Increasing the shear reinforcement ratio (ρ_w) can help meet architectural and structural requirements but often results in less reliable punching strength estimates from design codes. Nonlinear finite element analysis (NLFEA) has the potential to support a thorough assessment of the punching strength of slabs with shear studs, yet accurately modelling the interaction between concrete and transverse steel to capture the strength provided by shear rebars is challenging while using user-friendly software. This paper explores methodologies to assess the punching strength of slabs with double-headed studs with a commercial NLFEA program. Experimental tests were used to define the input parameters for the concrete’s nonlinear behaviour and to evaluate modelling approaches for shear studs, resulting in two strategies applied to slabs with varying ρ_w. NLFEA provided accurate punching strength estimates, consistently reproducing slabs’ rotations, crack patterns, and flexural strains. However, discrepancies in shear rebar strains highlight the challenges of using NLFEA to assess the response of slabs with shear reinforcement. Moreover, NLFE and experimental strengths were compared to estimates using the fib Model Code 2010 with levels of approximation (LoA) II, III, and IV, showing that, for the selected tests, increasing complexity in LoA IV did not consistently improve strength estimate accuracy.

Tunnel fires are relatively rare, but the consequences of damage can be large. This paper addresses the influence of tunnel fires on the ensuing damage to the concrete lining. To address this question, the existing literature is reviewed. This review focuses on different methodologies to get a well-rounded insight into the problem: relevant aspects of tunnel fire dynamics, theoretical considerations on the relation between the fire source and the resulting damage to the concrete, experimental evidences from testing concrete elements subjected to fire as well as data from tunnel fires that have taken place in the past, and insights from numerical analysis. The result is a comprehensive overview of what is currently known about the relation between a tunnel fire and the ensuing damage in the concrete, as well as guidance for the assessment of concrete tunnel linings under fire hazard and recommendations for future research to address the remaining open questions on this topic. To conclude, this paper gives a valuable overview based on different methodologies from the literature to give researchers, engineers, and asset owners a better insight in how fires can affect the concrete tunnel structure.

Major fire events in tunnels have shown severe consequences in their structural performance, as reported in several incidents in the last decades. Particularly, due to the enclos-ure geometry of tunnels, intense thermal loading may develop in comparison to typical fires in buildings, which may result in more damage. Even though tunnel linings are an important com-ponent in transportation infrastructure, the understanding of their behaviour under high tem-peratures is limited. This paper aims to study the thermo-mechanical response of tunnels subjected to fire using nonlinear finite element analysis (NLFEA). For this purpose, recent experimental tests of large-scale reinforced concrete tunnels with and without fire protection are simulated. Different modelling approaches and strategies are discussed, and a detailed descrip-tion of the constitutive model employed is presented. The results obtained in the simulations indicated that the numerical analysis can be used to investigate the thermo-mechanical behav-iour of concrete structures.