寒区高等级公路宽幅路基的随机温度场

Random Temperature Fields of High-Level Highway Wide Embankment in Cold Regions

寒区高等级公路宽幅路面比普通路面吸热面积更大,增加了保证路基稳定性的难度.在对其进行路基温度场的稳定性分析时,传统的有限元方法都是进行确定性分析,没有考虑到边界条件等因素的随机性、变异性,因此不能得知以上随机因素引起温度场的变幅.采用随机有限元法,由温度场的变分原理,通过摄动法建立随机温度场,从而得到随机温度场的有限元格式,理论公式可广泛适用于其他工程随机温度场问题.将宽幅路基气温边界条件参数设为随机变量,考虑升温效应,对寒区宽幅路基温度场进行计算,分析了温度场均值和方差的分布规律.结果表明:宽幅路基中部聚热效应明显,路基下部出现厚度不均匀的融化盘,可能造成路基不均匀沉降;边界条件的随机性造成温度场方差分布呈明显的边界效应,即越靠近路基上边界温度场方差越大,在一定深度以下趋于零.此外,不论是路基下出现的融化盘,还是温度场方差分布下边界都将随时间增长而扩大.

To construct expressway in western China is growing day by day.Some ways would be through cold regions unavoidably.Because road surface of the expressway has heat absorption area larger than that of normal highway,it is harder to make sure the stability of embankment in cold regions.Generally,it is necessary to take numerical analysis for the stability of embankment in cold regions.However,the conventional finite element methods for stability analysis always make deterministic analysis,which do not take random factors into account,such as material parameters and boundary conditions.Consequently,the results aredeterministic under this circumstance and cannot understand how much effect on stability of embankment with random factors.In this paper,using stochastic finite element methods,considering the parameters of boundary conditions as random variables,the random temperature fields for expressway with wide embankment are obtained and analyzed.The analyzed results indicate that the effect of heat accumulation in wide embankment central is obvious,and the temperature variance is increasing towards the upper boundary of the embankment.The above mentioned effects increase with time.