Excavation activities like open cutting and tunneling work may cause ground movements. Many of these activities are performed in urban areas where many structures and facilities already exist. These activities are close enough to affect adjacent structures. It is therefore important to understand how the ground movements due to excavations influence nearby structures. The goal of the proposed research is to investigate and develop analytical methods for addressing uncertainty during observation-based, adaptive design of deep excavation and tunneling projects. Computational procedures based on a Bayesian probabilistic framework are developed for comparative analysis between observed and predicted soil and structure response during construction phases. This analysis couples the adaptive design capabilities of the observational method with updated reliability indices, to be used in risk-based design decisions. A probabilistic framework is developed to predict three-dimensional deformation profiles due to supported excavations using a semi-empirical approach. The key advantage of this approach for practicing engineers is that an already common semi-empirical chart can be used together with a few additional simple calculations to better evaluate three-dimensional displacement profiles. A reliability analysis framework is also developed to assess the fragility of excavation-induced infrastructure system damage for multiple serviceability limit states. Finally, a reliability analysis of a shallow circular tunnel driven by a pressurized shield in a frictional and cohesive soil is developed to consider the inherent uncertainty in the input parameters and the proposed model. The ultimate limit state for the face stability is considered in the analysis. The probability of failure that exceeding a specified applied pressure at the tunnel face is estimated. Sensitivity and importance measures are computed to identify the key parameters and random variables in the model.

Esta pesquisa apresenta uma sÃntese das taxas de assoreamento observadas em reservatÃrios brasileiros, onde foram identificadas taxas de assoreamento variando aproximadamente de 1 a 7% do volume inicial por dÃcada (inferiores à mÃdia mundial de 10%), sendo os reservatÃrios localizados no Estado do Cearà aqueles que possuem menores taxas, provavelmente devido Ãs densas redes de reservatÃrios existentes nas bacias de contribuiÃÃo. Verificou-se tambÃm uma tendÃncia geral de decaimento das taxas de assoreamento com o volume inicial dos reservatÃrios. Em seguida, foram desenvolvidos dois mÃtodos expeditos para estimativa do assoreamento de reservatÃrios, os quais sÃo baseados em correlaÃÃes empÃricas ajustadas a partir de dados de campo, e com este mesmo objetivo foi realizada a aplicaÃÃo da Metodologia de Lima Neto et al. (2011) para os reservatÃrios brasileiros. Os mÃtodos propostos sÃo mais simples que as metodologias existentes na literatura, e dependem basicamente da pluviometria nas bacias de contribuiÃÃo e do volume inicial dos reservatÃrios. As diferenÃas observadas entre as diferentes metodologias foram inferiores a 30% . Este dado sugere que qualquer um dos trÃs mÃtodos pode ser utilizado para estimar o assoreamento de reservatÃrios, em nÃvel de planejamento. PorÃm, vale ressaltar que apesar da praticidade/simplicidade das equaÃÃes propostas, mediÃÃes de campo e/ou modelos mais sofisticados continuam sendo necessÃrios para se avaliar de forma mais precisa o assoreamento de reservatÃrios. / This research provides an overview of sedimentation rates observed in Brazilian reservoirs, where sedimentation rates were identified ranging approximately 1 to 7% of the starting volume per decade (the lower world average of 10%), and the reservoirs in the State of Cearà those with lower rates, probably due to dense existing reservoirs networks in contribution basins. It was found also a general trend of decay of sedimentation rates with initial volume of the reservoirs. Then we developed two empirical methods to estimate reservoir sedimentation, which are based on empirical correlations adjusted from field data, and with this same goal was carried out the implementation of Lima Methodology Neto et al. (2011) for the Brazilian reservoirs. The proposed methods are simpler than the existing methods in the literature, and depend basically the rainfall in contribution basins and the initial volume of reservoirs. The differences observed between the different methodologies were less than 30%. This suggests that any of the three methods can be used to estimate reservoir sedimentation in level planning. However, it is noteworthy that despite the practicality / simplicity the proposed equations, field measurements and / or more sophisticated models still needed to assess more accurately the reservoir sedimentation.

A vessel operating in the real world has to overcome wind, waves and ocean currents. The result of all the above is a motion of 6 degrees of freedom (DOF). Typically, for the maneuvering phase, the Newton-Euler equations are used to derive the equation of motion of the rigid body and the maneuvering theory to model the external forces and moments acting on a vessel. The main topic in this Master Thesis is to assess the maneuvering behavior of a specific container vessel through a 4DOF model. The purpose behind this study is to investigate the differences between the expected maneuvering behavior of the vessel and the operational one. To accomplish that, raw data from the vessel’s sea trials were used and a time domain simulation model created with the sway-roll yaw movements coupled and surge decoupled. The Son and No moto maneuvering model served as the base for the motion equations. The maneuvering coefficients (MC) were firstly estimated by semi-empirical formulas using the vessel particulars. The model was validated using the Esso Osaka sea trials data. The validation was limited to maneuvering parameters such as advance, tactical diameter, yaw overshoot angle etc. The final model was used on the sea trials data of the container vessel taking into consideration the wind forces through the Blender mann wind model. Moreover, correction factors for swallow water effects were used on the MC in order to provide a better accuracy and also to allow comparison between the operational data and the simulated ones since the sea trials depth could not be considered as deep waters. Finally, a system identification procedure was perfomed in order to investigate the possibility of identifying the exact MC values of a vessel. The results were encouraging. The simulation follows the patterns of the raw data relative accurately. In addition, the swallow water corrections provided enough evidence of the different behavior of the vessel depending on the depth under keel. From the SI side, a list of issues were encountered like parameter drift, multicollinearity and cost function prone to local minimum. A series of different procedures and algorithm proposed to overcome those difficulties and the results were promising.