This dissertation focuses on studying the impact of Human and Organizational Factors (HOFs) on structural safety within the Architectural, Engineering, and Construction (AEC) industry. It is widely acknowledged that human errors are the primary cause of the majority of structural failures. In addition, HOFs are pivotal task contexts that shape human performance at work and contribute to the occurrence of human errors. Therefore, this research aims to study the critical HOFs in the structural design and construction process and analyze their influence on structural safety from a sociotechnical systems perspective.@en

To stick to climate change targets and reduce global carbon emissions, the building sector needs to adopt a circular economy. In the steel sector, reuse or elements can reduce carbon emissions which are created in today's steel scrap recycling practices. This thesis contributes to closing the knowledge gap on design, costs, and environmental impact score for working with reclaimed steel elements. The tool Steel-IT is created to research the business-case and environmental impact score of low-rise office buildings. Steel-IT uses a donor element database and new office design, which are specified by the user, and generates new and reclaimed steel design alternatives. Using a weight and activity-based costing method, the costs of these design are estimated. Life-cycle analysis is used to quantify the impact. By generating results and analysing the effect of the input in the tool Steel-IT, the following conclusions can be made regarding the business-case and impact score of reclaimed steel in low rise office buildings. A case study using Steel-IT shows that a 25% impact reduction against minimal cost increase is possible. For this, the match between design and donor elements needs to be good. This match can be searched for using Steel-IT. In terms of design, connection detailing is the most critical factor in the success of a donor steel skeleton. Donor steel elements should be sourced from an existing building to limit storage costs and should not have toxic conservation systems applied to them. Both induce extra costs and make the business case of donor steel less competitive with new steel. In the future, currently suggested emission taxes do not affect the business-case significantly as these taxes are low compared to the total building costs. The most helpful action to increase the business-case is to apply donor steel more often. If the experience with donor steel and its availability grows, reuse will become easier. Steel-IT can contribute to this as it contributes to closing the knowledge gap on costs and impact and can help to match demand and supply.

Numerous structural failure incidents have occurred in the past years. It was found that current methods, such as NEN 2767, fall short in guaranteeing the structural safety of existing buildings. Although structural failure incidents infrequently result in casualties, there are also social and economic consequences that impact both building user as owner. Interviewed asset managers have noted that the current lack of insight into a building’s structural condition often leads to preventable maintenance and repair costs, and safety risks. When coupled with changes in the outdoor and built environment, such as a focus of continuity in use, these risks become increasingly challenging for owners to manage.
To ensure structural safety of significant public buildings within CC3, mandatory assessment via NTA 8790 must be performed. However, this method is exclusively tailored to CC3 buildings and only considers potential casualties as risk consequences. This strategy neglects CC2 buildings and other potential consequences, exposing them to elevated risks due to a lack of insight into their structural conditions. All the asset managers interviewed for this study, all managing CC2 buildings, reported these issues.
The goal of this thesis is to develop an efficient and effective assessment method to evaluate existing consequence class two buildings on structural safety to prevent incidents with structural failures. As a start (CC2) building typologies within the Netherlands were examined to determine the typologies for which the method should be optimised. Subsequently, structural failure incidents were analysed, resulting in a list of common causes that should be considered during the assessment. However, due to limited data availability, expert interviews and general literature this list is not exhaustive but rather an initial attempt. It can serve as a focus during the assessment but should not be solely relied upon. Finally, existing assessment methods were evaluated based on trustworthiness, effectiveness and efficiency. The findings from this evaluation have been incorporated into the development of an efficient and effective assessment process, which is described in the document.
The assessment process developed in this study was validated by applying it to two existing buildings, leading to the following conclusions. The assessment process developed in this study has proven effective in evaluating the structural safety of CC2 buildings, thereby preventing incidents relating to structural failures. While the necessity for comprehensive risk analyses does impact the time required for the assessment, these analyses have been optimised to concentrate on the most critical aspects. Along with other efficiency-enhancing aspects, it presents an efficient method within the parameters of effectivity and trustworthiness.
However, as revealed during validation, not all deficiencies can be detected using this method. There will always be hidden deficiencies that remain undetected and assessors are made aware of this limitation. Despite this constraint, the method provides an efficient and effective evaluation of the structural safety of existing buildings.

