Abstract
Superelevation is known as a transverse slope made available to mitigate the impact of centrifugal force and minimize the vehicle’s tendency to overturn and skid. However, in an intersection ...or interchange that has horizontal curves with small radius consecutively, it is difficult to design superelevation. If the superelevation arrangement is not good enough, the alignment is not smooth, causing unfavourable and unsafe conditions. Moreover, for expressway interchange, it become more complicated to design by manual method because the expressway requirements in term of safety and aesthetics is higher than that of conventional intersection. On the other hand, ADSCivil Road, a software in the ADSCivil solution suite for infrastructure design developed by Baezeni Soft Co, Ltd. is a useful tool for geometric road design. This paper presents the results of ADSCivil Road software application in designing the superelevation at the expressway. ADSCivil Road has arranged superelevation for an interchange ramp (with a design speed of 60 km/h) that includes the small radius circular curves connecting together (R=125 m and R=100 m). The results show that using the superelevation diagram and corridor model in ADSCivil Road makes the superelevation design process more intuitive, make it easier to adjust the slope at each point, and controls the rate of superelevation difference. In addition, ADSCivil Road automatically updates the superelevation change for profile, cross-section and plan. Also, 3D simulation results show that the superelevation layout for this interchange meets technical, economic, and aesthetic requirements. Obviously, it can be seen that can become an effective tool to help engineers solve complex problems in road design.
Emerging sutureless wound-closure techniques have led to paradigm shifts in wound management. State-of-the-art biomaterials offer biocompatible and biodegradable platforms enabling high cohesion ...(toughness) and adhesion for rapid bleeding control as well as robust attachment of implantable devices. Tough bioadhesion stems from the synergistic contributions of cohesive and adhesive interactions. This Review provides a biomacromolecular design roadmap for the development of tough adhesive surgical sealants. We discuss a library of materials and methods to introduce toughness and adhesion to biomaterials. Intrinsically tough and elastic polymers are leveraged primarily by introducing strong but dynamic inter- and intramolecular interactions either through polymer chain design or using crosslink regulating additives. In addition, many efforts have been made to promote underwater adhesion
covalent/noncovalent bonds, or through micro/macro-interlock mechanisms at the tissue interfaces. The materials settings and functional additives for this purpose and the related characterization methods are reviewed. Measurements and reporting needs for fair comparisons of different materials and their properties are discussed. Finally, future directions and further research opportunities for developing tough bioadhesive surgical sealants are highlighted.
The bicycle is a low-cost means of transport linked to low risk of transmission of infectious disease. During the COVID-19 crisis, governments have therefore incentivized cycling by provisionally ...redistributing street space. We evaluate the impact of this new bicycle infrastructure on cycling traffic using a generalized difference in differences design. We scrape daily bicycle counts from 736 bicycle counters in 106 European cities. We combine these with data on announced and completed pop-up bike lane road work projects. Within 4 mo, an average of 11.5 km of provisional pop-up bike lanes have been built per city and the policy has increased cycling between 11 and 48% on average. We calculate that the new infrastructure will generate between $1 and $7 billion in health benefits per year if cycling habits are sticky.
Despite their growing application and worldwide diffusion, the transformative potential of experiments aimed at achieving "streets for people" rather than "streets for traffic" remains largely under ...researched. There is little to no comparative assessment of already existing experiments, and no critical reflection on their specific added value for systemic change. Building from a literature review and discussion, this paper aims to fill this gap by addressing the following questions: Which types of city street experiments have been undertaken in the pursuit of the vision of "streets for people" instead of "streets for traffic"? What are their backgrounds, main characteristics, and reported impacts? And perhaps most importantly: How can these city street experiments trigger systemic change in urban mobility? These elements are detailed per experiment type, in order of ascending functional complexity: the re-marking of streets, the re-purposing of car parking, the re-purposing of sections of streets, and the re-purposing of entire streets. Illustrative examples from practice include intersection repairs, parklets, the pavement to plazas programme, play streets, ciclovias and open streets. The reviewed literature documents positive impacts on physical activity, active transportation, safety and social interaction and capital, and more mixed impacts on business activity. While street experiments aim to create fundamentally different arrangements of urban mobility, their potential as triggers of a greater systemic change is unclear. This paper uses the defining characteristics of "transition experiments" - a concept derived from the field of transition studies - to develop and illustrate a framework to assess this transformative potential. In the conclusions, the review and assessment framework are used to sketch a research and policy agenda for this increasingly topical phenomenon.
