岩土热物理指标的分析计算

地铁车站空调系统节能和通风节能计算需要利用岩土的热物理指标,地铁结构和围岩热物理指标差异在衡量隧道余热被吸收和传导作用时是设计研究的重点问题。一般条件下准确测试岩土的热物理指标比较困难,研究科学的解决方法是地铁勘察的重要课题之一。通过分析当前地铁通风设计和冻结法施工对热物理指标的需求现状,从热物理指标是岩土材料固有的物理性质出发,考虑了地铁工程的特点以及岩土孔隙率和温度对热物理指标的影响,在总结前人有关热物理指标计算方法优缺点的基础上,按照土力学理论进行推导,分岩土类别给出了导热系数和比热容的简化计算公式,公式中未知变量少,补充和完善了地铁勘察手段。将计算结果与实测值的统计结果进行比较,相对误差较小。

Analysis and Calculation of Soil Thermal Physical Indicators

Energy saving calculation of air-conditioning and ventilation system need to use the heat physical parameters of rock and soil. The differences of heat physical indicators of structure and soil is the key problem in design and research of the calculation of residual heat absorption and conduction effect . Under general conditions, the accurate measurement of heat physical indicators of rock and soil is difficult, to explore the reasonable solution is one of the important topics. Through the analysis of the present situation of the ventilation design and the freezing method construction demand for heat physical indicators, the heat physical indexes are the rocks and soils inherent properties, considering the characteristics of subway engineering, and the influence of rock soil porosity and temperature on the heat physical indicators. Based on advantages and disadvantages of heat physical indicators calculation method of previous studies, according to the theory of soil mechanics, and the simplified calculation formula was given for various geotechnical object about the thermal conductivity and specific heat capacity. In this formula unknown variables are less, giving supplement to and perfecting the subway exploration means. After comparing the calculated results with the statistical results, the relative errors are small.