Railway infrastructure is a complex system which comprises different subsystems. Long useful life span is one of the important aspects of this prime mode of transport. The useful life length of its assets is highly dependent on the maintenance and renewal strategy used during its life cycle. Today’s demands on the railway industry call for increased capacity, including more trains, travelling at higher speeds with higher axle loads. This increased usage will result in higher degradation of railway asset and higher maintenance costs. However, due to the competitive environment and limited budgets, railway infrastructure managers are compelled to optimize operation and maintenance procedures to decrease operation and maintenance costs while meeting high safety standards. To assure track safety and maintain high quality, a cost effective track maintenance strategy is required, one based not only on technical and/or safety limits but also on cost-effective maintenance thresholds. RAMS (Reliability, Availability, Maintainability and Safety) and LCC (Life Cycle Cost) analyses, which are derived from reliable track condition data, provide an approach to specify cost effective maintenance strategy to lessen corrective maintenance actions and downtimes.One of the main parameters to assure railway safety and comfortable railway service is to maintain high quality of track geometry. Poor track geometry quality, directly or indirectly, may result in safety problems, speed reduction, traffic disruption, greater maintenance cost and higher degradation rate of the other railway components (e.g. rails, wheels, switch, crossings etc.). The aim of this study is to develop a methodology to optimize track geometry maintenance by using historical geometry data. The methodology is based on reliability and cost analysis and supports the maintenance decision-making process to identify cost-effective inspection interval. An important phase of track geometry maintenance optimization is to estimate the track degradation rate. Obtaining knowledge about degradation helps to properly schedule maintenance activities such as inspection and tamping.The thesis provides a methodology to identify a cost-effective inspection interval based on track degradation rate and cost drivers. It contains state-of-the-art track geometry maintenance optimization. It describes Trafikverket’s (Swedish Transport Administration) maintenance strategy regarding measurements, reporting on and improving track quality, and it evaluates the efficiency of this strategy. Finally, it includes a case study carried out on the iron ore line in north of Sweden that runs from Boden to Gällivare to evaluate track geometry degradation and analyze the probability distributions of failures. A cost model is developed in order to find optimal inspection interval.Keywords: Track geometry degradation, Track maintenance optimization, Maintenance planning, Tamping

Railway signalling systems are composed of several different systems; each has its own purpose, but the main functionality of the overall system is determined by the interoperability between them. Railway signalling systems ensure the safe operation of the railway network, and their reliability and maintainability directly affect the capacity and availability of the railway network, in terms of both infrastructure and trains. The functionality of the signalling system is based on the principle of “fail safe”; this means that the railway section where a failure is located will be not fully operative until the failure is repaired (since safety cannot be ensured). Hence, the dependability of these systems directly affects the capacity of the network.Signalling systems take up a large part of the railway’s overall corrective maintenance. Railway managers need to have a holistic view of all systems to optimise maintenance. Signalling systems are especially important, given the need for interoperability. Given their complexity, knowledge must be correctly managed to ensure proper performance in all phases of the life cycle. Enhancing information logistics would lead to considerable improvements in this area. This licentiate analyses the dependability and maintenance of railway signalling systems and proposes various approaches to improve maintenance performance. External factors affecting the reliability of signalling systems are identified, such as their location. The signalling system is treated as a system of systems because of its interoperability and because failures occurring on different systems can be associated with the same failure effect. A data driven model for maintenance decision support is proposed, based on corrective maintenance work orders. The data driven model allows a holistic perspective of failure occurrence, as it integrates the information recorded in the many different parameters of the corrective maintenance work orders. With this model, existing maintenance policies could be reviewed and improved upon. This thesis proposes a model for configuration management, which simplifies the access and visibility of information. The model manages the change control process and ensures that configurations are updated in real-time. An enhancement of the configuration management has the potential to increase the efficacy of the maintenance actions in signalling systems by improving the accessibility of the information required to understand possible future failures. With increased accessible knowledge, the time needed to identify failures can be reduced, resulting in greater maintenance efficiency. It also establishes a framework for improving inter-organisational knowledge management between stakeholders, resulting in the creation of a holistic perspective of the maintenance and operation of the railway network, avoiding the loss of knowledge linked to outsourcing, and improving the effectiveness of the organisations involved.