Within the Netherlands, the building industry is startled every couple of years by an impactful structure collapse. Even though over the years, a large amount of structural failure investigation reports and studies have provided abundant lessons, regulations, and good practices, structural failures still occur occasionally. The question arises why the existing control measures and regulations have not led to safer building industry, with fewer (or none) structural failures.
A Human Reliability Assessment method is applied on a case study to test the effectiveness of control measures to increase the structural safety of temporary falsework. The control measures are self-checking, third-party check, and construction check.
Overall, this research has provided a framework to determine the effectiveness of control measures when dealing with human errors. It is possible to perform sensitivity analysis on project tasks, to find out when control measures are most effective. Therefore, this research brings the practical application of HRA models in the building industry a step further.

Mining activities at the Groningen gas field are causing earthquakes which result in building damage. This has started a discussion on what type of damage is caused by earthquakes. These discussions are typical in the forensic engineering field, especially in complex cases. The problem is the lack of regulations, in terms of standardizations and uniformization.
To solve that problem, experts can be provided with an independent tool which can contribute to the investigation of the cause of building damage. The tool can help to indicate potential damage causes. This will support the findings of experts. Also, it can draw attention to overlooked damage causes.
The tool is based on relations found in a database of damage cases that have been determined earlier. The database consists of damage cases in the Groningen province. Not all available damage cases were incorporated in this thesis, because processing the damage reports to a database was a labour-intensive job. The analysed dataset consists of 1830 damage cases in 49 buildings. Experts were able to determine the cause of damage in 1180 of these damage cases, which results in a ratio of 64.4% known cases. Only the known cases where applied in the analysis. The buildings were located in seven different areas in the province of Groningen.
Each analysed damage case consists of a damage cause and a description. A description has been structured in 191 characteristics. These characteristics have been categorised into three types: building characteristics, context characteristics and damage characteristics. Building characteristics say something about the function, materials and size of the building. Context characteristics explain the sub soil, vibration sources and external forces in the surrounding of the building. Damage characteristics describe how damage is presented in terms of position, location and shape of damage.
Whether the found relations can be deployed in practice, depends on how useful those relations are. Useful is defined as reliable and meaningful. Reliable is how a found pattern performs according to a test, mostly measured in terms of accuracy or coefficient of determination. Meaningful is whether the found relations are logical to be explained by literature or plausible damage situations. The pattern recognition can introduce some relations and can provide them with a reliability value. However, if the relations are not explainable, they do not mean anything for use in practice.
The relations in these data were found by deploying pattern recognition methods. Two algorithms were utilized as a pattern recognition method: decision tree and linear regression. A decision tree algorithm splits the data into groups by applying thresholds on case characteristics. These thresholds can be made visual in a decision tree figure. Linear regression tries to obtain a target value by means of a linear relation of characteristics. Therefore, the linear regression algorithm determines the slope value of each characteristic.
Classification analyses were done with decision trees on six damage cause categories. The results of that type of analysis were capable of determining if or which damage was caused by a certain cause. Linear regression was performed in order to find regression relations where the technical attributability of a damage cause could be calculated for each case. In the more complex task of regression analysis, only three damage cause categories were suitable for finding a relation.
To determine whether damage was caused by earthquakes, earthquake load in terms of PGV is an important characteristic. Also, the age of a building and trees has a possible significant influence on the occurrence of earthquake damage, according to the found pattern. A relation between those last two characteristics and earthquake damage is not described in literature. Besides that, this decision tree pattern seems to be the most useful pattern for in practice.
Another interesting finding is that hindered deformation mostly occurred at the inside of a building. Combined with other characteristics, a pattern on this damage cause performed with the highest score in this thesis. It has an accuracy of 77%. This means that 77% of the cases in the test set were correctly predicted by the produced classification decision tree. However, the found relation with the characteristics is not always explainable or meaningful so as to be applied in practice. More conclusions of classification analysis are shown in Table 1.
<Table 1, See abstract in report>
The presented findings above are classification relations. Regression analyses were difficult to execute. A desired positive coefficient of determination (R2) could not be reached without subjective interference in the pattern recognition. The best regression result was obtained on damage caused by earthquakes. It had a R2 of 0.48. Which means that 48% of the data was describable in a linear relation. More conclusions of regression analysis are shown in Table 2.
<Table 2, See abstract in report>
It has been interesting to study the relation between characteristics and damage causes. However, the results are not of decisive importance. The building and context characteristics supported by literature were not always selected or applied properly by the pattern recognition. Also, the potential of damage characteristics was not recognized by the algorithms. Nonetheless, the results of earthquake related damage seem promising. They even indicate characteristics which may be worth investigating more closely.

