Concrete Strain Distribution and Stiffness Variation Law of Short Straight Bolt Segmental Joints
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.
concrete segmentshort straight bolt segmental jointjoint stiffnessjoint concrete strainzone influenced by compressionfull-scale test
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维普
