框架地道桥降水与监测

Precipitation and Monitoring of Frame Tunnel Bridge

基坑在开挖过程中受到周围土体、地表荷载和坑底承压水的浮托力等各种荷载的作用,往往产生一定的变形和位移,当位移和变形超过基坑承受能力时,基坑就会产生破坏。基坑开挖时,场地里大量积水和地下水渗流会影响工程施工。基坑降水可以保证施工作业面的干燥;降低动力水压,降低坑底承压水水头;增强边坡和基坑稳定性;加速土体固结,加固地基。但同样基坑降水会引起周边管线及营业线不均匀沉降的问题。因此,降水采用堵水及降排水措施。为减少线路沉降,减少对线路安全的影响,在充分了解场地地质条件与基坑工程性质,做好抽水试验,进行降水及沉降预测,做到按需降水,严格控制水位降深。

In the process of excavation, the foundation pit is often subjected to various loads such as surrounding soil, surface load and buoyancy force of confined water at the bottom of the pit, resulting in certain deformation and displacement. When the displacement and deformation exceed the bearing capacity of the foundation pit, the foundation pit will be destroyed. During foundation pit excavation, a lot of water and groundwater seepage in the site will affect the construction. The dewatering of foundation pit can ensure the drying of construction working surface, to lower the dynamic water pressure and the head of the confined water at the bottom of the pit, and to enhance the stability of slope and foundation pit, to accelerate the consolidation of soil and consolidate the foundation. But the same foundation pit dewatering will cause uneven settlement of surrounding pipelines and business lines. In order to reduce the settlement of the line and its influence on the safety of the line, it is necessary to fully understand the geological conditions of the site and the engineering properties of the foundation pit, do well in the pumping test, and carry out the precipitation and settlement prediction, so as to achieve the precipitation as required and strictly control the water level to reduce the depth.