CAJ | 학술논문

土-水特征曲线是非饱和土力学研究中的一条重要曲线，其拟合参数对于分析非饱和土的各种性质具有重要意义。基于渗析法及滤纸法试验，测定了合肥市某工地非饱和膨胀土的土-水特征。以van Genuchten模型为基础，采用科学计算语言Matlab中的Lsqcurvefit函数对试验结果进行了曲线拟合，分析了土-水特征曲线拟合参数的多解性及其影响因素。拟合结果表明：渗析法试验得到的吸力范围偏低，拟合参数多解性较为明显；综合2种试验结果，可以得到较大吸力范围内的土-水特征曲线，且参数多解性较小；参与土-水特征曲线拟合的试验数据点的吸力范围应足够大，试验数据点应能够代表整条曲线的形状，试验点不必太过于密集，否则土-水特征曲线拟合参数的多解性较为明显；另一方面，只要试验数据点能代表整条曲线的形状，试验数据点的个数不必太多。这一研究结果对提高土-水特征曲线拟合参数的精度、提高试验效率有重要指导意义。
토-수특정곡선시비포화토역학연구중적일조중요곡선，기의합삼수대우분석비포화토적각충성질구유중요의의。기우삼석법급려지법시험，측정료합비시모공지비포화팽창토적토-수특정。이van Genuchten모형위기출，채용과학계산어언Matlab중적Lsqcurvefit함수대시험결과진행료곡선의합，분석료토-수특정곡선의합삼수적다해성급기영향인소。의합결과표명：삼석법시험득도적흡력범위편저，의합삼수다해성교위명현；종합2충시험결과，가이득도교대흡력범위내적토-수특정곡선，차삼수다해성교소；삼여토-수특정곡선의합적시험수거점적흡력범위응족구대，시험수거점응능구대표정조곡선적형상，시험점불필태과우밀집，부칙토-수특정곡선의합삼수적다해성교위명현；령일방면，지요시험수거점능대표정조곡선적형상，시험수거점적개수불필태다。저일연구결과대제고토-수특정곡선의합삼수적정도、제고시험효솔유중요지도의의。
Soil-water characteristic curve (SWCC) is a very important curve in the study of unsaturated soil mechanics;and the curve fitting parameters of SWCC are significant for analyzing the properties of unsaturated soils. To obtain the curve fitting parameters of SWCC accurately and efficiently, the experimental design and the curve fitting method of SWCC are studied. Based on the osmotic method and the filter paper method, a SWCC of an unsaturated expansive soil in a construction site in Hefei is measured. The van Genuchten model is used to represent the relationship between gravity water content and matric suction of the tested soil. The Lsqcurvefit function of the scientific language Matlab is adopted for carrying out the curve fitting of SWCC because the Lsqcurvefit function can set the lower limits and upper limits of fitting parameters. The problem of multi solutions of curve fitting parameters of SWCC and its influence factors are studied. It is demonstrated that when only the experimental data of the osmotic method is used, the range of suction is relatively small;and the multi solution phenomenon of SWCC’s fitting parameters is obvious. However, if the experimental data of both the osmotic method and the filter paper method are used, the range of suction is relatively large. Then, the multi solution phenomenon of SWCC’s fitting parameters can be diminished. And if the range of suction is large enough to represent the shape of the whole SWCC, the number of experimental data points need not be too much. Based on these conclusions, the experiment for measuring the soil-water characteristic curve can be designed more efficiently;and then the curve fitting parameters can be obtained more accurately.