钢管桩防腐护甲的冰磨蚀试验

Ice Abrasion Experiments on Steel-Pipe Pile Corrosion Protection System

在处于飞溅区的钢管桩上安装防腐护甲是避免其腐蚀破坏的有效方法.开展室内模型试验对防腐护甲上的冰磨蚀作用进行了研究.试验中首先进行冰速扫描,测试不同冰速下防腐护甲的受力和变形,冰速范围涵盖了冰排在桩前发生延性破坏、交替延性-脆性破坏直至脆性破坏时的特征冰速.试验结果发现防腐护甲上的最大冰力和变形出现在冰排发生交替延性-脆性破坏时,对应的冰速为150,mm/s.而后在此冰速下进行了防腐护甲的冰磨蚀试验.在试验中观察到防腐护甲上冰磨蚀效果明显,并且冰排对防腐护甲存在2种磨蚀作用模式,即冰排正面接触造成的浅层磨蚀和冰排边缘作用下的啃蚀效应.试验结果发现浅层磨蚀造成的划痕影响冰力明显,而啃蚀效应造成的凹痕控制累积磨蚀的增长水平.

Installing corrosion protection systems on steel-pipe piles in splash zone is an effective method for protect- ing the metal surface from corrosion. Model tests were performed to investigate the ice abrasions on the popular corro- sion protection system. Screening the ice speed that induces the maximum stress and deformation of the corrosion protection system was the first step of the model tests. The test conditions included the characteristic ice speeds that lead to ice sheet failing in ductile, alternated ductile-brittle and brittle behavior. In the tests, the corrosion protection system experienced the maximum ice force and deformation during the alternated ductile-brittle failure of ice, corresponding to the ice speed of 150 mm/s. Then the ice abrasion tests were performed at this ice speed. Obvious ice abrasions were observed on the surface of the corrosion protection system in the tests, and two ice abrasion modes were also observed. One is the shallow abrasion caused by the frontal contact of the ice sheet, and the other is the nibbling effect caused by the ice sheet edge. It was found that the nicks caused by the shallow abrasion influence the ice force obviously, and the concaves caused by the nibbling effect control the increase of the accumulated abrasion.