轴力对混凝土管片极限承载力影响的计算模型

发布时间：2018-01-12 05:11

本文关键词：轴力对混凝土管片极限承载力影响的计算模型　出处：《煤炭学报》2017年01期 　论文类型：期刊论文

【摘要】：针对混凝土管片受压区高度小和受压区钢筋未达到屈服极限问题,提出了混凝土管片极限承载力计算模型。在轴力和弯矩共同作用下,将混凝土管片简化为偏心受压柱,建立了管片截面力平衡和弯矩平衡表达式。基于管片截面平面变形假定,建立了受压区钢筋应力与受压区高度和混凝土极限应变之间的关系。通过2个地铁隧道管片工程算例,分析讨论了轴力对受压区高度、受压区钢筋应力和管片极限承载力的影响。研究表明,混凝土管片的极限弯矩随着轴力的增加而增加;混凝土管片的最不利荷载组合为最大弯矩与最小轴力的组合。混凝土管片受压区的钢筋往往没有达到屈服极限,有时甚至处于受拉状态;现有模型假设受压区的钢筋屈服与钢筋的实际应力状态差异较大,新的计算模型能够准确计算受压区的钢筋的应力。
[Abstract]:Aiming at the problem that the height of the concrete segment is small and the steel bar in the compression zone does not reach the yield limit, a model for calculating the ultimate bearing capacity of the concrete segment is put forward, under the combined action of axial force and bending moment. The concrete segments are simplified as eccentric columns, and the force balance and bending moment equilibrium expressions are established, based on the plane deformation assumption of segment section. The relationship between the stress of steel bar and the height of compression zone and the limit strain of concrete is established. Through two examples of metro tunnel segment engineering, the axial force to the height of compression zone is analyzed and discussed. The results show that the ultimate bending moment of concrete segment increases with the increase of axial force. The most unfavorable load combination of concrete segments is the combination of the maximum bending moment and the minimum axial force. The steel bars in the compression zone of the concrete segments often do not reach the yield limit, and sometimes they are even in the state of tension. The existing models assume that the stress state of the steel bar in the compression zone is different from the actual stress state of the steel bar, and the new model can accurately calculate the stress of the steel bar in the compression zone.
【作者单位】：大连理工大学工业装备结构分析国家重点实验室;
【基金】：国家重点基础研究发展计划资助项目(2015CB057804) 国家自然科学基金资助项目(11572079) 工业装备结构分析国家重点实验室开放基金资助项目(S14206)
【分类号】：U455.91
【正文快照】： pressive depth;bar stress钢筋混凝土管片是地铁隧道、水工隧洞、矿山竖井和巷道等地下工程的常见衬砌结构。混凝土管片优化设计和准确极限承载力分析是保证地下结构安全性和经济性的重要研究内容之一。在混凝土管片的优化设计方面已有很多专家学者进行了多方位的研究。Molle

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