Sustainable Issues in Transportation Engineering

This paper discusses results of a long-term onsite monitoring on ground subsidence and soil compressibility at the intersection of Expressway (Expwy) 78 and the High-Speed Rail of Taiwan (THSR). The intersection area is located on the Chuoswei River Alluvial Fan-Delta (CRAFD), the largest and thickest alluvial deposit to the mid-west of the island. The CRAFD has been subjected to serious subsiding problems for decades because of excess extractions of groundwater for agricultural and industrial usages. The constructions of Expwy 78 and THSR in the late 1990s imposed additional loadings on the soft ground and accelerated the subsidence problem, which was becoming a threat to the safety of THSR. An 8-year onsite monitoring program at the intersection was conducted between 10/2003 and 12/2011. The subsidence and compression of soils were measured through multi-leveled magnetic rings installed in the ground along boreholes of 300-m deep, as well as a GPS station and several level-surveying benchmarks. Results indicate the ground subsidence in the intersection area was 55.7 cm for the entire deposit in the 8-year monitoring period without the loadings of Expwy 78 and THSR. The loadings of Expwy 78 embankment and THSR piers/viaducts would contribute additional subsidence of 9.4 cm and 5.5 cm, respectively, to the ground in the same period. The total subsidence in the 8-year period was 70.6 cm, with an average rate of 8.6 cm/yr. Further analysis of the compression in soils with depth <300 m indicated that the shallower deposit (depth <70 m; Aquifer F1 and Aquitard T1) was least compressible, with a strain rate of <0.01%/yr; while the deeper deposit (depth 220–300 m; Aquifers F3, F4 and Aquitards T3, T4) was most compressible, with a strain rate of 0.03–0.05%/yr. Higher compressive rates in deeper soils suggest the extraction of groundwaters has gone deeper in recent decades.

This paper outlines the most common quality challenges testing laboratories are facing during their accreditation process. Accreditation is the independent evaluation of conformity assessment bodies (i.e. Testing laboratories) against recognized standards to carry out specific activities to ensure their impartiality and competence. Through the application of national and international standards, government, procurers and consumers can have confidence in the quality of test results, inspection reports and certifications provided.

The Non-Conformities were issued during the accreditation process of various testing laboratories specializing in different testing categories (Civil, Geotechnical, Mechanical, Electrical, Chemical, Microbiological, etc.). Findings vary from commonly reported quality management system issues to the most demanding technical challenges faced by testing laboratories.

The identified Non-Conformities were categorized and statistically processed. The trends are identified and analyzed per quality management system or technical category. Under the accreditation process, laboratories are required to respond to any significant findings with a submittal of a corrective action plan containing an analysis of the root cause, details of actions taken to resolve the issue and strategies to prevent reoccurrence. Various responses were analyzed and some suggestions and good practices were gleaned from these submittals. Opportunities for improvement are presented for each corresponding category of findings.

The usage of WIFI and in particular the urban WIFI has exponentially grown in the last years. However, the deployment of an urban WIFI system is a tedious labour that needs a lot of field work in order to deploy and later validation of the system. In this paper a novel approach for deploying urban WIFI is presented which is based on an urban 3D model and by mean of a web tool. The main objective of this tool is the development of a system that allows to obtain, from a 3D urban model, a catalogue of specifications and predefined rules; a proposal of solutions that indicate the ideal positions and the types of WIFI devices needed to increase the coverage offered at the minimum cost. In order to do that, the tool uses a web 2D and 3D viewer of coverage distribution maps and as it is possible to configure the catalogue, the predefined rules and all steps in the tool, as a result the needed access points and antennas are minimized.

It is practically important to monitor and warn the instability risk of high-steep slope of highway during cutting. The paper presents a case study carried out in a real slope in Liuzhou-Nanning Expressway Expansion Project. Grades of instability risks of slopes are firstly classified based on qualitative and quantitative assessment, and then different monitoring methods are adopted. Then, BDS (BeiDou Navigation Satellite System), Tilt photogrammetry, Internet of things are used to establish a 3D intelligent monitoring and warning system. The system was successfully to monitor and warn the risk during removal of support, and is now working well in service. In addition, a Leica TM50 high-precision measurement robot is used to calibrate the BDS + monitoring data. The results show that the trend obtained by the intelligent monitoring system is consistent with that measured by the robot.

Roads are terrestrial communication paths specially designed for the movement of vehicles and pedestrians and part of the national transport system. Maintaining proper road conditions is essential for traffic safety and road network availability. There are a number of factors that impact the decision-making process regarding the road structure programme management, including the technical condition of the roads, traffic safety, heavy traffic, the cost of maintenance works and the low funding allocated to this sector. Thus, an effective approach is needed to attain a balance between the program of maintenance/repair/rehabilitation activities and the works that can be executed within the limits of the available funds, so that the investment achieves the highest profitability. This paper aims to analyze the technical state of the road network in Romania using a multi-criteria decision analysis method, namely Electre method. The method was applied on only four sectors of National Road 1 (the method requires a large number of parameters: weights and different thresholds assigned by the road network authorities) and aimed at identifying those road sections with the most severe conditions regarding the technical condition of the roads.

