Study on prevention and treatment of capillary water rise for construction waste expansive soil subgrade

This paper solves the technical difficulties of the capillary water rising height of the construction waste improved expansive soil subgrade (CWS), analyses the capillary water rising mechanism of the construction waste improved expansive soil subgrade cushion and evaluates the improvement effect of the improved cushion by comparing different working conditions with simulation software. The analysis results show that: (1) a reasonable ratio of the improved subgrade bed can effectively improve the porosity of the cushion layer, thus effectively inhibiting capillary water rising height. (2) the practical improvement of the thickness of the cushion layer can slow the matrix suction effect of expansive soil, (3) the construction waste had a more significant influence on the particle gradation for the capillary water rise, poor grading cushion layer has a significant influence on the capillary water rise, (4) the construction waste particles in the improved graded cushion of construction waste have strong water absorption, which improves the matrix suction effect of expansive soil. (5) Through experiments and simulation tests, this paper concludes that the optimal grade subgrade bedding of construction waste expansive soil is of specific theoretical value and practical significance for developing the construction waste material transformation subgrade. Keyword: Construction Waste, the capillary water rise mechanism, well-graded CWS.