采用带锚固板竖向钢筋的预应力混凝土T梁受剪性能研究  

Study on shear behavior of prestressed concrete T-beams with T-headed vertical reinforcement

作　　者：石雪飞[1] 苏昶 邱志雄 孙向东 宋军[1] Shi Xuefei;Su Chang;Qiu Zhixiong;Sun Xiangdong;Song Jun(Tongji University,Shanghai 200092,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China;Guangdong Expressway Co.,Ltd.,Guangzhou 510000,China;Guangdong Communications Planning and Design Institute Co.,Ltd.,Guangzhou 510000,China)

机构地区：[1]同济大学,上海200092 [2]中铁第四勘察设计院集团有限公司,湖北武汉430063 [3]广东省高速公路有限公司,广东广州510000 [4]广东省交通规划设计院股份有限公司,广东广州510000

出　　处：《土木工程学报》2023年第12期110-121,共12页China Civil Engineering Journal

基　　金：国家重点研发计划(2018YFC0809606);广东省高速公路改扩建关键技术研究课题(JG2019-6242)。

摘　　要：为推动桥梁预制梁的钢筋智能绑扎进程,提出采用锚固板竖向钢筋代替传统箍筋的网片式配筋方案。为研究该配筋形式对预应力混凝土T梁受剪行为的影响,针对抗剪钢筋形式、剪跨比等参数,设计4个缩尺梁抗剪试验,并使用ABAQUS有限元软件开展实体非线性仿真计算,对试件的预应力效应、抗剪承载能力、失效模式、混凝土受力特征及钢筋受力特征进行分析,结合压力场理论解释其抗剪承载性能的差异,并利用参数分析给出锚固板竖向钢筋的合理设计建议。研究结果表明:在1.0~2.6剪跨比条件下,与常规箍筋梁相比,锚固板竖向钢筋的配置对预应力混凝土T梁受剪开裂荷载及未开裂刚度影响很小,且具有相同的受剪破坏特征,但锚固板竖向钢筋梁具有较大的开裂后刚度及抗剪承载能力,其抗剪承载能力提高约10%,这主要因为锚固板钢筋梁具有更小的混凝土斜压杆倾角以及更大的斜压杆影响区域,且锚固板钢筋可以充分发挥其屈服强度,为充分利用锚固板的优良锚固性能,建议锚固板承压面积宜取钢筋截面积的4.5~8.0倍,锚固板钢筋的屈服强度宜取400~500MPa。In order to promote the intelligent binding process of bridge prefabricated beam reinforcement,a mesh reinforcement scheme using T-headed vertical reinforcement instead of traditional stirrup is proposed.In order to study the influence of mesh reinforcement form with T-headed reinforcement on the shear behavior of prestressed concrete T-beams,four shear experiments of scale beams were designed according to the shear reinforcement form and shear span ratio,and then the solid nonlinear simulation calculation was carried out by using the ABAQUS finite element software.The prestressing effect,shear capacity,failure mode,concrete and reinforcement stress characteristics of the specimens are analyzed.Based on the theory of pressure field,the difference of shear bearing capacity is explained.The study results show that,under the condition of 1.0~2.6 shear span ratio,the T-headed vertical reinforcement beam has little effect on the shear cracking load and uncracked stiffness of the prestressed concrete T-beam,and has the same shear failure characteristics as the stirrup beam.However,the T-headed vertical reinforcement beam has a larger post cracking stiffness and shear bearing capacity because it has smaller inclined angle and larger influence area of the concrete compression bar,thus a the yield strength can be fully used.In order to make full use of the excellent anchoring performance of the Theaded,it is suggested that the bearing area of the T-headed should be 4.5~8.0 times the cross-sectional area of the reinforcement,and the yield strength of the T-headed reinforcement should be between 400 and 500 MPa.

关 键 词：网片式配筋 锚固板竖向钢筋 预制预应力T梁 抗剪承载能力 非线性有限元 

分 类 号：U443.35[建筑科学—桥梁与隧道工程]