The city of Amsterdam contains about 1600 bridges and 600 kilometres of quay walls. Of these walls, about 200 kilometres are of masonry walls placed on a timber floor and founded on timber piles. These quay walls are sometimes over 100 years old. Due to the increasing loads in the past century and the degrading of material properties in the masonry wall and timber elements, the quay walls are in bad shape. When designing a quay wall, a cross-sectional analysis is used to calculate the desired dimensions to withstand the loads. When this calculation is performed on a quay wall over a 100 years old, containing a failing pile foundation, the quay wall should fail. However, many of the quay walls under the condition of a partly failing foundation, are deforming, but still standing. During recent years, at 16 locations in Amsterdam, the risk of collapse appeared imminent, and emergency structures are put into place. Possible practical measures are removing trees on the quay walls, traffic limitations in the city centre and placing temporary struts and sheet piles to provide stability. Since the scale of the problem in Amsterdam is large, the time to renovate all the quay walls is lengthy. Therefore, there is a need for knowledge on the state of quay walls at the end of their life phase when partly failing. Different failure mechanisms occur, and various measures are developed to control those and provide (temporary) stability. This research answers the question: How can 2D analyses of quay walls, in multiple directions, under the condition of a partly failing foundation, provide insight into the hidden structural capacity within the masonry work? The study focuses on the severeness and scale of the foundation defects in the quay wall's cross-sectional and longitudinal direction. For the longitudinal models, the effects of the masonry material qualities are studied by using different material properties. Also examined is the effect of the failing foundation pile's post-peak behaviour, modelled as brittle and checked for plastic behaviour. Finally, the relevancy of the timber floor is studied for a stiff continuous floor and most notable, the full removal of the floor. To study this, two 2D regular plane stress, nonlinear elastic, finite element models are created in Diana FEA. The foundation piles are modelled as nonlinear elastic springs via a force-displacement diagram. The foundation piles' defects are modelled by assuming a smaller pile diameter, resulting in a weaker force-displacement diagram and larger displacements in the quay wall system. The foundation defects can be scaled over a small or big area by adapting multiple foundation piles over the length of the quay wall. The masonry's behaviour is researched by using a macro material model using smeared material properties for the brick and mortar, resulting in a continuous material. The material model used is the Total Strain Rotating Crack Model, which can be used in a 3D analysis of the quay wall system in future research. Finally, the interface between the timber floor and masonry is modelled using a coulomb friction interface criterion. This simulates the effects of the mortar layer connecting the timber floor and masonry work in a quay wall. The results conclude that analysing a foundation defect in the cross-sectional direction of the quay wall results in instability of the wall without further horizontal and vertical constraints to keep the quay wall in place. Modelling the pile foundation defects using a reduced pile diameter and consequently, a decreased force-displacement diagram as spring input provides the model with temporary stability. Ultimately, the cross-sectional analyses contribute little knowledge on residual strength and hidden structural capacity. Separately, the longitudinal model implements a vertical constraint in the masonry by using the bending capacities of the material. The results present an expected correlation between the scale of the foundation defects and the vertical displacements. Similar to the cross-sectional analyses, the reduced pile capacity of the foundation piles provides the model residual strength compared to the situation where the total failure of a timber pile is used. The timber foundation pile's failure mechanism needs to be researched in-depth since the results present a notable difference for crack patterns and force-displacement curvatures when modelled brittle or plastically. For brittle failure, a horizontal crack forms at the tip of the central, vertical crack, due to the abrupt enlargement in vertical displacement of the quay wall. The functionality of the timber floor in the longitudinal analyses presents itself when the crack patterns are analysed. The presence of the timber floor results in multiple smaller cracks instead of a single large crack when foundation defects of the quay wall system are analysed without a timber floor. It can be concluded that the masonry quality, most notably the tensile strength, affect the results significantly in terms of maximum values in the force-displacement diagrams and crack development. The material properties are based on Groningen masonry experiments, and it is recommended to perform experiments to the masonry quality of Amsterdam quay walls. Finally, the observed displacements related to the intervention points of the municipality conclude that foundation defects result in cracks for displacements below the marking points of 20 and 25 millimetres. For weaker masonry, the quay wall fails before the indication values. It is recommended to perform more measurements to the quay walls in Amsterdam and study the reliability of the intervention points.

In the past decades, gas productions in the province of Groningen in The Netherlands have caused a significant amount of shallow human-induced earthquakes. Its building stock has shown to be highly vulnerable to these unexpected events. Among various building typologies, damage has been reported for approximately 12.9% of the churches in Groningen. From the perspective of conservation and prevention of loss of our historical and cultural heritage, the assessment of churches is of importance. As a majority of historical structures have undergone restoration works, that can be favourable for their seismic performance, it is worth noticing that for historical structures strengthening may not be necessary. Consequently, the question arises whether structural modifications during the lifespan of historical unreinforced masonry churches, positively influences their seismic performance. This thesis researches the seismic performance of the historical unreinforced masonry Dutch church Zandeweer, prior and post structural modifications, in the earthquake prone area Groningen. The church, built by the Moncks of Abdij van Aduard in the year 1230, underwent major renovation works in 1931. Its structure is composed of masonry walls, masonry ribbed cross vaults and a timber roof with timber cladding. During the restoration works in 1931 steel columns were integrated in the piers of one of the façade in the longitudinal direction, window openings in the curved façade were closed and concrete beams were added on top of the main walls. Its seismic performance was investigating in the positive longitudinal direction by studying its global nonlinear response and structural elemental behaviour and by indicating uncertainties and damage. A Nonlinear Pushover Analysis (NLPO) and the Simplified Lateral Mechanism Analysis method (SLaMA) were employed to capture the influence on the seismic performance of the church models. Although, the acquired results for the church models showed to a certain extend an insight in the influence of the structural modifications, an insight in the ductility behaviour of the structure was not acquired. Additionally, from the eigenvalue it was concluded that adopted single-mode analysis methods (SLaMA and NLPO) were not suitable, as the structural response of the church is governed by multi-modes. Moreover, with the highly unpredictable behaviour of the vaults in the structure the presented results were greatly influence by physical and numerical instabilities. For future studies is recommended to dedicate a detailed study to the numerical modelling and analysis of masonry ribbed cross vault structures. Furthermore, to conduct a detailed study on the church walls, for which subsequently various analysis methods can be employed and the influence of orthotropy of walls on the global response can be studied. Lastly, the analysis method can be changed by using methods that consider multi-modes simultaneously and that are known for less numerical instability problems than static analysis methods.

