Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflector...Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflectors require further investigation.To date,few studies have investigated the impact of deflectors on controlling viscous debris flows for geological disaster prevention.To investigate the effect of rigid barrier deflectors on impact mechanisms,a numerical model using the smoothed particle hydrodynamics(SPH)method with the Herschel–Bulkley model is proposed to simulate the interaction between natural viscous flow and single/dual barriers with and without deflectors.This model was validated using laboratory flume test data from the literature.Then,the model was used to investigate the influence of the deflector angle and multi-barrier arrangements.The optimal configuration of multi-barriers was analyzed with consideration to the barrier height and distance between the barriers,because these metrics have a significant impact on the viscous flow pile-up,run-up,and overflow mechanisms.The investigation considered the energy dissipation process,retention efficiency,and dead-zone formation.Compared with bare barriers with similar geometric characteristics and spatial distribution,rigid barriers with deflectors exhibit superior effectiveness in preventing the overflow and overspilling of viscous debris flow.Recommendations for the rational design of deflectors and the optimal arrangement of multi-barriers are provided to mitigate geological disasters.展开更多
In order to advance the understanding of the impact dynamics of granular flow in complex geological settings,this paper studied the impact dynamics of granular flow on rigid barriers with a number of Material Point Me...In order to advance the understanding of the impact dynamics of granular flow in complex geological settings,this paper studied the impact dynamics of granular flow on rigid barriers with a number of Material Point Method(MPM)numerical tests.The impact behavior of granular flow on a rigid barrier was characterized by the initial dynamic impact stage,dynamic surge impact stage,compression impact stage and static stage of granular flow,where the impact force of granular flow was comprised of the dynamic and static forces of granular flow.The impact behavior of granular flow on a rigid barrier was characterized by the states of the fast or slow impact behavior of granular flow.The angle of slope and aspect ratio of granular soil greatly affected the impact behavior of granular flow on a column rigid barrier,where a power model was proposed to quantify the residual(Fnr)-over-maximum(Fnmax)normal impact force ratio of granular flow Fnr⁄Fnmax incorporating the effects of the angle of slope and aspect ratio of granular soil.With the increase of the column rigid barrier up to the semi-infinite column rigid barrier,the impact dynamics of granular flow gradually increased up to a maximum by progressively transforming the overflow into the dynamic surge impact of the incoming flow on the rigid barrier to capture more granular soil of granular flow against the rigid barrier.Presence of water in granular flow,i.e.,a mixture of solid and liquid in granular flow,yielded a dynamic coupling contribution of the solid and liquid,being accompanied by the whole dynamic process of granular flow,on the impact behavior of granular flow on a rigid barrier,where the liquid-phase material of granular flow,i.e.,the water,was predominant to contribute on the normal impact force of granular flow in comparison with the solid-phase material of granular flow.In addition,other factors,e.g.,the shape of rigid barrier(i.e.,the column barrier,arch barrier and circle barrier),and the gravity(i.e.,in the gravitational environment of the Moon,Earth and Mars),greatly affected the impact behavior of granular flow on a rigid barrier as well.展开更多
Rigid barrier is a straightforward and effective countermeasure widely used for mitigating debris flow.However,in current designs,it remains unclear how to optimize the rigid barrier to enhance its mechanical properti...Rigid barrier is a straightforward and effective countermeasure widely used for mitigating debris flow.However,in current designs,it remains unclear how to optimize the rigid barrier to enhance its mechanical properties.Therefore,this study investigates the influence of the shape of the upstream face of the rigid barrier,referred to as the'barrier shape',on the impact dynamics of debris flow entraining a boulder onto rigid barrier.This study employs a coupled numerical approach involving smoothed particle hydrodynamics(SPH),the discrete element method(DEM),and the finite element method(FEM).The simulation results demonstrate that the barrier shape can affect the mechanical properties of the rigid barrier by altering the interaction mode between the debris flow and the barrier.Compared to vertical and slanted barriers,a curved barrier exhibits superior mechanical properties when subjected to debris flow impact.Furthermore,reducing the slope of the upstream face appropriately proves to be an effective method for enhancing the impact resistance of slanted barriers.The relevant findings from this study can serve as valuable references for the structural optimization of rigid barriers.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42120104008 and 42207198).
