含约束围岩有限层法在隧道施工地面沉降分析的应用

Application of the Finite Layer Method with Constraints of Surrounding Rock in Ground Settlement Analysis of Tunnel Construction

严格控制地面沉降是保障隧道施工安全的关键措施。为了更加精准预测地面沉降,采用超级有限层元模拟复合地层围岩;增加内部约束模拟隧道衬砌,建立含约束围岩有限层法。通过工程实例应用获得结论:不同地层组段围岩隧道的地面沉降值与贯入度存在相关性,可根据拟合公式进行沉降预测,效果良好。如果不考虑贯入度,也可将含约束围岩有限层法直接应用于砂质黏土层围岩的地面沉降计算,预测精准度高。地面沉降理论计算的分布特征与实测数据的一致性表明含约束围岩有限层法的可靠性和适应性。

Strict control of the ground settlement is a key measure to ensure the safety of tunnel construction.In order to predict ground settlement more accurately,the super finite layer elements are applied to simulate the surrounding composite layers.The internal constraints are added to simulate tunnel lining.Then the finite layer method with constraints in surrounding rock is established.Based on the application analysis of engineering examples,it is concluded that there is a correlation between the ground settlement and tunneling penetration in different geological groups.Settlement prediction can be carried out based on the fitting formula with good effects.Ignoring the factor of penetration,this method can also be directly applied to the ground settlement calculation of sandy clay surrounding rock with the results of high accuracy.The consistency between the theoretical distribution characteristics and the measured data of ground settlement indicates the reliability and adaptability of the finite layer method with constrained surrounding rock.