In Groningen, seismic activity has increased due to the extraction of gas in the area. A large-scale research campaign has been launched with the aim to assess and safeguard structures in the region. However, an accurate assessment of these buildings turned out to be a challenge, due to the nonlinear behaviour of the masonry and the dynamic nature of a seismic load. A Nonlinear Time History (NLTH) analysis takes into account both these factors, but the computational demand of such a method is considerable. Another method that is widely used to analyse the seismic response of a structure is the Modal Response Spectrum (MRS) method. The computational demand of this method is considerably less compared to NLTH, but nonlinear material behaviour is only taken into account in an indirect manner via a behaviour factor, and the results are considered to be too conservative. A third method is the Nonlinear Pushover (NLPO) method. It takes nonlinear material behaviour into account and compared to NLTH, NLPO is computationally more efficient. Furthermore, an advantage is that it separates capacity from demand. Even though the NLPO method is commonly applied worldwide, its validity still needs to be proven for the Groningen case. Both objectives were studied by looking into a single case study, consisting of a low-rise URM apartment building. The behaviour of the structure is characterised by a weak and strong direction, in which the weak direction is characterised by a relatively low stiffness and lateral capacity compared to the strong direction. The seismic response of the structure is determined according to the MRS, NLPO and NLTH methods. Furthermore, the NLPO analyses are executed using two different computational discretisation methods, namely continuum FEM and macro EFM. DIANA is used as a FEM solver for the MRS, NLPO and NLTH analyses and 3MURI is used for the EFM model. Moreover, a modal and uniform lateral load pattern are taken into account for the NLPO analyses. The conclusions which are drawn from the case study can generally be applied to low-rise URM apartment buildings in Groningen. However, it must be noted that significant alterations in geometry and building materials might influence the results. Furthermore, modelling assumptions have been applied, and it is important to note that the possible influence of these assumptions, may partially limit the extent of the conclusions. Moreover, several limitations are inherent to the studied methods, and cannot be accounted for somehow. All analyses are performed by incrementally increasing the seismic load until one of the near collapse limit state criteria according to NPR 9998 is met. Furthermore, three target displacement methods are evaluated: the capacity spectrum method according to NPR 9998, the regular N2-method, included in the Eurocode 8, and an adaptation of the N2-method which is developed specifically for URM structures by Guerinni. The performance of the structure according to each of the methods is studied subsequently, by looking into the force-displacement behaviour, displacement profile and damage at failure, failure mechanisms and the maximum admissible seismic load. Two significant disadvantages of macro EFM were identified when comparing the results of the NLPO analyses using 3MURI and DIANA. First, the fact that out-of-plane behaviour is not taken into account in 3MURI could significantly influence the behaviour of a structure in terms of base shear capacity, which is especially true when structures are characterised by an extremely low total length of piers in the in-plane direction. Furthermore,DIANA allows for a more gradual softening behaviour, which helps the post-peak force redistribution. As a consequence, the maximum admissible seismic load according to DIANA could be higher. However, despite the two aforementioned disadvantages of the macro EFM method as implemented in 3MURI, all other relevant results of both methods are similar. The fact that the two identified disadvantages of 3MURI can only result in more conservative results, suggests that macro EFM, as implemented in 3MURI, is a suitable computational discretisation method for the seismic assessment according to the NLPO method for low-rise URM apartment buildings in Groningen. However, it should be taken into account that the conservativeness of 3MURI could lead to a significantly larger amount of required retrofitting, in comparison with DIANA. The applicability of the NLPO method is reviewed by comparing the results of the MRS, NLPO and NLTH methods. Similar behaviour of the structure according to the NLPO and NLTH method was captured, which suggests that the NLPO method is a suitable analysis method for the studied typology. The maximum admissible seismic load using the target displacement method according to NPR 9998 is in-line with the NLTH analysis. However, the governing load case made use of a uniform load pattern, which returns a structural behaviour different than that obtained by NLTH analyses, as can be seen from the force-displacement behaviour. If only the capacity curve according to the modal load pattern would be considered, then the allowable seismic load according to NLTH is similar to that of NLPO using the target displacement method of Eurocode 8. Furthermore, from the results of the case study can be concluded that the choice of target displacement method has a significant influence on the maximum admissible seismic load. For the case study, NPR 9998 is more conservative in the strong direction, and Eurocode 8 is more conservative in the weak direction. Regarding the MRS method, very conservative results were found. A reason that was found for these conservative results is that the prescribed behaviour factor by NPR 9998 is too low for the case study when compared to that derived from the NLPO analysis. However, even with a larger behaviour factor, the results according to the MRS method would still be conservative in the weak direction.

Additive manufacturing and 3D printing are rapidly developing digital fabrication techniques. After the first steps in printing of metals and plastics have been made, research from various groups around the world is now also focusing on printing in concrete and moving to larger scales. Using this technique it will be possible to create customised concrete designs in one go at low costs and high construction speeds. Additionally, this new technology will provide opportunities to create more efficient structures. Structures can already be optimised in the early stages of the design for weight and structural performance, but the resulting optimised structures are often difficult to manufacture due to their shape. Additive manufacturing can be the key to make this possible without high costs for moulds and labour. This thesis will present a novel methodology to include material and manufacturing constraints of 3D printed concrete in the optimisation process. The study examines the possibility to optimise concrete structures in the design phase. In order to save material and thus create more sustainable and more cost efficient structures, a topology optimisation tool has been created specifically for 3D printed concrete. Traditional topology optimisation methods consider isotropic and linear elastic material and will not necessarily produce realisable and reliable optimised structures. In the algorithm presented constraints of the printing process and material properties from physical testing of this layered material are both considered in the optimisation. By adopting this methodology more realistic and feasible optimal concrete structures can be designed.

