斯里兰卡某深水防波堤结构设计与稳定性试验

Structural design and stability test of a deepwater breakwater in Sri Lanka

为研究深水及强涌浪条件下防波堤稳定性,以斯里兰卡某深水防波堤工程为例,结合工程深水和强涌浪的特点,介绍了该深水防波堤的设计,并进行了波浪断面物理模型试验研究。研究结果表明,根据欧洲标准Rock Manual设计的护面块体和外坡堤脚块石经波浪断面物理模型试验研究可满足波浪作用下的稳定性要求;原方案内坡棱体平台高程较高,受到的越浪水体冲击作用很强,其在200a一遇波浪和200a一遇+20%波浪作用下均严重失稳;优化方案将防波堤内坡棱体平台高程降低了2 m,其受到的越浪水体冲击作用显著减弱,内坡棱体块石的稳定性显著提高。对于深水、强涌浪海域的防波堤工程,如防波堤堤顶高程较低时,建议不能单纯为了节省造价而一味提高内坡棱体块石平台的高程。为了提高防波堤在波浪作用下的稳定性,宜适当降低内坡棱体平台的高程。

To study the stability of the breakwater under the deepwater and strong swell wave conditions,a deepwater breakwater in Sri Lanka was studied as an example.Combined with the characteristics of deepwater and strong surge,the design of this breakwater was introduced,and the physical model test of wave section was carried out.The study shows that the armour units and the seaside toe rocks designed based on the European standard Rock Manual can meet the requirements of stability under wave action through the physical model test of wave section.The rear side prismatic platform in the original scheme has a high elevation and is strongly impacted by overtopping flow,which is seriously unstable under the action of 200 year return period and 200 year return period+20%wave action.For the optimization plan of the breakwater,the elevation of the rear side prismatic platform rocks is reduced by 2 m,the impact of overtopping flow on the platform reduces significantly,and the stability of the rear side prismatic platform rocks is improved significantly.For the breakwaters with relatively low crest elevation in the sea areas of deep water and strong swells,it is not suggested to simply increase the elevation of the rear side prismatic platform rocks to reduce the project cost.To improve the stability of the breakwater under wave action,it is suggested to appropriately reduce the elevation of the rear side prismatic platform.