A case study on the noise effects of elevating existing train tracks

When modeling rail noise on an elevated track, there are several adjustments that need to be considered relative to modeling at-grade operations. These adjustments include the effects of re-radiated noise from the track and support structure, reduced ground attenuation due to an elevated noise source and a reduction in the potential for shielding from adjacent rows of buildings. These adjustments are built into the model as a part of the design of a project. This case study examines a unique situation where a project involved elevating existing at-grade tracks to eliminate a bottleneck related to an at-grade crossing of two perpendicular train tracks. The project elevated one main track over the other and shifted the track closer to noise sensitive receivers. The US Federal Transit Administration and Federal Railroad Administration guidance, which were used to assess noise impacts, produced unexpected results during the initial assessment due mainly to the assumptions regarding the changes in shielding and ground attenuation with the elevated structure. This presentation will discuss the initial assumptions used in the project, the limitations of the model relative to changes in shielding and ground attenuation, and the solutions that were implemented to obtain reasonable results for the impact assessment.

Scheduling design of Jakarta-Cikampek II elevated toll road project (P.186 – P.187)

The key to achieving effective and efficient development goals is by increasing the quality of construction management by collecting up-to-date data about the project's resources, mainly about productivity. In this research space, productivity will be discussed, including human resources and their management. The case study is the project of Jakarta-Cikampek II Elevated Toll Road. This project was a developing project to improve the capacity of the existing Jakarta-Cikampek toll road. This elevated structure will be built right in the area (median and side edge) of the existing toll road, making it interesting to discuss how the construction is carried out. Scheduling analysis in this study was carried out at points P.186 to P.187 of the construction project. The analysis includes identifying the productivity index of labor resources and equipment that has a major role in shaping the scheduling concept. The concept will be performed by determining a network diagram that will use the Critical Path Method (CPM) rule. The data used in this analysis are construction drawing, s-curve plan, worker data, weekly job plan, work method, and some interviews with worker and field project manager. These results obtained the large productivity of workers and equipment, and the duration required to complete the construction starting prom point P.186 to P.187 is 248 working days

Observed long-term differential settlement of metro structures built on soft deposits in the Yangtze River Delta region of China

In this study, the measured differential settlements of five metro lines built on soft deposits were analyzed. The different structural combinations at various characteristic locations in the metro lines were examined, including at 67 joints of stations and tunnels, 55 connecting passage locations, 4 wind well locations, and at 3 joints of U-shaped grooves and adjacent structures. Moreover, the differential settlement between the track slabs and the bridge piers of a 16.57 km long elevated structure was analyzed. The results showed that the settlements of ∼85% of the stations were less than those of adjacent shield tunnels, and the settlements at the connecting passages of ∼73% of the tunnels were greater than those on either sides of the tunnel. The wind well exhibited lower settlement than its adjacent tunnels. The settlement of the U-shaped groove was greater than that of its adjacent elevated structure, but was less than those of the cut-and-cover and shield tunnels. Approximately 86% of the track slabs exhibited arch deformation, and the settlements of the bridge piers were greater than those of the track slabs. The stiffness transition between the different structures should be considered in the design of metro structures on soft deposits.

Problems of an Aerodynamic Interference between Helicopter Rotor Slipstream and an Elevated Heliport

An elevated heliport, as it has been defined by FAA (Federal Aviation Administration), is a heliport located on a rooftop or other elevated structure where the TLOF (touchdown and lift-off area) is at least 30 inches (76 cm) above the surrounding surface [1]. One of greatest advantages of such heliports is that they require less free space, which eases its build nearby existing buildings – especially in densely built-up areas. However, design of such heliports is more complicated, than ground level ones, while one must include an aerodynamic impact of the building below the elevated heliport and surrounding buildings. The aerodynamic interference between the helicopter and the buildings may result with decline of flight safety, due to sudden decrease of thrust (when flying above the edge of building) or because of increased turbulence in windy weather, wake behind surrounding buildings causing sudden gusts etc. Moreover, oscillations of pressure caused by helicopter rotor influence on the building structure also must be taken into account due to increased wear of upper part of the building or devices mounted on its roof (for example, elevator drives). These oscillation may also cause vibrations of building’s structure, which is especially important in case of medical heliports – which are a vast majority of elevated heliports (and heliports in general) – because of strict requirements for acceptable vibration level. The article is aimed on summarize aerodynamic issues, which should be taken into account during design of elevated heliport.

Construction Techniques and Development of 1st Monorail System in Thailand

<p>This paper aims to present the construction techniques and development of first and unique monorail system in Bangkok, Thailand. Bangkok is the capital and most populous city of Thailand. The city occupies 1,568.7 km<span>2</span> and has a population of over eight million, or 12.6 percent of the country's population. In the last decade, Bangkok has attracted millions of migrants seeking economic opportunity and city is expanding quickly. Recently, Mass Rapid Transit Authority (MRTA) Thailand has decided to adopt monorail system in Bangkok as a rapid transit system due to the limited space, narrow roads and sharp curves in the city. The design of monorail track lines permits flexible and various alignments that include curves of small radiuses and large slopes. The first two projects i.e., Pink Line and Yellow Line projects consist of elevated structure around 64.9 km long, 53 stations, 2 depots and 2 park-and-ride buildings. MRTA has awarded these projects (design, test run and construction of first two lines) to the BSR Joint Venture who invited Sino-Thai Engineering &amp;</p>