In this paper is proposed a set of empirical equations for parameters and initial conditions of a damped bipedal model with compliant legs. The parameters of the bipedal model are estimated by fitting numerical and experimental walking forces. Sixteen volunteers are recruited to participate in experimental tests to walk on a prototype footbridge. The vertical ground reaction forces (GRFs) induced by pedestrians are recorded by force plates and the accelerations of the structure are recorded by accelerometers. Multiple simulations within certain ranges of input parameters are performed to identify the best matches between the model’s predictions and experimentally measured GRFs. Based on empirical data, regression equations are proposed as functions of pedestrian’s mass, height, and walking speed. To validate the proposed equations, the experimental tests are simulated, and the predicted structure dynamic responses are compared to measured vibrations on the footbridge. To generate a more realistic pedestrian loading, the gait speed of each step is randomized within a range to reproduce the step-by-step variations. The results of this study validate the suitability of a set of parameters selected for the bipedal model, for use in predicting loads induced by humans and estimating the vibration response of pedestrian structures.

Guaranteeing tunnel integrity is an important issue for several countries worldwide. Due to the continuous increase in the number of tunnels, as well as the aging of old tunnels, several countries and companies have created manuals to standardize tunnel inspection and assessment. Most manuals still specify just visual procedures for tunnel inspection; however, because of underground conditions, the structural system of tunnels is often accessible only by one side, thus posing difficulties to the accurate evaluation of the structural conditions of the tunnel using only visual inspection. A possibility to improve the effectiveness of tunnel inspection is the use of non-destructive testing (NDT), which will assist in obtaining information about the inner condition behind the tunnel wall. The current advancements in the NDT methods allow them to be employed in all the different kinds of inspections (initial, routine, special inspection) suggested by the manuals. Therefore, in an attempt to help in the decision about the application of each method, this work provides an overview of some international practices for tunnel inspections and shows a review of different NDT methods (traditional and new methods) applied to tunnel inspections. Furthermore, this study describes their workability, advantages, and capability, and classifies the best fitting of each in the inspection procedures.

The evaluation of the structural integrity of tunnels in Brazil poses significant challenges due to the absence of established guidelines, manuals, or regulatory documents regarding the inspection and maintenance protocols. This article thus endeavors to relate the best international practices with those currently employed in Brazil to contribute to possible improvements. A comprehensive comparative analysis of inspection methodologies is presented, encompassing the classification of pathologies, prescribed inspection intervals, training protocols for inspectors, and methodologies for assessing assets' criticality. The study aims to inform the development of recommendations tailored to the Brazilian context for effectively inspecting concrete tunnels. By combining global and local practices, this research seeks to enhance the efficiency and safety of tunnel infrastructure in Brazil.