When a breakwater is under heavy wave attack, the concrete armour units will occasionally move, causing a collision between two concrete armour units. This process is called rocking, and induces stresses in the concrete, that may lead to breakage of the concrete armour units. This MSc Thesis provides a probabilistic method to predict breakage of concrete armour units, focussed on Xbloc®. The impact velocity is based on the forces on a unit under wave attack. This impact velocity is used as input to determine the impact force, based on an energy balance. The stresses at a critical location in armour unit will then be determined from a strut-and-tie model. With an estimation of the distribution of several stochastic variables, the eventual result is a probabilistic prediction of breakage of the concrete armour units.

In light of the global attempts to reduce material use by the construction industry, this research focuses on combining topology optimisation with additive manufacturing of steel. It is investigated whether an automated procedure can be developed to generate reliable strut and tie models for reinforced concrete elements, while satisfying the constraints that apply to 3D-printing using the Wire and Arc Additive Manufacturing(waam) technique. Additive manufacturing offers a fully automated production process where a large freedom in form can be achieved. Topology optimisation concerns with finding a good material distribution within a prescribed domain. A literature review was performed on current developments regarding both subjects. It was found that the waam-technique is very suitable for printing reinforcement designs. Sufficiently large models can be printed, and material properties can be achieved that match the properties of traditional reinforcement steel. This manufacturing process is expected to produce functional structures that can readily be used as reinforcement steel in buildings. Two main manufacturing constraints should be accounted for during design of the model. A minimum member inclination and a minimum member diameter are both expected to be necessary to ensure a smooth printing process. Several different topology optimisation algorithms are discussed in the second part of the literature review, and it is determined which algorithm is most suitable to continue with in the rest of this research. Examples are presented that explain the functionality of three important optimisation schemes: Bi-directional Evolutionary Structural Optimisation(beso, Solid Isotropic Material with Penalisation(simp) and Ground Structure Optimisation(gso). It was found that all three can be used to analyse reinforced concrete. Each algorithm has advantages and disadvantages, so there is no obvious best choice. However, motivated by the easy access to member forces and availability of a very good Python implementation, it is chosen to use gso for the remainder of this research. This Python script was modified to include the constraints that come with an additive manufacturing process. It was found that the minimum member inclination can straightforwardly be included. The new function that was proposed allows the user to specify a minimum inclination, and ensures that no members are generated within the design domain that violate this minimum angle. Experimenting with this new function revealed cases where material use increased significantly when this function was used. This lead to development of an alternative procedure to ensure a printable design. In this alternative procedure, an optimisation without any angle constraint is performed first. Then, in the form of a post-processing script, The complete model is rotated around two separate axes in an attempt to find a suitable printing orientation. The third and final proposition that was done in this part, consists of a post-processing script for the minimum member diameter. Including this minimum diameter in the optimisation would require rigorous changes to the optimisation script. Therefore it was chosen to investigate the performance of this post-processing script first. The case study that was performed in the third part of this research, proved that this post- processing script for member diameter is sufficiently efficient for practical implementation. Together with the ability to slightly suppress the amount of members that are generated in the design domain, the printing constraint for minimum diameter could relatively easily be enforced. A bigger challenge lies within ensuring the minimum member inclination. The 60◦ minimum that was set, proved to be very harsh on the solution space. In the example from the case study, no printable model could be generated without significantly reducing the material efficiency. However, it is argued that this minimum inclination constraint can possibly be relieved by recent developments in additive manufacturing techniques. An example of this could be a rotating printing surface, that has the potential to remove this angle constraint completely. Overall, the experience of combining topology optimisation, additive manufacturing and strut and tie modelling has been predominantly positive throughout this research. The combination of a state of the art manufacturing technique and a more performance driven design process with a labour intensive traditional calculation procedure has shown promising first results. In the example in this research, 30% less material was required to accommodate the tensile forces in the concrete.

The growing need to understand the behaviour of un-reinforced masonry URM), subjected to repeated light man-made earthquakes caused by the extraction of gas in the north-eastern part of The Netherlands has resulted in intense research to determine the exact process of crack initiation and propagation. The historical masonry buildings and Dutch terraced houses in Groningen are prone to light damages which become severe upon repeated lateral earthquake loading. Although there are material models that describe the behavior of modern brick masonry, they do not accurately represent the mechanical properties of 19th century clay brick masonry. This led to a large-scale research into the mechanical behavior of un-reinforced masonry and an orthotropic continuum macro-model called the Engineering Masonry Model (EMM) was proposed. The existing tension constitutive model in EMM assumes a secant unloading-reloading branch which does not consider the strength degradation of URM under repeated loading. Since tension mode-I fracture results in cracking of URM, it is important to study the effects of repeated loading on the propagation of the crack and its effects on the capacity of the structure. This thesis presents a degradation model to represent the strength deterioration of URM observed during repeated loading. The constitutive model formulated in this thesis is based on hyperbolic functions along with a secant slope for the unloading-reloading branch. To justify the model assumptions, a single linear 4-node element is analysed with the new model and the effect of varying different components of the constitutive equations is established. The window bank spandrel sample modeled as a 4-point bending test is analysed using the new model for 10, 30 and 100 repetitions. It is shown that the hyperbolic model can predict accurately the stress reduction within each repetition displacement set and also represent the crack width widening and crack propagation accurately when compared to the experimental results. The new model is tested on a wall with a window opening sample and the results closely matched that of the experiment. Finally, recommendations are provided for further development of the hyperbolic model and calibration of the material properties.

