深槽地基土加固方法对防渗墙的影响研究

发布时间：2018-03-05 18:05

本文选题：防渗墙　切入点：有限元模型　出处：《水利水电技术》2017年03期 　论文类型：期刊论文

【摘要】：以龙开口水电站坝基防渗墙工程为例,采用精细化有限元法,针对砂卵石层开挖施工工序,建立防渗墙墙后砂卵石地基在直接开挖、灌浆固结及设置旋喷桩加固三种加固方案下的有限元分析模型,研究不同加固方案下防渗墙变形、内力及应力的变化规律,分析不同开挖方案对防渗墙安全性的影响。分析结果表明:直接开挖方案和灌浆固结方案防渗墙最大变形为0.5~3.7 mm,最大正弯矩为300~1 000 kN·m,最大负弯矩为-2 100~-800 kN·m,最大剪力为800~1 300 kN;设置旋喷桩加固方案防渗墙最大变形为0.2~0.3 mm,最大正弯矩为100~150 kN·m,最大负弯矩为-300~-200 kN·m,最大剪力为300~400 kN。三种方案中直接开挖方案变形最大,最大变形不到防渗墙左侧宽13.6 m的万分之三;加固砂卵石层地基可显著降低防渗墙的变形、内力及应力,显著提高防渗墙的安全性。研究结果为龙开口水电站坝基深槽砂卵石层的开挖加固方案提供了理论基础,在保证防渗墙安全可靠的前提下优化了地基土加固方案的设计。
[Abstract]:Taking the impervious wall project of dam foundation of Longkou Hydropower Station as an example, according to the construction procedure of sand pebble layer excavation, the sand pebble foundation behind the cutoff wall is directly excavated by using fine finite element method. The finite element analysis models of grouting consolidation and grouting pile reinforcement are used to study the variation of deformation, internal force and stress of the cutoff wall under different reinforcement schemes. The effects of different excavation schemes on the safety of the cutoff wall are analyzed. The results show that the maximum deformation of the cutoff wall is 0.5 ~ 3.7 mm, the maximum positive moment is 300 ~ 1 000 KN 路m, the maximum negative moment is -100 ~ 800 KN 路m, and the maximum shear is maximum. The maximum deformation, positive moment, negative moment, maximum shear force and shear force of the anti-seepage wall are 0.20.3mm, 150kN 路m, -300-200kN 路m and 300-200kN 路m, respectively. Among the three schemes, the maximum deformation of the direct excavation scheme is the largest, and the maximum deformation of the anti-seepage wall is 0.2mm, the maximum positive moment is 100kN 路m, the maximum negative moment is -300-200kN 路m, and the maximum shear force is 300-400kN. The maximum deformation is less than 3/10000 of the width of 13.6m on the left side of the cutoff wall, and the deformation, internal force and stress of the cutoff wall can be significantly reduced by strengthening the sandy pebble layer foundation. The research results provide a theoretical basis for the excavation and reinforcement scheme of the deep grooved sand and pebble layer in the dam foundation of Longkou Hydropower Station, and optimize the design of the foundation soil reinforcement scheme on the premise of ensuring the safety and reliability of the impervious wall.
【作者单位】：郑州大学土木工程学院;中南大学土木工程学院;
【基金】：河南省高等学校重点科研项目(16A560025)
【分类号】：TV543.8

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