半灌浆套筒钢筋偏心连接受拉性能试验研究与数值模拟

Experimental study and numerical simulation on tensile behavior of eccentric rebar connection for half-grouted sleeve splice

为研究钢筋偏心缺陷对灌浆套筒钢筋连接受拉性能的影响,设计并制作了6组18个半灌浆套筒钢筋连接试件,考虑两种钢筋偏心类型,即钢筋垂直偏心和斜向偏心,分别用偏心率和偏心角表征其偏心程度。通过单向拉伸试验,研究钢筋偏心对套筒连接承载力、破坏形态、应变分布以及灌浆料损伤深度等受力性能的影响,并采用ABAQUS进行数值模拟和参数分析。研究结果表明:套筒表面纵向应变从出浆口两侧向灌浆口逐渐减小,出浆口位置为最薄弱位置,环向最大压应变位置受两种偏心影响显著;钢筋垂直偏心试件在钢筋贴近侧壁一侧的套筒表面纵向应变大于另一侧的纵向应变,斜向偏心试件套筒表面纵向应变随筒壁与钢筋距离的增大而减小;相同直径钢筋的套筒连接中,斜向偏心套筒连接的灌浆料损伤深度最大,垂直偏心的次之,垂直居中的最小;随着钢筋直径增大,灌浆料损伤深度及其占钢筋嵌入长度的百分比逐渐增大,最大约为钢筋嵌入长度的9.64%。数值模拟与试验结果吻合较好,模拟方法准确可行。

To study the effect of eccentricity of rebar on mechanical behavior of half-grouted sleeve,six groups,a total of 18 specimens were designed and manufactured.The eccentricity ratio and eccentricity angle respectively characterize the degree of vertical eccentricity and oblique eccentricity.The bearing capacity,failure mode,strain distribution and damage depth of grouting material were studied by uniaxial tensile test,and ABAQUS was used for numerical simulation and parametric analysis.The results show that the longitudinal strain of the sleeve is gradually reduced from the two sides of the vent hole to the grouting hole,and the position of the vent hole is the weakest position.The position of circumferential peak compressive strain is significantly affected by the two kinds of eccentricity.For the specimens with vertical eccentric defect,longitudinal strain on the sleeve of the sidewall near the rebar is larger than that on the other side.For the specimens with oblique eccentric defect,the longitudinal strain on the sleeve surface decreases with the increase of the distance between the cylinder wall and the rebar.As to the damage depth,the oblique eccentric specimens are the largest,and the axial tension specimens are the smallest.The damage depth at the grout end of the sleeve increases with the increase of rebar diameter,and the maximum embedded length of rebar is about 9.64%.The numerical analysis results agree well with the experimental results,and the numerical analysis method is feasible,which can be used for the inspection and evaluation of the grout,as well as the optimum design of the sleeve.