岩质地层地铁隧道风井施工受力及变形规律研究

Study on the Stress and Deformation Law of Subway Tunnel Ventilation Shaft During Construction in Rock Stratum

隧道风井施工,需密切关注其受力及变形,确保施工安全与稳定。本文采用数值模拟方法,探讨岩质地层地铁隧道风井施工受力特征与变形规律。结果表明:(1)竖井开挖过程中,开挖面附近隆起显著;开挖完成后,最大位移下移至竖井底部;开挖横通道时,风井整体变形不大。(2)开挖竖井阶段,竖井开挖面隆起呈线性增大;竖井底部衬砌施作时,隆起值略有减小;在横通道开挖阶段,隆起值再次缓慢增大。(3)风井开挖全过程中,开挖面与既有隧道、横通道、竖井连接部位存在应力集中;开挖全过程混凝土抗拉强度与抗压强度均满足要求。

In the construction of tunnel ventilation shaft,it is necessary to pay close attention to its stress and deformation to ensure construction safety and stability.In this paper,the numerical simulation method is used to discuss the stress characteristics and deformation law of subway tunnel ventilation shaft in rock stratum.The results show that:(1)during the excavation of shaft,the uplift near the excavation face is significant.After the excavation is completed,the maximum displacement moves down to the bottom of the shaft;when excavating the cross passage,the overall deformation of the air shaft does not change much.(2)In the stage of shaft excavation,the uplift of excavation face increases linearly;when the lining at the bottom of the shaft is constructed,the uplift value decreases slightly.In the cross channel excavation stage,the uplift value increases slowly again.(3)During the whole process of air shaft excavation,there is stress concentration near the excavation face and the connection between existing tunnel,cross passage and shaft.The tensile strength and compressive strength of concrete in the whole process of excavation meet the requirements.