盾构隧道壁后注浆性能及效果监测研究

Study on performances and effect monitoring for backfill grouting of shield tunnel

壁后注浆是盾构施工中一道非常重要的工序,也是盾构施工中主动地层沉降的控制措施。对于什么样性能的壁后注浆能更有效地控制地层沉降,目前缺乏统一的认识。针对南京长江隧道盾构壁后注浆,开展了浆液在地层压力作用下的固结变形特性的体积收缩试验。浆液的固结主要发生在注入盾尾8 h内,浆液的体积收缩率在10%以内。同时,对浆液的充填效果开展了现场地质雷达监测工作,浆体的厚度基本上与盾尾空隙厚度减去浆液体积收缩变形一致。因此,提出的浆液的体积收缩率是浆液控制地层沉降重要评价标准,对盾构施工具有重要参考价值。

Backfill grouting is a very important process of shield tunnelling, which is also a active measure to control strata settlement. For now, What kind of performance for grouting can control the strata settlement has been lack of unity of common view. For the backfilling grouting of shield tunnel ofNanjing Yangzi River, the thesis has made the experiments of volume contraction under the strata pressure. Grouting consolidation takes place within 8h after grouting, and volume contractive rate is within the range of 10%. At the same time, field monitoring for backfill grouting has been conducted in the site. Concretion depth of backfill grouting is on the whole equal to the difference between depth of shield tail void and grouting constraction deformation. Therefor, the contractive rate of backfilling grouting is a very important criterion to control the slrata settlement, which has important reference to shield tunnelling.