外包橡胶混凝土覆层对梁式桥墩防撞性能影响的试验研究

提出将橡胶混凝土以覆层形式外包在桥墩一定高度范围内以提高其防撞减振和能量耗散能力,试验研究了不同橡胶粒径、体积掺量的橡胶混凝土的基本力学性能;其次利用摆锤撞击模型墩柱试验,并结合ABAQUS/Explicit非线性动态碰撞仿真分析,研究了橡胶混凝土覆层对模型墩柱的自振特性、不同撞击速度下的撞击响应峰值及振动衰减规律的影响。结果表明,虽然橡胶混凝土强度、弹模较普通混凝土较低且受橡胶掺量影响显著,但橡胶混凝土覆层兼具防撞和减振的双重优势,可使撞击力峰值减小12.93%~15.87%,墩顶位移减小13.10%~32.11%,墩底应变减小13.1%~46.13%,还能增强原桥墩的主动耗能能力。该形式防撞装置可为桥墩提供有效保护且符合绿色环保的理念,值得推广。

Experimental study on the anti-collision performance of beam bridge piers-with wrapped crumb rubber concrete layers

Crumb rubber concrete(CRC) was proposed to be used as wrapped layers of bridge piers to improve their anti-collision, vibration absorption and energy dissipation capabilities.The mechanical properties of CRC were studied by using axial compression test.In the test, the influential factors of particle sizes and volumetric contents were considered.Then, pendulum impact tests on model piers with or without wrapped layers were carried out to obtain their natural vibration characteristics, impact response peaks and vibration attenuation properties.Also, the inflceences of different layer styles and impact velocities were studied in those pendulum impact tests.The results show that though CRC provides lower strength and elastic modulus than those of normal concrete(NC), CRC presents a dual effect of anti-collision and shock absorption.Wrapped CRC layers reduce the peak impact force by 12.93%-15.87%, the pier top displacement by 13.10%-32.11%, and the pier bottom strain by 13.1%-46.13%.Furthermore, it enhances the active energy consumption capacity of original piers.This type of anti-collision device can provide effective protection for piers and conform to the concept of green environmental protection, which is worth promoting.