环式土工管袋充填特性模型试验研究
Model Experimental Study of Filling Property of Ring-type Geotextile Tube
中国每年从江河湖库等水域疏浚淤泥量达数亿立方米,通常进行陆地自然堆存,长期占用大范围土地。本文提出一种新型环式管袋堆场蓄淤排水技术,能有效解决疏浚淤泥堆放场地有限的问题,其中,环式土工管袋的充填对环式管袋堆场蓄淤排水技术的实施至关重要。为研究环式土工管袋充填过程中形状、高度、充填机制、压力等特性,开展不同工况下环式土管袋充填室内模型试验,研究逆时针、径向、竖直3种充填方式条件下,充填速度分别为2.43、2.55、2.66和2.77 m/s时的土工管袋充填后高度及充填机制。结果表明:逆时针充填时,挟沙水流首先向逆时针方向流动,泥沙淤积至一定程度后,挟沙水流运动受阻,开始向顺时针方向流动;径向充填时,挟沙水流以一定角度向两侧进行充填;竖直充填时,挟沙水流撞击靠近地面管袋一侧后向两侧进行充填。当充填方式为逆时针、充填速度为2.77 m/s时,管袋充填后平均高度最高;当充填方式为径向、充填速度为2.43 m/s时,管袋整体充填后平均高度最高;当充填方式为竖直时,4种充填速度条件下充填后管袋内泥沙分布极不均匀,管袋充填后高度与充填速度无关。12种工况下,逆时针充填且充填速度为2.77 m/s时,管袋充填后平均高度最高(0.09 m),袋体内泥沙颗粒分布较为均匀。基于试验测得的管袋充填后高度,应用机器学习原理,使用随机森林算法对逆时针、径向、竖直3种充填方式条件下的管袋高度进行模拟预测,结果较为准确,均方误差值分别为5×10-5、3×10-4、2×10-5 m2。
Objective This study introduces a novel circular geotextile bag storage and drainage technology that effectively addresses the challenge of limited space for dredged silt storage. The filling process of circular geotextile bags is critical to the implementation of this technology. This study presents indoor model experiments conducted under various operating conditions to investigate the characteristics of filled circular geotextile bags, including their shape, height, filling mechanism, and pressure distribution. It examines the height and filling mechanisms of bags filled using three different methods, namely counterclockwise, radial, and vertical filling, at different filling speeds. Methods This study conducted indoor model tests of circular geotextile bag filling under various experimental conditions. It investigated the height and filling mechanism of geotextile bags after filling under three different methods: counterclockwise filling, radial filling, and vertical filling, with filling speeds of 2.43, 2.55, 2.66, and 2.77 m/s, respectively. Due to space limitations at the experimental site, the selected circular geotextile bag had an outer diameter of 1.2 m and an inner diameter of 0.7 m. Given that the sedimentation of coarse particles can potentially affect the electromagnetic flowmeter, a fixed-volume bucket was utilized to measure the filling speed before each test condition began. The bucket was filled uniformly within a specified timeframe, after which the filling speed was calculated. In addition, three repeated experiments were conducted to determine the accurate filling speed used in this study. The selected filling material was a mixture of sand and water. The circular geotextile bag was positioned horizontally, and a slurry pump was utilized to fill the bag with the sand‒water mixture. A polar coordinate system was established using the center of the circular geotextile bag as the origin to determine the radius and angle of typical points within the bag. Following the completion of each test condition, the height of the bag at various points was recorded. The random forest algorithm was applied to simulate and predict the height of the bag after counterclockwise filling, where the independent variables were the radius and angle of each point. During simulation and prediction, 75% of the data was randomly selected for modeling, and the remaining 25% was used for validation. The results were relatively accurate, with MSE values of 5×10-5, 3×10-4, and 2×10-5 m2, respectively. Results and Discussions The counterclockwise filling mechanism operated as follows: the sediment-laden water flow initially moved counterclockwise, causing sediment accumulation. When the sediment approached the filling sleeve, the flow of sediment-laden water was obstructed and began to move clockwise. Sediment continued to accumulate, and once it reached the filling sleeve again, the shape and height of the tube bag remained unchanged, indicating the completion of filling. At this point, the filling process was considered complete. The bag body featured a total of 10 recording points. During counterclockwise filling, the process was divided into two stages. In the first stage, sediment particles moved with the water flow as far as the area between positions 5 and 6, where sedimentation began. The sediment gradually accumulated up to position 2, where the water flow was obstructed, initiating the second stage of filling. The water flow then moved clockwise toward position 6 and continued to accumulate until reaching position 10. Since the tube mouth directly faced position 1 during filling, severe erosion occurred, resulting in no sediment accumulation at this position. When the filling speed increased to 2.77 m/s, the filling process was also divided into two stages. In the first stage, the