Construction projects become complicated and fragmented so that many specialty contractors are involved. In such changed environments, a general contractor’s overhead costs are increasing comparable to direct costs. In addition to an increase of volume, activities consisting of overhead costs play an important role in coordinating different participants who include different specialty contracto...

current practices in railway track analysis and design are reviewed and discussed in this paper. the mechanical behavior of railway track structure comprising of various components has not been fully understood due to the railway track structural complexity. although there have been some improvements in the accuracy of current track design methods in recent decades, there are still considerable...

Times of downturn in economy, tough competition, high costs, and large amounts of capital required for replacements have created growing need for cost cutting measures and for seeking better return on investment. This has also placed an increasing emphasis on maintenance practices to extend the service life of existing railroad bridges. This paper outlines the various factors which playa role i...

This paper proposes an active steering controller for Driven Independently Rotating Wheelset (DIRW) vehicles based on deep reinforcement learning (DRL). For the two-axle railway equipped with Wheelsets (IRWs), each wheel connected to a wheel-side motor, Ape-X DDPG controller, enhanced version of Deep Deterministic Policy Gradient (DDPG) algorithm, is adopted. Incorporating Distributed Prioritiz...

In the UK, the use of similar vehicle types by a range of privatised operators gives the opportunity to assess the influence of different route conditions and maintenance practices on wheel tread damage, wheelset life and costs. This paper investigates these influences, using data obtained directly from the train operators and maintainers. By disseminating best practice it is expected that whee...

The UIC Standard Suspension consists of a leaf spring (5) see the figure which rests on the axle box (6), which can move horizontally and vertically between the guidances (4). In the horizontal the guidance provides an end stop for the translations and the yaw of the wheelset (7). In the vertical direction the motion of the wheelset is restricted by the leaf spring with its nonlinear dry fricti...

the main design criteria of ballasted railway tracks include rail deflections, rail bending stresses, rail wheel contact stresses, sleeper bending moments and ballast sleeper contact pressures. numerous criteria have been defined for the design of ballasted railway tracks owing to the various mechanical properties of track components and their complex interaction. therefore, railway track desig...