人孔蓋花紋設計對抗滑能力影響之研究

Abstract

國內各管線單位實施管線地下化多年，並設置人/孔蓋以便於管線維護及事故搶修時，工作人員及材料得以快速進出。人/手孔蓋對於道路整體鋪面而言可視為小範圍變異點或面，經常在下雨過後表面潮濕或是經車輛磨耗後，使孔蓋表面變為光滑進而導致其抗滑能力之衰減，容易使車輛於行駛過程中產生打滑現象。有鑑於此，本文欲針對目前設置於市區道路之人孔蓋進行抗滑能力檢測，了解孔蓋花紋設計對抗滑能力之影響，並且模擬不同花紋樣式之抗滑能力差異，進而改良孔蓋表面花紋之設計。 本研究分為兩部份，第一部份針對管線單位人孔蓋進行抗滑試驗，經由英式擺錘試驗結果顯示，在低速檢測下孔蓋表面之平均花紋深度對於BPN值其影響並無規律性；而以BPT量測平滑的鑄鐵材質表面後，發現BPT橡膠滑片與孔蓋表面接觸面積百分比越大，抗滑能力越佳，但是當孔蓋表面具有高低不一之花紋後，因粗質紋理對於抗滑能力造成之影響較為顯著，使接觸面積百分比對乾、濕BPN值之相關性變得較低。而比較動態摩擦測試儀之數據後，當橡膠滑片以高速接觸到孔蓋表面時，平均花紋深度越深，讀取之60 km/hr下的DFT NO.（μ）數值越高，兩者呈現一高度正相關的趨勢，表孔蓋之平均花紋深度對於其高速動態下所提供之抗滑能力具有相當程度之影響。 第二部份為以石膏模擬孔蓋不同花紋樣式及配置方式量測其抗滑能力，以分析不同花紋設計對抗滑之影響。由平板狀試體之試驗，確認英式擺錘與待測表面接觸面積百分比呈高度正相關；然以不同花紋凹槽間隔之試體進行試驗時，間隔寬度增加，BPN會隨之提升，當間隔為1.5 cm，BPN出現最大值；接著改變花紋突起面積大小，BPN值隨面積縮小而提升，當面積為1.5×1.5 cm2，BPN出現最大值；再針對花紋深度探討，於乾及溼狀態下，花紋深度為0.3 cm及0.2 cm時，BPN值出現下滑之趨勢。另外根據其他不同花紋樣式，發現方形花紋之抗滑能力較佳但花紋排列方向影響不大之結果。 本研究最後根據兩部份實驗結果以及文獻回顧之各國抗滑專利孔蓋，提出新型孔蓋抗滑花紋之設計，提供給國內各管線實務單位作為孔蓋花紋改良之參考。

The pipe organizations in Taiwan had installed the pipe lines underground for many years and set manhole covers for maintenance. The material of manhole cover is different from pavement, so manhole cover is a special facility for roadway. After raining or wearing by vehicles, the surface of manhole cover will be slippery. And the ability of skid resistance of the manhole cover will become weaker. Vehicles occupy a great percentage of city trips. Manhole cover plays an even more important role of safety for the vehicles on urban streets road. On the experiment section, we measured the skid resistance values of the manhole covers which set on the urban street roads. According to data, the relativities between British Pendulum Number and the deep of the pattern were unobvious. And the apparent area between the pendulum and the surface of the cover made a great impact on the skid resistance values when the cover had a smooth surface. Pattern of manhole cover would cause hysteresis friction between the pendulum and the surface, so it could affect the relation between the apparent area and skid resistance. On the other hand, according to the DFT numbers (μ) measured by the Dynamic Friction Tester, we found that the DFT Numbers (μ) correlated with the deep of the pattern. It means when the vehicles pass through the manhole covers in high speed, deep pattern has better effect for the ability of skid resistance. On the Simulation section, we used gypsum to make several specimens and designed different kind of pattern on the surfaces of specimens. Then we measured the skid value of the specimens by using the British Pendulum Tester. According to the data collected from each phases of the experiment, it showed the influence of various designs of pattern. We confirmed that apparent area between the pendulum and the surface made a great impact on the skid resistance values, and knew that what kind of the pattern designs would make the specimens have great ability of skid resistance. Finally we designed a new type of the pattern of manhole cover based on the data collected from each phases of the experiment and provided the pipe organizations for improving the existing manhole covers set on the urban street roads.