吹填人工岛硬土层中超深沉井施工关键技术

Key technology for construction of ultra-deep well in hard soil layer of dredging human island

随着国民经济的发展及需要,超深沉井穿越复杂地质条件的工程案例越来越多,以北海市铁山港区污水处理厂尾水排海管工程为例,该工程2座超深沉井均位于海域内的2座人工岛上,下沉需穿越粉质黏土层和中粗砂等地层,为防止井外土体产生塌方的现象,保护人工岛的结构安全,全程采用不排水下沉施工工艺。下沉采用潜水员配合“空气吸泥”方式取土,助沉采用高压旋喷助沉和触变泥浆助沉,最终沉井顺利到达设计标高。

With the development and needs of the national economy,coastal areas will construct more and more cases of the ultra deep wells,article taken the tail-water discharge pipe project of tianyi district sewage treatment plant in Beihai city as an example,In this project,two the ultra deep wells locket artificial island,the subsidence should pass through silty clay layer and medium coarse sand layer,in order to prevent the collapse of the soil outside the well,to protect the structural safety of artificial islands,the construction process of undrained sinking is adopted in the whole process.Divers and air dredging are used to collect soil,high pressure rotary jet is adopted to help sinking and thixotropic mud is used to help sinking,finally,the caisson reached the design level smoothly.