In slender high-rise buildings wind-induced accelerations can become the governing design criterion. These issues can be solved by increasing mass, increasing stiffness, or increasing the damping ratio. The focus of this research is on the last option and investigates the opportunities of supplemental damping in the Dutch high-rise building context. The research report answers the following main research question: In what way can supplementary damping be applied in Dutch, slender, tall buildings to efficiently meet the structural design requirements? A literature research was conducted to the topics of wind-engineering, high-rise structures, and supplemental dampers. To answer the main research question two research methods have been applied. First, a variant study was performed in Karamba, a FEA plug-in for Rhino Grasshopper. Building height, floor mass, outrigger, stiffness limits, and damping ratio were varied. From this analysis charts were generated from which it could be determined which design requirement is governing. In this way opportunities for the application of supplemental damping could be determined. In the last phase of the research the mitigating effects of tuned mass damper (TMD) were modelled with the use of the theory of random vibrations and modal analysis. With a developed python script the reduced accelerations could be computed and the parameters of a TMD could be determined.

Cities like Amsterdam and Rotterdam are located on top of a compressible clay layer. Most of the buildings in these cities are founded on the foundation layer above the compressible layer. Therefore this compressible layer can induce problems when the soil pressure increases significantly due to the weight of the high-rise buildings. This deformation can cause inclination of the floors, damage to the structural and non-structural elements of the building. Therefore the structural design of a building must appropriately be designed to respond or resist these deformations.

The deformation, which causes the problems in the building itself, is the differential deformation (sagging). This is unequal deformation over the entire plot of the building. The uniform deformation of the building does not induce problems in the structure itself, but it can damage the adjacent buildings because the soil under these buildings will deform (hogging). The construction sequence decreases the problem for the higher levels because the deformation of the compressible layer start occurring during construction, and these levels are constructed horizontally independent on the amount of deformation of the
soil.

For this research, the following mitigating measures are considered: changing the construction sequence; increase the length of the foundation pile; application of a camber; increase the stiffness of the foundation slab; increase the stiffness of the superstructure; application of a jack-down system.

The primary factors which are affecting the applicability of the mitigating measures are the amount of settlement, the soil structure, and the time-dependent behavior. By a significant settlement of the soil, the mitigating measures of applying a camber and increasing the stiffness of the structure are not possible or less favorable. The soil structure determines if increasing the length of the foundation piles is possible, this mitigating measure put the foundation piles in the second foundation layer, which is situated under the compressible layer. With this measure, the problem of the compressible layer is solved, but it is an expensive mitigating measure. Adjusting the construction sequence depends on the time-dependent behavior of the settlement. It can be an option when the settlement happens mostly during construction. When the settlement of the soil takes longer than the construction time, the jack-down system can be applied to adjust the structure when needed, even when the building is finished.

The application of the jack-down system is definitely worth considering when a high-rise building is built on compressible soil. The other mitigating measures can be applied too, however, only under very specific conditions. This makes the jack-down system the most favorable mitigating measure.

A research into the influence of the main parameters in the preliminary structural design on the wind-induced dynamic behaviour, including soil-structure interaction effects, of high-rise buildings in the Netherlands. The dynamic behaviour becomes more and more important for higher and more slender structure. The dynamic response is controlled by the maximum acceleration at the top of the structure. The maximum acceleration is determined with a spectral analysis for a large amount of building variants, ranging from a 100 meters to 300 meters high. The influence of each parameter can be obtained from the generated data in this research within the considered domain. Having insight into the influence of design decisions on the dynamic response already in the preliminary design, can be beneficial for the whole design process and can result in a higher comfort level our high-rise buildings.

