Both preloaded and injected bolted connections are commonly used in steel bridges in The Netherlands. Where preloaded bolted connections are already used for a longer time, the injection of bolt holes is a method used from the 1970s onwards. Injection of bolts became a good alternative for the replacement of riveted connections. This injection increases the slip resistance of the connection by filling the clearance between the bolt and the plate. Combining both methods increases the slip resistance of a bolted connection and is therefore even more beneficial.
According to the standard NEN-EN1993-1-8 [17], it is safe to assume that the resistance of a preloaded and injected bolted connection is equal to the sum of the two individual obtained resistances from preloading and injection. The aim of this research is to validate this statement and thus investigate the resistance of a slip-critical steel-to-steel connection including preloading and/or injection.

The study addresses this manner through both experiments and numerical analysis, addressing all three types of connections. In addition, this potential of summation is considered for two different levels of preloading, implementing plastic and elastic preload preloading. These levels of preloading were considered for two reasons, embodying different applications and identifying the effect of the preload force on the resistance. Each experiment is based on a short-term testing method that is in compliance with the described method of the EN1090-2. These resistances are verified by a numerical analysis with the goal of gaining more insight into the behaviour of the connection and validation of the obtained results.

From both experimental and numerical results, it is concluded that a summation of the individual resistances overestimates the actual resistance of a preloaded and injected bolted connection when measuring at the edge of the plates. This overestimation is similar for both preload levels.
Based on these results, it is concluded that it is unsafe to assume that the resistance of a preloaded and injected bolted connection is equal to the sum of the individual resistances obtained from preloading and injection. However, this conclusion might change if a different criterion for measuring relative displacements at specific locations is implemented.

The resistance of a connection is defined at a fixed magnitude of relative displacement measured at the edge of the plate, assuming that this is representing the displacement of the bolt. However, it turned out that the assumed limit displacement of 0.15mm did not result in the same displacement at the bolt(group) for all connections due to the amount of preload force and the geometry of the plates. Therefore, it is recommended to investigate the sensibility of the measured displacements for different geometries of and preload levels in the connection.

Extreme folding damage of open-ended tubular piles could occur during piling in onshore practices. Amazonehaven unique quay wall removal gave the opportunity to study king pile’s failure close to toe. King piles are primary piles in a combined wall system, exposed to static and dynamic load. It is argued that the unexpected pile toe failure have been caused by dynamic load because of the uniaxial direction of the extreme deformations. However, research into pile toe failure in Amazonehaven shows that hammer-induced driving stresses are significantly lower than material’s yield stress close to pile toe, given Amazonehaven soil condition. Therefore, the dynamic load has not been solely detrimental to the pile toe integrity. The main reasons for pile toe failure are discussed to be (1) pile imperfection, (2) pile inclination and (3) pile inhomogeneous strength. Bear in mind that, pile toe failure to such extent when not limited might lead to dysfunction of the asset during its technical lifetime. Therefore, counteractions must be taken to assure quay wall’s safety and stability while operating. The remedies when such a piling risk event occur could be: replacement, early maintenance, or a reduction in its designed storage capacity. The reactive solutions will bring financial consequences of pile toe failure forward. In other words, the client will experience a reduction in its revenues due to asset’s malfunction. However, when proactive process-based alternatives are implemented in the current procedure in piling industry, the probability of occurrence of the failure is to be reduced. Therefore, financial consequences of piling risk event will remain limited.

The main personal objectives creating this master thesis are to present a: Compact, comprehensive, consistent, reader friendly, and to the point report.