A DESIGN METHOD OF ROAD TUNNELS IN COLD REGION

隧道中的冰柱和侧壁冰成为运输和维护的问题。近年来，在既有隧道中开发了一种用于衬砌表面防冰的隔热材料。本研究的目的是提出一种简化的隔热层厚度设计方法，主要内容如下：(L)给出了一个简单实用的隔热层厚度估算公式。该方程由一维隧道-地面模型和非稳态周期热分析得到。与其他解的比较表明，所提出的方程具有令人满意的精度。利用所建立的方程，可以合理地确定最佳绝热材料及其最佳厚度。此外，该方程还有助于更好地了解隧道-地面系统的热特性。(2)为了识别出现在所提出的方程中的未知热参数(导热系数和地面热容量)，采用扩展卡尔曼滤波与一维有限元热分析相结合。识别参数计算的温度与现场实测值的对比表明，该方法具有足够的精度。(3)为了估计某公路隧道规划现场的未知温度，在随机方法的基础上，采用了半Yarig图。将估算的温度与测量的FIRD数据进行比较，得到了令人满意的结果。

Icicles and side wall ices in tunnels became a problem for transportation and maintenance. Recently a heat insulator for icicle prevention at the lining surface has been developed in the existing tunnels. The purpose of this study is to propose a simplified design procedure for heat insulator.This project is summarized as follows :(l) A simple practical equation for estimating the thickness of heat insulator is presented. The equation is obtained by using a one-dimensional tunnel-ground model and a non-steady periodic thermal analysis. A comparison with other solutions suggests that the proposed equation provide satisfactory accuracy. By using the equation presented, we can reasonably determine the optimum material of heat insulator and its optimum thickness. In addition, the equation is useful for a better understanding for the thermal characteristics of the tunnel-ground system.(2)In order to identify unknown thermal parameters (thermal conductivity and heat capacity in ground) in appearing the proposed equation, the extended Kalman filter in combination with the one-dimensional finite element thermal analysis is used. A comparison of the temperatures calculated from identified parameters with the measured fild data shows that the method is sufficiently accurate for practical purposes.(3)In order to estimate the unknown temperatures at a planning site of road tunnels, Semi-Yariogram is used on the basis of the a stochastic method. A comparison of the estimated temperatures with the measured fild data gives satisfactory results.