复杂环境条件下河道内桥梁墩台基坑支护技术

Support Technology of Bridge Pier and Abutment Excavation in Rivers under Complex Environmental Conditions

摘要:

跨河桥梁在河道中设置墩柱，其墩台基坑的理想做法是用围堰截断上下游水流，围堰内抽水，为基坑施工创造宽松的干作业环境。然而，城市中的河道由于各种原因不允许断流而且要保证一定的过流能力，或者河道上有其他跨河建、构筑物影响施工。这就造成墩台基坑很多时候处于环境复杂、施工受限的条件下。结合具体工程实例研究了复杂环境条件下河道内桥梁墩台深基坑支护技术，主要是围堰与支护结构相结合的设计方法。同时将围堰计算模型简化，用同济启明星软件简化计算。为复杂环境条件下河道内基坑支护设计提供了参考。

Abstract:

For bridges crossing rivers, piers are set up in the river channel. The ideal practice for the excavation of the pier and abutment is to use the cofferdams to cut off the upstream and downstream water flow, and then pump out the water inside the cofferdam, which can create a dry working environment for the excavation construction. However, in urban rivers, due to various reasons, the water flow cannot be interrupted and a certain flow capacity must be guaranteed, or there are other river-crossing structures that affect construction. This often results in the excavation of the pier and abutment being in a complex environment with restricted construction conditions. Combined with the actual projects, the deep excavation support technology for the bridge pier and abutment in rivers under complex environmental conditions is studied. The main design method is the combination of cofferdam and support structure. At the same time, the cofferdam calculation model is simplified and the calculation is simplified using the Tongji Qimingxing Software, which provides a reference for the design of excavation support in rivers under complex environmental conditions.