小剪跨比RC柱及钢管增强RC柱多次冲击的响应行为  

Response Behavior of RC Column and Steel‑tube Strengthened RC Columns with Small Shear‑to‑span Ratios under Multiple Impacts

作　　者：陈林[1] 周戴江 李乐平 刘涛 CHEN Lin;ZHOU Daijiang;LI Leping;LIU Tao(School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学土木工程学院,湖南湘潭411201

出　　处：《防灾减灾工程学报》2023年第3期463-473,共11页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金面上项目(52278500);湖南省教育厅重点项目(21A0293)资助。

摘　　要：近年来钢筋混凝土(RC)墩柱遭受车船撞击的风险日益增加,且车船撞击一般发生在RC柱靠近地面或底部承台的位置,导致柱体出现小剪跨比条件下的脆性剪切破坏。而随着力学性能良好的钢管混凝土在工程中越来越广泛地应用,其在小剪跨比下的抗冲击性能也需要更加深入的研究。为进一步研究小剪跨比RC柱的剪切损伤机理以及钢管对RC柱抗剪性能的增强效果,使用大型刚性摆锤装置分别对1根RC柱、内置钢管增强RC柱和外置钢管增强RC柱进行了侧向冲击试验,考察了试件的损伤特征、冲击力和位移等试验结果。结果表明:RC柱在承受两次冲击后发生剪切破坏,而两个钢管增强RC柱在经历额外两次大能量冲击后仍保持较好的整体形态,即钢管可有效提升RC柱的抗冲击性能;在相同截面配钢率下,外置钢管增强RC柱相比内置钢管增强RC柱整体上具有更强的抗冲击性能,但内置钢管可更有效地降低核心混凝土的剪切损伤;由于外置钢管RC柱具有三者中最高的整体刚度和表面刚度,其对相邻构件承载力和刚度的要求也更高。In recent years,the risk of reinforced concrete(RC)piers being hit by vehicles and ships has gradually increased,and the collision of vehicles and ships on the RC columns generally occurs near the ground level or pile cap,which results in brittle shear failure of the columns under the condition of small shear-to-span ratios.As concrete-filled steel tubes with good mechanical properties are widely used in engineering practice,their impact resistance under small shear-to-span ratios also needs more in-depth study.To further study the shear damage mechanism of RC columns with small shearspan ratios and the enhancement effect of steel tubes on the shear performance of RC columns,lateral impact tests were conducted on an RC column,an internal steel-tube strengthened RC column,and an external steel-tube reinforced RC column,respectively,using a large rigid pendulum device.The damage characteristics,impact force,and displacements of the specimens were investigated.The results show that RC column experienced shear failure after two impacts,while the two steel tube reinforced RC columns remained in comparatively better overall conditions even after two additional highenergy impacts,highlighting that the steel tubes can effectively improve the impact resistance of the RC column;Furthermore,with an identical sectional steel ratio,the external steel-tube reinforced RC column demonstrated generally stronger impact resistance than the internal steel-tube reinforced one.But the internal steel tube was more effective in mitigating the shear damage of the core concrete;Given that the external steel-tube reinforced RC column presented the highest overall and surface stiffness among the three specimens,it would also place higher demands on the bearing capacity and stiffness of the adjacent members.

关 键 词：小剪跨比 钢管增强RC柱 侧向冲击 动态响应 抗剪性能 

分 类 号：TU398.9[建筑科学—结构工程]