基于正交试验土石坝热-流耦合模型参数的敏感性分析

Sensitivity analysis of thermal-hydro coupling model parameters in earth rock dam based on orthogonal test method

【目的】研究热-流耦合模型参数的敏感性,减小运行期土石坝热-流耦合模型参数校正过程的工作量,为土石坝热-流耦合模型参数选取提供依据。【方法】采用正交试验法,以某水库土石坝为例,基于大坝热-流耦合模型,以坝体与坝基平均温度作为敏感性分析的主要指标,对大坝热-流耦合模型各参数的敏感性进行分析。【结果】渗透率和土体比热容对土石坝温度场影响较敏感,其极差值分别为0.124 5和0.086 2,其余参数的敏感性由强到弱依次为孔隙率(n)、饱和含水率(θs)、导热系数(λ)、残余含水率(θr)和土体密度(ρ),极差值分别为0.046 5,0.029 3,0.026 6,0.014 3和0.011 3,相对于渗透率和土体比热容,这5个参数对于温度场计算结果的影响较小。【结论】在对土石坝温度场进行校正时,应将模型中的渗透率和土体比热容作为重点参数。

【Objective】The sensitivity of thermal-hydro coupling model parameters was studied to reduce the workload of parameter correction during operation,which would provide basis for parameter selection of thermal-hydro coupling model.【Method】Based on the dam thermal-hydro coupling model,the sensitivity of dam thermal-hydro coupling model parameters for the earth rock dam of a reservoir was analyzed using average temperature of dam body and foundation indexes.【Result】The permeability and specific heat capacity of soil were sensitive to temperature field of the earth-rock dam,with the range values of 0.1245 and 0.0862,respectively.The sensitivity of other parameters was in the decreasing order of porosity(n),saturated water content(θs),thermal conductivity(λ),residual water content(θr)and soil density(ρ)with range values of 0.046 5,0.029 3,0.0266,0.0143 and 0.0113,respectively.Compared to permeability and soil specific heat capacity,these five parameters had little effect on calculation of temperature field.【Conclusion】In the correction of temperature field of earth rock dam,permeability and specific heat capacity of soil should be used as key parameters.