The aim of this research is to make the early design process more efficient. This is done with a parametric model, which compares high-rise stability systems. The research is focused on the stability systems shear walls, core, outrigger and tube. All systems are executed in concrete cast-in-situ, in the range from 100 to 250 m. The parametric model is executed in Grasshopper and Karamba. Four performance criteria are checked in the model. These are strength, stiffness, foundation design and comfort. An optimisation procedure has been applied to find the most optimal system based on input and optimisation goal. Three optimisation goals have been appointed. These are slenderness of wall and column elements, total weight and carbon emission and flexibility. Flexibility is defined as effective floor area and ratio facade openings. The results of each optimisation goal are plotted with respect to the height to obtain insight in the suitability per system. Input parameters, optimisation procedure and performance criteria have been processed in a tool in Human UI. The model and tool have been applied on De Zalmhaventoren to verify the outcomes. It can be concluded that the model, tool and optimisation results have led to more insight in the high-rise early design process and ease decision making.

With increasing adoption of modular construction in the residential sector, its adoption in the Dutch healthcare sector is studied. Whilst the initial costs can be higher, this method of construction claims to have cost benefits over conventional construction. These are the benefits of construction speed and residual value at the end of lifespan amongst others. Modular buildings are also often advertised as sustainable, because the credentials gained from lean manufacturing coincide with a selection of sustainability objectives [1]. Healthcare projects have higher requirements and process hurdles, which make construction in healthcare much more complex than in the residential sector. However, in the UK, a study of offsite manufacture and modular volumetric construction methods concluded it to be the cost efficient solution necessary for the NHS, which led to 40 modular hospitals planned to be built until the year 2030 [2]. This means that the benefits and drawbacks of a modular approach must be weighed, and this is done in the Dutch context. A life cycle costing is proposed as the fitting tool of assessment.

Interviews were held with Dutch modular contractors to reveal the capabilities and specifics of building in a modular way and find proof for each cost factor. Experts in healthcare construction were interviewed to determine healthcare project priorities and find out whether these are catered for by modular construction. A live construction project of a hotfloor department was then studied. Several options competed in the tender project and were compared in the case study. By collecting the cost quotes and arguing for the monetary value of the identified cost factors, a life cycle cost calculation was done. Additionally, sustainability was considered by calculating the novel carbon tax. To expand the application of results to other projects, sensitivity studies were carried out for each life cycle cost parameter.

The study found that there is application for modular construction in healthcare in the Netherlands. Facilities, which do not host medical installations, do not differ to the construction used in residential modules. As for facilities such as the studied hotfloor department, larger modules and a lesser degree of finish offsite decreases the competitiveness of this construction approach. However, several evident cost factors were proposed to be considered within a life cycle costing. These were earlier income due to faster construction, a gain due to less interest and the residual value. It was found that these considerations allow for a 49,0% increase on the initial cost of a modular option in comparison to a conventional option. A hypothesis was further proposed, stating that the competitiveness of the modular option depends on three criteria. These include the initial modular option costs being up to 49,0% more expensive; the saving in construction time having a monetary value to the client; and life cycle costing results being used in total cost comparison.

