Study on Shear–Softening Constitutive Law of Rock–Concrete Interface

To study fracture properties and establish a shear–softening constitutive law for rock–concrete interfaces, direct tension, three-point bending, single shear push-out tests were conducted on composite specimens with different degrees of interface roughness. The relationships between tensile strength (ft), average (?av), initial toughness (Kini 1C), mode I energy (GIf) interfacial roughness determined based experimental results. A was developed by measuring strain variations rock surfaces under loading stages during defined (?max) II (GIIf). For practical applications, the ?max ft GIf GIIf statistically fitting data in such way that could be conveniently simply parameters interface. Also, numerical simulations carried out to investigate crack propagation interfaces mixed I–II fractures. Predicted load versus mouth opening displacement (CMOD) curves agreed well findings verified obtained this study.