基于微结构指标响应曲面法的固化盐渍土力学特性分析

固化土力学强度指标与固化土结构变化的关系是盐渍土特性研究中的重要问题。选取颗粒粒度分维D_(ps)、颗粒定向分维D_(di)、等效直径D_e为试验因素,利用响应曲面法进行试验。响应曲面模型可以对固化土的力学性能指标进行分析和预测,利用该模型研究石灰固化盐渍土的力学强度指标与最优微结构参数之间的关系,并进行了验证。结果表明,固化土微结构最优指标是粒度分维D_(ps)为0.8、颗粒定向分维D_(di)为0.93、等效直径D_e为1.75时,固化土无侧限抗压强度q达到1.636 MPa,与实测值仅相差0.038 MPa;黏聚力c为456.7 k Pa,与实测值完全一致;内摩擦角为39.6°,与实测值仅相差0.2°。该模型为探讨各类固化盐渍土物理化学指标、各掺加料比例及固化土微结构之间相互关系提供了借鉴和依据。

Analysis on mechanical properties of solidified saline soil with microstructure index-based response surface methodology

The relationship between the mechanical strength indexes of solidified saline soil and its structure change is an important problem within the study made on the characteristics of saline soil. The relevant experiment is made with response surface methodology by selecting particle size fractal dimension Dps，particle orientation fractal dimension Ddi，equivalent diameter De as the experimental factors. As the mechanical characteristic indexes of the solidified soil can be analyzed and predicted by the response surface model，the relationship between the mechanical strength indexes of the lime-solidified saline soil and its optimal parameters of the microstructure is studied with this model，and then is verified as well. The result shows that the unconfined compressive strength of q reaches to 1.636 MPa and is only different from the measured value by 0.038 MPa，the cohesion c is 456.7 kPa and fully coincides with the measured one and the internal friction angle  is 39.6°and is only different from the measured one by 0.2° for the solidified soil，when the optimal indexes of the solidified soil microstructure are 0.8 for the particle size fractal dimension Dps，0.93 for the particle orientation fractal dimension Ddi and 1.75 for the equivalent diameter De respectively. This model provides a reference and basis for the study on the correlation among all the physical and chemical indexes，all the proportions of the mixtures and the solidified soil microstructures of all kinds of the solidified saline soil.