Load Haul Dump (LHD) machines are used in underground mines to load and transport ore and minerals. Loading and hauling blasted ore from drawpoint to dumping point constitute a significant portion of the production costs for mining companies. There are a number of operation modes available for LHDs, and there are many criteria to consider when selecting the best one. The use of automated LHDs has been widely discussed due to the potential to increase productivity. The increasing focus on safety and ergonomics also gives an edge to automatically operated loaders over manually operated ones. Mine managers must decide when it is preferable to use manually operated loaders and when to complement or replace these with automatic ones. Automation focus has over the years gradually shifted from having automated fleets of vehicles to the more flexible solutions with semi-automatic LHDs gaining safety as one of the main goals. Several issues must be resolved to maximize the benefits of automation. One is to improve maintenance, and moving from operatorassisted “fail and fix” to planned maintenance. Since the operator is removed from the machine during automatic operation and maintenance staff is not always available on short notice, it is crucial to increase planned maintenance to maximize the investment in automation. Another issue is the complexity of the mining environment, including both the infrastructure and external disturbances like oversized boulders and road maintenance, as these can throw the entire investment in automation into question. The purpose of this thesis is to explore the maintenance actions connected to automated LHDs as well as the factors influencing the dependability of the machine. Research methods include a literature review, interviews, and data collection and analysis. Real time process data, operation and maintenance data have been refined, integrated and aggregated to make a comparative analysis of manual and automatic LHDs. The analysis show that 75% of the stop occasions causing idle time for LHDs relate to the operating environment, 21.5% pertain to machine related issues and 3.5% are related to the infrastructure of the automatic system installed in the mine. There is no difference in what kind of maintenance actions that are taken for manually and automatically operated LHDs, but there is a difference in what type of failures that occurs more frequently for the different operation modes. For automation of LHDs too much unplanned repairs and maintenance work significantly reduces the overall availability and can jeopardize the entire investment in automation. The difference between the semi-automatic and the manual LHD was found to be very small in terms of maintenance cost versus produced number of tons. However, a semi-automated LHD is an optimal machine regarding the ability to adapt to reconfiguring the operation mode to meet demands such as safety, flexibility and productivity.

Drill and blast is a dominant technique in several surface and underground mines in the world. The purpose of this technique is to break rock mass into fragments, which can be handled by mining equipment. The identified major influencing factors in rock blasting are stress waves and gas pressurization. In underground mines, especially in sublevel caving mines, the blast is performed under confined conditions. Hence, one more category of mechanisms has to be taken into consideration which describes the behavior of granular materials. Several small-scale tests have been conducted in order to define parameters which affect fragmentation by blasting as well as to measure the burden behavior during blasting. The purpose of these tests was to investigate how firing pattern, confinement and inter-hole delay time influence the fragmentation. Additionally, an incremental relative distance sensor was developed to measure the burden movement during blasting. The results showed that the burden moved with a velocity of approximately 29 m/s. The V-shaped firing pattern gave coarser fragmentation compared with sequential firing pattern for both the blasted material and confining material.After the small-scale tests, a zero pillar test was conducted under confined conditions to evaluate and validate a newly developed measuring system. The purpose of this system was to measure the burden dynamics. The system was calibrated in laboratory conditions under dynamic loading. This system was based on a piston-like structure and it was equipped with accelerometers and a potentiometric distance sensor. In addition to the measuring system, several installation and initiation procedures have been developed. The results of the measuring system showed that the burden moved 0.98 m at a velocity of 17-18 m/s. All the procedures performed as well as expected and designed.In addition to the study of blasting related mechanisms, the results of a blast also have to be measured. Sieving is usually not an option for large scale operations due to high costs. The alternative way is to implement digital image analysis. This procedure does not interfere with the production of a mine. Several trials have been conducted at the Aitik open pit mine to investigate the influence of short inter-hole delay time (1 ms, 3 ms and 6 ms or 0.14 ms/m burden, 0.43 ms/m burden and 0.86 ms/m burden) on fragmentation. The examined mechanism was the interaction of stress waves between neighboring blastholes. The fragmentation results showed that the trial with 3 ms inter-hole delay time gave a finer fragmentation by 10 % compared with reference blasts and other trials. However, there was an indication that the large specific charge at the mine overshadows the stress wave interaction mechanisms.An additional set of trials was conducted at the Kiruna mine to investigate the gravity flow of broken material. The fragmentation measurements were done with SplitDesktop®. This is a digital image analysis software which calculates fragmentation based on a delineation process of the particles in an image. The aim of in these trials was to develop a procedure to minimize the image editing time. The application of ‘Unsharp Mask’ filter improved the image quality and enhanced the contrast between the particles combined with a quick rating system (developed by LKAB) so that the image processing time was significantly reduced from 2 hours to 10-15 minutes.

