塑性混凝土防渗体系在高水头差船闸施工围堰中的应用

Application of plastic concrete anti-seepage system in construction cofferdam of ship lock with high head difference

为研究塑性混凝土防渗体系在高水头差船闸施工土石围堰中应用时,其渗透坡降、应力应变及围堰填筑材料、所处地层渗透系数对防渗墙渗透坡降的影响机理,结合万安二线船闸工程中应用的土石围堰监测结果,对塑性混凝土防渗墙的应力、应变进行有限元计算分析。采用不同的本构模型对土石围堰不同填筑区的填筑料进行模拟,结果表明:塑性防渗墙具有良好地防渗降压作用,所起作用的大小与围堰填筑材料及地层的渗透系数有关。应变监测结果表明,防渗墙在工作阶段主要受压应力作用,压应变值为-247.8×10^(-6)~0,处于-750×10^(-6)~100×10^(-6)允许应变范围,确保了防渗墙在工作阶段的安全可靠。

To study the mechanism of the influence of the plastic concrete anti-seepage system on the seepage gradient of the anti-seepage wall in the earth-rock cofferdam construction of the ship lock with high head difference,including its seepage gradient,stress,strain,cofferdam filling materials,and permeability coefficient of the formation,this paper calculates and analyzes the stress and strain of the plastic concrete anti-seepage wall by finite element method in combination with the monitoring results of the earth-rock cofferdam applied in the Wan'an second-line ship lock project.The calculation analysis simulates the filling materials in different filling areas of the earth-rock cofferdam with different constitutive models.The results show that the plastic anti-seepage wall plays a good role in seepage prevention and pressure reduction,and its effect is related to the permeability coefficient of the cofferdam filling materials and the formation.The strain monitoring results show that the anti-seepage wall is mainly subjected to compressive stress at the working stage,and the compressive strain value is -247.8×10^(-6)-0,which falls into the allowable strain range of -750×10^(-6)-100×10^(-6),ensuring the safety and reliability of the anti-seepage wall during the working stage.