Influence of joint form on shear characteristics of asphalt concrete core under steep bank slope condition

Abstract The connection performance between the core and the concrete plinth under steep bank slope conditions is related to the overall seepage safety of the dam. In this study, combined with the actual engineering, the steep slope control groups with slopes of 71°, 76° and 81° were designed. The research scheme not only considers the limit situation of the existing specifications, but also makes further exploration on the situation of high and steep valleys beyond the specifications. Considering the asymmetric valley and the symmetric valley, two contact forms of arc joint and flat joint are set up. Based on the numerical calculation, the influence of the joint embedding depth and the amplification angle on the shear action of the asphalt concrete core (ACC) is quantitatively studied. The results indicate that the symmetry of the valley will cause stress to deflect, affecting the characteristics of shear stress of the core. Under the condition of high-steep bank slope, large shear deformation occurs at the joint of ACC, and significant arching occurs near the bank slope. The overall stress level of the arc joint is higher than that of the flat joint, and it is highly sensitive to the change of the bank slope. Increasing the embedded depth of the joint, the local shear effect of the core wall becomes larger. As the joint magnification angle decreases, the stress level of the core and the maximum shear stress decrease. Expanding the contact surface of the joint can reduce the shear effect of the core. This study breaks through the conventional dam construction conditions and explores the mechanical properties of anti-seepage bodies in high and steep valleys. The research results of this paper can provide reference for the design of ACC joints under extreme steep bank slope conditions.