文摘Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflectors require further investigation.To date,few studies have investigated the impact of deflectors on controlling viscous debris flows for geological disaster prevention.To investigate the effect of rigid barrier deflectors on impact mechanisms,a numerical model using the smoothed particle hydrodynamics(SPH)method with the Herschel–Bulkley model is proposed to simulate the interaction between natural viscous flow and single/dual barriers with and without deflectors.This model was validated using laboratory flume test data from the literature.Then,the model was used to investigate the influence of the deflector angle and multi-barrier arrangements.The optimal configuration of multi-barriers was analyzed with consideration to the barrier height and distance between the barriers,because these metrics have a significant impact on the viscous flow pile-up,run-up,and overflow mechanisms.The investigation considered the energy dissipation process,retention efficiency,and dead-zone formation.Compared with bare barriers with similar geometric characteristics and spatial distribution,rigid barriers with deflectors exhibit superior effectiveness in preventing the overflow and overspilling of viscous debris flow.Recommendations for the rational design of deflectors and the optimal arrangement of multi-barriers are provided to mitigate geological disasters.
基金supported by the Sichuan Science and Technology Program-China(Grant no.2023ZYD0149)National Natural Science Foundation of China(Grant no.U22A20603)and CAS"Light of West China"Program-China(Grant No.Fangwei Yu)In addition,a special acknowledgement should be expressed to a famous Chinese television drama:Qin Dynasty Epic(Issuance license no.2020006)that accompanied me(Dr.Fangwei Yu)through the loneliness time of completing this study.
文摘In order to advance the understanding of the impact dynamics of granular flow in complex geological settings,this paper studied the impact dynamics of granular flow on rigid barriers with a number of Material Point Method(MPM)numerical tests.The impact behavior of granular flow on a rigid barrier was characterized by the initial dynamic impact stage,dynamic surge impact stage,compression impact stage and static stage of granular flow,where the impact force of granular flow was comprised of the dynamic and static forces of granular flow.The impact behavior of granular flow on a rigid barrier was characterized by the states of the fast or slow impact behavior of granular flow.The angle of slope and aspect ratio of granular soil greatly affected the impact behavior of granular flow on a column rigid barrier,where a power model was proposed to quantify the residual(Fnr)-over-maximum(Fnmax)normal impact force ratio of granular flow Fnr⁄Fnmax incorporating the effects of the angle of slope and aspect ratio of granular soil.With the increase of the column rigid barrier up to the semi-infinite column rigid barrier,the impact dynamics of granular flow gradually increased up to a maximum by progressively transforming the overflow into the dynamic surge impact of the incoming flow on the rigid barrier to capture more granular soil of granular flow against the rigid barrier.Presence of water in granular flow,i.e.,a mixture of solid and liquid in granular flow,yielded a dynamic coupling contribution of the solid and liquid,being accompanied by the whole dynamic process of granular flow,on the impact behavior of granular flow on a rigid barrier,where the liquid-phase material of granular flow,i.e.,the water,was predominant to contribute on the normal impact force of granular flow in comparison with the solid-phase material of granular flow.In addition,other factors,e.g.,the shape of rigid barrier(i.e.,the column barrier,arch barrier and circle barrier),and the gravity(i.e.,in the gravitational environment of the Moon,Earth and Mars),greatly affected the impact behavior of granular flow on a rigid barrier as well.
基金supported by the National Key Research and Development Program of China(No.2022YFC3005704)the National Natural Science Foundation of China(No.42277143)+3 种基金the Natural Science Foundation of Sichuan Province(2024NSFSC0100)the Fundamental Research Funds for the Central Universities(No.2682023ZTPY022)Projects of Science and Technology Research and Development Program of China Railway Group Limited(2021-Special Class-03)the Natural Science Foundation of Sichuan Province(2024NSFSC0834).
文摘Rigid barrier is a straightforward and effective countermeasure widely used for mitigating debris flow.However,in current designs,it remains unclear how to optimize the rigid barrier to enhance its mechanical properties.Therefore,this study investigates the influence of the shape of the upstream face of the rigid barrier,referred to as the'barrier shape',on the impact dynamics of debris flow entraining a boulder onto rigid barrier.This study employs a coupled numerical approach involving smoothed particle hydrodynamics(SPH),the discrete element method(DEM),and the finite element method(FEM).The simulation results demonstrate that the barrier shape can affect the mechanical properties of the rigid barrier by altering the interaction mode between the debris flow and the barrier.Compared to vertical and slanted barriers,a curved barrier exhibits superior mechanical properties when subjected to debris flow impact.Furthermore,reducing the slope of the upstream face appropriately proves to be an effective method for enhancing the impact resistance of slanted barriers.The relevant findings from this study can serve as valuable references for the structural optimization of rigid barriers.
