Fracture critical inspection team of the State of California Department of Transportation
Fracture critical inspection team of the State of California Department of Transportation
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DOI：
10.1117/12.209756
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发表时间：
1995-05
期刊：
影响因子：
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通讯作者：
P. Stolarski
中科院分区：
文献类型：
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作者：
P. Stolarski
加州州交通部（Caltranss）遵守联邦公路管理局国家桥梁检查标准第650.305节的规定，该规定规定桥梁应定期检查，间隔不超过两年。结构维护和调查办公室结构部负责对加州约26，000座桥梁进行检查。其中约有3,100座是钢桥，其中1,000座具有断裂临界构件。断裂临界构件是桥梁的受拉构件，其失效可能导致部分或整个桥梁倒塌。1980年，结构部建立了一个“A”类检查程序，确定了钢结构的断裂临界特征。所有的“成分”都存在于钢结构产生裂缝的过程中。结构物的年龄随着平均每日卡车交通量及其荷载的增加而沿着增加。20世纪50年代和60年代所要求的材料性能对断裂韧性没有要求。正确的焊接程序/质量仍然是当今实现的一个挑战，那些30至40年的结构也不能幸免于这个问题。加州交通局在该州有12个区，每个区至少有两名地区桥梁维修工程师（ABME）。加州交通局要求ABME是一名有执照的土木工程师。ABME在检查断裂关键构件时面临着重大责任。ABME没有接受过不同的无损评价方法（NDE）的培训，这对于一个从四年制工程课程毕业的工程师来说并不罕见。从1985年开始，运输实验室的焊接和金属技术分支协助结构部门使用NDE方法检查这些断裂关键特征。自1990年起，焊接和金属技术分支的断裂临界检验小组陪同AMBE进行预定的“A”类检验。
The Department of Transportation for the State of California (Caltrans) abides by the regulations of the Federal Highway Administration's National Bridge Inspection Standards section 650.305 that states that bridges are to be inspected at regular intervals not to exceed two years. The Division of Structures, Office of Structures Maintenance and Investigations is responsible for the inspection of approximately 26,000 bridges in California. Approximately 3,100 of these are steel bridges and of these, 1,000 have fracture critical members. Fracture critical members are tension members of a bridge whose failure will probably cause a portion of, or the entire bridge, to collapse. In 1980, the Division of Structures established a category 'A' inspection program which identified what fracture critical features were on the steel structures. All of the 'ingredients' are present for steel structures to develop cracks. The age of the structures has increased along with the average daily truck traffic and their loads. The material properties required in the 1950s and 1960s did not have requirements for fracture toughness. Proper welding procedures/quality remain a challenge to achieve today, and those structures that are 30 to 40 years old were not immune to this problem. Caltrans has 12 districts in the state with at least two area bridge maintenance engineers (ABME) per districts. Caltrans requires that the ABME be a licensed civil engineer. The ABME faces a heavy responsibility when inspecting fracture critical members. The ABME is not trained in different methods of nondestructive evaluation (NDE), which is not unusual for an engineer graduating from a four-year engineering curriculum. Beginning in 1985, the Welding and Metals Technology Branch of the Transportation Laboratory assisted the Division of Structures in the inspection of these fracture critical features using NDE methods. As of 1990, the Welding and Metals Technology Branch's Fracture Critical Inspection Team accompanies AMBEs on their scheduled category 'A' inspections.