Rock Mass behavior and Cap Rock Stability at the Malmberget MineThe LKAB Malmberget mine is mined using sublevel caving. This mining method requires continuous caving of the hangingwall, which also result in ground deformations on the surface. The Malmberget mine is located in the municipality of Malmberget; thus well planned residential relocations have been required as the caving area has expanded and associated ground deformations developed. This thesis aims to bring an increased understanding of the stress redistribution and likely failure mechanisms in the hangingwall of the Printzsköld orebody, one of the orebodies currently in production in Malmberget. Rock mass investigations have been conducted in the Printzsköld and Fabian orebodies to gain more understanding of the rock mass. These investigations included core logging, strength testing, borehole photography, joint mapping underground, and rock mass characterization in the Printzsköld orebody. The investigations showed that rock mass rating (RMR) scatter for Printzsköld and Fabian orebodies were 55 – 78 and 40 – 76 respectively, indicating a fair to good rock mass, albeit with some scatter and weak units present. The work also showed that there were three main joint sets in both the Printzsköld and Fabian orebodies. Conceptual continuum and discontinuum numerical analysis was conducted for the Printzsköld orebody, in order to study potential failure behavior of the hangingwall and cap rock, as well as to study the possible effects of large-scale structures inferred near the Printzsköld orebody. The results from the continuum analyses indicated high stress build-ups in the crown pillar and stress relaxation in the hangingwall of the orebody. Both shear and tensile failure were noted in the hangingwall and the cap rock. As mining proceeded to the level of 1225 meters, the stresses in the cap rock increased and the relaxation zone also increased. The hangingwall of the Printzsköld orebody can be considered as a beam fixed at the crown pillar and the cave bottom. Shear failure in the cap rock had the potential to cause failure in the hangingwall and this beam effect of the hangingwall lengthened. A parametric study of the strength parameters was conducted, which showed that lowering cohesion had a larger effect on the stress build-ups in the cap rock and destressing in the hangingwall than lowering other parameters such as tensile strength and friction angle.The discontinuum model results indicated that the presence of large-scale structures reduced the stress build-up in the crown pillar and that slip developed along these structures. A reduction in the angle of friction for the structures resulted in more slip, compared to a reduction in cohesion. The presence of large-scale structures did not affect the yielding pattern in the rock mass or the far field stress redistribution in the hangingwall and cap rock.Keywords: Strength parameters, hangingwall failure, cave propagation, failure mechanism, large-scale structures, crown pillar

