（山西大学土木工程系， 太原 030013）

［摘要］为研究不同拉结钢筋布置形式下钢纤维混凝土人防顶板的防护效能，以对边简支钢筋混凝土板为试验对象，分别采用3种不同拉结钢筋的布置形式、3种不同强度等级的混凝土、3种不同的钢筋配筋率进行板的静载试验。结果表明，在均布荷载作用下，人防混凝土顶板的变形是随着荷载的逐渐增大而逐渐增加，且中间最大，沿板边缘逐渐减小，整体竖向位移呈碟形，板的第一批裂缝首先出现在板底的中间部位，随后沿对角线方向向四角发展；随着钢筋配筋率的提高，板的位移幅值变小，混凝土板的抗变形能力提高，承载能力增大，混凝土的强度等级对板的抗变形能力及承载能力提高有限；在规范范围内，板内设置一定数量的拉结钢筋有利于受力钢筋和受压区混凝土整体协同工作，提高结构构件的延性，延缓结构坍塌时间，从而改善人防顶板的防护效能；拉结钢筋的布置形式对提高板的承载能力无明显影响，在板构件破坏前对提高板的抗变形能力不显著；纤维作为混凝土增强材料掺入到混凝土中，可显著提高人防顶板的抗裂性和抗变形能力，增强人防顶板的防护效能。

［关键词］人防顶板； 拉结钢筋； 纤维混凝土； 防护效能

中图分类号：TU375-2文献标识码：A文章编号：1002-848X(2019)04-0058-06

Experimental study on protection effectiveness of civil defense top slab of basement with linked pulling steel bars

Sun Bu， Chen Yu， Cao Ruidong， Wu Haiying

（Department of Civil Engineering， Shanxi University， Taiyuan 030013, China）

Abstract:In order to study the protection effectiveness of steel fiber reinforced concrete civil defense top slab of basement,with different arrangements of linked pulling steel bars, the reinforced concrete slabs simply supported at two ends were selected as experimental objects. The static load test was conducted on the slabs with three kinds of arrangement forms of linked pulling steel bars, three kinds of concrete grades and three kinds of reinforcement rates. The results show that under the action of uniform load, the deformation of civil defense top slab of basement increases gradually with the increase of load, and the largest deformation appears in the middle span, and the deformation decreases along the edge of slab gradually. The overall vertical displacement is dish-shaped. The first batch of cracks of the slab first appears in the middle part of the bottom of the slab, and then develops to four corners along the diagonal direction. With the increase of reinforcement ratio, the displacement amplitude of slab decreases, the deformability and bearing capacity of concrete slab increases, and the improvement of deformability and bearing capacity of slab by concrete strength grade is limited. Within the scope of the code, setting a certain number of linked pulling steel bars in the slab is beneficial to the overall coordination of the stressed steel bars and the concrete in the compression zone. The linked pulling steel bars also improve the ductility of structural members and delay the collapse time of structures, so as to improve the protection effectiveness of civil defense top slab of basement. The arrangement forms of linked pulling steel bars has no obvious effect on improving the bearing capacity of slabs, and it has no significant effect on improving the deformability of slabs before the failure. Fibers as concrete reinforcement materials are mixed into concrete to significantly improve the crack resistance, deformability and protection effectiveness of civil defense top slab of basement.

Keywords:civil defense top slab of basement; linked pulling steel bar; fiber concrete; protection effectiveness

*山西省重点研发计划项目（201603D121023-2）。

作者简介：孙补，学士，高级实验师，Email：sxdx0351.good@163.com。