全无缝桥梁接线路面拉伸力学特性理论和实验研究

Theoretical and experimental study on tension-deformation mechanical properties of continuously reinforced concrete approach pavement of FJSBs

为了掌握和模拟全无缝桥梁接线路面弹塑性拉伸特性,本文基于钢筋和混凝土的单轴拉伸平均应力-应变本构模型,推导出接线路面的宏观弹塑性拉伸P-Δ理论模型;并对室内总长28 m的接线路面足尺模型,进行了拉伸试验。结果显示:(1)接线路面的理论与实验拉伸P-Δ骨架曲线在钢筋屈服前后都吻合得很好,可以直接用于全无缝桥梁抗震设计和损伤评估;(2)接线路面实验模型的拉伸变形量Δ高达14 cm时,仍未拉断,其延性甚好、有利于抗震。

Because the elastoplascic tension character of the Continuously Reinforced Concrete Approach Pavement （CRCAP） is sensitive to the seismic response of the Fully Jointless Semi-integral Bridges（ FJSBs）, a macro elasto- plastic tension-deformation theoretical model （P -A model） of CRCAP was developed from the uniaxial tensile aver- age stress-strain constitutive model of the steel bar and concrete and a tensile test was carried out by using a full scale experimental model of CRCAP with a length of 28m. Results show that： the theoretical skeleton curve is in good agreement with the tested curve, whatever the steel bar is pre-yield or post-yield and the CRCAP is still not broken when its tensile deformation reaches up to 14 cm. Conclusion is that the theoretical skeleton P -A model can be used for the seismic design and the damage assessment of FJSBs and the high ductility of the CRCAP is helpful for the FJSBs to resist strong earthquakes.