An extensive subsurface investigation program was executed to characterize the formations in the city of Al-Burrulus site in the north coast of Egypt. The site is situated on the Mediterranean Sea coast with shallow ground water at the area. According to the subsurface ground investigations, thick layers of sands with relative densities varying from very loose to very dense sand underlain by very soft to hard clay and intermixed soils are characteristic of this area. A plethora of high quality laboratory and insitu tests were performed to identify the soil properties. The field tests include the Standard Penetration Test (SPT), Piezocone (CPTu), Seismic Piezocone (SCPT) and Downhole Test (DHT). Additionally, “undisturbed” specimens are extracted from the cohesive soils using Shelby tube samplers, while disturbed samples are obtained from cohesionless soil layers. Several laboratory tests were performed on the extracted specimens for classification purposes (e.g. grain size distribution and Atterberg limits). Tests on “undisturbed” samples are conducted to determine the strength properties (e.g. consolidated undrained triaxial test, unconsolidated undrained triaxial test, and direct shear tests). Site specific correlations are developed between the clay strength obtained from tests performed on high quality Shelby tube specimens and insitu tests. These correlations are beneficial to estimate clay strength in future projects in Al-Burrulus area based on field tests.

Gravel loss on unsealed roads is financially a major setback for all road agencies. The maintenance strategy in Australia is primarily based on visual inspection only which has inherent drawbacks. It is also environmentally unsustainable. Key challenges associated with the unsealed road management are identified as (i) difficulty to forecast behaviour, (ii) significant data collection needs and (iii) vulnerability in level of service & maintenance practices. The quality of gravel material is one of the major influencing factors. Various theoretical models have developed in the past to estimate gravel loss. These studies are used to estimate road deterioration and maintenance strategy in practice. A range of approaches such as regression analysis of field measured data, system dynamic modelling approach, laboratory measurements have been employed in the past. In the state of Queensland of Australia, the long-term gravel loss monitoring is planned in the region affected by frequent flood to assess the amount of gravel loss and associated maintenance issues. Recently, a mammoth maintenance work was undertaken on unsealed road network to cater for gravel loss due to Ex Tropical Cyclone Debbie. Visual inspection can be a useful tool to provide snapshot of unseal road network at a time. Most road agencies still use this visual inspection as a maintenance strategy tool. It is recommended in this study to integrate visual inspection with localised gravel loss model and roughness data. GPS based data can be integrated by using visual inspections, roughness and the gravel model.

Composite bearers, which are the long crosstie beams, are safety-critical components in railway switches and crossings. Recent adoption of composites to replace aging timber bearers has raised the concern about their engineering performance and behaviour. Since the design and test standards for composite bearers are not existed, most performance evaluations are based on the flexural tests in accordance with the test standards for railway concrete sleepers. In this study, both numerical and experimental studies into the flexural behaviours of composite bearers have been conducted to improve the understanding into the resilience and robustness of the components under service load condition. The full-scale composite bearers are supplied by an industry partner. The full-scale tests have been conducted in structures laboratory at the University of Birmingham. 3D finite element modelling of the bearers has been developed using Strand7. The comparison between numerical and experimental results yields an excellent agreement with less than 3% discrepancy. The results exhibit that the composite bearers behave in the elastic region under service load condition. This implies that they can recover fully under the load, enhancing engineering resilience of the turnout systems.

This paper investigates the current state of ICT use for travel by public and private transportation users in two different Southern African cities of Bloemfontein, South Africa and Gaborone, Botswana. ICT use is seldom in transportation systems in the developing world, the transportation systems are still conventional with minimal communication technologies supporting the system. This study investigates ICT use for travel and travel purposes for which ICT is currently applicable.

Before investigating ICT use, the study first establishes the need for travel and modal split between activities, then explores ICT knowledge and access in both cities to determine feasibility of promoting ICT for travel. The current state of ICT usage for transportation and travel purposes is investigated to determine ICT influence on travel. The study further investigates the perceptions of transportation users towards ICT in transport by investigating ICT components (devices, applications and software) which would be useful for travel at different stages of a trip, and the purposes for which the users would use them.

Road users’ characteristics are amongst the leading causes of traffic fatalities, leading to reduced levels of traffic safety. There are numerous characteristics of road users, yet, two of these characteristics standout, these include the visual acuity factor and the reaction process. There are various factors that contribute to the delay time and reaction process of drivers, and among these are the non-driving-related activities such as adjusting the stereo, environmental controls, conversing with passengers, using a cell phone, searching for street addresses, looking at/for a building…etc. However, there is not a lot of research on non-driving activities such as the use of navigation tools in the form of Global Positioning System (GPS) and navigation phone applications while driving. Through multiple data collection approaches, this study attempts to highlight the effect of navigation tools and risks involved when used while driving. Subsequently answering these questions on the drivers’ reaction process; (i) Can navigation tools be classified as non-driving activities, (ii) Do navigation tools influence drivers’ reaction and decision time and (iii) What are the possible remedies if it affects drivers’ decision time. The findings of the study highlight the risk, the impact of navigation tools on drivers’ behaviour, its influence on traffic crashes and propose the possible countermeasures to this effect.