土围堰在高水位下的受力分析研究

Stress Analysis on Soil Cofferdam under High Water Level

湖南省大岳高速洞庭湖大桥锚碇位于洞庭湖湖畔,且基坑开挖及锚碇基础施工处于洞庭湖汛期阶段,为保证锚碇基础施工的连续性和安全性,在距离锚碇基坑边线15 m处设置一环形土围堰用以阻挡洪水。采用有限元软件对环形围堰及现场环境等进行整体建模,从围堰高度验算、围堰渗流计算、围堰整体抗滑稳定性计算、围堰变形与应力计算及土围堰基底抗滑稳定性计算等5个方面进行计算分析。研究得出高水位条件下采用环形土围堰作为阻水结构的思路得当,既保证了施工区域的施工安全,又避免了汛期出现停工现象,大大降低了施工成本,同时为今后类似工程积累了宝贵经验。

The anchorage of Dongting Lake bridge in Hunan Dayue expressway is located at Dongting Lake side,the excavation of the foundation pit and the construction of anchorage foundation are in the stage of Dongting Lake flood season. In order to ensure the continuity and safety of the anchorage foundation construction,a circular soil cofferdam is set up at the distance of 15 m from the foundation pit sideline of the anchorage to block the flood. The finite element software is used for modelling the circular cofferdam and the site environment,and the calculation of the height,the seepage,the anti slide stability,the deformation and the stress,and the anti slide stability of the foundation of the cofferdam are calculated and analyzed. It is concluded that the idea of using the circular soil cofferdam as the water resistance structure under high water level is correct,it not only ensures the construction safety of the construction area,but also avoids the shutdown phenomenon in the flood season,greatly reduces the construction cost,and accumulates valuable experience for the similar projects in the future.