This thesis examines the load distribution on 60 m long piles under gradual static loading, considering the POST Rotterdam high-rise building as the study project. The research employs fibre optic (FO) instrumentation on site to monitor strain changes in the piles over time and assess load transfer mechanisms. This data is integrated into a Plaxis 3D model of the building's foundation to validate existing approaches on soil structure interaction (SSI), optimize SSI modelling, and assess the high-rise building's impact on nearby structures. Results show that at early stages, the resistance contribution comes from the shaft in contact with the Pleistocene sand layer. However, as loading progresses and the Kedichem clay layer consolidates, most of the resistance shifts to the tip and the shaft located in the deeper sands. The FO strain measurements follow a similar trend to the site stratigraphy, but there is high uncertainty about the results at early load stages. The latter requires further investigation to corroborate once the building is finalised. The piles were incorporated into the Plaxis 3D model by means of EBR with a layer-dependent force distribution. The resulting spring stiffness of various pile groups reveals the significance of the group effect. Regarding the impacts of POST loads on the adjacent Old Post Office building, an angular distortion of 1/555 in 50 years was obtained, which indicates a conservative result of slight damage in the structure. For the Timmerhuis building, a resulting angular distortion of 1/1428 indicates no damage. This study addresses gaps in understanding load distribution in 60 m long piles, offering a practical modelling approach and recommendations for future research. It contributes to optimizing design and safety protocols as the use of such piles becomes more common in Rotterdam. By utilizing advanced sensing techniques like FO, this research may lead to more accurate pile design and criteria, potentially reducing construction costs and enhancing safety for high-rise buildings and their surroundings.

This research looked into the influence of negative skin friction on timber piles in Amsterdam. Tensile load tests were performed on new, instrumented timber piles at Overamstel in Amsterdam. The negative skin friction calculated from the test data was compared to the negative skin friction from NEN 9997-1 for a single pile. The test results came close to the values from NEN 9997-1. A reduction of the factor required for timber piles when calculating negative skin friction using NEN 9997-1 seems necessary, but further studies are needed.

Alpha factors were derived from the test data, and comparison to the alpha factors from compression load tests confirmed the influence of tapering on the timber piles.

The research also confirmed the suitability of fibre optic sensors for pile load tests on timber piles.

In the city of Amsterdam, many structures, such as houses,bridges and quay walls, are founded on wooden piles. In order to gain insightinto the safety of such structures, assessment of the foundations is required.As part of an experimental framework assessing the safety of bridges and quaywalls in the city of Amsterdam, a number of piles are instrumented with fiberoptic sensors and load tested in compression. These tests aim to providedetailed information on the behavior of timber piles subjected to loading. Thisinformation can be used to determine the geotechnical bearing capacity of suchpiles. An in-depth analysis is conducted on 8 timber piles tested within thisframework.  The conducted analysis has resulted in a variation ofoutcomes. Without including the effects of residual loads, an average baseresistance of 130 kN is observed. Upon inclusion of residual loads the averagetrue base resistance increases to a value of 188 kN. The average shaftcapacities in the bearing sand layer for scenarios excluding and includingresidual effects are 48 and 60 kN respectively.  The correlation factor α_p is derived usingthree cone resistance averaging techniques. The Koppejan method hasconsistently resulted in the highest derived α_p factors withvalues of 1.09 and 1.61 for scenarios excluding and including residual loadsrespectively.  The scenario excluding residual effects has resulted in anaverage α_sof 0.009 for the bearing sand layer. Upon inclusion of residual loads, thederived α_sfactor for the first sand layer amounts to 0.012. This increase in shear forcesis also observed in the Pleistocene peat layer. Therefore, residual loadsredistribute the capacity of the piles by increasing the shaft resistance inthe bearing sand and Pleistocene peat, while simultaneously decreasing theshear stresses in the Holocene layers above.  Conclusively, timber pile characteristics such as variationin geometry and mechanical properties have significant effects on the capacityof the piles. Additionally, these variations result in fluctuations in thecalculated load distribution along the pile. Local smoothing of thesefluctuations results in higher apparent loads, most specifically at the pilebase. Therefore, smoothing algorithms are not implemented in this analysis. Thevariation in diameter along the entire length of each pile directly affects theload distribution. Despite this influence, no trend is observed for thevariation of α_p factors with respect to pile tip diameter. Anapparent relationship between the tapering of the pile in the bearing sandlayer and the derived α_s factors suggests that tapering effectivelyincreases the shear forces along the shaft in that layer.  Furthermore, the usage of fiber optic sensors on woodenpiles has proven to be effective. The variation in local behavior of wood isclearly illustrated through the conducted analysis. As a consequence of thebiological nature of wood, the local behavior of wooden piles is best capturedby sensing technologies measuring strains at high spatial frequencies.  

During construction in urban areas often noise and vibrations are not tolerated. For the installation of the foundation piles in these cases there is often chosen for screwed displacement piles. These piles can be installed without nuisance for the vicinity, but do induce large soil displacements during installation. The soil displacements can cause increased soil pressure on adjacent structures. Because urban areas are getting more densely built, these problems will occur more often in the future. The effects can be minimilized when they are known in advanced. This research looks into the possibility of predicting the installation effects of screwed displacements piles on adjacent structures. This is divided in the prediction of the soil displacement in a finite element analysis and in the effect of the soil displacement on adjacent piles. This is done with two case studies. First data from tests in Shanghai is used to create a finite element model. After this measurements are done in Rotterdam to verify this model for Dutch cases.
Combining all the analysis of the measured and modelled displacements showed that the displacement is depended on the stiffness of the soil layers, the initial displacement at the edge of the pile and the distance from the pile. The soil parameters influence the initial displacements in each soil layers. When the initial displacements are correctly determined with tests, it is possible to predict the soil displacement due to the installation of a screw pile with a finite element model. No conclusion could be made on the effect of the soil displacements on adjacent structures.