol pile in the zone of permafrost is created,and changes of temperature field of permafrost caused by hydration heat of concrete are calculated.Results show that the effect of hydration heat of concrete on temperature field of permafrost is notable in the first half year after concrete has been casted,and that the contract time（temperature of thaw permafrost resumes the crude state） is over two years.When some quantities of fly ash and silica fume replace some cement,the effect of hydration heat of concrete on thermo conditions of permafrost is reduced.