软岩隧道丢失变形规律模型试验研究

Model Test Research on Loss and Deformation Law of Soft Rock Tunnel

通过隧道开挖模型试验,研究不同应力条件下软岩隧道拱顶和拱腰的变形及丢失位移变化规律。拱顶和拱腰丢失的变形量随测点与掌子面距离的增加出现先增大后逐渐趋于稳定的趋势,拱顶比拱腰的变形量丢失状况严重。增加衬砌后可有效减小拱顶竖向沉降和拱腰横向变形的最终值,力学性质表现得更为稳定。随着地应力的升高,拱顶和拱腰丢失位移逐渐增加,丢失位移与地应力呈正相关关系。

To study the deformation characteristics and lost displacement variation law of soft rock tunnels, a tunnel excavation model test is carried out to study the deformation and lost displacement of the tunnel vault and waist. On this basis, considering the change of the maximum in-situ stress, the deformation law of the tunnel under different stress conditions is studied. The results show that with the increase of the excavation distance, the vertical settlement value of the vault of each section increases and then tends to be stable, with the vertical settlement of the section vault after lining significantly reduced. The loss of deformation of the vault and waist increases with the increase of the distance between the measuring point and the face of the face, and the increase is larger and larger,and the loss of deformation of the vault is greater than that of the waist. The addition of lining can effectively reduce the final value of the vertical settlement of the vault and the lateral deformation of the vault, and the mechanical properties are more stable. With the increase of the maximum in-situ stress, the loss displacement of the vault and the arch waist gradually increases, and the loss displacement is positively correlated with the maximum in-situ stress.