Influence of Shield Tunnel Oblique Penetration Construction on Existing Large-Span Masonry Structures

Abstract

When the shield tunnel obliquely penetrates the large-span masonry building, the ground deformation caused by shield construction may cause the risk of deformation and cracking of the existing masonry structure held above. Based on a shield tunnel obliquely penetrating a large-span masonry building in Zhengzhou, a three-dimensional finite element model of building-stratum-shield tunnel interaction was established by MIDAS-GTS, and the laws of settlement, deformation, and damage of the building were studied. Results show that when the first line (left line) of the tunnel is penetrated, the settlement groove along the horizontal direction of the building presents a “ V ” shape, while after the second line (right line) is penetrated, which changes from “ V ” shape to “ W ” shape, and the maximum settlement value of the building caused by the first line can account for about 2/3 of the total settlement value. The maximum tensile strain of both the building’s south and north walls occurs at the bottom of the wall within the range of the tunnel, which develops upward and gradually weakens. Influenced by the oblique crossing angle, the maximum positions of settlement and strain for the building’s front and rear walls are offset to some extent. With the masonry building’s stiffness increasing, the uneven settlement of buildings decreases linearly, and with the tunnel oblique crossing angle increasing, the uneven settlement increases exponentially, while with the tunnel buried depth increasing, the uneven settlement shows an exponential downward trend.