强潮河口丁坝坝头砂肋软体排护底稳定性试验研究

通过对土工织物软体排护底应用情况以及钱塘江河口潮流特征的分析,认为丁坝坝头砂肋软体排铺设后的稳定性好坏是护底成败的关键。利用长35m、宽4.3m的水槽,对砂肋软体排在不同压载厚度条件下进行不同行近流速、不同坝长、不同水深的多组次室内试验研究,得到砂肋软体排的稳定性主要与压载的块石层厚度有关,铺设在丁坝坝头的砂肋软体排临界块石压载稳定厚度与行近流速、丁坝长度以及水深等因子有关,采用相关因子多元回归分析得到丁坝坝头砂肋软体排临界稳定的压载厚度经验公式,可指导现场施工实践。

Experimental study on stability of sand ribbed soft mattress of dike head for macro-tidal estuary

Based on the analysis of the application situations of geotextile soft mattress and the characteristics of tidal current in Qiantang Estuary,the stability of sand ribbed soft mattress in the dike head is considered to be the major problem of river bottom protection.Using the flume which is 35 m in length and 4.3 m in width ,by multiple groups stability experiments of sand ribbed soft mattress at dike head under conditions of different dike lengths,approach velocities,water depths,and block thicknesses,it shows that the stability is related to the block thickness on the sand ribbed soft mattress, the ballast thickness is correlative with the dike length, approach velocity and water depth.Through correlative factors regression analysis, the empirical formula of block ballast thickness of sand ribbed soft mattress at dike head were obtained.