Railway traffic is steadily increasing, having a negative impact on maintenance and resulting in decreased track availability, comfort, and safety. Swedish railway track maintenance mostly focuses on the actual track condition via a nationwide condition-based maintenance (CBM) strategy. For maintenance to be conducted in an appropriate way, data on the actual track condition must be accurate; furthermore, those data need to be converted into accurate information for maintenance decisions. An information assurance (IA) framework has the potential to deal with the system risks from a technical perspective. The framework is a guideline that can be implemented within CBM to understand both condition monitoring data behaviour and the information processing used to reach maintenance decisions.This research investigates ways of an information assurance (IA) framework can be implemented in the following CBM steps: data collecting, data processing and making maintenance decisions on Swedish railway. The framework can be used to understand data behaviour, information processing and the communication between information layers for decisions at organisation, infrastructure and data/information levels. The research uses both qualitative and quantitative methods to investigate critical information data, parameters, and problems and to suggest which areas need improvement. Quantitative analysis of the Swedish track geometry database reveals specific information about the behaviour of the railway data and their processing to make maintenance decisions.A case study shows how certain sections of a railway track are monitored and evaluates maintenance practices on those sections. The study finds several different types of measurements are taken using several different measurement systems. It is difficult to integrate these data for proper processing. In addition, there are problems of incomplete or irregular data; this affects the derivation of information and the use of models to understand track irregularities.Given the problems of data processing and subsequent decision making, the study suggests implementing an IA framework with CBM. The study checks the achievement of three IA principles in the existing data: authenticity, integrity and availability. The results show data have problems of authenticity and integrity, something also mentioned by the stakeholders in interviews. In particular years and on certain track sections, CM data are more than 5 percent incomplete, significantly affecting analysis. Incomplete track measurement data reach as high as 63 percent for the parameters of standard deviation (STD), longitudinal level and STD cooperation. Inaccurate measured values for alignment long wavelength within certain speed limits reach as high as 71 percent. These indicators are important for calculating track quality but are either incomplete or incorrect, negatively affecting the calculation of the Q-value and estimations of the track quality. This, in turn, negatively affects the maintenance decisions. Using information assurance will increase the system performance by permitting stakeholders to make accurate decisions.The suggested information assurance framework can discover technical problems but it needs to be improved using technologies, techniques and services to ensure complete and accurate data are available to be processed for maintenance decisions.

According to the European program Horizon 2020, multifaceted challenges in transportinfrastructure include 1) making infrastructure more resilient to keep pace with the increasing mobility needs; 2) reducing the impact of infrastructure on the environment;and 3) dealing with declining resources to maintain and upgrade transport infrastructure. New design and maintenance approaches must be developed to handle these issues, ascurrent methods are inadequate.In maintenance practices of railway infrastructure, most attention has been placed on RAMS (Reliability, Availability, Maintainability and Safety) study to meet asset safety and availability requirements. In Sweden, a popular development of the concept is RAM4S which incorporates supportability, sustainability, and security. However, the reality is more complex than these concepts suggest; various natural or operational uncertaintiescan cause “unfavourable” conditions requiring a quite different approach.Resilience studies can improve the ability of an infrastructure to withstand disturbances caused by uncertainties. To this point, most studies have considered extreme events,including natural events, like earthquakes or floods, and man-made events, like deliberateattacks on infrastructures. However, both naturally caused and operationally caused unfavourable conditions which do not belong to extreme events need to be studied as well. This represents a significant gap in the research.Robustness as a part of resilience has attracted much attention in recent years as it may be able to sufficiently consider those unfavourable conditions. In railway systems, however, robustness studies have mainly been aimed at timetable management to handle delays (including secondary delays) within the system. Yet according to statistics on total delays for the year 2015, from the follow-up system of the Swedish Transport administration (Trafikverket), LUPP, more than 30% of the root causes of delays are due to non-robustinfrastructures.To fill the above research gaps and support decision making of a railway infrastructure manager, the study described in the thesis conducts a holistic examination of railway infrastructure robustness considering its attributes, evaluation, assurance and improvement by investigating, exploring and developing new definitions and approaches. First, it develops a new road map for railway infrastructure robustness, including a novel definition and a framework. Its overview of robustness related topics results in a unique definition that identifies attributes of railway infrastructure robustness and clarifies the research boundaries between robustness and reliability, resilience, and risk. The study’s ground-breaking framework, named house of robustness management (HORM), is based on continuous improvement to support infrastructure robustness management in railway;HORM consists of robustness management goals and guidance, a continuous improvement process, and support systems through which assurance and improvement can be supported. Second, in addition to the qualitative evaluation of railway infrastructure robustness enabled by the road map, the study proposes a new quantitative evaluation approach by considering a dataset of “specified disturbance”, a corresponding “acceptable functionality”, and a dataset of weights of risk preference. Third, to apply railway infrastructure robustness to the development of sustainability, it provides a case study on energy efficiency optimisation in Sweden.This thesis consists of two parts. The first gives an introductory summary of the subjectand research, followed by a discussion of the appended papers, suggested extension of the research and conclusions. The second part consists of three appended papers. The first paper concerns the new road map including the definition and a framework. The second paper proposes a new quantitative evaluation approach for railway infrastructure robustness. The third paper is a case study on railway switches & crossings which will be further pursued under the topic of “green robustness”. The three subsequent papers develop the dependability improvement of railway infrastructure considering information logistics and risks, as well as maintenance cost.

