A FINITE ELEMENT STUDY OF THE EFFECT OF SLOPE AND RAINFALL INTENSITY ON SUBSURFACE OUTFLOW OF PERMEABLE FRICTION COURSE PAVEMENT

Abstract

Permeable friction course pavement is designed with high porosity so that water can infiltrate into its pores and drain out laterally through the side. This study observes the subsurface outflow of a permeable friction course pavement via the finite element analysis program SV Flux 2D. A series of analyses were conducted for the permeable friction course pavement with different slope and rainfall intensity values. The results showed that different slope values provided different results for the subsurface outflow. As the slope increased, the subsurface outflow of the permeable friction course pavement increased. It is noticed that the effect of slope on the subsurface outflow decreased when the slope increased from 6% to 8%. In addition, this study also found that as the time of rain events increased, the subsurface outflow pavement was reduced. The investigation of the effect of rainfall intensity on the subsurface outflow of the permeable friction course pavement showed that as the rainfall intensity increased, the subsurface outflow steadily increased. However, it is noted that at the higher rainfall intensity, the pavement became saturated faster and the overflow happened earlier. In the future, further studies focused on the drainage of permeable friction course pavement including subsurface and surface outflow should be carried out.