The consolidation behavior of mixed in place cement and lime/cement mixed column was studied. Consolidation of the composite foundation was modeled as a three dimensional axi symmetric problem. The authors used t...The consolidation behavior of mixed in place cement and lime/cement mixed column was studied. Consolidation of the composite foundation was modeled as a three dimensional axi symmetric problem. The authors used the finite difference method to obtain the pore pressure variation with time at any location below the surface. A computer program developed by the authors was used to draw some interesting conclusions about the consolidation behaviors of cement and lime/cement mixed pile foundation. Finally, a combined model including the permeability coefficients of cement mixed piles and soil, was studied and its feasibility was evaluated.展开更多
The collapsibility of loess ground can directly affect stability of subgrade. Therefore, how to adopt practical technical measures to reduce or eliminate its collapse deformation is an important content in foundation ...The collapsibility of loess ground can directly affect stability of subgrade. Therefore, how to adopt practical technical measures to reduce or eliminate its collapse deformation is an important content in foundation design in collapsible loess zone. Selecting collapsible loess from Fuxin-Chaoyang highway in Liaoning, the authors conducted a series of tests for improving loess with cement. The loess in different water content was mixed with the cement in varying proportions, unconfined compression strength for the samples at four different curing periods were tested, and the relationships of improved soil strength among cement mixture ratio and curing periods were analyzed. When the curing periods are certain, the strength of loess increases along with the mixture ratio increases; when the cement mixture ratio is 5%-15%, the scope of increases is quite obvious; when the mixture ratio is greater than 15%, the tendency of intensity increases turns slow. When the mixture ratio for the specimen is certain, the intensity of the test specimen increases along with the curing period increases, the intensity grows obviously in 28 days, and the growth rate is small in 28-90 days, the intensity tends to be steady in the curing period of 90 days.展开更多
Complex formation of cerium （Ⅲ） with l-phenyl-2,3-dimethylpyrazolone-5-azo-4-pyrogallole （L） in the presence and absence ofcetylpyridine chloride （CPC） was investigated. Homogeneous CeL- and mixed ligand CeL-CP...Complex formation of cerium （Ⅲ） with l-phenyl-2,3-dimethylpyrazolone-5-azo-4-pyrogallole （L） in the presence and absence ofcetylpyridine chloride （CPC） was investigated. Homogeneous CeL- and mixed ligand CeL-CPC compounds are formed at pH 6. Constants of stability of the complexes are （IgKD 5.15±0.02 （CeL）, 7.98±0.03 （CeL-CPC）. Ratio of reagents in composition of homogeneous is （1 ：2） and in different ligand it equals to （1：2：2）. Beer＇s law is observed in interval of concentration 1.12-11.2 μg/ml Ce. The technique for photometric determination of cerium was worked out in artificial mixture.展开更多
文摘The consolidation behavior of mixed in place cement and lime/cement mixed column was studied. Consolidation of the composite foundation was modeled as a three dimensional axi symmetric problem. The authors used the finite difference method to obtain the pore pressure variation with time at any location below the surface. A computer program developed by the authors was used to draw some interesting conclusions about the consolidation behaviors of cement and lime/cement mixed pile foundation. Finally, a combined model including the permeability coefficients of cement mixed piles and soil, was studied and its feasibility was evaluated.
基金Project supported by Natural Science Foundation of China (No. 40972171)
文摘The collapsibility of loess ground can directly affect stability of subgrade. Therefore, how to adopt practical technical measures to reduce or eliminate its collapse deformation is an important content in foundation design in collapsible loess zone. Selecting collapsible loess from Fuxin-Chaoyang highway in Liaoning, the authors conducted a series of tests for improving loess with cement. The loess in different water content was mixed with the cement in varying proportions, unconfined compression strength for the samples at four different curing periods were tested, and the relationships of improved soil strength among cement mixture ratio and curing periods were analyzed. When the curing periods are certain, the strength of loess increases along with the mixture ratio increases; when the cement mixture ratio is 5%-15%, the scope of increases is quite obvious; when the mixture ratio is greater than 15%, the tendency of intensity increases turns slow. When the mixture ratio for the specimen is certain, the intensity of the test specimen increases along with the curing period increases, the intensity grows obviously in 28 days, and the growth rate is small in 28-90 days, the intensity tends to be steady in the curing period of 90 days.
文摘Complex formation of cerium （Ⅲ） with l-phenyl-2,3-dimethylpyrazolone-5-azo-4-pyrogallole （L） in the presence and absence ofcetylpyridine chloride （CPC） was investigated. Homogeneous CeL- and mixed ligand CeL-CPC compounds are formed at pH 6. Constants of stability of the complexes are （IgKD 5.15±0.02 （CeL）, 7.98±0.03 （CeL-CPC）. Ratio of reagents in composition of homogeneous is （1 ：2） and in different ligand it equals to （1：2：2）. Beer＇s law is observed in interval of concentration 1.12-11.2 μg/ml Ce. The technique for photometric determination of cerium was worked out in artificial mixture.
