【作者】 蔡武林；

【导师】 万五一；

【作者基本信息】 浙江大学 ， 水力学及河流动力学， 2011， 硕士

【摘要】 随着社会和经济的发展,人们越来重视河口的开发利用。为了充分发挥河口的航运、防洪和养殖等综合效益,有时需要对天然河口进行改造,在河口区建水工建筑物,如挡潮闸、防洪闸、堵坝等,是人们改善河口的重要手段。通常情况下,近海区域的水工建筑物会影响河流入海径流,导致感潮河流的入海口的泥沙冲淤特性发生较大变化,影响河口的原有地形和生态环境。分析和预测近海水工建筑物对河口的形态及环境影响,对保护和充分利用河口具有重要的意义。本文对金清河口采取截弯取直的改造后,堵坝下游至近海区域的泥沙淤积特性进行了数值模拟和试验研究,分析了堵坝截断径流后,其下游原河道在潮汐作用下的泥沙淤积分布特性和淤积过程。主要研究内容包括如下：(1)根据水文泥沙资料,从平面二维水流泥沙的基本方程和基本理论出发,采用平面二维数学模型,对堵坝下游河口的潮流泥沙进行数值模拟,分析了原河口区域的潮流运动特征,得到泥沙淤积分布。(2)在模拟的潮流流场基础上,对堵坝下游的泥沙淤积过程及分布特征进行数值模拟,模拟结果表明,堵坝修建后三年淤积速度较快,而后淤积速度变慢,并且逐步达到新的平衡。(3)通过1：40的河口水工模型,对堵坝下游河道的淤积特性进行了反演测试,并将物理模型试验结果与数值模拟计算进行了对比,二者吻合良好。(4)利用水工模型对堵坝下游河道的放水冲淤措施进行了探讨和预测分析,对三种特定工况的冲淤方式进行了试验。更多还原

【Abstract】 With the social and economic development, people pay more attention to the estuary’s management and exploitation. In order to make full use of the estuary, such as navigate, flood control and aquiculture, natural estuary is usually adjusted according to the improvement. Hydraulic engineering usually change the natural river by floodgate and dam, which will increase the sediment and inflect the terrain and environment. It’s significant to analysis and study the influence of hydraulic engineering on the sediment of estuary, which will protect and make full use of the natural estuary.The thesis studied the influence of dam on the sediment of near estuary, based on the Jinqing estuary. The distribution and time history of sediment were simulated. The key researches are following:(1) According to the hydrological datum and theoretical analysis, the 2-Dnumerical model was established to simulate the fluid field and sediment pattern of natural estuary area.(2) According to the simulation of fluid field, the distribution and develop process were analyzed. The result shows that the sediment was developed in three years, and then sediment gradual become slowly.(3) A test model with scale 1:40 was established to simulate the distribution and time history of sediment. The experiment proves the numerical result.(4) Through the experiment, river erosion and deposition was discussed and analyzed, and three kinds test result of deposition and erosion in river were presented.更多还原