摘要
随着新开软岩巷道数量的增多,因锚杆、锚索等主动支护结构难以锚固松软岩体,被动支护的优势逐渐显现。埋入式柱脚作为H型钢柱-钢筋混凝土底梁新型被动支护结构的重要连接节点,对其力学性能的研究至关重要。以该新型结构柱脚节点为研究对象,通过数值计算的方法得到了其在复合加载下的力学性能指标和埋入段的应力分布,讨论了埋入深度、混凝土强度、底板尺寸和厚度、型钢截面高度对柱脚节点承载能力和破坏形式的影响。结果表明:引入Cohesive粘结滑移的柱脚节点有限元模型可以较好的反应试验现象以及力学特性,相对误差在8%之内;埋入段柱脚深度在0~140mm之间时,弯矩和剪力更多是由型钢承担;钢柱埋深从225mm提高至450mm,极限荷载提高了13%,混凝土强度从C30提高至C70极限荷载提高了16%;改变底板尺寸、厚度以及型钢截面高度影响柱脚节点最终的破坏形式。以此提出了柱脚节点的优化设计方法,数值分析结果表明优化后的柱脚节点极限荷载提高了47%。
With the increase in the number of newly opened soft rock roadways,the advantages of passive support are gradually emerging because active support structures such as bolts and anchor cables are difficult to anchor soft rock.As an important connection joint of the new passive support structure of H-shaped steel column-reinforced concrete bottom beam,the research on its mechanical properties is very important.Taking the column base joint of the new structure as the research object,the mechanical performance index and the stress distribution of the embedded section under composite loading are obtained by numerical calculation.The influence of embedded depth,concrete strength,base plate size and thickness,section height of steel on the bearing capacity and failure mode of the column base joint is discussed.The results show that the finite element model of column base joint with Cohesive bond slip can better reflect the experimental phenomena and mechanical properties,and the relative error is within 8%.When the depth of the embedded section column base is between 0 and 140mm,the bending moment and shear force are more borne by the steel.When the buried depth of steel column increases from 225mm to 450mm,the ultimate load increases by 13%,and the concrete strength increases from C30 to C70 by 16%.Changing the size or thickness of the base plate and the height of the steel section affect the final failure mode of the column base joint.Based on this,the optimal design method of column base joints is proposed.The numerical analysis results show that the ultimate load of the optimized column base joint is increased by 47%.
作者
毕涵喆
韩天宇
刘年增
郑鹏
聂明月
BI Hanzhe;HAN Tianyu;LIU Nianzeng;ZHENG Peng;NIE Mingyue(School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《建筑结构》
北大核心
2023年第S01期1825-1833,共9页
Building Structure
基金
国家自然科学基金项目(52274148)
关键词
被动支护
埋入式柱脚
有限元
复合加载
结构优化
passive support
ECB
finite element
complex loading
structural optimization
