To study the compression performance of reinforced-concrete(RC)columns under the coupled action of the colliery ground environment and load,14 large-biased RC columns were prepared.The coupling effect of the colliery ground environment and load was investigated for 0,2,4,6,8,10,and 12 test periods.The property degradation laws of concrete and longitudinal reinforcement in the columns were analyzed,and the influence of degraded concrete and longitudinal reinforcement on the compression performance of the columns was investigated.Based on this,the calculation formulas for the bearing capacity of large eccentric compression columns with rectangular sections in Chinese,American,and European codes were modified.The results show that,compared with the load action alone,the coupling effect of the colliery ground environment and load aggravates the deterioration of the columns.With an increase in the coupling action time of the colliery ground environment and load,the concrete neutralization depth of the columns increases linearly,whereas the compressive strength decreases gradually.Meanwhile,the corrosion rate of the longitudinal reinforcement increases gradually;however,the yield strength and ultimate strength decrease linearly,and the yield strength of the longitudinal reinforcement is negatively correlated with the corrosion rate.The bearing capacity of the columns decreases with an increase in the coupling action time of the colliery ground environment and load.The yield load and ultimate load of the column decrease with the increase in the corrosion rate of the longitudinal reinforcement.By introducing the degradation coefficients of strength of concrete and rebar after the coupling action of the colliery ground environment and load,the load-bearing capacity calculation formulas for large eccentric compression columns with rectangular sections in the Chinese,American,and European codes can be modified effectively.
关键词
桥梁工程/承载力计算方法/试验研究/RC柱/受压性能/煤矿地面环境与荷载耦合作用
Key words
bridge engineering/calculation method of bearing capacity/experimental study/RC columns/compression performance/coupled action of colliery ground environment and load