Design of pressure tunnel with consideration of construction sequence influence

ანოტაცია

The paper presents a study of the stress state of the “tunnel-surrounding massif” unified system taking into account the technological scheme of tunnel construction. During tunnel construction, during the staged development of the ground, there will be a gradual development of mining loads on the existing tunnel lining. Unlike the sudden construction scheme, such a scheme is close to the correct assessment of the loads developed on the lining and, accordingly, the calculation of the lining structure. On the basis of the numerical calculation carried out for the design solution of the Aspindza HPP pressure tunnel, the stress state parameters reflecting the joint operation of the “tunnel-surrounding massif” system were obtained, taking into account the differentiated influence of the construction technology (sudden construction and staged construction). In particular, the vertical normal stresses in the lining cross-section increased insignificantly, while the horizontal normal stresses decreased by 25%. In the cross-section of the foundation, the compressive stresses increased in the construction state (up to 20%), while in the operational state, the compressive stresses decreased (up to 30%).