连续墙施工引起的地层移动现场监测分析

通过对地下连续墙成槽开挖及混凝土浇筑施工的现场监测数据分析,分别讨论了槽段分段开挖、泥浆持荷时间、泥浆压力及混凝土浇筑对槽段周围土体侧移和地表沉降的影响.监测结果表明:地下连续墙开挖会引起周围地层土体侧移(向连续墙内侧)和地表沉降,且变形主要发生在软土层;土体侧移和地表沉降值随槽段开挖深度的增加而增大,随距槽段水平距离的增加而下降;泥浆持荷时间对土体侧移和地表沉降的影响不大,但施工中应注意土体变形速率的变化;提高泥浆液面高度可以减小土体侧移,对地表沉降影响不大,但液面下降过多会显著增加土体侧移和地表沉降;混凝土的浇筑可有效地降低土体侧移和地表沉降值.

In-situ monitoring analyses of ground movements caused by diaphragm wall construction

The controlling factors,including slurry trenching depth and sequences,slurry holding time,variations of slurry pressure and concreting of the panel,are studied to evaluate the effects of the construction of a diaphragm wall on adjacent ground responses based on the in-situ monitoring results,which consist of lateral soil movements and ground settlements.Analyses of the monitoring data show that slurry trenching of the panel will lead to dramatic ground movements,especially in the soft strata.The effects of slurry holding time on ground movements are not significant,but attention should be paid to soil deformation velocity.Ground movements decline a little with the raise of slurry level,while lowering slurry level causes significant increase of ground movements.Concreting of the panel pushes the soil back and decreases ground movements.