Timber structures are experiencing a revelation in the build environment due to new technologies and production techniques. However, the longest spans created with timber structures still don't compete with the span widths of structures made of steel. This thesis provides a preliminary design for the long-span football stadium roof structure of The New Feyenoord stadium, which expends far beyond the existing maximum spans of timber structures. The aim is to provide insight in the feasibility of a long-span structure in timber. New Feyenoord stadium The city of Rotterdam is planning to built a new football stadium for the football club Feyenoord with a magnificent roof structure. This stadium is used to determine initial boundary conditions for the preliminary design in this thesis. A perfect bowl with an elegant flat, almost floating, roof that allows unobstructed viewing is desired. The playing field needs to be exposed to the weather conditions for the natural quality of the grass. The stadium will consist of three tiers with a total height of 40 metres, that need to be covered by a roof structure with a width of 205 metres, and length of 245 metres. Structural timber for a grand roof Timber has a high strength-to-weight ratio that is beneficial for long-span structures in which the self-weight of the structure is a significant part of the load. It has natural durability, a good performance in fire conditions, ease of workability, and a high ratio of prefabrication. The latter two result in an ease of construction and less human induced errors. Engineered wood products make it possible to create complex timber structures with more reliability than wood in its natural shape. The most promising are laminated veneer lumber (LVL) and glued laminated timber (Glulam), where LVL made of beech hardwood has the highest strength properties. Furthermore, new types of connections diminish the impact that connections traditionally have on the structural performance of timber structures. The enormous size of this stadium means that multiple connections are necessary due to dimensional restrictions for transport. Which reduces the amount of prefabrication. Structural systems for long-span stadium roofs Promising configurations for a long-span stadium roof structure are the single span, stress ribbon, shell roof system, and tension / compression ring. First, several existing stadium roof structures are presented to gain better insight on the possibilities of these systems. These stadiums are De Kuip, preliminary design of The New Feyenoord stadium by RHDHV, the Allianz Riviera stadium, the Wanda Metropolitano stadium, the Estadio Municipal, and the Tokyo National stadium. Initial designs are made for each structural system applicable to the case of the New Feyenoord stadium. These initial designs are explored on their structural behaviour and benefits for the case of the New Feyenoord stadium in combination with the material behaviour of timber. Structural forms for long-span timber structures Several structural forms are applied in long-span timber structures showing their applicability. These forms are the arch, box girder, truss, shell structure, space frame, and stress ribbon. This is explored by means of respective reference projects. These projects are the Multi-use Arena in Lisbon, Trade Fair Hall 11 in Frankfurt, the Anaklia-Ganmukhuri bridge in the Georgian Republic, the Maicasagi bridge in Nord-du-Quêbec, the geodesic domes in Brindisi, the Elephant House in Zurich, the Allianz-Riviera stadium in Nice, the Grandview Heights Aquatics Centre in Surrey, and the Essing bridge in Essing. These existing long-span timber structures mainly span only half of the required length of the New Feyenoord stadium. Possibility to create an efficient structural design for a long-span stadium timber roof structure After a rough assessment of the design concepts it is found that a combination between a tension / compression ring structure and a stress ribbon configuration shows the greatest potential for an efficient roof structure for the New Feyenoord stadium. Their are still many uncertainties for this type of structure for such a long span. There is no reference project and thus there can not be learned from mistakes. Also, the system is mathematically very complex because of its non-linear behaviour. Consequently, the structural system is modelled and verified in the parametric FEM environment of Grasshopper and Karamba3D. The found structural behaviour is verified by the strength verifications for timber structures. Tension / compression ring with radial stress ribbons The design consists of a triangular truss for the outer ring and a flat truss for the inner ring with radial stress ribbons in between. The structural design shows a feasible solution for the highest downward load, namely loads instigated by wind. The strength verification is performed on the maximum occurring force combination within a element group. Only the strength verification of shear stiffness in the bottom chord at the inside perimeter of the outer truss ring is not met. Which is a very localised effect and hence can be strengthened. Furthermore, the element groups of the rings show a undesirable utilisation distribution due to the non-circumferential perimeter of The New Feyenoord stadium. Large cross sections are required to provide stiffness to the entire structural system. The ribbons make use of their inherent bending stiffness to carry the loads in the long and short straight sides of the stadium. An elegant and stiff tensile force flow is found for the ribbons in the corners. At last, the designed connections for the ribbons which are attached to the timber fulfil the strength verifications. These connections consist of self-drilling dowels with slotted in steel plates, self-drilling screws, and glued in steel rods. Many steel fasteners are used to increase the efficiency factor of the joint. Suggested connections for the complex nodes in the ring trusses consist of slotted in steel plates with bolts and dowels, glued-in rods, and cast steel parts. The structural system is supported on roller bearings. The presented structural design only takes downward loading into account. Potential solutions for the severe upward loading are increasing the weight of the structural elements in the loaded area, tensile ties in the long and short side of the stadium, or tensile cables attached to the bottom side of the ribbons in the long and short side. An more in depth analysation of its stability against uplift forces and asymmetrical loading is needed to verify the proposed solutions. Recommendations are made to improve the design for The New Feyenoord stadium, for general possibilities for the chosen structural system, and for improvements and advice on the feasibility of special timber structures. It is concluded that a timber long-span stadium roof structure consisting of the chosen structural system shows potential to be a feasible solution for the New Feyenoord stadium. It will be a grand architectural statement that makes a stadium iconic, being the only timber tension / compression ring stress ribbon roof structure spanning with an exceptional distance.

