摘要
长期渗漏是导致灵渠秦堤塌陷病害的主因,严重影响了灵渠的保护工作。以飞来石段秦堤为研究对象,分析地下渗流场及渗漏原因,评价相应治理措施的效果。对秦堤的渗漏问题进行了现场勘查,评价了区域工程地质和水文地质条件。采用防渗墙来封堵渗漏通道,并布置地下水位观测孔进行地下水监测。建立地下水渗流场的数值模型,模拟自然条件下的地下水渗流,将模拟结果与监测数据对比,验证模型的准确性。进行不同工况下的地下水渗流模拟,对比分析设置防渗墙后渗流场的变化。模拟得到防渗墙的等效渗透系数分别为7×10-7、7×10-7、7×10-8m/s,封堵了渗漏通道,改变了渗流途径。治理后,河间地块的每延米渗流量由2.640 m3/d减至0.176 m3/d,减少了93.3%。分析表明:水位高差大、渗流途径短、砂卵石层及灰岩中的岩溶裂隙渗透性强是该区域发生渗漏的主要原因,利用高压旋喷桩形成防渗墙可有效治理渗漏。
The long?term leakage problem is a major cause of Qin Dike collapse, and seriously affects the protection and the inscription work of the Ling Canal. Taking the Qin Dike as the research object, its underground seepage field and the causes of the leakage was analyzed and the efficacy of the corresponding control measures was evaluated. Firstly, According to the leakage problem of Qin Dike, scene investigation was adopted, and the regional engineering geological and hydrogeological conditions were evaluated. To solve this problem, the cut?off wall was used to seal leakage passage, underground water level observation holes were arranged for the monitoring of groundwater. Secondly, the numerical model of groundwater seepage field was established used to simulating groundwater seepage under natural conditions. By comparing the results with the monitoring data, it verified the accuracy of the model. Then groundwater seepage was simulated under different conditions, comparing and analysis the change of seepage field before and after building the cut?off wall. The equivalent permeability coefficient of 7×10-7 m/s, 7×10-7 m/s and 7×10-8 m/s of cut?off wall was obtained by simulation respectively. The cut?off wall sealed the leakage channel and changed the seepage route. Before and after treatment, The per meter seepage flow decreased from 2.640 m3/d to 0.176 m3/d in the block between rivers, effectively reducing 93.3% of the original amount of leakage to achieve the effect of seepage control. The analysis shows that large of water level elevation difference, shorter seepage pathway and the stronger permeability of the sand?cobble layer and the karst fissure in the limestone are the main cause of the leakage problem occurred in the region. The cut?off wall formed by high pressure jet grouting piles can effectively control the leakage problem.
出处
《人民黄河》
CAS
北大核心
2016年第3期144-148,共5页
Yellow River
基金
国家自然科学基金资助项目(50908217)
关键词
渗漏
监测
渗流场
数值模拟
成效分析
灵渠秦堤
leakage
monitoring
seepage field
numerical simulation
effective analysis
Qin Dike
