短直螺栓接头混凝土应变分布及刚度变化规律  

Concrete Strain Distribution and Stiffness Variation Law of Short Straight Bolt Segmental Joints

作　　者：叶宇航 张帆[2] 罗旭 高学奎 徐文田 柳献[2] YE Yuhang;ZHANG Fan;LUO Xu;GAO Xuekui;XU Wentian;LIU Xian(Guangzhou Metro Design&Research Institute Co.Ltd.,Guangzhou 510010,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;China Airport Planning&Design Institute Co.Ltd.,Beijing 100029,China)

机构地区：[1]广州地铁设计研究院股份有限公司,广州510010 [2]同济大学土木工程学院,上海200092 [3]民航机场规划设计研究总院有限公司,北京100029

出　　处：《铁道建筑》2024年第10期13-19,共7页Railway Engineering

基　　金：交通运输行业重点科技项目(2021-MS1-044);广州市重点研发计划(20220602JBGS01)。

摘　　要：依托下穿白云机场盾构隧道工程,开展了不同偏心距作用下短直螺栓接头足尺试验,分析了接头混凝土和螺栓的应变特征,探究了接头刚度变化规律。结果表明:在靠近接头端面处接头受压核心区压应变呈现出规律性变化,而非受压区应变较小;拉压区混凝土应变不满足平截面假定,随着远离接头端面混凝土应变表现为沿管片厚度线性变化,接头影响逐渐削弱,接头的影响区域约为距离接头端面338 mm内;在影响区域内混凝土应变不均匀时的压缩变形与假定为混凝土应变均匀时的压缩变形等效的前提下,计算得到混凝土压缩变形影响深度约为300 mm;将该影响深度值带入接头受力解析式中计算,接头刚度理论值与试验值基本相等,验证了该值的正确性;试验和理论计算均表明正弯矩作用下,随着偏心距增大,接头刚度以指函数形式减小。Based on the underpass tunnel project of Baiyun Airport,the full-scale test of the short straight bolt joint under different eccentricities was carried out.The strain characteristics of joint concrete and bolt were analysed,and the stiffness was investigated.The results show that,in the zone close to the joint surface,the concrete strain in the compression core zone of the joint changes regularly,while the strain in the non-compression zone is small.The concrete strain in the tension and compression zone does not meet the plain section assumption.When the concrete is far away from the joint face,the concrete strain shows a linear change along the thickness of the segment,and the influence of the joint is gradually weakened.The zone influenced by the joint is about 338 mm from the joint surface.Based on the assumption that the compressive deformation of the concrete in the influenced zone when the strain is uneven is equivalent to the compressive deformation when it is assumed to be uniform,the influence depth of concrete compression is calculated to be 300 mm.This value is brought into the analytical formula for calculation.The theoretical value of joint stiffness is almost equal to the experimental value,which verifies that the value of the influence depth of concrete compression is right.Both the test and theoretical analysis show that the joint stiffness decreases as an exponential function with eccentricity increasing under a positive bending moment.

关 键 词：混凝土管片 短直螺栓接头 接头刚度 接头混凝土应变 压缩变形影响区 足尺试验 

分 类 号：U451.5[建筑科学—桥梁与隧道工程]