Building failure incidents are occurring within the Netherlands and these incidents can be a valuable source of technical data regarding improvements in structural safety. This research has attempted to utilize this information gained to develop a tool to aid the building construction sector in identifying hazards during building construction projects. For that purpose, this research has investigated risk assessments and structural failure incidents. To be able to develop a tool, deeper knowledge of risk assessments is required and therefore risk assessments were studied to understand how they should be performed and what characteristics makes them effective. The research of Terwel (2012) on the Cobouw database formed the basis for the analysis of structural failure incidents. This thesis investigated how other research used structural failure databases to improve structural safety and studied the data available from the Cobouw database for developing a tool. The analysis of risk assessments has shown that identifying hazards is a crucial step in the assessment process. It was concluded that it would be beneficial to a project team if it had information on which hazards related to structural failure can occur, the probability of occurrence of hazards and the possible impact they can have. An investigation into structural failure databases showed that no other research could provide a tool that fulfilled the above requirements and in addition it was concluded that the database available to this research was only sufficient to provide information on which hazards can occur. There was not enough data available to make a justified estimate regarding the consequences of a hazard or probability of occurrence. Therefore it was chosen to use a different approach to analyze the database. The Cobouw database has been restructured into a fault tree format, to relate hazards to specific components of a building structure. Afterwards an attempt was made to discover why many hazards have occurred or which building components were prone to hazards. There was not enough data available to draw conclusions on that subject either. Finally this research concluded that the most efficient way of developing a tool, from the data available to this research, is to create a guide which can be used during the design phase to caution the project team about frequently occurring hazards. The method that was used to create the tool can also be used as an inspiration for future research, because this research was limited not only by the amount of available incidents, but also by the source of the incidents, which was from a news site that would most likely not focus on low-profile failure incidents and the reporting of precise technical details. Therefore the most important recommendation this research has, is to introduce a large scale collaboration in the construction industry focused on gathering accurate data on structural failure incidents.

High-rise buildings are a potential solution to the environmental impact caused by the built environment and the increasing demand for space in urban areas. As recent developments focus on reducing the impact by operational energy (OE) (heating, cooling, hot water and ventilation during use phase), impact by the embodied energy (EE) (production, construction, maintenance and demolition of materials) becomes increasingly significant. Structural materials account for the biggest part of embodied carbon (EC) in buildings. The number of studies that address the environmental impact of high-rise building structures has grown only recently, research is still limited. Moreover, it is doubtful to which extent these researches are applicable to the Netherlands.

This thesis aims to provide insight in the environmental impact of structural systems for high-rise buildings of 150, 200 and 250 meters in the Netherlands. Five different stability and three floor different systems were designed in cast-in-situ concrete, prefab concrete and steel. All of the models contained a concrete core. 2-dimensional static linear calculations were performed in order to determine the cross-sections and reinforcement.

Through parametric modelling, an automated design and analysis work-flow was developed and a total number of 146 models was assessed. The environmental impact was calculated by using the fast track life-cycle analysis (LCA) method. A cradle-to-gate analysis (production phase only, A1-3) was performed by using data from the Nationale Milieu Database (National Environmental Database) (NMD) and steel data from Bouwen met Staal, which contain the environmental impact for multiple impact categories, measured in environmental cost (shadow price). The construction and demolition phases were left out of scope.

It was found that all steel structures had a 6% to 35% higher cradle-to-gate environmental impact compared to concrete structures with the same stability and floor system. Furthermore, no significant differences were found between the cradle-to-gate impacts of cast-in-situ and prefab concrete models. Differences in impact between the materials are likely to be affected by inclusion of the construction phase (A4-5) and foundation structure. It is expected that the gap in environmental impact between steel and concrete is reduced by inclusion of these aspects. Floors were responsible for 32% up to 73% of the total environmental impact.

Regarding the stability systems, results showed that, when subjected to wind loads, systems with axially loaded elements scored significantly better than systems with elements loaded in bending. The outrigger structure decreased the total environmental impact of the concrete models by 5% to 16% and 20% to 26% of the steel models, compared to the tube structure. The braced tube only decreased the impact for the 200 and 250 meter models, with 7% to 12%, compared to the tube structures. The diagrid structure had the best performance at all heights and reduced the environmental impact by 17% to 28% for concrete and 28% to 41% for steel models, compared to the tube structures.

