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Rainfall-induced slope failures in Taiwan
Published in H. Rahardjo, D.G. Toll, E.C. Leong, Unsaturated Soils for Asia, 2020
The rain intensity must be greater than 36 mm/hr (the coefficient of soil permeability of the studied lateritic soil) in order to form the wetting front, if no run-off is considered. Assuming a return period of 50 years for the analysis and using the rain intensity-duration-frequency curve (Fig. 5) from the Linkou rainfall data, the corresponding effective duration is determined to be 7.3 hours when the rain intensity is 36 mm/hr. Other parameters Sf, Si, n, and k are determined as 1.0, 0.7, 0.495, 0.001 cm/sec (36 mm/hr), Respectively. Substituting these parameters into (2), the maximum thickness of the wetting front h is 1.77 m. However, according to the site condition, the run-off coefficient is 0.5. In such case, the rainfall intensity needs to be increased to 72mm/hr to form the wetting front. The duration corresponding to a rain fall intensity of 72 mm/hr is 2.5 hours. Then the thickness of wetting front became 1.2 m. In this study, the maximum thickness of wetting front is conservatively assumed to be 2 meters.
Computational investigation on surface water distribution and permeability of porous asphalt pavement
Published in International Journal of Pavement Engineering, 2022
Xiao Chen, Hao Wang, Chang Li, Weiguang Zhang, Guangji Xu
It is not always the case that the rainfall would last for 12 h without changing its intensity. Thus, it could be more accurate to take the dynamic rainfall intensity into consideration. Currently, Chicago hyetograph method is a classical and well-known method proposed by Keifer and Chu (1957) to calculate design rainfalls of urban storm water infrastructures, which presents rainfall rates as continuous functions of time, one valid for times before peak and another for after peak. It could provide the rainfall intensity variation as time goes for obtaining design hyetographs, namely intensity–duration–frequency curve. After transmission, the intensity–duration–frequency curve of the violent rain according to Chicago hyetograph method is shown in Figure 10.