Time-dependent lateral bearing behaviour of corrosion-damaged RC pipe piles in marine environments
Time-dependent lateral bearing behaviour of corrosion-damaged RC pipe piles in marine environments
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DOI：
10.1016/j.conbuildmat.2017.09.134
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发表时间：
2017-12
影响因子：
7.4
通讯作者：
W. Shao;Danda Shi;J. Jiang;Youliang Chen
中科院分区：
文献类型：
--
作者：
W. Shao;Danda Shi;J. Jiang;Youliang Chen
氯离子腐蚀是海洋环境中钢筋混凝土（RC）管桩早期劣化的主要原因之一，它会导致RC管桩在水平荷载作用下的长期承载力下降。因此，有必要对海洋环境中钢筋混凝土管桩水平承载性能的劣化规律进行系统的研究。在本研究中，一个数学模型来描述氯离子扩散到钢筋混凝土管桩。采用时变钢筋锈蚀模型模拟钢筋混凝土管桩中钢筋的锈蚀过程。此外，在试验研究的基础上，建立了桩身刚度退化系数与腐蚀损失之间的关系。基于拟合关系，研究了海洋环境中钢筋混凝土管桩腐蚀损伤后桩身刚度的衰减规律。采用有限差分法研究了海洋环境中腐蚀损伤钢筋混凝土管桩水平承载力随时间的变化规律。分析结果表明，海洋环境中钢筋混凝土管桩的水平承载性状具有明显的时变特性。桩身刚度随暴露时间的增加呈非线性下降。当Ca =Cb= 4.5 kg/m3和Ca =Cb= 9.0 kg/m3时，桩身刚度退化系数分别为0.32和0.30。最大负剪力和侧向挠度随暴露时间的增加而增加，而弯矩随暴露时间的增加而减小。
Chloride-induced steel corrosion is one of the major causes of the premature deterioration of reinforced concrete (RC) pipe piles in marine environments, inducing the degradation of the long-term resistance of RC pipe piles subjected to lateral loading. It is essential to conduct systematic research on the deterioration law of the lateral bearing behaviour of RC pipe piles in marine environments. In the present study, a mathematic model is developed to describe the chloride diffusion into an RC pipe pile. A time-dependent reinforcement corrosion model is adopted to simulate the reinforcement corrosion process in an RC pipe pile. In addition, the relationship between the degradation coefficient of the pile stiffness and the corrosion loss is established based on the experimental investigation. Based on the fitting relationship, the attenuation law of the pile stiffness of corrosion-damaged RC pipe piles in marine environments is investigated. The time-dependent lateral bearing behaviour of corrosion-damaged RC pipe piles in marine environments is investigated using the finite difference method. The analysis results demonstrate that the lateral bearing behaviour of RC pipe piles in marine environments has obvious time-varying characteristics. The pile stiffness decreases nonlinearly with the increase in exposure time. The degradation coefficient of the pile stiffness reduces to 0.32 and 0.30 forCa=Cb= 4.5 kg/m3andCa=Cb= 9.0 kg/m3, respectively, for an exposure time of 90 years. The maximum negative shear force and lateral deflection increase with the increase in exposure time, whereas the bending moment decreases with the increase in exposure time.