硬塑高黏度地层盾构施工土体改良试验研究

Experimental Study on Soil Conditioning of Shield Construction in Hardplastic Highviscosity Layer

摘要:

以上海⑥号土中盾构施工为研究背景，进行硬塑高黏度土体改良的室内试验.选择3种添加剂研究其对渣土性能的影响，并综合分析其最优注入率范围.研究表明：单独使用泡沫需在增加土样含水率到30.0%条件下，控制泡沫注入率（质量比，下同）为30.0%时较好；高分子材料和减黏剂则需在同样含水率下使其注入率分别为6.0%、5.5%时最佳；高分子材料和泡沫组合在高分子材料注入率、泡沫注入率分别为3%、20%时，减黏剂和泡沫组合在减黏剂注入率、泡沫注入率分别为3%、15%时效果更为合适.利用该配比方案进行现场掘进试验，所得结果可为类似地层盾构施工土体改良提供参考.

关键词:硬塑高黏度土; 土体改良; 室内试验; 注入率

Abstract:

A series of soil conditioning laboratory tests with three types of additives were performed to investigate and assess the conditioned effect of hardplastic highviscosity soil in Shanghai ⑥ layer, and analyze the optimal injection rate ranges synthetically. It is shown that the optimum foam injection ratio is 30.0% under 30.0% moisture content (MC). While the optimum injection ratios of polymer and detackifier are 6.0% and 5.5% respectively under the same MC. Moreover, the optimum injection ratios of combination materials with polymer and foam are 3% (polymer) and 20% (foam) respectively, and the optimum injection ratio of combination materials with detackifier and foam are 3% for detackifier and 15% for foam respectively. Succeeding field tests show that the optimum injection ratios of additives significantly improve the performance of earth pressure balanced (EPB) excavation and can be used as guidelines under such soil conditions.

Key words:hardplastic highviscosity soil; soil conditioning; laboratory tests; injection ratio