|Abstract: ||本文針對柔性鋪面施工檢測厚度、平坦度及壓實度之方法，嘗試以LiDAR(光達)技術做一次性量測，利用其三維空間圖資所具有的全面性與可比較性併同分析，做為審定柔性舖面施工是否符合規範要求，以評估取代目前使用高低平坦儀或三米直規檢測之可行性，及減少鑽心取樣之破壞性檢測為目的。本研究選定臺北市士林區新安路219號前之1999民眾反映道路缺失維修工區為案例，於施工前、中、後進行LiDAR掃描量測，解算立體點雲圖成果，並繪製斷面圖及等高線圖，再判讀超出規範要求標準(平坦度±2.6mm，厚度>5cm±0.5cm)之相對位置及範圍。 本研究LiDAR量測採固定站3次量測覘標之距離標準差均小於1mm，顯示採用固定站短距離觀測量精密度佳，具有一定的可信度，LiDAR應足以使用在柔性鋪面之檢測作業。鋪面平坦度由等高線圖及間距50cm之各縱斷面剖析，計算得本次案例之平坦度不合格率達69.518%。鋪面厚度則由等差分布圖之漸層顏色分辨，再計算各區塊面積，不合格之範圍可相當明確顯示，相較於不定點式鑽心取樣檢核更具全面性。而壓實度是否達規範要求標準，係以量測實際填方體積與比重之相對關係，求出瀝青混凝土應有用料重量，再與廠商估算用料量之比值評估，本次案例計算結果壓實度為83%(小於95%)，判屬不合格，得再針對厚度較高處採鑽心取樣複驗。由於目前應用LiDAR於柔性鋪面之厚度、壓實度檢測作業尚無人從事研究，因此，本文研究所使用之LiDAR掃描量測、及分析計算平坦度、厚度、壓實度等方法，應能提供國內柔性舖面工程檢測作業技術精進參考。|
In this study, we tested the thickness, flatness, and compaction of flexible pavement constructions. We used Light Detection and Ranging (LiDAR) technology to conduct comprehensive measurements. The comprehensiveness and comparability of 3D spatial mapping information were combined with analysis to examine whether flexible pavement constructions conform to code requirements, and thereby evaluate the feasibility of replacing the currently available high-low detectors or conducting 3-m straightedge inspection using LiDAR and achieving the objective of reducing the use of destructive testing (i.e., sampling by core drilling). A case involving the site of maintenance construction for a flawed roadway reported by citizens through the 1999 line at Number 219 Xinan Road, Shilin District, Taipei City, was selected in this study. LiDAR was conducted to scan and measure the site before, during, and after construction and resolve the 3D point cloud results. Subsequently, a cross-section map and a contour map were plotted to determine the locations and ranges that exceeded the code requirement standards (flatness: ± 2.6 mm; thickness: > 5 ± 0.5 cm). In this study, LiDAR measurements were conducted 3 times at a fixed station. The standard deviation of the measured target was lower than 1 mm, indicating that adopting fixed-station measurement for a short distance yielded excellent precision and a certain degree of reliability. Therefore, LiDAR can be used in testing flexible pavement. The flatness of pavement was analyzed using the contour map and vertical sections with an interval of 50 cm. After calculation, the flatness failure rate in the studied case reached 69.518%. The pavement thickness was determined using the color gradient of arithmetic distribution before calculating the area of each block. Nonconforming ranges were manifested clearly. The proposed method was more comprehensive compared with the use of random core drilling for sampling testing. We determined whether the compaction fulfilled the standard code requirements by calculating the material weight of asphalt concrete based on the relative relationship between the actual fill volume measured and the specific weight. The obtained material weight was compared with the ratio of material weight estimated by the manufacturers for evaluation. The calculated results of compaction in this case was 83% (lower than 95%), which was considered as a failure. A retest must be conducted using core drilling to conduct sampling in areas containing flexible pavement with higher thickness. Because no studies regarding the application of LiDAR in testing flexible pavement thickness and compaction have been conducted previously, the LiDAR scanning, measurement, analysis, and calculation methods used to determine flatness, thickness, and compaction can provide references for improving testing operations and technologies used in domestic flexible pavement construction.