裂隙岩体等效热传导系数探讨

Study on the equivalent thermal conductivity coefficient of fractured rock masses

对于裂隙岩体温度场的研究一般是按照各向同性介质进行处理,直接按照岩块热传导系数或者根据孔隙度计算的等效热传导系数进行计算.但在大量裂隙存在的情况下,由于不同走向裂隙填充物所起到的隔热作用,仍按照各向同性介质研究就存在误差.为考虑存在裂隙的影响,提出将热流量沿裂隙面方向及裂隙法向进行分解,按照热流量等效原理来推导等效热传导系数阵,并编制子程序进行验证.通过含裂隙算例的计算对比说明本方法是有效的,与常规方法差别很大,在同一位置点最大温差可达8.29℃.

The fractured rock masses are usually regarded as isotropic media in the analysis of temperature field.In fact,when there are a lot of fractures in the rock masses,the computation result will have greater error because of the heat insulation of the filling material in the fractures.Under the condition of considering the influence of the fractures,the equivalent thermal conductivity coefficient matrix is derived according to the equivalence of heat flux in multi-fractured rock masses.In this method,the heat flux is divided into the tangential and normal components of the fracture surface.The computation results of two cases show that this method is effective.There is greater error between the results computed by this method and traditional method separately.The maximum temperature error at the same point in the temperature field can reaches to 8.29 ℃.