关键词: 吹填淤泥, 浅层超软土加固, 常规方案, 单排单管方案, 单排单管加密方案, 硬壳层

Abstract: Some problems of reinforcement of shallow ultra-soft soil in Tianjin Binhai New Area are analysed. Three reinforcement schemes of shallow ultra-soft soil are proposed, including conventional scheme, single-row to single-tube scheme and small spacing scheme. Relying on a project in Tianjin Binhai New Area, field comparison test is carried out. A comparative analysis of the reinforcement effect of three schemes is done with monitoring test results and some further recommendations for reinforcement are provided. Engineering practice shows that, a hard crust with a certain strength and thickness forms after treated by three reinforcement schemes and the physico-mechanical properties of soil are significantly improved, which fully meet the construction requirements of hydraulic fill sand cushion and prefabricated vertical drains. In addition, the reinforcement effects of single-row to single-tube scheme and small spacing scheme are significantly better than that of conventional reinforcement scheme. The first two schemes are beneficial to the formation of hard crust thickness, which are preferable from the point of view of long-term perspective.

Key words: hydraulic mud fill, reinforcement of shallow ultra-soft soil, conventional scheme, single-row to single-tube scheme, small spacing single-row to single-tube scheme, hard crust