管道开挖缺陷点破损程度评价研究

开挖检查是挖开管道直接观察和测试管道腐蚀及防护状况的过程,是管道外检测的重要工作之一。目前对管体存在的缺陷点破损程度的判断,主要由现场工作人员根据经验,由管道防腐层的缺陷点尺寸来判断破损程度。但是影响缺陷点破损程度的还有管体的阴极保护、杂散电流、管体表面腐蚀等情况。为了综合评价各种因素对缺陷点破损程度的影响,通过分析2007年、2008年西气东输东段3个标段的开挖数据,考虑管体的腐蚀情况、土壤腐蚀性、是否漏出管体、杂散电流干扰情况、缺陷点在管体上所处位置、管段类型（直管、弯头等）等6个方面对缺陷点破损程度的影响,提出一种新的判断管体缺陷破损程度准则。

Pipeline Excavation Damage Degree Evaluation of Defects

Pipeline excavation is the direct observation and testing of the pipeline corrosion and protection status,which is one of the important jobs of testing.The extent of damage due to pipeline defects is decided from the experience of field staffs,usually based on the defects of pipeline coatings to determine the damage degree of dot size.But the extent damage caused by pipeline defects includes cathodic protection,stray current,pipeline surface corrosion,etc.For evaluation of various factors like the extent of defects,by analyzing the excavation data about the West-East natural gas transport project,including pipeline corrosion,soil corrosion,pipeline leak,stray current interference,and point defects in places where the pipeline is located(pipe type,straight pipe,elbow,etc).A new criterion for judging pipeline defects is brought forward here.