摘要
在我国东南沿海的填海造陆区采用盾构法施工隧道时,不可避免地需要穿越海域吹填砂地层。吹填砂具有强度低渗透性高等特点,若此类地层隧道临界覆土厚度取值不合理,很可能引起工程事故或造成资源浪费。本文以厦门地铁3号线双沪站空港经济区站盾构隧道穿越海域吹填砂层工程为背景,在考虑盾构隧道开挖面稳定与盾尾管片抗浮稳定的前提下,提出了一种临界覆土厚度的修正算法。并与传统方法计算的临界覆土厚度对比,再通过数值分析模拟了地层和管片的响应规律。结果表明,当覆土厚度从5.9 m增加到9.4 m时,对地表沉降、孔隙水压力、管片水平位移和弯矩的响应规律基本一致,而隧道拱顶和仰拱处管片竖向位移的响应在覆土厚度为8 m时相反,因此管片竖向位移可作为判断临界覆土厚度取值合理性的主要指标。此方法可为类似地层的盾构施工提供理论指导。
When the shield tunneling method is used to construct tunnels in the reclamation area along the southeast coast of China,it is inevitable to cross the dredged sand stratum in the sea area.Hydraulic fill sand has the characteristics of low strength and high permeability.If the critical cover depth in such stratum is unreasonable,it is likely to cause accidents or resource waste.Based on the background that Shuanghu-Airport Economic Zone Station of Xiamen Metro Line 3 crosses the coastal hydraulic fill sand stratum,a correction algorithm for critical overburden thickness is proposed to maintain the stability of tunnel faces and the anti-floating stability of shield segment.Afterward,the response of strata and segment lining is simulated by numerical analysis and compared with the critical cover depth calculated by traditional method.The results show that:The response regularities of the ground surface settlement,pore water pressure,segment lining horizontal displacement and bending moment are consistent when the cover depth increases from 5.8 m to 9.4 m.However,the pattern of segment lining vertical displacements for the tunnel vault and bottom reverses at a cover depth of 8 m.Therefore,the vertical displacement can be used as the main index to judge the critical cover depth.This method provides theoretical guidance for shield construction in similar strata.
作者
王大海
钱伟丰
王炳楠
Qian Weifeng;Wang Dahai;Wang Bingnan(Rail Transportation Branch,China Communications Construction Company Limited,Beijing 100088,P.R.China;School of Civil Engineering,Fuzhou University,Fuzhou 350108,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2023年第S02期583-592,616,共11页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(41972276)
福建省"雏鹰计划"青年拔尖人才项目(00387088)
福建省自然科学基金(2020J01310246)
关键词
盾构隧道
吹填砂地层
临界覆土厚度
理论计算
数值分析
shield tunnel
hydraulic fill sand
critical cover depth
theoretical calculation
numerical analysis
作者简介
王大海(1974—),男,吉林松原人,高级工程师,主要从事盾构施工的相关技术研究工作。E-mail:676344573@qq.com
