高水头差船闸围堰防渗墙塑性混凝土试验研究

Test on plastic concrete of cutoff wall in ship lock cofferdam with large head difference

依托江西万安高水头差船闸围堰,并依据水利水电相关试验标准,通过调整防渗墙塑性混凝土的水胶比、膨润土掺量等参数,确定适用于高水头差围堰的高极限应变、低抗压强度、低弹性模量及低渗透系数的塑性混凝土配合比(即水胶比为0.80、膨润土掺量为25%),并经现场注水试验及高密度电测法检测。结果表明,该塑性混凝土防渗墙抗渗性能优异、区段连续性及总体完整性良好。在围堰使用期内,通过监测塑性混凝土防渗墙内部的应变,发现塑性混凝土均处于安全的受压状态,防渗墙止水效果良好。

Relying on the ship lock cofferdam with a large head difference in Wan'an,Jiangxi Province,this study adjusts the water-binder ratio,the bentonite content,and other parameters of the plastic concrete mix used in the cutoff wall according to water resources and hydropower engineering standards.The paper determines the optimal plastic concrete mix ratio(the water-binder ratio is 0.80,and the bentonite content is 25%)with high ultimate strain,low compressive strength,a low elastic modulus,and a low permeability coefficient for cofferdam with a large head difference,then tests the plastic concrete by the field water injection test and the high-density electrical method.The results show that the plastic concrete cutoff wall has excellent impermeability,good section continuity,and good overall integrity.During the service period of the cofferdam,the strain monitoring results in the plastic concrete cutoff wall indicate that the plastic concrete is in a safe compressive state,and the cutoff effect of the wall is good.