兰州地下轨道交通围岩热物理参数试验研究

Thermal Physical Parameters Test on the Surrounding Rocks of Lanzhou Underground Rail Transit

地下轨道交通暖通空调系统的优化设计与地下轨道交通隧道围岩的热物理参数性质密切相关。文章以兰州地下轨道交通原状土样为研究对象,使用Hot Disk热常数分析仪探究了兰州地下轨道交通围岩的热物理性质。研究结果表明:兰州地下轨道交通围岩土样的导热系数随深度的增加而增加,深度13 m处的中砂层导热系数和热扩散系数最大,明显比其它深度处的黄土层和淤泥质土层的导热系数和热扩散系数大,而中砂层体积比热较小;围岩土样的导热系数随含水率增加呈线性增长,体积比热随含水率增加先降低后增高,热扩散系数随含水率增加先升高后缓慢降低。

The optimum design of HVAC system in metro station is closely related to the thermophysical parame ters of surrounding rocks of Metro tunnel.Taking the original soil sample of Lanzhou metro station as the research object,the thermal physical properties of the surrounding rocks of Lanzhou metro station are investigated by using Hot Disk thermal constant analyzer.The results show that the thermal conductivity of the surrounding rocks of Lan zhou metro increases with the increase of depth,the thermal conductivity and thermal diffusivity of the medium sand layer at 13 m depth are the largest and they are obviously larger than that in loess and silty soil,while the volume specific heat of the medium sand is small;the thermal conductivity coefficient increases linearly with the increase of water content,and the volume specific heat decreases first and then increases with the increase of water content,the thermal diffusion coefficient increases first and then decreases slowly with the increase of water content.