长江南京段八卦洲汊道天河口段崩岸成因分析及治理

Analysis and Control of Causes of Bank Collapse in Tianhekou Section of Baguazhou Branch of Yangtze River in Nanjing

摘要:

为探究长江南京段八卦洲汊道天河口段崩塌险情的主要原因，基于现场调研资料和分析计算，认为天河口段岸坡地质二元结构、抗滑稳定系数偏低、滩地回填土加载是导致工程段崩岸发生的主要原因。在此基础上，提出了滩地削坡减载及袋装土+抛石防护的治理方案，既提高了水下岸坡稳定性和岸坡的抗冲能力，又减少了土方外运，节省了工程造价。工程实施后，崩塌段发生明显回淤现象，未发生新的崩塌，说明工程发挥了良好的防护效果。

Abstract:

To investigate the main causes of the bank collapse risk at the Tianhekou section of the Baguazhou Branch of Yangtze River in Nanjing, based on the field survey data and analytical calculations, the results indicate that the dual geological structure of the bank slope, low stability factor against sliding, and loading from backfilled soil in the tidal flats are the primary causes of the bank collapse in the engineering section. On this basis, a control scheme involving slope cutting and load reduction in the tidal flats along with bagged soil and riprap protection is proposed, which not only enhances the stability and erosion resistance of the underwater bank slope, but also reduces the need for soil transportation, thereby saving the engineering costs. After the implementation of the project, there is a significant siltation phenomenon in the collapsed section, but without new collapses occurred, indicating that the project has achieved a good protective effect.