Research and Application of Anti-floating Schemes of Deep Foundation Pit of Subway for Underwater Excavation and underwater concrete sealing

Ranken Railway Construction Group Co., Ltd., Chengdu, Sichuan, 610045, China

^* Corresponding author’s e-mail: 14691436@qq.com, phone:18615720077

Abstract

To implement deep foundation pit of subway construction with underground continuous wall adopting underwater excavation and waterproofing concrete bottom sealing curtain, the depth of bottom concrete must first meet the anti-floating requirements of the foundation pit. Since the elevation of the bottom slab of the station is certain, the thicker the sealing concrete, the deeper the excavation depth of the foundation pit, the greater the buoyancy of the water to be withstood, and eventually the thicker the sealing concrete, so the selection of foundation pit anti-floating scheme is very critical. This paper combines the practical construction of the deep foundation pit of the main structure of Yongdingmenwai station which is in the third phase of Beijing Metro Line 8 construction project, and analyzes and compares the anti-floating scheme of the foundation pit, so as to select a more reasonable anti-floating scheme, in order to apply experiences for future similar projects and construction.