Lysimeter experiments were conducted under greenhouse conditions to investigate canola (Brassica napus L.) plant water use, growth, and yield parameters for three different water table depths of 30, 60, and 90 cm. Additionally, control experiments were conducted, and only irrigation was applied to these lysimeters without water table limitations. The canola plant’s tolerance level to shallow groundwater was determined. Results showed that groundwater contributions to canola plant for the treatments at 30, 60, and 90 cm water table depths were 97%, 71%, and 68%, respectively, while the average grain yields of canola were 4.5, 5.3, and 6.3 gr, respectively. These results demonstrate that a 90 cm water table depth is the optimum depth for canola plants to produce a high yield with the least amount of water utilization.

In today's world, the needs for transportation have increased and the existing solutions have become insufficient in response to the demand especially with the increase of urban life and the widespread urbanisation. For this reason, local authorities aim to improve urban public transportation services, one of the effective in-city transportation solutions, in order to solve the current needs of transport and reduce or regulate the current traffic intensity. In this study, geographical information system (GIS) was used to analyse the relationship between the bus routes and related stops being offered by Sakarya Metropolitan Municipality (SBB) public transportation service along with the population living in the region to evaluate the level of available current service to the population in each region. An alternative optimisation for the locations of bus stops was presented through a proposed model by comparing the results obtained from the existing positions.

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The failure of cracking is one of the main concerns regarding the performance of hot mix asphalt (HMA). Since the characteristic of the materials of the mixtures has impact on their cracking potential, the main conception of this research is to evaluate the effect of the type of size and additive percentage of crumb rubber modified (CRM) on the resistance of mixtures to crack at mid and low temperatures. For this purpose, rubber bitumen containing 10% and 15% crumb rubber with fine and coarse sizes with wet process was prepared. Asphalt mixtures with dense and gap grading were designed by using rubber bitumen produced by superpave method. The three-points bending test of semicircle bending sample (SCB) was used to evaluate the fracture characteristics of asphalt mixtures at low and middle temperatures (25°C and -12°C). Accordingly, the failure characteristics of asphalt mixtures were evaluated in two modes with short-term and long-term aging. The failure test results indicated that the produced mixtures with crumb rubbers additive have high resourcing resistance compared to control mixtures (without crumb rubber additive), were also revealed. Mixtures with dense grading and fine crumb rubber have high fracture resistance compared to mix with gap grading and coarse crumb rubber. Also, the increasing of the percentage of crumb rubber improved the resistance of the mixed failure. In general, it can be stated that the addition of crumb rubber increases the fracture resistance of asphalt mixtures which can improve its performance before cracking at mid and low temperatures.

In this study effectiveness of lime stabilization and geocell reinforcement techniques of roads was investigated for low bearing capacity subgrades. For this purpose, a large-scale plate load test was designed and used. Clayey soil with high moisture content was reinforced with different percentages of hydrated lime (5%, 10%, 15% dry weight of the soil). The deflection and stress results indicated that lime stabilization or geocell reinforcement alone did not significantly increase subgrade reaction coefficient and bearing capacity values. Promising results were obtained on stabilization of weak subgrade when both techniques were used together. It was determined that cellular reinforcement increased the reaction modulus coefficient value and bearing capacity of the subgrade soil by more than 15% compared to the lime stabilization.