摘要
平陆运河是新中国成立以来建设的第一条通江达海的运河工程。该运河航道河床泥岩底质占比高,且部分航道为干地开挖,泥岩岩层存在暴露、浸水后崩解的可能,崩解后的泥沙颗粒将在水流作用下输运沉积,增加航道淤积风险。以往泥岩的研究较多聚焦于干湿循环后的崩解特性,但对其在不同暴露风干条件下,再浸水崩解的研究较少。本研究利用自行设计的泥岩暴露风干后再浸水崩解测量装置,开展了泥岩自由浸水崩解特性试验,系统探究了不同暴露风干时长、浸水时间及不同泥岩样品质量对泥岩崩解速率、崩解量的影响。研究结果表明:崩解过程可分为缓慢崩解、快速崩解和崩解放缓三个阶段;暴露风干时长较长的泥岩在浸水过程中体积膨胀开裂现象显著,且累积崩解比例高;崩解后的颗粒平均粒径约为0.1 mm,且暴露风干时间越长,粒度分布越均匀。最后,基于不同风干时间的泥岩崩解结果,建立了崩解时间T与初始含水率w之间的对应关系,为泥岩崩解及航道淤积机制的研究提供了理论依据。
The Pinglu Canal is the first canal project that connects rivers to the sea in China since 1949.In its channel bed,mudstone substrate accounts for a high proportion,and part of the channel is dry excavation.A possibility exists that the mudstone strata will disintegrate after being exposed and submerged in water;disintegrated sediment particles will be transported and deposited under the action of water flow,increasing the risk of sediment siltation in the channel.Previous studies on mudstone have focused more on its disintegration characteristics after wet-dry cycling,but less on its re-immersion disintegration under different exposure to air-drying conditions.In this study,we conduct an experiment on the characteristics of mudstone disintegration under the conditions of free immersion using a self-designed device that measures the mudstone exposed to air-drying first and then immersed in water.We focus on a systematic study on the disintegration behaviors of mudstone effected by different time periods of air-drying exposure,different immersion starting instants,and different mudstone sample qualities.Results show the disintegrating process can be divided into three stages-slow disintegration,rapid disintegration and slowing-down disintegration.Mudstone with a longer air-drying exposure time period has a more volume expansion and more cracking in the period of water immersion,and thus has a higher proportion of cumulative disintegration.The average particle size of disintegrated particles is roughly 0.1 mm;the longer air-drying exposure,the more uniform the particle size distribution.Finally,based on the results of mudstone disintegrating at different air-drying time,we have derived a relationship of disintegration time T versus initial water content w,laying a basis for further study of mudstone disintegration and channel siltation mechanism.
作者
张瑞鹏
郝宇驰
严晓威
孙健
陈立华
朱苏鹏
ZHANG Ruipeng;HAO Yuchi;YAN Xiaowei;SUN Jian;CHEN Lihua;ZHU Supeng(CCCC National Engineering Research Center of Dredging Technology and Equipment Co.,Ltd.,Shanghai 201208,China;Key Laboratory of Dredging Technology,CCCC,Shanghai 201208,China;State key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China;Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China;School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China)
出处
《水力发电学报》
北大核心
2025年第11期50-56,共7页
Journal of Hydroelectric Engineering
基金
广西科技重大专项(桂科AA23023009)
中交集团重大专项课题(2023.13.ZJ.10)。
关键词
平陆运河
泥岩
崩解
风干时长
浸水时间
航道淤积
Pinglu Canal
mudstone
disintegration
air-drying time
immersion time
channel siltation
