Experimental study for effects of terrain features and rainfall intensity on infiltration rate of modelled permeable pavement.

In order to investigate the effects of the terrain slopes and rainfall intensity on the steady infiltration rate of permeable pavement, an experiment with the combinations of three types of permeability, three kinds of rainfall intensity, different cross slope and longitudinal slope are undertaken. Through analyzing the experimental data, it is indicated that: (1) the relation between the steady infiltration rate and the cross and longitudinal slopes can be described by power functions, i.e. as the slopes increase, the steady infiltration rate decreases. The steady infiltration rate can be reduced by 23.3%-72.2% and 12.6%-22.2% for the slopes ranging from 0° to 5° and from 5° to 10°, respectively, illustrating the infiltration is more sensitive to the 0°-5° slope; (2) Under the same conditions, the effect of the cross slope on the steady infiltration rate is about 1.1-1.4 times as high as that of the longitudinal slope, i.e. the cross slope varying could lead to more obvious infiltration change, comparing to the longitudinal slope; (3) The relation between the rainfall intensity and the infiltration rate can be reflected by power function as well. The higher the rainfall intensity, the more the steady infiltration rate increases; (4) The comprehensive effect of the cross slope, longitudinal slope and rainfall intensity on steady infiltration rate can be expressed by quadratic polynomial functions. The main purpose of the manuscript is to determine how the slopes and the rainfall intensities affect the infiltration process and guide the plan and design of the permeable pavement in practical engineering.