The purpose of this research work is to explore and describe human factors affectingmaintenance execution. To achieve the purpose of this study, the influencing factors have been identified using a literature survey. They have been categorized into four main groups namely organizational, workplace, job and individual factors. The Analytical Hierarchy Process (AHP) method is employed on data questionnaires to rank the priority of the factors. The interrelationships between these factors have been recognized by theInterpretive Structural Modelling (ISM) model. In the present case studies, MICMAC1analysis technique is also implemented for identifying the driving, dependent, linkage and autonomous factors. The data was collected through a questionnaire survey involving the participation of 16 and 25 maintenance staff and 10 mining experts in Swedish and Iranian mines, respectively. Within the study, it has been identified that the temperature, work layout, tools design and tools availability are the most important factors in both mines related to these categories. However, the significant factors in the organizational and individual categories are different in the selected mines. The effect of workplace factors on the maintainability of mining equipment is discussed and thereafter a methodology for maintainability management in the design and operation phases is developed. In the thirdcase study HEART2 is applied to estimate the probability of human error occurring duringmaintenance execution in an Iranian cable company. This research supports maintenance management to gain knowledge of human factors that affect maintenance execution. Further, this understanding could be useful in the development of strategies to improve the execution of maintenance.Keywords: Human Factors, Maintenance Management, Human Reliability, HumanPerformance, AHP, ISM, MICMAC, HEART

In this thesis, three different single-family house types were meticulously studied with the aim of improving energy efficiency through a variety of measures. These measures were identified, simulated, and combined to create specific action packages for each single-family house type. The individual measures simulated using BIM Energy software included basement wall insulation, exterior wall insulation, attic floor insulation, window and door replacements (only for house type 1, as other single-family houses had already undergone these replacements), installation of FTX ventilation, and installation of solar panels. After simulating the individual measures, three distinct action packages were created by combining the individual measures. The results demonstrated that the action packages had a positive impact on energy efficiency and influenced various aspects, such as energy performance, heating, energy losses, and the U-value. The three created action packages were designed to improve the building envelope and energy performance. Action Package 1 consisted of FTX ventilation, exterior wall insulation, and window and door replacements. In Action Package 3, FTX ventilation, attic floor insulation, and exterior wall insulation were combined, with the combination for single-family house type 3 being the same as that for single-family house type 2. Simulations revealed that single-family house type 2 was the only one that met the energy performance requirements according to BBR 29 after implementing the action package. Single-family house types 1 and 3 did not fully meet the energy requirements, but they came close to compliance after implementing the action package. As for the U-value, it was only met in house type 2 when implementing individual measures, specifically exterior wall insulation. Single-family house type 3 came close to meeting the requirements, while single-family house type 1 required substantial improvements to comply with the standards. In summary, this research highlights the importance of selecting the right measures to enhance energy efficiency in single-family houses, with specific measures tailored to each single-family house type.

This project investigated and analyzed a variety of energy efficiency measures in a residential area with townhouses in Tierp, Sweden, known as Makrillvägen, currently supplied with district heating. The aim of the project was to determine the area’s current heating demand and primary energy rating, identify the necessary measures to enable the area to achieve a classification aslow-energy buildings, and evaluate the economic aspects of these measures. To achieve these goals an analysis of the area’s heat energy consumption was conducted by modelling the area in software program called VIP-Energy, commonly used to evaluate buildings’ heat demand. The different energy-efficiency measures were then simulated in the same program to determine which measures concluded in a low-energy building classification. The various measures investigated were additional insulation of the attic, replacement of windows, installation of exhaust and supply air ventilation with heat recovery and exhaust air heat pump with solar cells. The results showed that for the area with 111 apartments, installations of exhaust air heat pumps together with solar cells were the only measure that could reduce the heat demand sufficiently. The conclusions of the project concludes that installation of exhaust air heat pumps meant an increased amount of consumed property electricity as a result of the pumps drawing electricity .Therefore installation of solar cells were added, to supply a majority of the increased electricity demand. By quantifying the economic aspects of these measures, they resulted in a payback time of 13,6 years with a total of yearly savings of 914,2 kSEK.