青藏铁路冻土路基温度场随机有限元分析

STOCHASTIC FINITE ELEMENT ANALYSIS FOR THE TEMPERATURE FIELD OF FROZEN SOIL ROADBED OF QINGHAI-TIBET RAILWAY

从一阶Taylor展开式入手,结合冻土温度场计算有限元法,推导了冻土路基温度场随机有限元方程及有关计算公式,并对青藏铁路北麓河试验段冻土路基温度场进行了随机有限元分析,结果表明温度标准差与温度场的分布趋势大致相同,在垂直方向上,最大值都出现在路基上部,向下逐渐减小,但两者分布范围略有不同,路基内部标准差的分布范围明显较大,在一定深度处达到均化。

Based on the first order Taylor series expansion and finite element method, a stochastic finite element model is presented for the temperature field. The random temperature field of the frozen soil roadbed in the Bailu River section of Qinghai -Tibet Railway is calculated using the model. The simulation results show that the distribution of temperature - standard deviation is close to the temperature distribution in the roadbed, however, the standard deviation distribution inside the upper part of the roadbed presents a larger area than that of the corresponding temperature distribution. The effect of environmental temperature is remarkable at the top of the roadbed, and diminishes with depth. The values of standard deviation become uniform at the lower part of the roadbed. This paper also discusses advantages of stochastic finite element method.