Browse

11 - 20 of 74 items :

  • Materials Sciences, other x
  • Business and Economics x
Clear All
Role of CPEC in Development of Trade, Transport and Economy of Pakistan

Abstract

The objectives of the study were to measure the efficiency in trade and transport through China Pakistan Economic Corridor (CPEC) and to ascertain efficiency in trade and economic development through developed transport infrastructures. The present study was conducted in Peshawar, Pakistan. The data was collected from the relevant developing sectors and stakeholders through CPEC including investors of Khyber Pakhtunkhwa Chamber of Commerce and Peshawar Railway Station track employees. Majority of bi-variate analysis through chi-square test result showed that there was a strong and significant association between the project of CPEC and efficiency in trade and transport in terms of economy. Similarly, a strong and significant association was found between the development of transport routes through CPEC and smooth transportation of goods and services. Furthermore, a strong and significant association was found between CPEC project and improvement in travelling potential. Similarly, a significant association was found between development in transport infrastructure and fastness and reliability in business travelling. In the same way, a significant association was found between CPEC and increase in the geographical size of the labour market. As in the chain, a strong and significant association was found between the development of transport infrastructures through CPEC and increase in labour force productivity along with an increase in the range of choice of individual and firms. This could come true that CPEC as a project would ensure smooth efficiency transportation of trade goods and services in terms of reducing time distance and cost. CPEC as a project should not be only limited to economic activities, rather it should contribute to the overall socio-economic development of the region.

Open access
Steel and Concrete Elasto-Plastic Models at Bridges with Steel Beams Embedded in Concrete

Abstract

For new railway bridges with short spans (L ≤ 35.00 m) superstructures with steel beams embedded in concrete are recommended or used, which can ensure the requirements of strength and stiffness in particular, regardless of velocity. They are built relatively easily compared to reinforced concrete structures or steel structures, they have high durability if designed, built and maintained correctly and don’t have high sensitivity to fatigue degradation in service. They are also used for road bridges when it is desired to achieve a reduced construction height.

In all the design prescriptions used so far for structures with steel beams embedded in concrete, the calculation is a simplified one, made on a single insulated longitudinal beam of the deck, if certain conditions related to the geometry of the structure are met (obliquity, curvature). Simplifications are also made regarding the state of deformation of the decks made in this constructive solution by introducing an effective moment of inertia in the displacement calculation, as an average of the inertia moments of the cross section considered to be cracked and respectively un-cracked.

The article aims to validate steel and concrete elasto-plastic models, based on an experiment from the technical literature, necessary for complex analyses of the percentage of concrete involved in the stiffness of the cross-sections, in case of bridges with steel beams embedded in concrete.

Open access
Study on Indirect Tensile Strength of Plastic Waste Bituminous Concrete for Road Construction

Abstract

The rutting and cracking of pavements has become very common problem in India. Also the quantity of plastic waste has significantly increased in the recent year due to industrialization and population growth. Improper disposal of these plastic wastes has caused various environmental problems, hence the alternative use of waste plastic in bituminous concrete for road construction has been encouraged by the community. In the present study the Indirect Tensile Strength Test has been carried out on Marshall Samples confirming to ASTM D6931-12. Three different processes (dry process, wet process and combined process) of mixing of waste plastic were used during experimentation. It was found that the indirect tensile strength (ITS) and tensile strength ratio (TSR) of sample significantly increase up to 8%, 6% and 12% for dry process, wet process and combined process respectively for LDPE and HDPE type of waste plastic.

Open access
Analysis of Delays and Extension of Execution Duration of a Road Project

Abstract

The implementation of road infrastructure projects often results in delays due to objective causes, with repercussions on the final execution deadline and with value implications. The use of critical path method for planning and the executin windows, will result in better time process management and optimization delays.

Open access
Influence of high temperatures on technical state of streets and roads structures with asphalt surfacing

Abstract

In this paper will be presented the influence of high temperatures on asphalt street pavement in terms of the influence of temperature on permanent deformations and thus the technical condition of the streets, comparable to the effects induced on extra-urban roads.

Environmental factors are one of the mayn factors being assaulted in operation and road structures are very important in terms of the influence they can have on the state road transport technical infrastructure.

Will be presented differences between urban road structures (streets) and extra-urban (road) both in terms of construction, the demands of traffic and environmental conditions to which they are subject.

Road structures extra-urban and urban areas are required differently in terms of the environmental conditions of the location ambient different thereof, that is, when the streets they are inside localities and the built environment significantly affect road infrastructure, unlike in the case of roads where they are located just outside the settlements, reducing the effect of air currents accumulation pavement surface temperature.

