利用穷举搜索法准确确定地下热物性参数

Exhaustive Search Method to Measure the Ground Thermal Parameters With High Credibility

利用穷举搜索法结合参数估计方法确定地下岩土热物性参数,通过模拟验证该方法的可靠性,并用于实际工程测量,且与优化方法计算结果进行对比分析。结果表明穷举搜索法可以在搜索区域得到目标函数方差和最小值,基于此得到热物性参数值可靠性较高;而优化方法得到的目标函数方差和为局部区域的极小值,其确定的土壤导热系数可靠性较高,但钻孔内热阻和容积比热计算结果可信度相对较低。

Combine with the parameter estimation method,the exhaustive search method is used to measure the ground thermal properties,which reliability is verified by simulation.The exhaustive search method is applied for projects,and the ground thermal parameters calculated are compared with those obtained by the optimization method.The result and analysis demonstrate that the exhaustive search method can find the minimum objective function variance within the search domain and obtain soil thermal parameters with high credibility.As comparison,though the optimization method can also find the minimum objective function variance and obtain the ground thermal conductivity with high credibility,the borehole thermal resistance and volumetric heat capacity determined by it have relative lower credibility.