急紊流条件下深水铺设D形排施工工艺

Construction technology of sinking D-shaped soft mattress in deep water in rapid and turbulent flow

长江干线武汉-安庆段6 m水深航道整治工程(Ⅳ标段)马当左槽中段潜坝工程D形排施工时,由于水深和流速较大,出现了铺排船走锚、横向控制不住船位等现象,在采取增加上游锚缆长度以增加锚抓力、下连环锚等一系列措施而仍然没有彻底解决问题的情况下,提出2种增加锚泊力的施工方案:方案1是在铺排船的上游增加1艘辅助铺排船;方案2是把设计的排头梁换成2片联锁片进行排头锚固,利用排头的水下摩擦力增加铺排船的锚泊能力。对2种方案的船舶锚泊力和排体受力进行分析。现场试验结果表明方案2是可行的,而方案1由于多种因素的影响,铺排船仍然出现了走锚。

The geotextiles-laying vessel appeared“dragging anchor”during sinking of D-shaped soft mattress in Madang section for the 6 m depth channel regulation project in the section from Wuhan to Anqing of the Yangtze River main line due to deep water and large flow velocity.Some traditional measures,such as increasing the length of upstream anchor cable and dropping linking anchor were proved ineffective for solving the problem completely.Therefore,two construction schemes for increasing the mooring force were presented:scheme I is to add another geotextiles-laying vessel in the upstream of the working vessel,while scheme II is to replace the head beam of soft mattress with two concrete interlocking blocks so as to increase the friction force on the head of the soft mattress.This paper analyzes the mooring force and the stressed state of flexible mattress.The field tests indicate that the scheme II is feasible,but scheme I cannot solve the problem of“dragging anchor”due to multiple influential factors.