To demonstrate the influence of high temperatures on the pavement were conducted laboratory tests on asphalt mixtures in order to demonstrate the occurrence of reduction of physical characteristics, with adverse implications on the performance of applications similar to traffic.

Open access
Mathematical Models for Nonlinear Soil Behavior

Abstract

Actually, the seismic movement has an irregular cyclic character.This can be equivalent to a determined number of uniform cyclical stresses equivalent in terms of effect.

Modeling the behavior of the soil to cyclical stress, is usually done, by establishing a relationship for primary loading like τ = f (γ) and after drawing the diagram “effortless strain curve”, in which τ is the stress, and γ is shear deformation. For modeling nonlinear behavior of the soil, we used like nonlinear models. The best known are the hyperbolic model and the Ramberg-Osgood model.

Open access
Parametric Study on How the Lateral Forces Acting on a Deep Foundation Influences the Axial Forces Developing in the Piles

Abstract

A missing piece in the design of bridge substructure is that the equation given in structural mechanics that assesses the axial forces in the piles of a deep foundation does not take into account the effect of lateral forces acting on the pile cap. In practice, pile forces are determined using a FEA software. This method, however, can not be easily incorporated into an automated program that performs local and global optimizations of a structure. One of the reasons is that this method is particularly demanding on the computational resources. Since a bridge can have a number of deep foundations, which must be verified for various combinations of actions, which need to be optimized, recalculated in various scenarios and then the entire process reiterated for all structural solutions, computational cost can become prohibitive. Another reason is that due to the lack of a relation between all the parameters and dimensions that influence the behaviour of a deep foundation, their optimization is difficult.

For this purpose, a parametric study has been carried out to investigate what parameters influence the relation between the lateral forces applied to the foundation and the axial forces that develop in the piles, and ultimately propose an equation that takes into account the lateral forces. The study is carried out using experimental data obtained on models using the finite element analysis method using SAP 2000 (v.15) software.

Open access
The Sunet System for Monitoring Noise Pollution in Cluj-Napoca

Abstract

In Europe the need for local authorities to provide a high standard of living for their communities led to the establishment of the European noise mapping directive 2002/49/EC. Whilst Noise mapping itself doesn’t need continuous noise monitoring, states must produce a noise action plan which highlights actions they intend to take to reduce the number of people affected.

SUNET platform (System for Urban Noise and Eco-Traffic) was designed for improved management of the noise pollution in Cluj-Napoca and to provide up-to-date public data on a user-friendly interface. The implementation of the application over the entire municipality is highly advantageous for it creates a link between the town’s administration (the local authorities, the City Hall of Cluj-Napoca) and the user (the citizens) through this system which is dynamic, modern and compliant with the European regulations.

Open access
Considerations on the Benefits of Using Recyclable Materials for Road Construction

Abstract

A current worldwide economy problem includes both the responsible management of the planet's non-renewable resources and the waste management. The benefits of using recyclable materials and recycling technologies with asphalt mixtures consist mainly of reducing fuel consumption and greenhouse gas emissions. It is well known that oil (from which bitumen is obtained) is a non-renewable resource, hence the its price increase. Therefore, at present, the world is looking for solutions that will lead to a better use of natural resources and to an economic integration of sub-products from various industries. This paper intends to raise awareness of the possibilities for asphalt mixtures recycling and of the recyclable materials that can be used as additives with benefits of each.

Open access
Dynamic Test of a Viaduct on the Orastie–Sibiu Highway

Abstract

Dynamic testing of bridges has as target to establish their response on pulse forces between the wheels and unevenness of road surface. Generally, during the tests, real time accelerations or deformations are to be measured and which through successive processing methods lead to other data as velocities, displacements, dynamic impact factor, but also the damping ratio. In order to validate the bridge response following testing, the measured data are compared both with allowable limits existing in standards and with the results obtained using analytical or numerical models.

In Romania, the dynamic testing of bridges is recommended by the current standards, only for important bridges, erected in complex or special solutions and also for large span bridges.

The aim of this paper is to outline the results obtained from the on-site measurements during dynamic testing of a viaduct placed on the motorway A1, sector Orăştie-Sibiu. The bridge superstructure is a composite one, continuous girder on 12 spans: 40+10×60+40 m, the substructure consisting in 11 piers with lamellar elevations and variable height in the range 8.50-24m.

In the paper a finite element model is also presented which was used for time-history analyses using an impulse type load. Finally, the results obtained on the site and using the numerical model are compared and discussed.

Open access