Abstract: Starting in 2015, Vertical Access has worked with Puget Sound Energy to perform conditions assessments at two concrete dams. Lower Baker Dam (a gravity-arch dam completed in 1925) and Upper Baker Dam (a gravity dam completed in 1959) are located in Skagit and Whatcom Counties, Washington. As part of the conditions assessment, Vertical Access technicians gained hands-on access to selected areas using industrial rope access techniques. Once in place, technicians documented existing conditions using a direct-to-digital system called TPAS, for Tablet PC Annotation System. Using this system, notable and representative conditions such as cracks and spalls in the concrete were mapped out on elevation views of the dams. Photographs taken of each condition are hyperlinked to the annotated drawing, and automatically renamed with a file name that can be customized for the project. The deliverables provided to Puget Sound Energy include the annotated elevation drawings, photographs and a written report describing the observed conditions.
With the condition survey reports provided by Vertical Access, Puget Sound Energy is able to improve surveillance and monitoring of the dams. The annotated drawings and photographs serve as a baseline condition that provides reference for visual observations made during routine inspections. The inability to safely access the downstream face of the arch dam, the spillway chute, and concrete face wall of the gravity dam by other means have limited the quality of information available to identify new concrete defects or document ongoing deterioration. Isolated photographs taken during inspections are often difficult to confidently locate on a large structure because the photographs are focused on the defect. Use of TPAS to directly input visual and numerical survey information on the structure provides the detailed information to be accurately located and effective for monitoring deterioration.

Key words: condition assessment, rope access technology, inspection

摘要： 从2015年开始，Vertical Access有限责任公司与普捷湾能源公司（Puget Sound Energy）合作，对两座混凝土大坝进行了工况评估。下贝克大坝（Lower Baker Dam）是1925年建成的重力拱坝，上贝克大坝（Upper Baker Dam）是1959年建成的重力坝，分别位于华盛顿州的斯卡吉特县和霍特科姆县。作为工况评估的一部分，Vertical Access有限责任公司的技术人员通过使用工业绳索技术，直接进入了选定区域。一旦到位，技术人员利用TPAS直接数字转换系统，对现有工况进行记录。利用该系统，在大坝的高程视图上绘制出混凝土裂缝和破损等值得注意和具有代表性的工况。就每种工况拍摄的照片将被超链接到带注释的绘图中，并自动用为项目定制的文件名对其进行重命名。提供给普捷湾能源公司的可交付成果包括标注的高程图、照片和描述观测到的工况的书面报告。
通过Vertical Access有限责任公司提供的工况调查报告，普捷湾能源公司可改进大坝监控和监测工作。注释的图纸和照片作为基本工况，为常规检查期间的目视检查提供参考。采用其他方法无法安全到达拱坝的下游面、溢洪道和重力坝的混凝土墙，这对可获取的信息质量形成了限制，而这些信息是用来辨识新的混凝土缺陷或记录正在发展的恶化情况的。检查过程中拍摄的独立照片，通常很难在大型结构物上进行精确定位，因为这些照片重点关注的是缺陷。使用TPAS直接输入结构物的视觉和数值测量信息，可提供精确定位的详细信息，并有效地监测恶化情况。

关键词: 工况评估, 绳索技术, 检查