Humanitarian crises related to building and infrastructure damage, i.e. natural hazards and collateral damage during warfare, result in many hundreds of thousands of casualties on a yearly base. Earthquakes, for example, are responsible for taking around 50.000 lives on a yearly base due to falling debris and collapsing buildings, making them one of the most deadly natural disasters known to mankind. These casualties are caused by both direct effects (falling debris) as well as indirect effects (being trapped by debris without access to air/water/food). In the first hours after an earthquake hit an area, a clear overview of the situation is hard to obtain due to inaccessible roads and damaged communication systems, which in its turn hampers setting up rapid disaster response operations. In order to assist the search and rescue teams in wide-area situation awareness, remote sensing techniques can be used to acquire and create damage detection maps which could be used to prioritize their tasks and help save more lives.

Spaceborne Synthetic Aperture Radar (SAR) is one of the most promising techniques in rapid disaster response as it is an active sensor which remains unaffected by the weather, smoke, cloud cover and/or daylight. The Sentinel-1 mission is a relatively new SAR mission that acquires data over the entire Earth's surface every 3 days in any viewing geometry. More importantly, this mission has an open-data policy and hence provides the opportunity to easily perform multi-temporal data analysis instead of the bi- and tri-temporal change detection approaches proposed in previous studies. The development of a fully automatic change detection algorithm has been done in the Google Earth Engine: an online, open-source processing tool that allows users to run algorithms on geo-referenced Earth observation imagery stored on Google's infrastructure, with one of these datasets being the global Sentinel-1 GRD dataset. The time reduction that results from bringing the algorithm to the data instead of vice versa as well as the possibility to easily combine various geo-referenced datasets both benefited the rapid disaster response operations.

The processing of the data is performed completely automatically based on the date and location of the disaster as input, making it easy to use for non-remote sensing specialists. Using these two parameters, the Sentinel-1 images overlapping the area of interest are selected after which a change detection algorithm is applied to the timeseries. The resulting damage detection maps has been validated in terms of operability and accuracy for wide-area situation awareness in search and rescue operations for three case studies: the 2016 M6.2 Central Italy earthquake, the 2017 M7.1 Central Mexico earthquake and the 2018 Syria military strikes. Overall, the algorithm performs well in terms of damage detection, with a low amount of false positives and an even lower amount of false negatives, for both damage due to natural hazards and intentional or collateral damage during warfare. The algorithm experienced difficulties when identifying individual collapsed buildings in a dense urban environment as around 50\% of the collapsed buildings were detected as such. However, the accuracy of the damage detection is much better when looking at clusters of damaged buildings in urban areas or at individual buildings, which are equal to or larger than the size of a SAR resolution cell, in less dense urban environments.

The complete approach and final damage detection maps have been presented to the Urban Search And Rescue team of The Netherlands, whom are the potential end-users of these maps. They saw great potential in this approach in general to help prioritize their search and rescue operations, with the only bottleneck being the data latency. We showed that once a new image has been acquired after the disaster, the total data latency by ESA and the GEE is at most 72h. This is also the maximal time the USAR team has in order to move from their home base to any country in the world in case of a disaster. The data latency time frame is a maximum, so actual averages are lower and the final damage detection map will be completed and ready to use once needed by the USAR team. This illustrates that the approach proposed in this research can be used on an operational base to assist in rapid disaster response situations.

In the Netherlands, there are generally two categories of structural forensic investigations. The first category are extensive investigations with the goal to learn from failure by investigating all aspects: technical, human and organisational. The second category are investigations that focus mainly on technical causes and the investigation goal is often determining the failure cause including designing repair measures. For this category, little information is available on used investigation processes.

In literature, several investigation methodologies have been described. However, they often describe only a very general process or on the other hand very specific material related laboratory tests. Descriptions and recommended techniques on how to perform the proposed steps of an investigation are scarce. To a client ordering a damage investigation, the most important parts of the investigation are the conclusion and the recommendations. The client expects that the conclusion is correct. Therefore, it is important to ensure that the used investigation process results in a reliable (consistently good quality and able to be trusted) outcome. Basic knowledge of bias may help to indicate possible threats to the reliability of investigations. Techniques used to increase the validity and reliability of case study research can assist in developing strategies to achieve reliable forensic structural investigations. Therefore, the question of this research is: what is a reliable methodology to perform investigations into the technical cause of damages to concrete structures?

