基于响应曲面法优化二灰滨海盐渍土的配合比设计

为了确定固化盐渍土的最优改良方案,应用响应曲面法优化了石灰与粉煤灰复合改良盐渍土的室内试验方案。通过室内试验,测试了改良后盐渍土的无侧限抗压强度值,应用Design-Expert8.0软件分别选取含盐量X_1、石灰掺量X_2、粉煤灰掺量X_3为试验因素,利用Box-Behnken响应曲面法进行试验设计,分析了含盐量、石灰和粉煤灰掺量对固化盐渍土无侧限抗压强度的影响,并确定了盐渍土的合理改良方案。结果表明,二灰固化盐渍土最优配比:含盐量X_1为3%,石灰掺量X_2为12%,粉煤灰掺量X_3为24%时,固化土的无侧限抗压强度指标达到最大,该模型预测值为0.784MPa,与实测值仅相差0.014 MPa。响应曲面法可以用于各类固化盐渍土改良方案的比选和研究,对滨海盐渍土的其他固化方法具有一定的参考价值。

Response surface methodology-based optimization of design of mixing ratio of inshore saline soil with lime-fly ash

In order to determine the optimal improvement scheme of solidified saline soil，the scheme for the lab experiment on the lime-fly ash compound improved saline soil is optimized with the response surface methodology. Through the lab experiment，the unconfined compressive strength of the improved saline soil is tested，and then the salt content X1，lime content X2，fly ash mixed X3 are respectively selected as the test factors with the software of Design-Expert 8.0，while the Box-Behnken response surface method is adopted for the design of the experiment； from which the impacts from the salt content，lime and ash mixtures on the unconfined compressive strength of saline soil are analyzed and a reasonable improvement scheme for saline soil is determined as well. The result shows that when the optimal mixing ratio of the solidified saline soil mixed with lime and fly ash is to be salt content X1 of 3%，lime content X2 of 12% and fly ash mixed X3 of 24%，the index of the unconfined compressive strength of the solidified soil is the maximum，for which the predicted value from the model is 0.784 MPa with only a difference of 0.014 MPa to the measured one. The response surface methodology can be used for the comparative selection and study of improvement schemes of various solidified saline soils，thus has a certain reference to the other solidifying methods for the inshore saline soil.