丹江口土石坝砂卵石坝壳静压注浆渗控效果研究Ⅰ:二维渗流计算

Seepage Control Effect of Static Pressure Grouting in Dam Shell for Danjiangkou Earth-rock Dam Ⅰ: Two-dimensional Seepage Calculation

在对前期大坝各渗透性分区填料的试验结果进行分析整理的基础上,选取代表性断面1+180进行了二维渗流计算分析,确定了不利计算参数组合;针对不利计算参数组合,分析评价了心墙无缺陷条件下静压注浆体的渗控效果;并对心墙产生水平裂缝的渗流状态以及静压注浆体的渗控效果进行了计算分析。计算结果表明,静压注浆弥补了老坝心墙局部尺寸不够的情况,在心墙出现裂缝等极端情况下,静压注浆体能够有效控制裂缝渗漏带来的影响。同时,计算还揭示了下游砂卵石坝壳料局部渗透比降偏大的情况,建议通过在排水棱体和下游挡墙前设置合理的反滤层以提高下游坝壳料渗透稳定性。

The experiment results of the prior dam partition stuffing of permeability are analyzed and arranged. By the two dimension seepage calculation and analysis of the 1 ＋ 180 representative section, the combination of disadvantaged computation parameters are ascertained. According to it, the seepage control effect of the static pressure grouting is analyzed and calculated at the condition of core wall without cracks. And the seepage state of which core wall leads to cause the horizontal crack and the seepage control effect of the static pressure grouting are analyzed. The calculation showed that the injecting cement paste can make up the partial size shortage of the core wall of the old dam effectively. When some extreme conditions of the core wall occurs such as cracks to arise simultaneously, the static pressured grouting body can control the leakage effectively. Also the status of the greater seepage gradient of the dam shell gravel at backward position is indicated. So the filter layer is set behind the drainage filter and in front of the ward wall reasonably to improve the stability of the dam shell materials at backward position.