高位滑坡对建筑集群的冲击破坏时常导致严重的人员伤亡,基于光滑粒子流体动力学-离散元法-有限元法(smoothed particle hydrodynamics-discrete element method-finite element method,SPH-DEM-FEM)耦合的数值模型,开展了高位滑坡对框...高位滑坡对建筑集群的冲击破坏时常导致严重的人员伤亡,基于光滑粒子流体动力学-离散元法-有限元法(smoothed particle hydrodynamics-discrete element method-finite element method,SPH-DEM-FEM)耦合的数值模型,开展了高位滑坡对框架结构建筑群的冲击过程、建筑结构破坏机理、冲击力时程与框架柱关键点应力和弯矩等动力机制研究。研究结果表明:SPH-DEM-FEM耦合数值方法能够有效地模拟碎石土滑坡中土(SPH)石(DEM)混合物的抛射弹跳、爬高绕流冲击运动过程。考虑了常规建筑垂直、平行于滑坡流向的三排建筑组合布局,位于滑坡近端的纵向排列建筑表现为连续性倾倒破坏,横向排列的建筑则呈现整体倾倒破坏;因前排建筑群对滑坡冲击能量的耗散及滑坡自身摩擦耗能,位于滑坡后端建筑表现为引流面墙体和前排柱发生局部破坏,结构保持稳定,损毁程度依次为上游无建筑缓冲耗能的建筑>有横向排列的建筑>有纵向排列的建筑;纵向、横向排列的建筑冲击力衰减幅度分别31%、21%。横向框架建筑整体倾倒的损毁机制表现为框架柱的直接剪断或节点塑形铰链失效;纵向框架建筑连续性倾倒的损毁机制表现为前排框架柱的失效引起后排框架柱轴向压力和极限弯矩增加,持续冲击荷载超过其极限弯矩致使后排框架柱发生弯曲破坏,最终结构倾倒。系统能量在动能、内能和摩擦耗能间转化,其中摩擦耗能占65.5%,结构耗能占23.6%,动能快速下降与内能急剧增加是建筑破坏的关键特征。展开更多
沙湾大沟泥石流位于云南省昆明市寻甸县,发育历史悠久,活动性强,有过多次大规模爆发记录,其原有阶梯型导流槽磨蚀损毁严重,几近失效。因此,为减缓泥石流对原有结构的磨蚀效应,在三期治理工程中提出将导流槽底面设计为“曲面跌水”的特...沙湾大沟泥石流位于云南省昆明市寻甸县,发育历史悠久,活动性强,有过多次大规模爆发记录,其原有阶梯型导流槽磨蚀损毁严重,几近失效。因此,为减缓泥石流对原有结构的磨蚀效应,在三期治理工程中提出将导流槽底面设计为“曲面跌水”的特殊形式,该结构实际运行后效果良好,为进一步研究沙湾大沟泥石流对导流设施的冲击过程及动力响应特征规律,该文引入光滑粒子流体动力学-离散单元法-有限单元法耦合方法(smoothed particle hydrodynamics-discrete element method-finite element method,SPH-DEM-FEM),构建沙湾大沟泥石流导流系统流固耦合模型,对泥石流冲击“曲面跌水”导流设施进行运动过程分析,并与二期原有阶梯型导流槽开展对比研究。结果表明,泥石流冲击“曲面跌水”导流设施过程中导流槽右侧积聚和爬升现象明显,左右两侧峰值速度分别为24.96、17.38 m/s,不同坡度衔接段及出口处水平段受冲击较大,等效应力峰值为722.3 kPa。在相同的工程条件下,曲面型导流槽对泥石流颗粒的减速消能效果更好,在保证排导功能基础上,其使用寿命优于阶梯型导流槽,研究成果为该类型导流槽的设计及应用提供了一定的参考依据及理论支撑。展开更多
To evaluate the dynamic interactions between debris flows,entrained material sources,and infrastructure in the Naojiao Gully watershed of Beijing,and to develop a predictive framework for mitigating geohazard risks th...To evaluate the dynamic interactions between debris flows,entrained material sources,and infrastructure in the Naojiao Gully watershed of Beijing,and to develop a predictive framework for mitigating geohazard risks through energy-based strategies,debris flow dynamics are investigated,a coupled SPH-DEM-FEM multiscale model integrating fluid dynamics(SPH),granular mechanics(DEM),and structural mechanics(FEM)is developed to simulate debris flow propagation,material source behavior,and frame structure responses,and to capture cross-scale failure mechanisms.Key findings include the identification of a critical flow velocity threshold of 12 m/s,beyond which solid-phase kinetic energy dominates,inducing 60%-75%capacity loss in central columns via through-cracking.Furthermore,a novel compound failure criterion is proposed based on the solid-liquid energy proportion.The model achieves a boulder impact force prediction error of only 5.47%,significantly outperforming empirical methods in cross-scale accuracy.An optimized 0.3 m layered configuration experimentally reduces impact pulse peaks by 57%through directed energy redistribution,thereby shifting mitigation strategies from structural reinforcement to media modulation.These results establish a robust framework for quantifying failure thresholds,enhancing predictive precision,and innovating energy-based mitigation.By bridging multiscale modeling gaps in geohazard analysis,this study provides actionable insights for infrastructure resilience in debris flow-prone regions through energycentric design principles.展开更多