Uncertainties regarding structural safety of reinforced concrete structures may warrant a need for a detailed assessment. A detailed assessment using nonlinear finite element analysis is one of the alternatives which could help in decision-making about maintaining, upgrading or even demolishing and rebuilding of the structure. A reliable assessment should account for the existing damage in the structure, which may cause re-distribution of stresses within the structure, giving rise to unexpected failure modes. The existing approaches in nonlinear finite element analysis which account for the effect of already undergone damage in concrete, pose a number of limitations which either makes structural analysis ambitious or the uncertainty of concrete damage is not effectively accounted for. An alternative approach is adopted in this thesis, which is phenomenological and probabilistic in nature. Existing damage in concrete is conceived as a statistical field, which can be input into a finite element model, such that the existence of damage is taken as the starting point of the structural analysis. Focusing on indications of damage on the surface of concrete, i.e. crack patterns, an exploratory methodology based on image analysis is developed, to account for information obtained from crack pattern observation into nonlinear finite element analysis of reinforced concrete structures. The methodology is implemented on MATLAB and validated on damaged experimental specimens. Results of the computational analyses indicate good efficiency in predicting residual load carrying capacities and failure modes, alongside insightful numerical crack patterns. Through a critical examination of the obtained results and reflection upon the assumptions and simplification made in the methodology, recommendations for future research are provided.

The implementation of timber as a load-bearing and stabilizing material for high-rise structures has significantly increased over the last decades due to its potential of reducing the environmental footprint of a structure. Timber structures present a reduced global stiffness and self-weight compared to structures incorporating traditional construction materials, making them prone to high accelerations caused by wind load which affects the structural integrity and user comfort. The acceleration of a structure is a highly complex parameter that must be determined using modal analysis computed by a full-scale finite element model, and is significantly influenced by the magnitude of the wind and vertical loads, as well as the global stiffness of the structure. During the preliminary design phase, it is the responsibility of structural engineers to determine the feasibility of the design and estimate the amount of material required and the distribution of the structural elements. However, this process must be done under a limited amount of time, forcing engineers to rely on rules of thumb and previous experience, which are not currently available for the design of timber high-rise structures. Therefore, the goal of this investigation is to perform a parametric study to determine the influence of various parameters on the design of timber high-rise structures and assist structural engineers in making well-argued decisions during the preliminary design phase. The preliminary design parameters to be studied in the parametric study are: stability system design, connection stiffness and building height. The ranges for the parameters were selected based on extreme values such that clear trends regarding their influence on design could be visualized. This decision limits the design feasibility of some configurations studied in this investigation. The selected stability systems to be studied are glulam frame, CLT core and glulam diagrid. The design verification for each design alternative is done using ULS and SLS criteria provided by Eurocode, as well as a simplified method to estimate the dynamic response of the structure. Finally, the sizing of the structural elements and data collection was done by the implementation of evolutionary algorithms. From the data collected it was determined that the most influential design parameter for the design of timber high-rise structures is the stability system selection given that it determines the global stiffness, which showed a significantly higher influence on the dynamic response of the structure than its self-weight. Moreover, the efficiency of the different stability systems was assessed based on the maximum slenderness they could achieve compared to the amount of material they required. Based on this definition, it was determined that the glulam diagrid is two times more efficient than the CLT core and three times more efficient than the glulam frame. The efficiency of the glulam diagrid is caused by its high global stiffness provided by the triangular configuration of the diagonal elements. These observations prove that the effect of timber’s low density can be mitigated by the implementation of efficient stability systems. The influence of connection stiffness was determined to be directly related to the ability of the stability system to provide lateral stability to the structure. The influence of this parameter on form stable structures such as the CLT core and the glulam diagrid, proved to be nearly negligible, while for non-form stable structures such as the glulam frame it proved to be highly influential. However, it was also determined that the addition of rotational stiffness in the connections causes an exponential increase of the costs and environmental footprint of the structure, which decreases their design feasibility. Finally, the influence of building height on the design is visualized by its effect on the dynamic response of the structure caused by the logarithmic increase of the wind speed as this parameter increases, as well as a decrease of the global stiffness proportional to the efficiency of the stability system.

During the early stages of the construction process of a building, the potential impact of design decisions is at its greatest. One of the reasons is the lack of computational tools at these stages. The main objective of this research project was the expansion of StructuralComponents by the development of a parametric real-time computational tool prototype to quickly determine the feasibility of mid-rise buildings designs with rigid frames as stability members. A study of rigid frames behaviour was performed to define a range of applicability of the existing analytical representation and to develop two new methods to analytically represent rigid frames behaviour: a correction method for the shear beam representation and a method based on the Timoshenko beam theory. To allow for vertical connections of different rigid frame geometries, an analytical method to consider a different stiffness along the height was developed. The results showed that the analytical shear beam representation of rigid frames has a reduced range of applicability for parametric purposes. This reduced applicability is due to the combined shear and bending behaviour. The correction method follows from the prediction of the error when using the shear beam representation. In addition to the correction of the shear beam representation, the prediction of the error was defined as a parameter to classify the behaviour of a rigid frame as a shear, flexural or combined type. Both, the applicability range and the correction method are based on analytical and numerical comparisons, as well as the performed validations. The implemented software comprises Maplesoft to get the analytical solutions and Grasshopper with Karamba3D (which contains the finite element solver) to get the numerical solutions. The method based on the Timoshenko beam theory comes from the theoretical derivations of a serial system that takes into account both, bending and shear deformations. It was found that it is more appropriate to analytically represent the general behaviour of rigid frames with the Timoshenko beam theory and by additionally considering a different stiffness calculation for the ground floor. Also, it was shown that the vertical connections of rigid frame geometries can be addressed with the calculation of an analytical solution for each different geometry along the height. Both analytical approaches, the Timoshenko beam representation and the method for vertical connections were implemented in the tool prototype. Such a tool consists of a calculation method to assess the structural performance of a building by the simultaneous structural analysis of every rigid frame subjected to a lateral load. The three main characteristics of the tool prototype are the parametric adaptability, the instantaneous display of results and the stacking “Lego-type” connection between components. The validations in this research project showed that the proposed and implemented methods are suitable for preliminary design stages because the error for the most unfavourable geometric configurations resulted in less than 15 percent. It is recommended to conduct further research and tool development. In so doing, more informed decisions can be made during the preliminary design stages.

