盾构引起地表沉降预测模型与影响因素分析

Influencing Factors and Prediction Model of Ground Settlement Caused by Shied Tunnel Excavation

以武汉地铁四号线某区间隧道作为研究对象,对该盾构区间隧道所获得的地表沉降监测数据进行分析和处理。对地铁隧道引起的地表沉降规律进行了深入的分析,探讨了建筑物与隧道轴线的距离、隧道埋深等因素对地表沉降的影响。结果表明,建筑物和隧道轴线的距离L与隧道直径D的比值大于3.21时,建筑物对地表沉降的影响较小,比值小于3时,地表沉降急剧增大,其中,比值在1～3之间,将导致明显的建筑物倾斜,比值接近于零时,建筑物呈现整体下沉趋势。最后,基于Peck公式,提出了实用的沉降分析模型,并将其应用于工程实例,验证了预测模型的有效性。

Taken the project of subway internal tunnel of 4th Line of Wuhan Metro as research,the data of ground settlement obtained from the shield tunnel has been analyzed.The law of ground settlement of subway tunnel has carried on deep analysis.The influencing factors on the ground settlement,such as the distances from buildings to tunnels and depths of tunnels,have been discussed.The results showed that when L/D≥3.21,the building has little influence on ground settlement and when L/D3,the ground settlement increase dramatically.Building inclination would be caused when L/D=1～3,integral sinking occurred when the value of L/Dcloses to zero.Which Lis defined as distance from tunnel axis to building axis and Dis defined as diameter of tunnel.Finally,apractical analysis model of settlement has been proposed based on Peck＇s formula.And its validity has been testified in practice.