基于修正Kostiakov模型的土石混合物入渗性能测量方法

Method of Soil-rock Mixture’s Infiltration Performance Based on Modified Kostiakov Model

针对传统土壤入渗试验耗时较长的问题,采用一维垂直入渗试验,基于修正Kostiakov模型建立了土石混合物入渗过程测量方法,依据前11min任意两时刻入渗率实测值和饱和导水率实测值推算土石混合物完整入渗过程。土壤重度设定为1.2、1.3、1.4g/cm^3,分别设置10%、20%、30%、40%四种不同碎石含量和0.2~0.4、1~2cm两种碎石粒径,测量过程持续150min直到土石混合物达到稳定入渗。以入渗前11min的三组正交试验数据(2,5),(2,11),(5,11)min推算完整入渗过程的入渗率计算值与实测值,采用计算值与实测值的比例系数、相对误差δ和均方根误差RRMSE来验证该测量方法的准确性。结果表明,该测量方法入渗率计算值与实测值吻合结果较好,土壤重度1.2、1.3、1.4g/cm^3的土石混合物δ值分别介于1.14%~13.05%、4.37%~21.06%、1.53%~18.82%之间,RRMSE值分别介于4.15~10.72、2.74~9.66、2.17~6.31mm/h之间,说明该方法能较大程度地缩短土石混合物入渗测量时间,且具有较高精度。

In view of the long time-consuming problem of traditional soil infiltration test,one-dimensional vertical infiltration test was used to establish a measurement method for the infiltration process of earth rock mixture based on the modified Kostiakov model.The complete infiltration process of earth rock mixture was calculated according to the measured values of infiltration rate and saturated hydraulic conductivity at any two times in the first 11 minutes.The soil bulk density was set as 1.2,1.3 and 1.4 g/cm3,with four different gravel contents of 10%,20%,30%and 40%and two gravel sizes of 0.2-0.4 and 1-2 cm respectively.The measurement process lasted for 150 min until the soil rock mixture reaches stable infiltration.According to the infiltration before 11 min of the three groups of orthogonal test data(2,5),(2,11),(5,11)min,the calculated and measured values of infiltration rate in the whole infiltration process were estimated.The accuracy of the measurement method was verified by the ratio coefficient,relative error and root mean square error RRMSE of the calculated and measured values.The results show that the calculated values of infiltration rate are in good agreement with the measured values.The values of soil rock mixture of 1.2,1.3 and 1.4 g/cm3 are respectively between 1.14%-13.05%,4.37%-21.06%,1.53%-18.82%,and the RRMSE values are respectively between 4.15-10.72,2.74-9.66 and 2.17-6.31 mm/h.It is shown that this method can shorten the time of soil and rock mixture infiltration measurement to a large extent and has high accuracy.