應用行動測繪技術於橋面版之3D建置與損傷檢測研究

Abstract

橋梁為道路系統之一環，尤其橋梁更肩負著跨越兩岸（地）障礙，且承載大量交通運輸工具與載重，是連通兩地整個道路系統之關鍵，因此需定期檢測橋面版的變形與損傷狀況以評估其安全性。目前臺灣各橋梁管理單位對於橋梁安全之一般性巡查及定期性檢測大都仍仰賴以人工為主之巡查與檢測方式進行。有關橋面版變形檢測目前是以每兩年一次的頻率進行橋面版的水準高程測量，雖然水準測量具備高精準度，但因只能獲得離散點的資料，故無法知道橋面版的地形全貌及全面檢測出橋面版之變形與損傷情形，且檢測人員在車流眾多環境下進行檢測作業極具高危險性，無法達到講求效率、準確、安全之現代化橋檢要求。 本研究利用行動測繪技術（Mobile Mapping Technology, MMT）突破現行橋檢作業模式，所建置之立體環景行動測繪系統（Stereo Panoramic Mobile Mapping System, SPMMS）經過實地驗證結果，不僅具備可隨時出動之快速與機動性及可加速檢測頻率外，藉由攝影測量（Photogrammetry）與電腦視覺（Computer vision）技術重建3D橋面版，並由數值地表模型（digital surface model, DSM）連續高程剖面來檢測橋面版的沉陷變形，以及利用多時期的正射影像（Ortho Images）來觀察伸縮縫與鋪面的損壞變化狀況。經以臺北市民權大橋等現場實際驗證結果，可獲得具備公分級的定位精度（RTK）（水平2公分，高程5公分）、量測精度小於 1 mm、控制測量精度可達6 mm、解析度高達6 mm等級之數值表面模型（DSM）與解析度高達3 mm等級之正射影像（Ortho Images）之橋面版的沉陷變形、伸縮縫變形與損傷、以及鋪面劣化與損傷等之檢測資訊。有效解決現有檢測方法「偏人工、單點資料、工作不安全」等缺點，成功建立一個以行動測繪技術（MMT）方式辦理之新的橋梁檢測方法，達到「科學化、科技化」具有「高效率、高準確度、高安全性」的新橋梁維護管理技術與方法。

Bridges are part of the road system. In particular, bridges are responsible for crossing obstacles on both sides of the river (land) and carrying a large number of transportation vehicles and loads. They are the key to the entire road system connecting the two places. Therefore, it is necessary to regularly inspect the deformation and damage of the bridge deck to evaluate its safety. Currently, Taiwan's bridge management units still rely on manual inspections and testing methods to conduct general inspections and periodic tests on bridge safety. Currently, bridge deck deformation detection is carried out by measuring the bridge deck level every two years. Although leveling is highly accurate, it can only obtain data from discrete points, so it is impossible to know the overall topography of the bridge deck and fully detect the deformation and damage of the bridge deck. In addition, it is extremely dangerous for inspectors to perform inspections in an environment with heavy traffic, and it is impossible to meet the modern bridge inspection requirements that emphasize efficiency, accuracy, and safety. This study uses mobile mapping technology (MMT) to break through the current bridge inspection operation mode. The built stereo panoramic mobile mapping system (SPMMS) has been verified in the field. It not only has the rapidity and mobility to be deployed at any time and can accelerate the inspection frequency, but also reconstructs the 3D bridge deck through photogrammetry and computer vision technology, and detects the sinking and deformation of the bridge deck through the continuous elevation profile of the digital surface model (DSM), and uses ortho images from multiple periods to observe the damage changes of expansion joints and pavement. Through actual verification results on the Minquan Bridge in Taipei, we can obtain detection information on bridge deck subsidence deformation, expansion joint deformation and damage, and pavement deterioration and damage with centimeter-level positioning accuracy (RTK) (2 cm horizontally, 5 cm vertically), measurement accuracy less than 1 mm, control measurement accuracy up to 6 mm, numerical surface model (DSM) with a resolution of up to 6 mm, and orthoimages with a resolution of up to 3 mm. It effectively solves the shortcomings of existing inspection methods such as "manual, single-point data, and unsafe work", and successfully establishes a new bridge inspection method based on mobile mapping technology (MMT), achieving a new bridge maintenance management technology and method that is "scientific, technological, and highly efficient, accurate, and safe".