【作者】 张志军；

【导师】 李守义； 雷韦锁；

【作者基本信息】 西安理工大学 ， 水利工程， 2003， 硕士

【摘要】 黄河宁夏段属黄河上游下段，全长397km，重点治理的平原河道长266.7km，根据其特性可分为三段。其中下河沿至仁存渡河段为非稳定性分汊型河道；仁存渡至头道墩河段为弯曲型河道；头道墩至石嘴山河段为游荡型河道。河道床质也不相同，仁存渡以上河段为沙卵石，以下河段为沙质。为了探索适宜黄河宁夏段河道特性和演变规律的整治方案、工程布局、工程措施及有关参数，开展黄河宁夏段河道坝垛冲刷坑和根石走失试验研究，具有十分重要的理论意义和实用价值。 本文通过对青铜峡市细腰子拜和陶乐县下八顷河段冲刷坑的试验研究，对冲刷坑的形成及根石走失成因进行了分析研究。冲刷坑的形成与横向环流、上游回流和绕流丁坝造成流速及流态不均匀等因素有关；根石走失与根石在水中的稳定性和河床性质及坝脚附近冲坑有关。另外，对设计中通常采用的冲刷坑计算公式进行了详细演算和对比分析，除蒋焕章公式以外，马特维也夫、波尔达柯夫等都可选择应用。经过理论计算和试验观测研究，提出了仁存渡以下沙质河床，丁坝最大冲刷坑水深为10—13米，个别受主流持续顶沖的丁坝，最大冲刷坑水深可达20米。根据整治方案，结合治河实际情况，推荐了网罩护根防冲和混凝土四脚体护脚这两种比较有效的护根措施。该研究成果对黄河宁夏段河道整治工程设计和施工具有重要参考价值。更多还原

【Abstract】 The Ningxia river section of the Yellow River, which is 379Km long, belongs to the upper section of lower reaches of the Yellow River. The plain watercourse to be harnessed emphatically, which is 266.7Km long, is divided into three sections. The river section from Xiaheyan to Rencundu is unstable and divergent, and the one from Rencundu to Toudaodun is cooked, and the one from Toudaodun to Shizhui Mountain is wandering. The quality of the riverbed in the upward Rencundu, which is made up of scree, is different from the one in the downward Rencundu, which is made up of sand. In order to explore harness scheme, layout, measurements and parameters concerned of the project, which are appropriate for the characteristic and the evolvement law of the watercourse of Ningxia section of the Yellow River, the study on the experiment of the scoured pit of the dam buttress and runoff of the root rock of Ningxia section of the Yellow River is of important theoretical meaning and practicable value.The cause of the formation of the scoured pits and the runoff of the root rocks are studied through the experiment of the scoured pits which are along the river section from Xiyaozipai in Qingtong city to Xiabaqing in Taole town. The formation of the scoured pits is related with such factors as the unstable flow velocity and the unstable flow state caused by the circumfluence in the cross direction, the upstream circumfluence and thecircle flow around the embankment. The runoff of the root rocks is connected with the stability of the rocks when they are submerged in water, the quality of the riverbed and the pit nearby the dam toe. In addition, the contrast analysis and calculation of the computational formulas commonly used in the scoured pit designs are conducted. It concludes that Makeweiyefu formula and Boerdakefu formula can be chosen for use besides Jianghuanzhang formula.Through theoretical computation and experimental observation, it is put forward that the maximal depth of the scoured pits of the embankment is from ten to thirteen meters, and for several pits whose top are rinsed by main flow continuously, their scoured depth have reached twenty meters. According to renovation scheme and connecting with practical river harness situation, netlike cover protection and quadruped concrete hose measurements, which are comparatively effective, are commended. The results will provide important reference value for the design and construction of the watercourse harness of the Ningxia river section of the Yellow River.更多还原