文摘高位滑坡对建筑集群的冲击破坏时常导致严重的人员伤亡,基于光滑粒子流体动力学-离散元法-有限元法(smoothed particle hydrodynamics-discrete element method-finite element method,SPH-DEM-FEM)耦合的数值模型,开展了高位滑坡对框架结构建筑群的冲击过程、建筑结构破坏机理、冲击力时程与框架柱关键点应力和弯矩等动力机制研究。研究结果表明:SPH-DEM-FEM耦合数值方法能够有效地模拟碎石土滑坡中土(SPH)石(DEM)混合物的抛射弹跳、爬高绕流冲击运动过程。考虑了常规建筑垂直、平行于滑坡流向的三排建筑组合布局,位于滑坡近端的纵向排列建筑表现为连续性倾倒破坏,横向排列的建筑则呈现整体倾倒破坏;因前排建筑群对滑坡冲击能量的耗散及滑坡自身摩擦耗能,位于滑坡后端建筑表现为引流面墙体和前排柱发生局部破坏,结构保持稳定,损毁程度依次为上游无建筑缓冲耗能的建筑>有横向排列的建筑>有纵向排列的建筑;纵向、横向排列的建筑冲击力衰减幅度分别31%、21%。横向框架建筑整体倾倒的损毁机制表现为框架柱的直接剪断或节点塑形铰链失效;纵向框架建筑连续性倾倒的损毁机制表现为前排框架柱的失效引起后排框架柱轴向压力和极限弯矩增加,持续冲击荷载超过其极限弯矩致使后排框架柱发生弯曲破坏,最终结构倾倒。系统能量在动能、内能和摩擦耗能间转化,其中摩擦耗能占65.5%,结构耗能占23.6%,动能快速下降与内能急剧增加是建筑破坏的关键特征。
文摘泥石流作为高破坏性混合流体,其携带的块石对框架结构的冲击机制尚未得到充分研究。为揭示含块石泥石流冲击框架结构的动力响应与损伤机制,基于光滑粒子流体动力学-离散元法-有限元法(smoothed particle hydrodynamics-discrete element method-finite element method,SPH-DEM-FEM)耦合数值方法,构建流体-块石-结构的多耦合数值模型,模拟不同冲击速度和角度下框架结构的损伤过程,并结合两相溃坝试验来验证模型有效性。研究表明:泥石流冲击导致结构损伤经历“接触-扩散-反弹-堆积/冲击”四个阶段,当冲击速度超过6.00 m/s时,结构产生不可恢复损伤,且块石阻隔作用使流体上部冲击力大于下部,引发结构中部最先发生集中损伤;此外,冲击力峰值随速度和角度增大呈非线性增长,10.00 m/s与90°工况下框架柱底冲击力达497.17 kN,超过结构抗冲击承载力;最后,数值模拟与经验公式所得冲击力结果误差在13.95%~29.00%,数量级一致,验证了模型可靠性。研究结果可为泥石流高发区框架结构的抗冲击设计提供参考。
文摘沙湾大沟泥石流位于云南省昆明市寻甸县,发育历史悠久,活动性强,有过多次大规模爆发记录,其原有阶梯型导流槽磨蚀损毁严重,几近失效。因此,为减缓泥石流对原有结构的磨蚀效应,在三期治理工程中提出将导流槽底面设计为“曲面跌水”的特殊形式,该结构实际运行后效果良好,为进一步研究沙湾大沟泥石流对导流设施的冲击过程及动力响应特征规律,该文引入光滑粒子流体动力学-离散单元法-有限单元法耦合方法(smoothed particle hydrodynamics-discrete element method-finite element method,SPH-DEM-FEM),构建沙湾大沟泥石流导流系统流固耦合模型,对泥石流冲击“曲面跌水”导流设施进行运动过程分析,并与二期原有阶梯型导流槽开展对比研究。结果表明,泥石流冲击“曲面跌水”导流设施过程中导流槽右侧积聚和爬升现象明显,左右两侧峰值速度分别为24.96、17.38 m/s,不同坡度衔接段及出口处水平段受冲击较大,等效应力峰值为722.3 kPa。在相同的工程条件下,曲面型导流槽对泥石流颗粒的减速消能效果更好,在保证排导功能基础上,其使用寿命优于阶梯型导流槽,研究成果为该类型导流槽的设计及应用提供了一定的参考依据及理论支撑。
基金funded by the Natural Science Foundation of Hebei Province(D2025201012)Highlevel Innovative Talents Program of Hebei University(Grant No.521100222055)President's Fund of Hebei University(Grant No.XZJJ202205)。
文摘To evaluate the dynamic interactions between debris flows,entrained material sources,and infrastructure in the Naojiao Gully watershed of Beijing,and to develop a predictive framework for mitigating geohazard risks through energy-based strategies,debris flow dynamics are investigated,a coupled SPH-DEM-FEM multiscale model integrating fluid dynamics(SPH),granular mechanics(DEM),and structural mechanics(FEM)is developed to simulate debris flow propagation,material source behavior,and frame structure responses,and to capture cross-scale failure mechanisms.Key findings include the identification of a critical flow velocity threshold of 12 m/s,beyond which solid-phase kinetic energy dominates,inducing 60%-75%capacity loss in central columns via through-cracking.Furthermore,a novel compound failure criterion is proposed based on the solid-liquid energy proportion.The model achieves a boulder impact force prediction error of only 5.47%,significantly outperforming empirical methods in cross-scale accuracy.An optimized 0.3 m layered configuration experimentally reduces impact pulse peaks by 57%through directed energy redistribution,thereby shifting mitigation strategies from structural reinforcement to media modulation.These results establish a robust framework for quantifying failure thresholds,enhancing predictive precision,and innovating energy-based mitigation.By bridging multiscale modeling gaps in geohazard analysis,this study provides actionable insights for infrastructure resilience in debris flow-prone regions through energycentric design principles.