This research investigated in which ways the material environmental impact of the main load-bearing structure of a high-rise building can be reduced. To determine this material environmental impact, the shadow price for each material and product has been determined by using ten environmental impact categories. One of these categories is global warming potential.

In this research the material environmental impact of the main load-bearing structure for the building for the European Patent Office has been determined and optimized. The originally designed main load-bearing structure for this building consists mainly of steel columns and beams, and Slimline floors.
The optimisation has been done for a design lifespan of 50 years and for 200 years. Additionally, a higher live load that creates more flexibility for the 200-year scenario is examined. The original function for the building is “office” and the other considered function is “meeting”.
As alternatives for the beams and columns, steel, concrete, and timber elements have been considered. Hollow core slabs and Lignatur floors were explored as alternatives for the Slimline floors.

In this research it has been found that it is beneficial to prolong the design lifespan of building. The environmental impact per year is much lower for a lifespan of 200 years than for a lifespan of 50 years. In order to increase the chance of a longer lifespan, it is wise to create flexibility concerning the function of the building. A higher live load will result in slightly more material needed, but still, the environmental impact per year is much lower than for 50 years.
Additionally, there can be looked at choosing the best material for each application. For a design lifespan of 50 years, the difference between the materials is such small, that no preference can be determined. For a lifespan of 200 years the differences are still small, but an entire steel structure or a combination of steel beams and concrete columns result in the smallest environmental impact. For floors, no matter the lifespan, with a big span and where no in-situ concrete can be used, hollow core slab floors proved to be the best choice.

Currently there are a lot of contract types available for building projects. It is not always clear beforehand what type of contract a client should choose for his project. The goal of this study is to solve this problem by advising clients which type of contract to use for moveable bridge projects. Therefore, the following research question will be answered: How does the model look like that predicts which type of contract is best for a moveable bridge project? In order to answer this question, literature is studied and interviews are conducted to show which parameters and characteristics are of influence for this contract decision. This information is used to set up an initial model which advises what type of contract to use. This initial model is verified with the use of case projects in order to get the final model. Due to the wide range of building projects, this master thesis is focused on moveable bridges in the Netherlands only. Moveable bridges are multidisciplinary projects which makes the decision for a specific type of contract ambiguous. Making it the a perfect type of project to test the model. The literature and interviews highlighted eleven criteria that are of influence for the types of contracts incorporated in the model. The contract types that are included in this model are: RAW-bestek, Design & Build, Design, Build & Maintain and Turnkey. The decision to incorporate these four contract types is based on the fact to include traditional and integrated contracts. RAW-bestek is the traditional contract type that is common to use for moveable bridges in the Netherlands. The choice for an integrated contract form for moveable bridges is bigger. Therefore, integrated contracts with different ranges of integration are included. Starting with Design & Build as a conventional integrated contract form followed by Design, Build & Maintain as a more integrated contract form and Turnkey as totally integrated contract form. This initial model is verified with the use of four moveable bridge cases. For three of the case projects the model advised well. These projects went according plan and the advice from the model matched the contract that was actually used or the model highlighted the main headings for which the different incorporated contracts match the actually used contract. For example, case A used the contract type Engineer & Construct, this type of contract is not included in the model. The initial model showed exactly on which statements the Design, Build & Maintain contract and the RAW-bestek scored well for this case project. The statements on which they scored well are exactly the items for which an Engineer & Construct type of contract would be suited. If Engineer & Construct as a contract type would have been incorporated in the model, it would most likely be advised by the model. The verification of case B was not a match between the used type of contract and the advice from the initial model. The project did not went according to plan, but the advised type of contract would probably not have improved the situation. Several improvements are suggested based on comparison between this case and the other case projects. It is concluded that the model is functioning, based on the cases. However, it is recommended to extend the model with more types of contracts, such as the contract type Design & Construct, Engineer & Construct and Bouwteam. The second recommendation comes from the ambiguity concerning the benchmark score for the criterion complexity. The positive correlation between complexity and flexibility was stated in literature, meaning that when the complexity of the project increases the need for more flexibility also increases. However, other literature contradicted this; it was unclear which viewpoint should be preferred. Therefore, the decision was made to adopt the positive correlation for the initial model. After verifying this initial model, the benchmark scores for complexity were adjusted in order to be in line with the other literature. The advice from the initial model and the initial model adjusted for complexity were compared. However, based on this comparison no firm conclusion can be made about which viewpoint is preferred over the other concerning complexity. Therefore, it is recommended to further verify the model for the criterion of complexity. Furthermore, it is recommended to verify this model with more moveable bridges and cases for other types of projects in order to increase the validity, usability and applicability of the model.

