生態安全護岸栽植孔之水理現象研究

Abstract

In order to apply the vegetation bags and make green on the reinforced concrete revetment, the diameter of the drainage holes is enlarged to thirty centimeters. The modified reinforced concrete revetment not only maintain safety but also beautify the appearance. For the sake of effectuation in worksite, this research chooses experimental revetment model to discuss, the characteristics of flow velocity and discharge within revegetation holes. In addition, this study discussed the hydraulic characteristics under the combinations of two types of refilled sediment, four revegetation holes with different slopes, and the relationship of drawdown with time series. In summary, there are some results concerning this study. They are presented as follows: 1. The refilled sediment was the main factor. In similar slope, both the velocity and the discharge of the refilled with the uniformity coefficient 10.45 sediment are bigger than the uniformity coefficient 19.92 sediment. 2. In the same refilled sediment, when the slope of revegetation hole is increased, both the velocity and the discharge are lesser. 3. In similar slope, the drawdown with time series of the filled with the uniformity coefficient 19.92 sediment is longer than the uniformity coefficient 10.45 sediment. 4. In the same refilled sediment, when the slope of revegetation hole is increased, the drawdown with time series is longer.

為改善現有之鋼筋混凝土護岸，將排水孔直徑加大至30公分，使之能填充植生包植生綠化護岸，此能較符合生態之原則，且鋼筋混凝土之結構也具安全性，護岸的外觀亦可砌石加以美化。本文採用試驗護岸模型以探討栽植孔之排水流量及流速等現象。 本試驗針對生態護岸模型所設置的栽植孔進行試驗，以二種不同均勻係數之回填砂石(10.45及19.92)、四種不同斜率之洩水管(-8°、0°、4°及8°)以及水位洩降與時間之關係進行探討。 由試驗結果可以得到： 1.回填砂石粒徑為影響排水孔流速及流量之最主要因素。於相同洩水管坡度的情況下，回填均勻係數10.45之試驗砂石時所量得的流速及流量皆大於回填均勻係數19.92試驗砂石時之值。 2.於相同回填砂石粒徑情況下，洩水管愈向上傾斜，流速及流量亦愈小。 3.於相同洩水管坡度的情況下，回填均勻係數19.92之試驗砂石時，水位洩降所需時間較回填均勻係數10.45之試驗砂石長。 4.於相同回填砂石粒徑情況下，洩水管愈向上傾斜，水位洩降所需時間愈長。