高滩滩面守护工程试验研究

发布时间：2018-01-26 00:57

本文关键词： 航道整治高滩守护护岸水槽试验护滩带植草格　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：长江干线横穿我国东、中、西部地区，素有“黄金水道”之称，三峡工程蓄水以后，中下游沙质河段受来沙减少的影响，高滩崩退普遍发生，成为造成河道展宽，浅滩恶化的主要影响因素之一。为充分发挥长江“黄金水道”的效益，近年来长江中下游广泛实施航道整治工程中的高滩守护工程。高滩守护工程是稳定滩槽格局，改善航道条件的有效手段，但由于长江中下游岸坡组成松散，在明流顶冲条件下，稳定性极差，虽然近些年来工程结构一直在不断改进，但守护工程设计的难度仍较高，选择合适的研究手段，开展高滩守护工程方案的优化研究工作，意义重大。本研究以长江中游大马洲水道的丙寅洲高滩为例，开展了明流顶冲条件下高滩守护工程的研究。近年来大马洲水道内丙寅洲高滩受水流顶冲持续崩退，引起了主流的摆动，水道内浅滩形态交错发展，航道条件近年来急剧恶化，实施丙寅洲高滩守护工程是十分必要的。该守护工程不仅需要确保高滩的稳定，还兼具对主流摆动的控制，更加值得注意的是，丙寅洲高滩滩面高程相对较低，，还应考虑洪水期滩面的保护，因此，有必要对一般性的护岸工程结构进行针对性的优化后再行应用。通过建立了丙寅洲高滩局部概化模型，采取模型左侧动边界、进口格栅墙及转流屏控制局部模型的水流条件，完成了多级流量的相似性验证，可满足方案优化的需要。研究表明，高滩守护工程水下护底边缘通过排上压载，设置防冲石，预设备填石等方式，能够有效确保排体边缘的稳定；从控制河道深泓向丙寅洲一侧摆动并遏制浅滩交错发展的不利态势这一角度，大幅加宽护底排宽度，效果更好。但外滩滩面与高滩后方衔接处在天然情况下容易发生局部冲刷，还需要进一步的守护措施。通过对丙寅洲外滩概化水槽模型，研究不同护滩带、植草格生态护滩守护结构对滩面冲刷的影响。实验表明，在主汛期流量滩面U/Uc比值较小时，采取低矮坝高、小间距的护滩带结构，基本满足守护要求；在外滩滩面流速较大的区域，采取植草格全守护的生态护滩措施，对局部流场的干扰小，滩面守护效果较好。另外，即使是过流相对较弱的高滩滩面，护岸工程坎顶边缘与原滩面衔接位置由于工程扰动产生了集中流速，也会发生较为明显的冲刷，应采取散抛片石守护结构对滩面工程的边缘进行保护。本项研究成果在丙寅洲高滩守护工程的设计中得到了较好的应用，且具备一定的推广价值。
[Abstract]:The main line of the Yangtze River crosses the east, middle and west of China, known as the "Golden Waterway". After the three Gorges Project impounded, the middle and lower reaches of the sandy river are affected by the decrease of the sediment, and the collapse of the high beach is common. It has become one of the main influencing factors of river widening and shoal deterioration. In order to give full play to the benefit of the "golden waterway" of the Yangtze River. In recent years, the high beach guarding project has been widely implemented in the middle and lower reaches of the Yangtze River, which is an effective means to stabilize the beach channel pattern and improve the waterway condition, but because of the loose composition of the bank slope in the middle and lower reaches of the Yangtze River. The stability is extremely poor under the condition of open-flow roof impact. Although the engineering structure has been continuously improved in recent years, it is still difficult to design the guardian engineering, and the appropriate research means are chosen. It is of great significance to carry out the optimization research work of the high beach protection project. This study takes the Boyinzhou high beach in the middle reaches of the Yangtze River as an example to carry out the research on the high beach protection project under the condition of open current roof scouring. In recent years, the Boyinzhou high beach in the Damazhou waterway has been continuously collapsing and retreating by the top of the current, which has caused the mainstream swinging, the shoal shape in the channel has interlaced and developed, and the waterway conditions have deteriorated sharply in recent years. It is necessary to carry out the high beach protection project of Boyinzhou, which not only needs to ensure the stability of the high beach, but also has the control of the mainstream swinging. It is more noteworthy that the elevation of the high beach is relatively low. Therefore, it is necessary to optimize the general revetment structure and then apply it. By setting up the local generalized model of Boyinzhou high beach, adopting the moving boundary on the left side of the model, the flow condition of the inlet grille wall and the local model controlled by the turret, the similarity verification of multistage flow is completed. It can meet the needs of the optimization of the project. The research shows that the stability of the outfall edge can be effectively ensured by discharging ballast, setting the anti-flushing stone and filling the stone with pre-equipment in the underwater protecting bottom edge of the Gaotan Guardian Project. From the point of view of controlling the river channel deep wobble to one side of Boyin Island and restraining the unfavorable situation of the shoal interlaced development, the width of protecting bottom row is greatly widened. The effect is better. However, it is easy to occur local scour when the bund surface is connected with the high beach in the natural situation, and further protective measures are needed. Based on the generalized flume model of Bund in Boyinzhou, this paper studies the effect of ecological beach guard structure on beach surface erosion in different beach protection zones. The experiment shows that the ratio of U / U c is small in the main flood season. Adopt low dam height, small spacing beach protection belt structure, basically meet the requirements of protection; In the area where the velocity of velocity on the Bund surface is high, the ecological beach protection measures of planting grass grid are adopted, the disturbance of local flow field is small, and the protective effect of beach surface is better. In addition, even the higher beach surface with relatively weak overcurrent is adopted. Because of the concentrated velocity produced by the engineering disturbance, there will be more obvious scour in the connecting position between the top edge of the bank and the original beach surface of the revetment project. The edge of the beach surface engineering should be protected by the scattered stone daemon structure. This research result has been applied well in the design of the high beach guard project in Boyinzhou and has certain popularizing value.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U617

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