高地热区铁路隧道岩石热物理性质及其影响因素

Experimental Study on Rock Thermophysical Properties of Railway Tunnel in High Geothermal Area

为了研究高地热区铁路隧道岩石热物理性质及其影响因素,以隧道中不同岩性试样为研究对象,开展了室内岩石热物理(导热系数、比热容)及基本物理力学指标测试,分析了不同岩性热物理性质差异,厘清了岩石各物理力学指标及矿物成分与岩石热物理性质间相关关系。结果表明:不同岩性热物理性质差异显著,其中沉积岩导热系数最大、岩浆岩次之,变质岩最小;岩石单轴抗压强度、干密度、纵波波速、石英含量越大,岩石导热系数越大;岩石单轴抗压强度、干密度、纵波波速与岩石比热容呈负相关关系,而岩石含水率则相反。

In order to study the thermophysical properties and influencing factors of railway tunnel rocks in the high geothermal area,this paper takes different lithologic samples in the tunnel as the research object,carries out indoor rock thermophysical(thermal conductivity,specific heat capacity)and basic physical and mechanical index tests,analyzes the differences of thermophysical properties of different lithologic rocks,and clarifies the correlation between rock physical and mechanical indexes and mineral composition and rock thermophysical properties.The results show that:the thermophysical properties of different lithology are significantly different,among which the thermal conductivity of sedimentary rock is the largest,followed by magmatic rock,and metamorphic rock is the smallest;the higher the uniaxial compressive strength,dry density,longitudinal wave velocity,and quartz content of rocks,the greater their thermal conductivity;the uniaxial compressive strength,dry density and longitudinal wave velocity of rock are negatively correlated with the specific heat capacity of rock,while the water content of rock is on the contrary.