This thesis focusses on the application of vertical profiled mortar connections in precast concrete shear walls that are built up with a stacked element configuration. The goal of the project is to develop a practical modelling approach in order to be able to apply the connections in a FEM model for structural analyses. For this purpose several research aspects concerning the behaviour of the connection were analysed.

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.

This thesis ‘A decision support model for analysing the reuse potential of hollow-core slab floor components’ describes the development of a decision support model to investigate the reuse potential of a structural building component. For this research, the hollow-core slab floor component is chosen as the structural building component to be reused. The main research question to be answered is: ‘How can various methods and knowledge be integrated into a decision support model for deciding on the reuse potential of a hollow-core slab floor component to close the material cycle?’ The ambition of the Dutch Government is to transform from a linear economy to a circular economy, whereby waste is excluded and products will remain in the system for longer at a high-level value. However, the barrier preventing the implementation of high-value reuse is the lack of knowledge to understand the opportunities and the impact of high-value reuse. It appears that the reuse of hollow-core slab floor components is not yet common because of the uncertainty and risks involved in the reuse of these components. The component has various properties that are advantageous for the reuse of these components, such as the lightweight of the component, the long technical lifespan and the standard dimensions of the component to use it all over the world. By way of contrast, a concrete topping, bonded connections, and the high costs for the deconstruction of the components are seen as barriers to reuse the components. However, it has been investigated that it is possible to use these floor components for longer than they are currently being used. Still, this is only possible if there is a full understanding of the reversibility, the reuse options, and how to increase the reuse potential of these floor components. The ‘reuse potential factor’ is a factor between 0 -“waste-like”- and 1.0 -“resource -like”- and it is defined as a factor measuring the ability of a construction component to retain its functionality after the end of its primary life related to the economic and environmental impact of reusing this component. Therefore, the factors related to the quality – qualification factors – should be tested and the factors related to the economic and environmental impact – quantification factors – should be determined.
There is a demand for a model that tests the performance of building components to assess the reuse potential of building components at the end-of-life stage. It is about making a decision about the consideration of the use of a new manufactured structural building component or a reused structural building component where the impact on the environment and economy remains limited. The first step to measure the reuse potential factor of the floor component is the reuse analysis in which the quality of the reused component should be determined based on the qualification factors. The qualification factors to be tested are the lifespan performance, technical performance, functional performance, aesthetical performance, and additional performance. The second step is the reuse evaluation where the ‘costs’ of the reused component are calculated based on the quantification factors. The quantification factors are the environmental impact costs and the economic impact costs based on the LCA and LCC tool. The decision support model analyses the relationship between the qualification and quantification factors of the reused hollow-core slab floor component and to compare the outcomes with the factors of a new manufactured hollow-core slab floor component. The qualification factors of the existing floor component are tested to see if they meet the required performance of the new construction project, or if the component must be adjusted. This will influence the ‘costs’ and the reuse potential factor. This model can be a tool that positively contributes to the ambition of the ambition of the Dutch Government about the transition to a circular economy.  

