轨道交通的超限深基坑支护设计

Design of Over Limit Deep Foundation Pit Support for Rail Transit

文章结合工程实例,在了解基坑边坡及轨道交通条件、地质条件、岩土参数的基础上,提出超限深基坑支护设计难点与常见的设计问题,根据施工安全、质量可靠等要求探讨解决措施,提出“门字形双排桩+桩间旋喷止水帷幕”的综合支护方案,评估对既有轨道结构安全性的影响,结合变形监测结果验证超限深基坑支护方案的可行性。实践表明,该工程采用的超限深基坑支护方案有一定的可行性,能取得良好的支护效果,如保障轨道交通运营安全、防护生态环境、改善现场施工条件等。

Based on engineering examples and understanding the slope and rail transit conditions,geological conditions,and geotechnical parameters of foundation pits,this article proposes the difficulties and common design problems in the design of ultra deep foundation pit support.Based on the requirements of construction safety and quality reliability,solutions are discussed,and a comprehensive support scheme of"double row piles in the shape of a gate+rotary jet sealing curtain between piles"is proposed to evaluate the impact on the safety of existing track structures,Verify the feasibility of the support scheme for exceeding the limit deep foundation pit based on deformation monitoring results.Practice has shown that the ultra deep foundation pit support scheme adopted in this project is feasible and can achieve good support effects,such as ensuring the safety of rail transit operation,protecting the ecological environment,and improving on-site construction conditions.