The Netherlands is currently in the process of transitioning from a linear economy to a circular economy, in accordance with the ”Nederland Circulair 2050” policy. To increase the circularity of buildings, several approaches can be integrated. In this research, the so-called Design for Deconstruction and Donor Structural Framework concepts are elaborated as possible approaches. The first concept focuses on taking the future de- and remountability of a building into consideration during the design process. This concept allows buildings that approach their end-of-life phase to be (partially) reused as structural components, on a new location. The second concept can be applied during the construction phase of a building, where structural components of an old building are dismantled and reused in the to be constructed building. The difference between the two concepts thus being the life cycle in which they are applied. Therefore, the resulting benefit of using a Donor Framework can be seen immediately, whereas the benefit of applying the Design for Deconstruction concept can only be stated in the future. Unfortunately, the current procedure to measure the sustainability score of a building, the Life Cycle Assessment methodology, does not take these concepts into account. This makes determining their impact on the environment hardly possible. Also, due to the fact that detailed information about a design is required, a Life Cycle Assessment is made only once the design is final. In this order, all design variables are set such that designing towards sustainability is not an option. This research focuses on solving the introductory problems and aims to enable sustainable material choices for a structural design possible in the early design phase. Both the Donor Structural Framework and the Design for Deconstruction concepts were taken into consideration. This main goal has been split into two sub–questions:- How to assess the environmental impact of a steel, concrete and timber load bearing structure in the early design phase? -How to implement the Donor Structural Framework and the Design for Deconstruction concept into the existing Life Cycle Assessment methodology? The research questions have been answered by executing the following approach: 1.A parametric model is used in which not only the geometry and structural calculations are included, but the Environmental Impact Calculation as well. In the event of a design change, the Environmental Impact Calculation is automatically reiterated, which means different designs can be compared quickly based on their environmental impact. The model constructed for this study is suitable for designs in steel, concrete and timber. For each material a reference design is created. The Bill of Materials of these designs serves as input for the Environmental Impact Calculation on which the materials were compared in a later research phase.2.First, an existing end-of-life allocation method has been adjusted to include reuse during both the construction phase (Donor Structural Framework) as the end-of-life phase (Design for Deconstruction). Secondly, the Building Circularity Index, which recognizes a ”circularity score”, has been implemented in this method. In this study the Building Circularity Index is assumed as the ”probability of future reuse of the building”. The modified method was implemented in the parametric model to enable a real-time Environmental Impact Calculation. This approach has been fully implemented into a parametric visual script, executed in the Grasshopper, a parametric environment plugin of Rhino which enables visual scripting. Input parameters are imported from Excel, the Grasshopper script calculates the environmental impact and exports the results to Excel where they are visualized in a dashboard. Ultimately, the developed parametric model has been divided into a part containing the geometry and structural calculations of the reference designs and a part where the newly developed Environmental Impact Calculation method is implemented. Combining the results of both parts in the total model, it becomes possible to assess whether a design is best built in a certain material in the early design phase. The final model can provide results with or without the use of a Donor Structural Framework and with or without application of the Design for Deconstruction concept. For the purpose of demonstrating the functioning of the model, a reference design in steel, concrete and timber was implemented as a basic geometry. This geometry was assumed equal across all designs and for comparability purposes, dimensions were fixed. Consequently, it can be concluded from the results of these reference designs that using a Donor Structural Framework results in a lower environmental impact than applying the Design for Deconstruction concept by maximizing the remountability of a structure. Until a lifespan of 75 years, using a timber donor framework is the most sustainable solution for the reference design. From 75 until 100 years this is the case for steel and from 100 years onward, a concrete design, whether or not using a donor framework, results in the lowest environmental impact. In the current design practice of a building, the default lifespan has been determined by the function of the building (Functional Service Life). By using the model developed here, this lifespan can be determined on the basis of sustainability requirements instead of functional requirements. The differences in environmental impact for different lifespans can easily be compared. Therefore, it is made possible to steer towards a certain lifespan, in order to determine the most sustainable construction based on the clients requirements. This is currently not possible in the Dutch construction industry. However, these results do have their limitations, as they should not be interpreted as general but rather specific conclusions. The following points of attention apply: -Results should not be interpreted as general results, but these results only apply on the three reference designs as elaborated further in the research. These reference designs are not optimized for every material used. -Changing input parameters can have a significant impact on the results. In addition, a number of important parameters (reuse percentage, material lifespan etc.) have been assumed due to insufficient existing research. -The developed allocation equations include the incineration of timber too favorably. This results in a significant deviation in timber environmental impact for lifespans much shorter than 75 years. This flaw can be either due to the model, or the impact parameters as stated in the NIBE EPD app. Lastly, it is recommended to further research the assumed parameters in this research, especially the material lifespan and the incineration impact parameters. As these parameters can have a major impact on the environmental impact of a specific design.

