Waste tires are widely used for geotechnical applications as backfill material that is either a substitute for natural soils or combined with them. This paper determines the shear strength parameters of tire chip-sand-geotextile mixtures using a triaxial test apparatus. For this purpose, tire chip–sand mixtures with mixing ratios of 0:100, 15:85, 25:75, 35:65, and 100:0 by volume were used as fill materials. Also, for the reinforcing of these mixtures, the layer of geotextile is used. In all tests, the strain rate has been kept the same. Three confining pressures have been applied in all experiments. The influences of the tire chip content, number of geotextile layers, and confining pressure at the strain levels of 3%, 6%, 9%, 12%, 15%, and 18% on the sample were studied and described. This paper focuses on the stress-strain behavior of different mixtures. The results show that the imposed strain level on the samples plays an essential role to increase the strength of the tire chip-sand mixtures compared with sand alone. It implies that the beneficial effect of tire chip content to enhance the strength of samples appears in high strain, especially for reinforced samples with geotextile, while in low strain, tire chip does not have a beneficial effect. Hence, it is necessary to consider the strength of tire chip-sand mixtures compared with sand alone at the imposed strain level.

Today, the air pollution is a serious environmental problem becoming global concern for human beings Air quality is influenced by emissions, meteorological parameters and topography. The effect of these parameters can be predicted using statistical methods. In current study, the data in the period of March 2012 to October 2013 are used. These data have been gathered from the stations of the Department of Environment and Air Quality Control Organization (Azadi and Sharif stations) in Tehran city. The main purpose was to predict the air quality of the next day and emissions of carbon monoxide and suspended particles under the influence of instability indices and meteorological parameters using the Artificial Neural Network. Results of modeling process showed that the concentration of pollutants is strongly influenced by meteorological parameters. In addition, prediction of the PM10 concentration of the next day using meteorological parameters (RMSE=29.03, R=0.76), instability indices and meteorological parameters (RMSE=28.13, R=0.76) were better than those obtained for AQI predicted by meteorological parameters (RMSE=20.81, R=0.50) and instability indices and meteorological parameters (RMSE=19.23, R=0.47). In general, the predicted values of PM10 and CO were better compared to AQI. It can be concluded that artificial neural network couldn’t load the model properly for AQI compared to PM10.

Moving two rivers from the middle of the Terminal 5 project site at London's Heathrow airport to a new alignment around the western airport perimeter was a critical and highly environmentally sensitive sub-project of the T5 programme. The rivers diversion had to be completed before the original river structures could be demolished to enable continuation of the main terminal development. As described in this paper, the £45 million diversion project included the creation of two 3 km long river channels, phased realignment of 3 km of highway and landscape works to the western boundary of Heathrow.

Transport engineering offers a potentially rich and fulfilling career, not just financially but in terms of the holistic service that transport engineers can offer society long into the future. This paper, which is based on the author's recent Paviors’ Lecture in London, explains that it is not just about getting things done, it is about getting the right things done, which means taking the broadest possible view of what transport engineering is about. In addition to building the right vehicles and infrastructure it also means developing good policies and carrying out good research.

The university city of Cambridge in eastern England has long been a popular place to live—even more so now it has become the UK's equivalent of Silicon Valley. But as with many other historic cities in Europe enjoying an economic boom, balancing increased transport demands with the need to maintain an attractive urban environment is a continual problem.This paper reports on the pioneering yet practical initiatives undertaken in and around Cambridge with varying degrees of success over the past 35 years, culminating in virtual daytime closure of the city centre to car traffic. It involves an innovative scheme of rising bollards for buses and taxis and one of the most advanced park-and-ride schemes in the world.

There is now a real shortage of civil engineering graduates in the UK and, more importantly, a shortage of graduates with appropriate skills to meet the needs of the construction industry. As this paper explains, this is one of several drivers for change in the educational base of civil engineers—the others being the UK Spec, the national qualification framework and the newly formed ConstructionSkills council. But to encourage students to enter the profession there also needs to be clear, simple messages to define civil engineering and what civil engineers do so that the excitement, importance and challenge of the profession can emerge. This will be achieved through increased interaction between industry and higher education.