盾构施工过程中产生的大量渣土不仅污染环境，而且会增加运输和处置成本。为解决这一问题，以南京地铁6号线某区间工程为依托，提出将盾构开挖排放的粉质黏土层渣土回收再利用于壁后注浆的技术方法。通过室内试验、SPSS（statistical package for the social
sciences）多元非线性回归分析及多目标规划优化方法，研究渣土浆液性能随水灰比、硬化剂A和硬化剂B掺比（与水泥质量之比）的变化规律，并确定渣土浆液性能与成本的最优配比。研究主要结论为： 1）TW-G系列产品适用于高含泥量浆液，其中硬化剂A具有缓凝和减水作用，硬化剂B具有促凝作用。2）多目标规划优化结果显示，性能最优配比为水灰比0.75，硬化剂A掺比为0.86%，硬化剂B掺比为12.95%； 成本最优配比为水灰比0.84，硬化剂A掺比为3.66%，硬化剂B掺比为2.91%。3）现场实践表明，相比于普通单液硬性浆，渣土浆液性能更佳，用于盾构壁后注浆后地表沉降控制在12 mm以内，管片上浮控制在25 mm以内，且能够减少渣土外运10%以上，成本降低35%左右。
Shield tunneling produces a significant volume of
excavated soil, leading to environmental pollution and elevated transportation
and disposal costs. To address this issue, a case study is conducted on a
section of the Nanjing metro line 6. A technical method is proposed to utilize
the silty clay generated by shield tunneling for grouting behind lining. The
performance of the grout, incorporating various water-cement
ratios and mixing proportions of hardeners A and B, is evaluated through laboratory
testing, non-linear regression analysis using
statistical package for the social sciences (SPSS), and multi-objective optimization to identify the optimal mix for both
performance and economic efficiency. The main findings are as follows: (1) TW-G is suitable for high-clay-content grout. Hardener A exhibits retarding and water-reducing effects, while Hardener B enhances coagulation and early
strength. (2) Multi-objective optimization results
indicate optimal performance at a water-cement ratio of
0.75, with 0.86% hardener A and 12.95% hardener B. The grout with a water-cement
ratio of 0.84, 3.66% hardener A, and 2.91% hardener B achieves the greatest
economic benefit. (3) Field application demonstrates that, compared to
conventional single-component hard grout, the grout
mixed with shield muck yields superior performance. After application, surface
settlement is limited to within 12 mm, segment uplift is controlled within 25
mm, and mucking is reduced by over 10%, resulting in a 35% cost reduction.
