| Model Development and Simulations in Multiphase Landslide, Debris Flows and Avalanches Bhadra Tuladhar1; 1KATHMANDU UNIVERSITY, Kavre, Nepal; PAPER: 313/Mathematics/Regular (Oral) SCHEDULED: 15:15/Wed. 30 Nov. 2022/Arcadia 3 ABSTRACT: To make the earth a better place to live in as the ultimate goal for the sustainable development, mankind has to understand different earth processes and their dynamics. Nepal is a mountainous country where landslide, debris flow, land tsunami and other gravitational mass flow hazards claim many human lives every year. For the prevention and mitigation of such hazards, systematic study of such events is needed. We discuss our modeling and simulation techniques related to different gravitational mass flows, especially with physics-based two-phase mass flow model [1]. We discuss our attempts to model Glacial Lake Outburst Floods (GLOFs), in three different initial and boundary conditions for the lake geometry, volume, and conduits. The results reveal different interesting flow dynamics of the solid and fluid-phases, lake-emptying process and levee formation during the flow [2]. We also discuss the interaction of two-phase debris flow with obstacles of different orientations and number at different locations of the flow path. The results show many naturally inline phenomena, like flow redirection, formation of vacuum behind the obstacles and the phase-separation. The computation of the novel barycentric impact pressures computed from the separate phasic impact pressures are important for the design of the structural mitigation measures [3]. For the flow through laterally converging channels, we relate the flow obstruction and the contraction ratio. We also discuss our full dimensional model developed for the modeling of bulk mixture of solid and fluid [4] and simulate the dry and wet snow avalanches of different water contents [5]. In the unified modeling and simulation techniques, we also discuss the dynamics of subaerial and partially submerged landslide and the interaction with a fluid reservoir downstream. The resulting short land tsunami wave generation, amplification and propagation along with the submarine mass movement [5, 6]. The different physics, mechanics and dynamics of the solid and fluid phases in the gravitational mass flows as revealed in our models and simulation results have enriched our understanding in the multiphase geophysical mass flow processes. References: [1] S.P. Pudasaini, J. Geoph. Res. 117, F03010 (2012). [2] P. Kattel, K.B. Khattri, P.R. Pokhrel, J. Kafle, B.M. Tuladhar, S.P. Pudasaini, Ann. Glaciol. 57(2016) 349-358. [3] P. Kattel, J. Kafle, J.-T. Fischer, M. Mergili, B.M. Tuladhar, S.P. Pudasaini, Eng. Geology. 242 (2018) 197-217. [4] P.R. Pokhrel, K.B. Khattri, B. M. Tuladhar, S.P. Pudasaini, Int. J. Non-Lin. Mech. 99(2018) 229-239. [5] K.B. Khattri, J.-T. Fischer, B. M. Tuladhar, M. Jaboyedoff, S.P. Pudasaini, Proc. ISSW-International Snow Science Workshop (2018). [6] J. Kafle, P.R. Pokhrel, K.B. Khattri, P. Kattel, B.M. Tuladhar, S.P. Tuladhar, Ann. Glaciol., 57 (2016) 232-244 |