Existing sophisticated numerical micro- and macro models have already proven to be capable of simulating typical masonry behaviour. However, assessing the global response of masonry buildings using brick-to-brick micro modelling or even simplified macro modelling, in which masonry is regarded as a continuum material, takes such an amount of time that these methods cannot be considered as cost-effective. For the last two decades it has been recognized that, for the global structural behaviour of masonry buildings, simplifications have to be made. The idealization of a masonry wall as an assemblage of numerically integrated (or fibre) beam elements could considerably reduce the computational burden and therefore this study addresses the following research question: To what extent are numerically integrated beam elements applicable for assessing the global response of masonry structures? Whereas existing equivalent frame methods are usually based on lumped plasticity models, the approach discussed here considers the entire member (e.g pier or spandrel) as an inelastic element in which the sectional response is evaluated via a fibre discretization in which each fibre (or integration point over the depth) may follow a material uniaxial nonlinear stress-strain relation. Initially the shear response is kept linear, automatically idealizing the structural response as purely flexural. The proposed model will be hereinafter named FFM (Fibre Flexure Model). Additionally, an extension of the FFM has been proposed, describing the shearing behaviour by means of a structural nodal interface element. Adopting the nodal interface element, placed between two nodes of adjacent beam elements, the axial and bending behaviour is described with the fibre-section discretization and the shear behaviour is modelled via an equivalent Coulomb-type criterion describing the shear force limit. The proposed model will be hereinafter named FF-LSM (Fibre Flexure – Lumped Shear model) because it lumps shearing nonlinearities in one single interface element located in the centre of the structural component, whereas flexural and crushing behaviour is evaluated via smeared crack beam elements. To validate the numerical models, two different types of benchmarks have been investigated, respectively representing the behaviour of either a single structural component (masonry pier) or a composite façade. All numerical models have been subjected to static nonlinear (pushover) analyses and results have been compared with experimental and numerical data through the use of a reference continuum model. First, it has been demonstrated that the FFM, idealizing the structural response as purely flexural, is capable of simulating the rocking failure mode of unreinforced masonry walls, whereas it fails to simulate typical masonry shearing modes such as diagonal cracking and sliding. The use of the model for squat members that are characterized by shear failure leads to significant overpredictions, making the model not applicable for the analysis of masonry structures containing relatively squat structural components, having shear span to depth ratios less than approximately 1. Second, the shortcoming of the FFM regarding the shearing failure mode has been overcome by combining the numerically integrated beam elements with a structural nodal interface element describing the shear behaviour. The FF-LSM including the nodal interface is able to correctly predict the shear capacity of both slender and squat walls, although the observed level of accuracy depends largely on the adopted shear failure criterion. Various shear force criteria (Coulomb friction based) have been considered: the Mann and Muller (1982) criterion, the correction proposed by Magenes and Calvi (1997) and the modification according to Abrams (1992). Generally it was observed that the criteria developed by Abrams (1992) was the most accurate and that especially for a decreasing shear ratio the criterion developed by Magenes and Calvi (1997) appeared to be less precise. Third, analysing a composite façade, with respect to the reference continuum model the FFM and FF-LSM significantly reduce the number of elements, nodes and integration points, consequently minimizing the computational effort and maximizing the computational robustness. In comparison with the corresponding continuum model the computational time decreases by a factor of approximately 10. Despite the limitations of the FFM regarding the shearing failure mode, the model shows an acceptable accuracy in terms of initial stiffness, stiffness reduction and peak strength. Adopting the FF-LSM the numerical model predictions were significantly enhanced and both flexural and shearing failure modes (in piers and spandrels) were detected correctly. Therefore, the result of the investigation has proved to be very promising as with the FF-LSM an acceptable balance between computational cost and accuracy is found, applicable to the global analysis of two dimensional masonry structures constituting slender as well as squat walls. As many problems in engineering practice require solutions in three-dimensional space, a fully three-dimensional extension of the FF-LSM is highly recommended.

This research investigates if confining rubble stone masonry by timber bands and columns increases resistance against earthquake loads, by performing a number of numerical analyses in the finite element software program Diana. In order to establish a reliable model, the input parameters are investigated by means of a literature study and sensitivity study. Additionally, the numerical model is validated by comparing the results to an analytical study. From the analytical study it is determined that the failure mechanisms are correctly estimated by the numerical analysis. However, differences between the values of ultimate strength and ductility were observed. The effect of the confinement is investigated by a pushover analysis on a shear wall with two different masonry tensile strengths: ft = 0.01 N/mm2 and ft = 0.03 N/mm2. These values are selected to show how such a small difference in tensile strength results in a different failure mechanism of the wall, and therefore results in a vastly different displacement capacity and ultimate strength. Additionally, a shear wall with and without a window opening is studied. If the building is constructed with extremely low-strength masonry (ft = 0.01 N/mm2), the timber frame confinement will increase the resistance of the wall (with or without window opening) against the pushover load. If the building is constructed with masonry having a tensile strength of 0.03 N/mm2 or higher, the confinement has a negative impact on the ductility of the closed wall. For the wall with window opening the confinement triples its ultimate strength. Weather a strong or a ductile structure is more desirable, depends on the demand with respect to the seismic spectrum. If the ground motion demands a strong structure, it is advised to confine the masonry with a timber frame consisting of four timber bands, and columns at each wall junction. The design of the timber frame as recommended by the Nepali building codes is determined to not be sufficient and must be altered in order to provide this positive impact on the structure’s resistance. Firstly, the columns must be placed at both sides of the band, instead of on the inner side only, to avoid eccentric loads on the bands. Secondly, the cross-sectional dimensions of the bands and columns must be increased avoid failure of the connections and splitting of the timber. Taking these aspects into account, a new design for the confinement method is presented in this study. The limitations of the conclusions of this research follow from the investigation of a single, in-plane wall only. One of the goals of the use of bands is to improve the box behaviour, for which the out-of-plane performance must be investigated. Moreover, an analysis on a three-dimensional structure is needed to fully answer the research question. In a three-dimensional study, the closed walls and walls with opening give a combined response to the load, therefore, the advantages and disadvantages of the confinement are combined as well.

This paper presents the development of a feasibility analysis tool for the Architecture Engineering and Construction (AEC) industry called StructuralComponents 5.0. It is the fifth paper in a series of developments starting with Breider (2008), which discussed modelling and analysing 2D tall buildings with an emphasis on quick generation and simple evaluation of designs. This paper expands the concept of bridging the gap between architectural modelling and structural engineering analysis tools used in the conceptual design process, by focusing on mid-rise buildings with three main characteristics. First, it implements a flexible modelling process to support architectural creativity during the conceptual design phase. The conceptual model is composed of building blocks that can be combined and parametrically adjusted to form a whole structure. Second, it helps the users understand the structural behaviour by visualising the force flow in near real-time. Instead of the conventional finite element method, the behaviour results of individual and combined building blocks (super elements) is computed using a symbolic differential equation method. Third, it includes feasibility checks and visualises them for both disciplines to improve understanding and encourage collaboration during the decision making process.

