SBIR Phase I: Pneumatic Scour Measurement System

这个小型企业创新研究(SBIR)第一阶段项目解决了在洪水条件下测量桥梁基础周围冲刷深度的问题。洪水携带的碎片聚集在桥墩周围形成鸟巢，通过产生多余的湍流和阻止传统的冲刷检测技术来加剧冲刷。气动冲刷检测系统(PSDS)既解决了通过碎石鸟巢测量冲刷的问题，也解决了抵御洪水携带的碎石的破坏的问题。这项技术是基于通过垂直排列的烧结黄铜制成的多孔过滤器对气流的差动阻力。过滤器阵列被密封在用作探头的探头的壁上，并像大钉子一样穿过鸟巢进入码头附近的河底。较浅的过滤器暴露在水中，较深的过滤器暴露在合格的土壤中。2002年国家大桥清单列出了22,414座关键冲刷桥梁，其中许多都是由碎片组成的鸟巢。洪水携带的碎片遮盖了码头周围的河底，使目前所有可用的冲刷检测仪器，如声纳深度探测仪、探地雷达，都变得无效，并妨碍了目视检查，限制了桥梁工程师在洪水期间确定桥梁安全的能力。PSDS探头永久安装在冲刷临界桥墩附近，在探头顶部捆绑了多个气动软管，以便在洪水事件正在发生或预计发生时，轻松连接到非现场便携式压力测量仪器。安装后，桥梁工程师可以获得桥墩冲刷情况的实时信息，使他们能够在危险条件出现时关闭桥梁。此外，每年对冲刷情况的监测为桥梁工程师提供冲刷深度的知识，然后能够在桥墩移动之前安排补救，将维护成本保持在最低水平。

This Small Business Innovative Research (SBIR) Phase I project addresses the problem of measuring scour depth around bridge foundations under flood conditions. Flood-borne debris collecting around bridge piers forms bird's nests that aggravate scour by creating excess turbulence and preventing conventional scour detection techniques. The Pneumatic Scour Detection System (PSDS)addresses both problems of measuring scour through a bird's nest of debris and withstanding the ravages of flood-borne debris. This technique is based on the differential resistance to airflow through a vertical array of porous filters made of sintered brass. The array of filters are sealed into the wall of a probe used as a probe and battered through the bird's nest into the river bottom adjacent to the pier like a large nail. Shallow filters are exposed to water, and deeper filters are exposed to competent soil.The 2002 National Bridge Inventory lists 22, 414 scour-critical bridges, many with bird's nests of debris. Flood-borne debris masks the river bottom surrounding the pier, making ineffective all currently available scour detection instrumentation, such as sonar depth sounders, ground-penetrating radar, and precludes visual inspection, limiting the bridge engineers ability to determine the safety of the bridge during flood events. The PSDS probe is permanently installed adjacent to scour-critical piers with the multiple pneumatic hoses bundled at the top of the probe for easy connection to an off-site portable pressure measurement instrument when flood events are in progress or anticipated. Once installed, the bridge engineers have available real-time information of the scour conditions at the pier, enabling them to close the bridge to traffic when dangerous conditions develop. Additionally, yearly monitoring of the scourconditions provides the bridge engineer the knowledge of depth of scour and is then able to schedule remediation before pier movement occurs, keeping maintenance costs to a minimum.