Optimisation of slab track design considering dynamic train–track interaction and environmental impact

Modern railway tracks for high-speed traffic are often built based on a slab track design. A major disadvantage of slab track compared to conventional ballasted track is that the environmental impact of the construction is higher due to the significant amount of concrete required. In this paper, the dimensions of the rectangular cross-sections and the types of concrete used in slab tracks are optimised with the objective to minimise greenhouse gas emissions, while considering the constraint that the design must pass the static dimensioning analysis described in the European standard 16432-2. The optimised track design is also analysed using a three-dimensional (3D) model of vertical dynamic vehicle–track interaction, where the rails are modelled as Rayleigh–Timoshenko beams and the concrete parts are represented by quadratic shell elements. Wheel–rail contact forces and the time-variant stress field of the concrete parts are calculated using a complex-valued modal superposition for the finite element model of the track. For the studied traffic scenario, it is concluded that the thickness of the panel can be reduced compared to the optimised design from the standard without therisk of crack initiation due to the dynamic vehicle load. In parallel, a model of reinforced concrete is developed to predict crack widths, the bending stiffness of a cracked panel section and to assess in which situations the amount of steel reinforcement can be reduced. To reduce the environmental impact even further, there is potential for an extended geometry optimisation by excluding much of the concrete between the rails

Mapping the nexus of transitional justice and peacebuilding

This paper explores the convergences and divergence between transitional justice and peace-building, by considering some of the recent developments in scholarship and practice. We examine the notion of ‘peace’ in transitional justice and the idea of ‘justice’ in peacebuilding. We highlight that transitional justice and peacebuilding often engage with similar or related ideas, though the scholarship on in each field has developed, largely, in parallel to each other, and of-ten without any significant engagement between the fields of inquiry. We also note that both fields share other commonalities, insofar as they often neglect questions of capital (political, social, economic) and at times, gender. We suggest that trying to locate the nexus in the first place draws attention to where peace and justice have actually got to be produced in order for there not to be conflict and violence. This in turn demonstrates that locally, ‘peace’ and ‘justice’ do not always look like the ‘peace’ and ‘justice’ drawn up by international donors and peace-builders; and, despite the ‘turn to the local’ in international relations, it is surprising just how many local and everyday dynamics are (dis)missed as sources of peace and justice, or potential avenues of addressing the past

WPS, peace negotiations, and peace agreements

Peace negotiations and their outcomes have long-term repercussions for post-conflict politics and societies. Yet, one of the most striking patterns of contemporary peace diplomacy is the gross underrepresentation of women at the negotiation table, which reflects the gendered nature of diplomacy as an institution. The research question raised in this chapter concern how gender impacts peace negotiations, and how women’s participation is conceptualized in theory and framed in policy? The chapter first takes stock of contemporary policy discourses on women’s participation and the state-of-the art of scholarly work on gender and peace negotiations. It then moves on to depict where women are descriptively positioned in peace negotiation and analyzes the gendered dynamics of peace negotiations. It highlights some enabling and constraining factors, which influence women’s participation in peace negotiation. The chapter concludes with a discussion of how a research agenda can be advanced on gender and peace negotiation