Due to gas extraction, seismic activity has become a major problem in the province of Groningen. Existing buildings are not designed to withstand seismic loads and are likely to be structurally unsafe. Two storey terraced houses with concrete floors and large openings in the ground floor façade walls are onsidered vulnerable, since the in-plane behaviour of these walls is weak. This research aims to investigate the possibilities of enhancing the seismic in-plane performance of this building type with the application of timber elements. Non-linear static pushover analyses are performed to assess the in-plane behaviour according to the Dutch guidelines for the Near Collapse limit state using a macro-element modelling approach in ETABS, a 3D non-linear analysis software. Variants of the typology are studied to investigate the sensitivity to certain geometrical and structural parameters, such as the height, width and depth of a building and the applied masonry type. Based on the results, a timber strengthening design is proposed and the effect on the behaviour is studied. The majority of the un-strengthened buildings presents rocking behaviour caused by the slenderness of masonry piers due to the large openings in the façade walls. This ductile behaviour ensures relatively large lateral displacement capacities, often resulting in the satisfaction of the safety standards. Moreover, results show that structures with wide masonry piers, calcium silicate element masonry and extremely large openings at ground floor level (up until 70% of opening) are likely to be unsafe. Therefore, strengthening is required. Global capacity of the numerical models depends heavily on prescribed drift limits. Therefore, establishing the appropriate limits for each model is essential. The analysis indicates that assessment according to other guidelines, can lead to different outcomes. The proposed retrofit design consists of a timber framework connected to the inner masonry piers, with an OSB panel nailed on top of it to increase the stiffness. The retrofit is attached to the foundation by tension anchors. Gravity loading of the structure is mainly carried by the masonry elements. Implementation results in stable rocking behaviour of the piers, which ensures higher displacement capacities. Analysis demonstrates that the application of the timber retrofit leads to the satisfaction of the Near Collapse limit state, when higher drift limits can be prescribed. Furthermore, applying the reinforcement results in a change from unfavourable shear behaviour to rocking behaviour. However, increase of strength is limited, since the resistance of the anchors to the lateral forces is largely depending on the design of the foundation and structural elements to which they are attached. Therefore, the retrofit is not suitable for significantly increasing lateral resistance, which is required for structures with extremely large openings in the façade walls. Experimental testing is recommended to quantify the increase of drift limits. An overall consistent definition of capacity values and corresponding drift limits for each possible failure mechanism is essential for reliable evaluation of the in-plane response, especially when buildings are assessed using non-linear analyses.

Building construction is a complex industry. A wide range of requirement should be achieved within the limited resources by a multidisciplinary team. Hence, errors are likely to occur, and the accumulation of individual mistakes might lead to building failure.
Even though construction is tightly regulated, failure of the modern date buildings still happened.
As a part of the investment, safety measures need to be applied to prevent failure. Engineers often neglect the safety measure because its efficiency regarding risk reduction and the financial matter is not known. To examine the effectiveness of measures, this thesis is carried out by learning from ten cases of both collapse and near-collapse situation. A quantitative approach is taken for this thesis.

This thesis research focusses on the development of a reliable and efficient 3D calculation model of an existing high-rise, reinforced concrete building in the Groningen area, in order to analyse the dynamic behaviour of the existing and subsequently retrofitted main bearing structure of this high-rise building. The assessment of the existing building is performed through a Non-Linear Time History analysis in Simulia Abaqus, in which cracking of concrete and yielding of reinforcement is taken into account. Multiple NLTH analyses are performed for optimisation of the 3D model in order to obtain correct results with a minimum amount of calculation costs. This optimisation process results in a clear understanding of the dynamic behaviour of the building and the main sensitivities of the model.
The 3D model is verified by means of a simplified 1D beam type model, developed and analysed with the software package Matlab. This 1D model consists of three elements, corresponding to the three main structural parts of the building. Next to this, a ‘modal response spectrum analysis’ is performed for verification of the 3D model results.
The seismic assessment of the building is performed according to the Near Collapse criterion of the NPR. The results show that the building meets this criterion, based on one record of the NPR. Since at least seven various records should be applied, it is possible that the building does not meet the Near Collapse criterion for one of these records. Also from a structural point of view, it is interesting to develop and analyse strengthening possibilities for this specific building. therefore, three strengthening proposals are developed and initially analysed with the 1D model in Matlab.

