To investigate the dynamic damage evolution characteristics of bank slopes with serrated structural planes,the shaking table model test and the numerical simulation were utilized.The main findings indicate that under ...To investigate the dynamic damage evolution characteristics of bank slopes with serrated structural planes,the shaking table model test and the numerical simulation were utilized.The main findings indicate that under continuous seismic loads,the deformation of the bank slope increased,particularly around the hydro-fluctuation belt,accompanying by the pore water pressure rising.The soil pressure increased and then decreased showed dynamic variation characteristics.As the undulation angle of the serrated structural planes increased(30°, 45°, and 60°),the failure modes were climbing,climbinggnawing,and gnawing respectively.The first-order natural frequency was used to calculate the damage degree(Dd)of the bank slope.During microseisms and small earthquakes,it was discovered that the evolution of Dd followed the“S”shape,which was fitted by a logic function.Additionally,the quadratic function was used to fit the Dd during moderately strong earthquakes.Through the numerical simulation,the variation characteristics of safety factors(Sf)for slopes with serrated structural planes and slopes with straight structural planes were compared.Under continuous seismic loads,the Sf of slopes with straight structural planes reduce stalely,whereas the Sf for slopes with serrated structural planes was greater than the former and the reduction rate was increasing.展开更多
爆炸作用下地面建筑目标的破坏分析对制定实战打击策略和工程防护具有重要的实践指导意义。采用LS-DYNA有限元分析软件对已有含填充墙钢筋混凝土(reinforced concrete,RC)框架结构的近区爆炸试验进行复现,充分验证了所采用的精细化数值...爆炸作用下地面建筑目标的破坏分析对制定实战打击策略和工程防护具有重要的实践指导意义。采用LS-DYNA有限元分析软件对已有含填充墙钢筋混凝土(reinforced concrete,RC)框架结构的近区爆炸试验进行复现,充分验证了所采用的精细化数值仿真方法的适用性。结合建筑结构混合单元建模方法,对典型三层含填充墙RC框架结构在典型战斗部(100 kg和200 kg TNT当量)爆炸作用下的动态响应开展了仿真分析,考察了爆炸波在结构内部的传播和结构损伤特性。基于等效单自由度(single-degree-of-freedom,SDOF)方法预测了爆炸荷载作用下框架结构梁、柱、板和填充墙等构件的损伤等级,建立了内爆炸作用下建筑目标的破坏简化分析方法,并通过与精细化数值仿真结果对比检验其适用性。结果表明,在100 kg和200 kg TNT爆炸工况下,精细化数值仿真分析中建筑物整体功能性和结构性毁伤等级均为中度和轻度,等效SDOF简化分析得到的相应毁伤等级与数值仿真结果一致。此外,从各构件的毁伤等级可以看出,相比于板、梁和柱等承重构件,砌体填充墙更易发生破坏,从而导致爆炸波在层内水平方向房间的毁伤破坏范围更大。展开更多
基金supported by the National Natural Science Foundation of China(No.41972266)the China Postdoctoral Science Foundation(No.2023M730432)+1 种基金the Special Funding for Chongqing Postdoctoral Research Project(No.2022CQBSHTB1010)the Chongqing Postdoctoral Science Foundation(No.CSTB2023NSCQBHX0223).
文摘To investigate the dynamic damage evolution characteristics of bank slopes with serrated structural planes,the shaking table model test and the numerical simulation were utilized.The main findings indicate that under continuous seismic loads,the deformation of the bank slope increased,particularly around the hydro-fluctuation belt,accompanying by the pore water pressure rising.The soil pressure increased and then decreased showed dynamic variation characteristics.As the undulation angle of the serrated structural planes increased(30°, 45°, and 60°),the failure modes were climbing,climbinggnawing,and gnawing respectively.The first-order natural frequency was used to calculate the damage degree(Dd)of the bank slope.During microseisms and small earthquakes,it was discovered that the evolution of Dd followed the“S”shape,which was fitted by a logic function.Additionally,the quadratic function was used to fit the Dd during moderately strong earthquakes.Through the numerical simulation,the variation characteristics of safety factors(Sf)for slopes with serrated structural planes and slopes with straight structural planes were compared.Under continuous seismic loads,the Sf of slopes with straight structural planes reduce stalely,whereas the Sf for slopes with serrated structural planes was greater than the former and the reduction rate was increasing.
文摘爆炸作用下地面建筑目标的破坏分析对制定实战打击策略和工程防护具有重要的实践指导意义。采用LS-DYNA有限元分析软件对已有含填充墙钢筋混凝土(reinforced concrete,RC)框架结构的近区爆炸试验进行复现,充分验证了所采用的精细化数值仿真方法的适用性。结合建筑结构混合单元建模方法,对典型三层含填充墙RC框架结构在典型战斗部(100 kg和200 kg TNT当量)爆炸作用下的动态响应开展了仿真分析,考察了爆炸波在结构内部的传播和结构损伤特性。基于等效单自由度(single-degree-of-freedom,SDOF)方法预测了爆炸荷载作用下框架结构梁、柱、板和填充墙等构件的损伤等级,建立了内爆炸作用下建筑目标的破坏简化分析方法,并通过与精细化数值仿真结果对比检验其适用性。结果表明,在100 kg和200 kg TNT爆炸工况下,精细化数值仿真分析中建筑物整体功能性和结构性毁伤等级均为中度和轻度,等效SDOF简化分析得到的相应毁伤等级与数值仿真结果一致。此外,从各构件的毁伤等级可以看出,相比于板、梁和柱等承重构件,砌体填充墙更易发生破坏,从而导致爆炸波在层内水平方向房间的毁伤破坏范围更大。
