N-JET隔断风井基坑深层承压水的应用

Application of N-JET in Isolating Deep Confined Water in Foundation Pit of Air Shaft

摘要:

在风井基坑开挖的过程中，承压水造成的影响不可忽视，无论是基坑突涌、管涌还是基底隆起破坏，都会给风井周围的地下管线和建筑构物造成损害，目前国内处理基坑承压水的方法主要分3类：降压、隔水以及封底。当施工区域周边存在大量建筑构物或管线，仅依靠降压或封底等措施难以符合工程设计及规范的要求，为保障安全性和技术可行性，国内更倾向于同时采取隔离水源，以有效控制承压水体。有必要探求一个稳定的隔断承压水方法。依托上海轨道交通机场联络线工程6号风井基坑工程，验证了新兴工艺N-JET工法在隔断风井基坑深层承压水方面的可行性。

Abstract:

During the excavation of air shaft foundation pits, the impact of confined water cannot be ignored. Whether it is foundation pit surge, pipe surge or basement uplift failure, it will cause damage to the underground pipelines and building structures around the air shaft. Currently, the methods for treating the confined water of foundation pits in China are mainly divided into three kinds of pressure reduction, water isolation and bottom sealing. When there are many building structures or pipelines around the construction area, it is difficult to meet the requirements of engineering design and standards by taking the measures of pressure reduction and bottom sealing. In order to ensure the safety and technical feasibility, it is preferred to isolate water sources at the same time in China to effectively control the confined water. Therefore, it is necessary to explore a stable method for isolating the confined water. Relying the No.6 air shaft foundation pit project of the Shanghai Rail Transit Airport Connection Line Project, the feasibility of the emerging process N-JET in isolating the deep confined water in the air shaft foundation pit is verified.