A waterproofing membrane has an important role in a sprayed concrete lined (SCL) tunnel. In this study, the mechanical behaviour of an SCL with a sprayed waterproofing membrane was investigated by laboratory testing. Two different types of tests were performed to examine the behaviour at different parts of an SCL tunnel linings around a tunnel junction. A four-point bending test was conducted to investigate the behaviour of tunnel linings under a large bending moment, which would represent a section near the opening of a tunnel junction. An eccentric compression test was conducted to investigate the behaviour of tunnel linings under a large compressive axial force (hoop stress) and a relatively small bending moment, which would represent a section at the opposite side of the opening of a tunnel junction. Both test results indicate that an SCL with a sprayed waterproofing membrane behaved as a composite section with very limited slip at the interfaces. Designing the primary lining, the waterproofing membrane and the secondary lining of an SCL tunnel as a composite section could have significant practical implications including time and cost savings.

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Monopiles are the favoured foundation type for offshore wind turbines due to a relatively simple design and installation process. This paper investigates using coupled three-dimensional finite element analysis the load-deformation behaviour of extra-large (XL) and extra-extra-large (XXL) monopiles in low-shear strength over-consolidated Kaolin clay subjected to monotonic lateral loading at varying load eccentricities. The sub-loading tij constitutive model, robustly calibrated using data from centrifuge tests carried out by the authors, has been adopted in these analyses. For the 16 cases analysed, a detailed discussion is provided on the behaviour of XL/XXL monopiles, including their mode of deformation, lateral capacity, deflection, rotational stiffness, bending moment & shear force, and the response of the clay in terms of soil resistance and excess pore pressure. It is also demonstrated that the p-y method is inaccurate in designing monopiles in this size range.