碩士 / 國立臺灣海洋大學 / 河海工程學系 / 98 / In present study, the recently established formulae in European Overtopping Manual (EurOtop，2007) were adopted with SWAN wave model to simulate wave overtopping over commonly seen composite seawalls in the typhoon periods. The ocean surface wind velocity by CCMP(Cross-Calibrated oasMutli-Platform) and Alves and Banner (2003) white capping wave dissipation are adopted in SWAN simulation. It is found that the generally encountered under-estimation of wave period has been greatly improved.
Results by formulae of the European Overtopping Manual are further compared with the model experiment of Pingtung seawall by Water Resources Agency to evaluate the applicability to composite seawalls. The results showed that, run-ups predictions by EurOtop formulae in cases with flat slope beaches in shallow waters are quite different from the experimental measurements. In addition, for the case with water level +0.91m, both predictions and measurements are quite close to each other. The differences of estimated overtopping by Typhoon Chanchu only amount to about 16%. However, for tests with water level +1.50 m the calculations have demonstrated that the differences could be even higher. The simulations of the overtopping discharge due to Typhoon Utor (2001) in Pingtung Fanzilun seawall have illustrated that the seawalls could withstand the wave impact and protect the pedestrians on and after the seawall according to CEM(Coastal Engineering Manual, 2003),. Effects of the adjusted structure parameters on the overtopping discharges are further discussed. It is found that the riprap beach or the armour units comes across the accident to rcaduce roughness . The maximum overtopping discharges will increase by 7.9 times and 32.7 times. In cases at the maximum overtopping occurring with the spring tide, the maximum overtopping will increase by 3.9 times. In the case design with crest elevation of +6.0 m, the lower down of seawall crest to elevation of +5.72 m, the resulting overtopping discharge will increase about 1 times.
| Identifer | oai:union.ndltd.org:TW/098NTOU5192085 |
| Date | January 2010 |
| Creators | Chi-Chung Ho, 何積忠 |
| Contributors | Shiaw-Yih Tzang, 臧效義 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 121 |
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