The Study Of Rapid And Long-runout Characteristics Of Wenjiagou Landslide Based On PFC3D

The mechanism of long-runout landslides is always being a key and difficultsubject for the researchers. Taking the Wenjiagou landslide as a typical case, based onthe field investigation and series of indoor tests, this paper studied the mobility anddeposition characteristics of this landslide by using the discrete element softwarePFC3D for the first time. Meanwhile, the influence of topography, landslide’s volumeand lithologic characteristics for debris flow were also described, with the use of thethree-dimensional numerical simulation method. And the main contents and results ofthe paper:First of all, it brought out that the topography and grain size distribution have agreat influence on the mobility of debris. With the grain size distribution gets better orworse, and with the existence of “V” valley, it adverses to the produce of high speedand long-runout of debris flow. In addition to the particle size and morphology havingno obvious effects on the mobility of debris, it was found that, with the volume orthe friction coefficient gets larger, the harder the debris travels forward.For the second, it used the PFC3D software to simulate the whole process ofWenjiagou landslides from start to stop by sliding the source into parts. It turned outthat the results get close to the site investigation quitely. Besides, it obviously had thephenomenon of turning, climing and exceeding during the landslide of simulation.The results showed that the landslide took120seconds from start to stop as wellas the maximum speed was43.5m/s and136.4m/s, for the mass center and rockrespectively. What’s more, the maximum travel distance of the mass center and rockhad the value of2088m and4717m. It was obvious that the landslide hadalready turned into debris flow at last.