下沉式竖井掘进工法在软土地区的应用研究

Application of vertical shaft sinking method in soft soil area

城市地区的深层地下管网建设产生了大量超深竖井建设需要,而传统施工技术难以同时满足超深竖井施工低影响、高效且节约的需求。为此,本文介绍了一种新型施工技术——下沉式竖井掘进工法(VSM),与沉井工法、地下连续墙围护开挖工法等传统施工方法相比,该工法具有施工速度快、环境友好、工程造价低等优点。通过对VSM工法特点的总结,探讨了基于该工法的超深竖井设计要点。该工法应用于软土地区时,应注意需要满足土体抗隆起稳定性及地基承载力要求。最后,介绍了上海软土地区首个采用VSM工法的超深竖井工程。对该竖井施工过程的监测结果表明,VSM工法在上海软土地区有较好的适用性,竖井开挖施工对周边环境的影响可满足上海地区环境保护等级为一级的基坑变形控制要求。

The construction of deep underground pipe networks in urban areas has generated a large number of ultra-deep shaft construction needs.However,the traditional construction technologies are difficult to meet the low-impact,high-efficiency,and economical requirements of ultra-deep shaft construction at the same time.A new construction technique,vertical shaft sinking method(VSM),was introduced in this work.Compared with traditional construction methods such as caisson construction method and underground diaphragm wall enclosure excavation method,it has the advantages of fast construction speed,environmental friendliness,and low construction cost.By summarizing the characteristics of VSM,the key points of ultra-deep shaft design based on VSM were discussed.When VSM is applied to soft soil areas,attention should be paid to meeting the requirements of soil anti-uplift stability and foundation bearing capacity.Finally,the first ultra-deep shaft case using the VSM in the soft soil area of Shanghai was introduced.The measured results of the shaft construction process shew that the VSM had good applicability in the soft soil area of Shanghai.The impact of shaft excavation on the surrounding environment could control the deformation of foundation pits in the Shanghai area with an environmental protection grade of level one.