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为能精确计算地铁隧道围岩内的传热量,模拟了地铁隧道围岩内的热传导,研究了地铁围岩内的温度分布规律,并通过试验结果对土体热导率进行反算。分析表明:同一时刻,距隧道壁面不同距离处的温度以指数形式进行变化,距离越远,温度越小;时间越久,隧道内流体的温度影响范围越大。除隧道外壁面外,距隧道壁某距离处的温度,随时间的增长而逐渐增长,距隧道壁较近处土体温度较高,温度增长速率随时间的增长而逐渐减小;距隧道壁面距离较远处温度较低,其增长速率随时间的增长而逐渐增大。传热时间超过某一值后,围岩内温度增长率逐渐平稳趋于一定值。根据模型试验结果能较精确得到土样的热导率数值。
In order to accurately calculate the heat transfer in the surrounding rock of the subway tunnel, the heat conduction in the surrounding rock of the subway tunnel was simulated. The temperature distribution in the surrounding rock of the subway tunnel was studied. The thermal conductivity of the soil was calculated by the test results. The analysis shows that: at the same time, the temperature at different distance from the wall of the tunnel changes exponentially; the farther the distance is, the smaller the temperature is; and the longer the temperature, the greater the influence range of fluid temperature in the tunnel. Except for the outer wall of the tunnel, the temperature at a certain distance from the tunnel wall gradually increases with the increase of time. The temperature of the soil near the tunnel wall is higher and the rate of temperature increase decreases with time. The temperature is lower at a distance and the rate of increase gradually increases with time. When the heat transfer time exceeds a certain value, the temperature growth rate in the surrounding rock gradually becomes stable to a certain value. According to the model test results, the thermal conductivity of soil samples can be obtained more accurately.