Combined with the engineering example of cast-in-place bored pile in the area of deep miscellaneous fill, according to the single variable factor analysis method, the key factors of hole collapse of cast-in-place bore...Combined with the engineering example of cast-in-place bored pile in the area of deep miscellaneous fill, according to the single variable factor analysis method, the key factors of hole collapse of cast-in-place bored pile are determined. The results show that the main factors of hole collapse are loose structure of miscellaneous fill layer, insufficient settlement consolidation and low slurry viscosity of retaining wall. In order to improve the compactness of miscellaneous fill and the low viscosity of mud, the foundation dynamic compaction was adopted to accelerate the self-weight settlement and consolidation of miscellaneous fill, and the mud viscosity was tested. According to the effect of mud under different viscosities, the optimal viscosity ratio was selected. The verification test of cast-in-place bored piles is carried out after the improvement of the two factors. The results show that, under the conditions of improving the compactness of miscellaneous fill and improving the viscosity of mud, the effect of improving the qualified rate of one-time hole formation of cast-in-place bored piles is obvious. In an engineering example, the hole collapse rate can be reduced to less than 10%, which has reference significance for practical engineering application.展开更多
文摘Combined with the engineering example of cast-in-place bored pile in the area of deep miscellaneous fill, according to the single variable factor analysis method, the key factors of hole collapse of cast-in-place bored pile are determined. The results show that the main factors of hole collapse are loose structure of miscellaneous fill layer, insufficient settlement consolidation and low slurry viscosity of retaining wall. In order to improve the compactness of miscellaneous fill and the low viscosity of mud, the foundation dynamic compaction was adopted to accelerate the self-weight settlement and consolidation of miscellaneous fill, and the mud viscosity was tested. According to the effect of mud under different viscosities, the optimal viscosity ratio was selected. The verification test of cast-in-place bored piles is carried out after the improvement of the two factors. The results show that, under the conditions of improving the compactness of miscellaneous fill and improving the viscosity of mud, the effect of improving the qualified rate of one-time hole formation of cast-in-place bored piles is obvious. In an engineering example, the hole collapse rate can be reduced to less than 10%, which has reference significance for practical engineering application.