While many studies have investigated the application of BIM in helping the integration of architectural, construction or manufacturing projects, however, it has been barely used in road engineering ...due to the lack of pavement structure analysis in the present Road-BIM products. The aim of this research is to develop a framework for the integration of BIM and structure verification to improve the application of BIM in road engineering and thus reduce the mistake and repetition in pavement design. Relying on the capabilities of Dynamo, a three-dimensional road model with pavement controllable parameters was first established. Successful implementation of this step can facilitate the designer with more flexible and convenient needs in design process. Secondly, a subroutine is developed based on Python to combine Dynamo with the Mechanistic-Empirical Pavement Design Guide (MEPDG) which provides the pavement structure analysis. As a response to long-term development between BIM and road engineering, this paper contributes by offering innovative and practical solutions for integration of road design and pavement analysis, which effectively solves the long-existing defect that the pavement structure cannot be analyzed in the environment of BIM, and thus, will significantly promote the further application of BIM technology in the road industry.
•Automatic road modeling and pavement structural analysis are realized in BIM.•Three-dimensional road model with controllable structural parameters is developed.•A test-based rutting prediction model is realized by using Python subroutine in BIM.•The proposed model is applied and validated by cooperating an expressway project.
The problem of determining the slope at a point on a map using level curves has practical applicability in designing the roads. This problem is reduced to the problem of finding the shortest length ...segment through a point that connects two coplanar lines. Two methods to solve this problem are presented: a fast approximate method and a slower but exact algorithmic method. The results are compared at the end.
► Accurate models of earthwork are critical to evaluating potential road designs. ► A new method for incorporating blocks into earthwork models is created. ► Earthwork models are shown to be more ...accurate if blocks are included. ► New algorithms for solving the earthwork model with blocks are designed and tested.
In road construction, earthwork operations account for about 25% of the construction costs. Existing linear programming models for earthwork optimization are designed to minimize the hauling costs and to balance the earth across the construction site. However, these models do not consider the removal of physical blocks that may influence the earthwork process. As such, current models may result in inaccurate estimates of optimal earthwork costs, leading to poor choices in road design. In this research, we extend the classical linear program model of earthwork operations to a mixed integer linear program model that accounts for blocks. We examine the economic impact of incorporating blocks via mixed integer linear programming, and find significant savings for most road designs in our test-set. However, the resulting model is considerably harder to solve than the original linear program. Based on structural observations, we introduce a set of algorithms that theoretically reduce the solving time of the model. We confirm this reduction in solve time with numerical experiments.
Abstract
This study aims to practically test, identify vulnerabilities and analyses the limits of working tools for assessing road network safety and validate the integrated method proposed by the ...European Commission in the context of different technical classes of national roads in Romania. The research aims to adapt, convert, and transform the calculation values of the formulas of the proactive evaluation tool to the values used by national norms for road design and construction. 2 evaluation parameters are analysed, which represent the width of the traffic lane, respectively the widths and type of shoulders. On the other hand, the study is a tool for analysing road infrastructure safety, for efficiently allocating resources and for prioritising specific road safety inspections on the most dangerous sections of roads. The case study is the comparison of the results obtained from the safety assessment of DN 2 road infrastructure, both by the proposed test method and by the method adopted by the European Commission following Member States’ comments.
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