长江双涧沙整治工程异常冲刷原因分析及有关施工停歇的思考

2016年汛期长江发生流域性大洪水,南京以下12.5 m深水航道二期工程整治工程因环保要求处于施工停歇期,期间双涧沙头部潜堤工程区域发生异常冲刷。采用水流数学模型和理论分析方法,复演了阶段工程状态相应水情下工程水域流场及流态,揭示工程护底范围内、外发生的异常冲刷原因,取得有关软体排护底设计的深化认识,并探讨因施工停歇要求设计、施工及管理等各方将面临新的工作,可供类似工程建设时参考。

Analysis of causes of abnormal scouring incurred in the Shuangjiansha construction area of the Yangtze River and discussion on construction suspension of works

During the flood season in 2016,the Yangtze River had caused floods in the whole basin,and the 12.5 m deepwater channel regulation project phase II downstream of Nanjing had been suspended as required for environmental protection purposes,during which abnormal scouring occurred in the submerged dike area at the head of Shuangjiansha in the Yangtze River.Using flow mathematical model and theoretically analytical methods,we simulate the flow field and regime of the construction area on various water conditions during different execution stages of the project,and find the reasons for the abnormal scouring arising within and out of the limits of the bottom protection,which will give new insights into the design of mattress for bottom protection.We further discuss new jobs that designers,owners,contractors,and all the other parties concerned may encounter owning to the ecological requirement for construction suspension,which can be used as a reference for similar large-scaled inland channel regulation projects.