The extraction of natural gas in the northern part of the Netherlands, from the region of Groningen, has been causing human-induced seismic activities for the past several decades. This is a problem since the existing building stock in this region, which consists of mainly unreinforced masonry buildings and historical structures, are not designed to withstand seismic events due to the lack of empirical earthquake-resistant design features. Further, the combination of a soft topsoil and the gas extraction, is responsible for ground settlements which may compromise the capacity of the existing buildings. The bed-joint reinforcement technique is a strengthening method which consists of cutting a slot in the bed-joints and installing steel bars embedded in a high-strength repair mortar. Although this strengthening method is commonly applied in the Netherlands to counteract settlement damage, limited investigations on the performance against seismic loading are available in the literature. Therefore, an experimental campaign (Licciardello et al., 2021) was conducted at Delft University of Technology in which a quasi-static cyclic in-plane test on a full scale wall was performed to characterize the performance of the bed-joint reinforcement technique. The wall featured artificially introduced cracks (pre-damage), achieved by the inclusion of plastic sheets between bricks and mortar, to account for the settlement-induced damage. Compared to the un-strengthened walls, tested in a previous experimental campaign (Korswagen et al., 2019) under similar conditions, it is observed that the bed-joint reinforcement technique can provide a significant increment in terms of displacement capacity and ductility of the wall but not in terms of the force capacity. In this thesis, numerical simulations of both un-strengthened and strengthened walls from the experiments were performed using 2D-models and the nonlinear static analyses (monotonic and cyclic) were carried out in the finite element software DIANA. The objective of this research was to compare different numerical modeling approaches and material models to find the best suited one for simulating the in-plane seismic response of both un-strengthened and strengthened masonry walls. Moreover, the objective was also to extrapolate the experimental results to other wall configurations, which are not experimentally tested, to investigate the combined effect of the bed-joint reinforcement technique and the change in size and location of the window opening on the in-plane response of the wall (parametric study). In the scope of this thesis, three numerical modeling approaches were investigated (Figure i). The bricks and mortar joints are modeled as one homogeneous continuum in the macro-model. On the other hand, the bricks and mortar joints are modeled separately for the continuous and detailed micro-model where interface elements are included at the brick-mortar bonds for the latter one. The discrete (simplified) micro-model was not investigated because the reinforcement bars cannot be connected to the mortar joints since they are substituted by zero-thickness interface elements. Moreover, the Discrete modeling approach of the reinforcement was used in order to simulate the pull out behavior of the bars. Cracks were modeled using the discrete cracking approach and the smeared cracking approach where the former one was used at the brick-mortar interfaces and the latter one was used for cracking in the mortar joints (micro-models) and in the masonry composite (macro-model)…

The main motive for this research was to study the behaviour of quay walls when there is an uneven pile foundation present. This means that the number of piles varies in the thickness of the quay wall along the length. The inspiration came from the failure of the Grimburgwal (Amsterdam, the Netherlands) that collapsed in 2020, which had a length of 65 meters, according to Korff et al. (2021). Korff et al. (2021) reported that the main failure mechanisms that are considered in the case of the Grimburgwal, is the deformation of the piles due to horizontal bending, in the section where there were only two instead of three rows of piles present in the thickness of the wall. A 2D model with a length of 22.5 meters in the longitudinal direction (along the length of the quay) wall is used in this research, to study the influence of the uneven pile foundation in the thickness of the wall. The quay wall’s out-of-plane behaviour is not considered. The masonry and timber floor are modelled with linear plane stress elements. An interface condition is used to model the interaction between masonry and the timber floor. The longitudinal support beams and kespen are modelled as one element. The piles are modelled as equivalent translational springs that are evenly distributed in the longitudinal direction. In the central area, one spring represents two piles in the cross-section, while the rest of the springs represent three piles. After the application of the deadweight of masonry and timber, a uniform distributed load was used on top of the model to cause settlement of the piles and wall. The dilatation joint was modelled with a nonlinear interface with a high dummy stiffness and no tension, and with a gap of one millimeter. If the length of the section with two rows of piles is increased, the capacity of the wall reduces. The cracks at the bottom of the masonry, still do not increase significantly if the length of the length of the section with two rows of piles is increased, but it does take less load to generate the same cracks. The boundary conditions also play a large role in the distribution of forces, since it is seen that the piles near the dilatation joint are less critical than the piles near the constrained edge. In the end, this model does give information on how the forces in the piles distribute and how the piles settle, before both brittle and ductile failure of the piles occurs and cracking within the model. However, it should be kept in mind that the model that is considered is a 2D model, whereas the problem of a quay wall is a 3D problem, so the results are not expected to be accurate.

The rapid development in statistics, information technology, and computational power have en- abled numerous innovative methods to emerge in Structural Health Monitoring (SHM) for structural damage detection, both in practical application and research. The intention of such methods is to use the data obtained from the monitoring system to extract sufficient information to identify damage types that may appear in the structure. However, the following type of questions are mostly unanswered for realistic structural types and monitoring systems: Which responses of the structure should be monitored? Which sensor locations and sensor combinations carry the most information? Among the currently available computational algorithms, which one is the most suit- able one in this context? Hence, this study aims to contribute on this front and provide answers for practical applicability. A comprehensive study of a realistic, prestressed concrete bridge built by the cantilever method - the Lezíria Bridge in Portugal is undertaken to provide insight into these questions. The engineering challenge is studied in a probabilistic framework where the uncertainty sources are model uncertainty and measurement uncertainty. The Bayesian paradigm is used to handle the uncertainty component and a validated Finite Element (FE) model is applied to capture the mechanical behavior. The influence of the potential damage scenario, severity of damage, sensor type, the combination of sensors, prior knowledge of the structure, and the extent of uncertainty of the FE model and measurements are analyzed in this thesis. The informativeness of the Damage Identification (DI) process is reflected by the information content of its resulting posterior distributions. The information content is quantified using measures based on information entropy and the area of credible regions. It is demonstrated that selecting different responses to monitor may lead to a significant change in the informativeness of the result. It is also shown that for all analyzed cases using the most informative sensor type provides adequate information that reflects the damage state, while the rest types could only complement very limited information. In addition, the hybrid Markov Chain Monte Carlo(MCMC) seems more efficient and effective to conduct Bayesian inference. The findings provide valuable, quantitative insight into the design of new monitoring systems.

