紧邻大直径浅埋原水管深基坑工程设计与实践

Engineering design and practice of deep foundation pit adjacent to large-diameter shallow buried raw water pipe

以福州江阴电力管廊隧道项目为例,针对长距离紧邻的大直径原水管的保护,介绍深基坑工程的实施方案,重点说明所采取的拉森钢板桩和外侧增加H型钢的围护体结构,竖向设置两道钢管水平支撑和坑底进行旋喷桩被动区加固等关键技术方案。监测结果表明,在基坑开挖和换撑过程中引起的管线位移限值均在可控范围内,采用的设计方案是合理有效的。

This article takes the Fuzhou Jiangyin electric cable tunnel project as an example,and introduces the overall design scheme of the deep foundation pit project for the protection of long-distance and adjacent large-diameter raw water supply pipes.Key technologies such as Larsen steel sheet piles with an outer H-shaped steel enclosure structure,vertical installation of two steel pipes for horizontal support,and passive zone reinforcement of rotary jet grouting piles at the bottom of the pit are emphasized.The monitoring results indicate that the pipeline displacement values caused during excavation and support replacement of the foundation pit are within the control range,and the adopted design scheme is reasonable and effective.