【作者】 邱兆国； 梁力； 张凤鹏；

【Author】 QIU Zhao-guo 1 , LIANG Li 2 , ZHANG Feng-peng 3 (1. School of Science, Northeastern University, Shenyang 110819, China; 2. College of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, China; 3. Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines, Northeastern University, Shenyang 110819, China)

【机构】 东北大学理学院； 东北大学资源土木学院； 东北大学深部金属矿山安全开采教育部重点实验室；

【摘要】 采用非线性有限单元法研究钢筋混凝土梁损伤相互影响及其安全性评价问题。通过预设裂纹模拟竖向裂缝损伤,通过降低配筋率模拟钢筋锈蚀,利用混凝土强度与弹性模量的关系,通过减低弹性模量来模拟混凝土强度降低,以梁跨中挠度为目标量,通过挠度变化率w来描述损伤影响程度,研究三类典型损伤对钢筋混凝土梁安全性的影响,探讨跨中挠度、损伤相关性系数对损伤等级和载荷的敏感度,建立考虑多损伤相关性的钢筋混凝土梁安全性评价新方法以及损伤影响权重的计算方法,分析活动载荷的影响。结果表明:竖缝损伤和钢筋锈蚀间存在较强的非线性相关性,显著降低了桥梁的安全性,加重了超载对梁的损伤程度。更多还原

【Abstract】 The damages interaction of reinforced concrete beam and its safety evaluation method have been studied by the nonlinear finite element method. The influences of three typical damages on the deflection of the beam have been studied. The vertical cracks damage (VC) has been simulated by pre-cracks, the reinforced steel corrosion damage (RSC) by reducing the effective area of the reinforced steel, and the concrete strength degradation (CSD) by changing the elastic modulus of concrete based on the relationship between concrete strength and its elastic modulus. The deflections at mid-span of the beam are used as the target and the deflection variation rates are adopted to describe the influence of the damages. Based on the above, the effects of damages on the safety of the reinforced concrete beam have been studied, and the sensitivity of the mid-span deflection and damage coefficients to damage levels and live loads are investigated. A new safety evaluation method of the reinforced concrete beam based on the damage interaction and the calculation method of damages’ weight coefficients have been put forward, and the effects of live loads on the beam have been discussed. The resultsshow that there is a strong nonlinear correlation between VC and RSC, and the beam’s safety states are significantly weakened, the damage degree of overloading on concrete beam magnified, due to the interaction of the damages.更多还原