Old bridges in the Netherlands are reassessed to prove their structural safety because of the increased traffic loads. The Eurocode model for the shear capacity of prestressed concrete beams with sufficient shear reinforcement was found to be very conservative for small amounts of transverse reinforcement, which is typical for old bridges. Code provisions based on the modified compression field theory appear to be much more accurate (Bentz, Vecchio, & Collins,2006). On the other hand, these models make no distinction between flexural shear and shear tension failure, while 25% of the bridges consists of T-, I-, or box beams which are sensitive to shear tension failure. The aim of this thesis is to present a more accurate prediction for shear tension failure based on the modified compression field theory (MCFT). The report focuses on both the CSA-model and Response-2000. The CSA-model is a simplification of the MCFT for beams under the assumption that σ_z=0. The CSA-model shear resistance consists of a concrete and steel part. Response-2000 is a cross-sectional analysis program that works as a non-linear finite element analysis and not only takes into account bending but also shear.Response analysis of 32 beams (experiments of Xie (Xie, 2009), Choulli (Choulli, 2005), Hanson (Hanson & Hulbos, 1965) and Leonhardt (Leonhardt, Koch, & Rostasy, 1973)) have been made and compared with the experimental observations. The failure load is predicted with a mean ratio of 1.38 and a COV of 19% compared to the experiments. It was found that for small a/d-ratios predictions are more conservative. Failure mechanisms: rupture of the stirrups, crushing of the web concrete and slipping/major crack opening are found in Response. 87% of the failure mechanisms was predicted correctly compared to the experiments. The critical cross-section compared with the experimentally observed failure zone showed that 60% of the beams was predicted in the failure zone. The shear force in the cross section is resisted by reinforcement steel, aggregate interlock and the uncracked concrete, which were found to take up respectively 1/2, 1/6 and 1/3 of the shear force. The steel part is predicted accurately while the aggregate interlock part is underpredicted due to an over prediction of the crack spacing. The uncracked part is overpredicted for small amounts of reinforcement and underpredicted for larger amounts of reinforcement. The data of the Response analysis have been used to modify the CSA-model to a model solely describing shear tension failure. The comparison showed that the CSA-model underestimates the steel part, overestimates the concrete part, takes a to large cracked height and doesn't take into account the contribution of the uncracked part. From this comparison, modifications for β,θ,V_max,h_crack and ϵ_x are proposed using Response data and proposals from Esfandiari (Esfandiari & Adebar, 2009). The flanges are taken as uncracked and the contribution of the uncracked part is described with a linear elastic shear stress distribution. This has led to a proposal for a model that solely describes shear tension failure, where the most important addition is the contribution of the uncracked height. Calculations show that the model gives conservative predictions compared to the experiments (mean ratio of 1.36 and a COV 22%) and the predictions are almost the same as for Response. The parameters are predicted conservative compared to the Response-2000 predictions.

In recent decades, gas production has caused numerous human-induced shallow earthquakes in the province of Groningen, The Netherlands. The buildings in this area were not designed for these unexpected earthquake loads and have shown to be vulnerable. However, current strengthening measures are considered to be time-consuming, expensive, and a great hindrance to the residents. Consequently, the question rises whether unconventional strengthening measures can offer relatively simple and quick-to-implement alternatives. This thesis researches if replacing existing windows by structural windows could provide an effective strengthening alternative. The structural window design aims to increase the in-plane seismic force capacity of an existing masonry structure by utilising the glass pane as a structural element. The structural window is designed to be composed of a timber frame, a semi-rigid adhesive, and a double glazing unit. The structural layer of the double glazing unit has a thickness of 20mm and is composed of two laminated annealed glass panes with equal thickness. The potential of the structural window is investigated in various numerical studies, using DIANA FEA 10.2. The numerical studies are split into validation studies and seismic strengthening predictions. In the validation studies, results from numerical models are compared to and validated against experimental results reported in literature. Subsequently, the potential of the structural window is assessed by seismic strengthening predictions that combine and extrapolate the validation studies. A mass proportional one-directional monotonic pushover loading scheme is adopted. The seismic strengthening predictions address masonry walls and one type of terraced house (Dutch: “Rijtjeshuis") with two rigid floors, masonry spandrels, and two large windows in the front façade wall. The numerical strengthening predictions of the masonry walls and the terraced house indicate that a structural window improves the in-plane seismic performance significantly. It is found that strengthening not only greatly increases the seismic force capacity, but also reduces the expected damage. For example, the strengthened terraced house with openable window sections reaches 205% of the seismic force capacity of the unstrengthened terraced house. Furthermore, it is found that the stress levels in the glass pane are expected to remain well below the stress levels at the onset of glass cracking. The numerical strengthening predictions are promising. Therefore, it is recommended to validate these numerical predictions with an experimental testing campaign.

Rapid developments of both new (digital) fabrication techniques and innovative software facilitate the possibility to design, check and construct objects with great complexity and uniqueness without a large price tag. After new techniques slowly entered the field of architecture, the next step is to apply them in civil engineering to design load-bearing structures, dealing with a large number of load cases, outdoor conditions and strict safety requirements. The application of digital fabrication in civil engineering is examined through a case study: the design of a pedestrian frame bridge made of timber using CNC-milling techniques. In this research a strong focus is on the design, optimisation, detailing and testing of the connections. This research demonstrates that the combination of a reciprocal gridshell structure in combination with interlocking joints (lap joints) is particularly suitable for digital timber fabrication since a stable system can be obtained without the use of fasteners. The uniqueness of all connections and the strong relation between them makes the design process complex. Nevertheless, with the help of digital design tools like Grasshopper and evolutionary it is possible to deal with a large number of parameters with a complex relation between them. Additionally lab tests were carried out to get insight in the shear capacity of notched members. The tests show that the verification method for notched members in Eurocode 5 does not accurately predict the shear strength when hardwood is applied. Additional research on the fracture energy of hardwood is required to propose an improved calculation method. Furthermore, the tests have shown that the application of rounded edges and screws as reinforcement significantly improve the shear capacity of notched members. It is therefore always advised to apply rounded edges, if possible in combination with screws. All in all, the case study has shown that it is possible to design a load bearing free-form gridshell timber structure on both global and connection level, using the advantages of digital design and fabrication techniques.