water flow moved both counterclockwise and clockwise simultaneously, with the counterclockwise flow playing the dominant role. The counterclockwise flow caused sedimentation near the filling sleeve, while the clockwise flow caused sedimentation at position 7. The amount of sedimentation in the clockwise direction was relatively small. When the counterclockwise sediment particles accumulated near the filling sleeve, the water flow became obstructed and began to move clockwise. Simultaneously, the sediment particles deposited during the first stage were lifted and redistributed, rapidly filling the bag. Since the tube mouth directly faced position 1 during filling, severe erosion occurred, resulting in no sediment accumulation at this position. Under radial filling conditions, when the filling speed was 2.43 m/s, the filling mechanism operated as follows: water flowed simultaneously to both sides, causing sediment particles to accumulate gradually. Once the accumulation reached a certain level, the pressure inside the bag increased, pushing sediment particles forward on both sides. In the counterclockwise direction, the particles were pushed to position 4, while in the clockwise direction, they were pushed to position 6, resulting in rapid filling of the bag. As the filling speed increased, the filling mechanism changed. The filling tube mouth aligned directly with the interior of the tube bag. After the water flow struck the tube bag, part of its kinetic energy was dissipated, causing the water to flow toward both sides at a certain angle. With the increase in filling speed, the sand discharge rate also increased. Therefore, sediment particles accumulated rapidly near the filling sleeve, obstructing water flow and reducing the travel distance, enabling rapid filling of the bag. In the vertical filling method, water flowed vertically into the inner side of the tube bag near the ground, significantly reducing the flow velocity. Sediment accumulated rapidly near the filling sleeve, obstructing water movement and resulting in a shorter travel distance. Conclusions Under 12 different working conditions, when the tube bag is filled counterclockwise at a speed of 2.77 m/s, its average height after filling reaches a maximum value of 0.09 m, with a relatively uniform distribution of sediment particles inside the bag. The heights of filled tube bags under three different filling methods, namely counterclockwise, radial, and vertical filling, were simulated and predicted using the random forest algorithm based on experimentally measured heights by leveraging machine learning principles. The results demonstrated high accuracy, with MSE values of 5×10-5, 3×10-4, and 2×10-5 m2, respectively. The findings presented in this study provide an important theoretical basis and technical reference for the construction of circular tube bag yards.
| [1] |
|
| [2] |
朱远胜,靳向煜,方汉明.充泥管袋技术的应用探讨[J].产业用纺织品,2000,18(6):36‒38. |
| [3] |
|
| [4] |
胡振琪,王萍,黄晓燕, |
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
丘富顺,胡云飞.土工管袋脱水工艺在城市内湖生态清淤中的应用[J].港口航道与近海工程,2023,60(6):113‒116. |
| [9] |
|
| [10] |
|
| [11] |
黄涛,沈保根,鄢俊, |
| [12] |
来志强,樊科伟,江恩慧, |
| [13] |
来志强,江恩慧,王仲梅, |
| [14] |
樊科伟,邹维列,来志强, |
| [15] |
|
| [16] |
张文斌,谭家华.土工织物充填管状袋的设计研究[J].中国港湾建设,2004,24(5):25‒29. |
| [17] |
|
| [18] |
邱长林,闫玥,闫澍旺.泥浆不均匀时土工织物充填袋特性[J].岩土工程学报,2008,30(5):760‒763. |
| [19] |
|
| [20] |
邱长林,闫澍旺.大尺度土工织物充填袋受力特性分析[J].工程力学,2009,26(1):92‒97. |
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
刘欣,雷国辉,张坤勇.考虑外部接触面摩擦的堆叠土工管袋的力学分析[J].中南大学学报(自然科学版),2015,46(11):4281‒4291. |
| [25] |
|
| [26] |
陈亮,雷国辉,赵仲辉.充泥过程中土工织物管袋的受力和变形分析[J].河海大学学报(自然科学版),2015,43(1):22‒27. |
| [27] |
|
| [28] |
张仪萍,王淼,刘伟超.摩擦填料作用下土工充砂袋充填特性[J].江南大学学报(自然科学版),2012,11(2):194‒198. |
| [29] |
|
| [30] |
|
| [31] |
孙立强,官婷婷,郭伟, |
| [32] |
|
| [33] |
闫玥,闫澍旺,邱长林, |
| [34] |
|
| [35] |
|
| [36] |
刘伟超,杨广庆,汤劲松, |
| [37] |
|
| [38] |
刘伟超,张仪萍,杨广庆.土工管袋充填特性模型试验研究[J].岩石力学与工程学报,2013,32(12):2544‒2549. |
| [39] |
|
| [40] |
吴海民,田振宇,束一鸣, |
| [41] |
|
| [42] |
|
| [43] |
|
| [44] |
满晓磊,鲍永健,吴海民, |
| [45] |
|
| [46] |
吴海民,束一鸣,常广品, |
| [47] |
|
| [48] |
吴海民,束一鸣,常广品, |
| [49] |
|
| [50] |
武霄,白帆.充填粉土的大尺度土工织物充填袋参数分析[J].水运工程,2013(12):183‒187. |
| [51] |
|
| [52] |
|
| [53] |
|
| [54] |
|
| [55] |
|
| [56] |
|
| [57] |
宋迎俊,邓昌,顾培英, |
| [58] |
|
| [59] |
周汉民.基于模袋法堆坝的尾矿坝稳定性研究[D].北京:北京科技大学,2017. |
国家重点研发计划项目(2023YFC3206203)
黄河水利委员会优秀青年人才科技项目(HQK‒202312)
河南省优秀青年科学基金项目(232300421065)
中央级公益性科研院所基本科研业务费专项项目(HKY‒JBYW‒2021‒1)
黄河水利委员会黄河水利科学研究院推广转化基金项目(HKY‒YF‒2022‒03)
国家自然科学基金面上项目(52379066)
北京江河水利发展基金会水利青年科技英才项目(JHYC202306)
/
| 〈 |
|
〉 |