Differential vertical shortening (DVS) is the relative vertical shortening between two adjacent vertical load bearing elements. DVS originates because axial loading conditions on- and the design of adjacent vertical load bearing elements are different. Due to these differences, the reaction of the adjacent vertical structural elements expressed as length change can be different.

The aim of this thesis is to research differential vertical shortening effects in high-rise buildings that use a concrete core as a lateral stability system and a timber pendulum structure as a gravitational system. The Tallwood House in Brock Commons is a perfect example of such a structural system where the engineers have considered the shortening effects which will be reviewed in this research. Furthermore, this research will look for measures in the design and implementation phase that have influence on the magnitude of differential vertical shortening deformations.

In the Tallwood House project the problem was only tackled on basis of the individual column shortening and the effect it would have on vertical mechanical systems. A clear understanding of the relative difference between core and column shortening (DVS) and the effect it can have on secondary building systems is lacking. The determination of criteria on which the DVS deformations are assessed in the Brock Commons building, are based on the deformation capacity of the vertical mechanical systems, which does not necessarily relate to the DVS deformations. A more methodological approach is necessary for the prediction of DVS deformations and the determination of criteria regarding DVS deformations.

The sub question have the aim to reach to a more general and methodological approach in predicting DVS deformations and determining criteria for DVS deformations.

“What are the criteria on which differential vertical shortening deformations in the building structure should be assessed in order to guarantee the functional performance of the building during its service life?”

“How can differential vertical shortening deformations be quantified for a timber-concrete high-rise structure?”

After answering the sub-questions that relate to the criteria on DVS deformations and the quantification of DVS deformations, a research can be conducted to the influence of some input variables for the design and construction process to answer the main question of this research:

“What are effective measures which can be applied in the design and construction phase to mitigate the differential vertical shortening during the service life of high-rise buildings that uses a timber gravitational load bearing system with stabilizing concrete cores?’’

Problem areas where DVS deformations can have a negative effect on secondary building structures are researched. A general approach for the determination of criteria for DVS deformations is elaborated, based on principles for vertical deformation criteria that are described by the Eurocode.

The response mechanism of axially loaded concrete load bearing elements and axially loaded timber load bearing elements on external influences is researched qualitative by a literature study. The CEB-fip 2010 strain model is used to predict deformations in concrete. For timber, the strength class system is used according to Eurocode 5 to determine the elastic strains. The creep and shrinkage strains in timber are determined by experimental results that are found in a literature study.

The influence of the building process on DVS deformations is researched by a literature study. Staged construction analysis provides the possibility to simulate the sequential loading in a building process and to distinguish the DVS-deformations that can affect secondary building elements (post-DVS deformations) from the total-DVS deformations.

A case study on the Tallwood House at Brock commons in Vancouver is conducted to provide a basic geometric model in which DVS deformations can be predicted in which all previous research in this thesis serves as input properties of the model. From this basic model, variables in the design and building process are altered to conduct a sensitivity analysis of these variables. The building height expressed in number of floors, column cross section and the building speed of finishings in a building are taken as the analysed variables.

Increasing the column cross section can be an effective measure to decrease post- and total-DVS deformations due to elastic and creep strains. The effectiveness decreases with the increase of the column cross section because shrinkage strains are not affected. The post-DVS deformations can be decreased by postponing the building process of secondary structural elements in the construction schedule. The effectiveness decreases with increasing building duration because DVS-deformations due to loads of the finishes itself are not affected. Total-DVS deformations are not affected. Compensation has effect on the total difference in vertical position between the floor supports. The vertical translational movement is not prevented. This means that post-DVS deformations cannot be influenced by compensation.