Aimed at the impact force of the debris flow occurred on July 10,2013,which buried the facilities including Duwen highway at the deposition fan of Taoguan gully,the formation condition and development characteristic of the debris flow through field investigation were identified,and relevant kinematics parameters were determined by using the rain flood method.Applying large scale fluid dynamics software CFX,the process of 10th July debris flow in Duwen highway segment and its motion feature were simulated.The motional dynamics and hazardous zone of the debris flow were obtained.The distribution of the velocity field and the influence on facilities localized along the debris flow gully were analyzed.Meanwhile,the impact force of the debris flow and the corresponding risk on the bridge pier of Duwen highway were intensively studied.The simulated results agreed well with the calculated ones by empirical formula with an error of only 5.8%.