The research question has been answered by studying available literature on structural forensic investigation techniques, interviewing investigators, researching investigation techniques used for aerospace accident investigations and fire cause determination, studying human error theory and case study research and concrete damage mechanisms.

Based on the resulting information from studying all these disciplines the conclusion can be drawn that using a structured investigation process is essential. Therefore, this information has been used to develop an investigation methodology called the ‘investigation process model’. The model recommends the following phases: orientation, data collection, hypothesis generation, hypothesis analysis, conclusion, reporting and follow-up. These phases are split into individual steps that guide the investigator through the process. Each step contains suggestions for specific techniques varying from taking meaningful photographs on location to using a standard layout for reporting in order to execute the step properly. The investigator can select the most appropriate techniques for the project. Special attention has been paid to provide techniques to generate and analyse hypotheses in a reliable way. An example is the tool ‘Concrete Damage Handbook’ to assist the investigator in linking visual damages to possible causes. As a common thread through the model measures have been provided to limit the negative influence of bias (based on the Delft approach).

Validation of the model with 1) a test case based on a real damage file, 2) comparison with real investigation reports and 3) scientific papers proved that the model relates to the daily working practice and is usable, practical and functional within the scope of the defined criteria.

In most of city centres in the Netherlands, there is a growing demand for residential housing. However, as most of the land is occupied by existing buildings, developers recur to demolish and build higher buildings, in order to fulfil the urban need. Even though demolition, may be the simplest option in technical and economic terms, it can also destroy architectural heritage, cause noise disturbances and damage the environment.
On the other hand, refurbishment can be a sustainable option in building scale, but does not provide extra capacity for the densification demands of the city.

Structural extensions can be an attractive alternative that combines the benefits of the last two options, gaining more residential capacity in city centres and respecting the architectural heritage, and at the same time, reduce environmental impact by re-using old structures.
Although, an ambitious extension can pose important technical constraints, many successful precedents have been realized. This can be an indicator that some of the complexities will partly overcome in the near future. This work aims at increasing the awareness of structural extension possibilities in existing buildings, as an alternative for ambitious architectural and structural projects, with sustainable considerations.

The trend of the slender and high-rise building has made the structure prone to dynamic loading. This thesis is focused on the dynamic behavior of the high-rise building subjected to wind action. The acceleration becomes a limiting criterion in designing such structure which can be categorized as the comfort criteria of the building. Nausea and motion sickness from the acceleration of the building has been studied by human experience, and numerous building code has included this in the design criteria [6]. The tuned mass damper (TMD) comes from the basic vibration absorber theory by Frahm in 1909; then the studied continued and applied in a building. At present, the TMD is a well-known technology to mitigate vibration, but it is not always applicable in every building case. Therefore a study of the interaction between the building properties also the soil structure interaction (SSI) is made in the application of the TMD.This thesis aims to study the dynamic behavior of a high rise building with the implementation of TMD and to take into account the SSI, also to indicate which type of building is preferable to apply a TMD. The model for the high-rise building is an analytical one-dimensional model which is validated by the finite element program (FEP). The analytical model can give a good fit for the building response but due to the model of the wind load is a random load, it is challenging to match precisely the TMD performance due to the comparison of different load phase. The physical characteristic and tendency of the TMD performance to different building parameter still can be studied in this analytical model. It is shown in this study that the damping plays an important role not only to reduce the acceleration of the building but also influence the effectiveness of TMD. The acceleration is drastically reduced in the lower damping ratio area, which makes theTMD more effective if the building has lower damping ratio contributed from the material, structural joints, and SSI. The reducement of the acceleration by increasing stiffness and mass is very limited compared to the application of TMD. There are two building data for the base of the analysis; the first is the European Patent Office EPO building which is designed by Zonneveld Ingenieurs and the new proposal of slender high rise building in Rotterdam. The EPO building has a unique geometry which the contribution of torsional vibration is high. The slender high rise building shows that the TMD is more effective in reducing the acceleration in this case. The reason is the slender high rise has higher acceleration compare to EPO building when the required building stiffness for the deformation limit is applied.