This research analyzes the peaks-over-threshold (POT) method for designed flood estimation needed to plan river levees, spillways and water facilities. In this study, a one-parameter exponential probability distribution has been modified by including the coefficient of λ, which represents an average number of floods and enables return period calculation within the specified period of time. The study also compares results using the Log-Pearson Type III distribution of maximum annual flows and a standard exponential distribution of the selected peaks over the threshold level. The aforementioned approach represents the standard mathematical tools for river flood design, while the proposed modification of the exponential distribution highlights the estimation of flood quantiles with longer return periods (e.g., 100, 1000 and 10,000 years). Moreover, the sensitivity analysis of the threshold selection is proposed to assist in the flood design flow estimation alongside the proposed modification of the exponential probability distribution. The study was carried out at the Danube River, and the Novi Sad hydrological station (Republic of Serbia) was used for the long-term recorded period from 1876 to 2015. The results suggest that the POT method derives more reliable estimates of design floods than the traditional statistical tools for flood estimation. The results suggest the theoretical values of the water level of the 10,000 years return period is equal to 867 cm, while the Log-Pearson Type III distribution of annual maximum flows underestimated this value for 14 cm.

The hydropower potential in the Republic of Serbia, as the most important renewable energy source, has been estimated at around 17000 GW·h per year, where approximately 2000 GW·h could be obtained from small hydropower plants (SHP)....

The objective of this research was to determine the probability of road overtopping occurrence for a road culvert caused by surface runoff from the upstream catchment. A hydrological–hydraulic model was used for the development of an algorithm for road culvert maintenance based on the overtopping occurrence probability (CMOOP algorithm) for small mountain catchments. The hydrological model defines the regression dependence between the runoff hydrograph peak values and the probability of occurrences, whereas the hydraulic model calculates the culvert flow capacity by including in the calculation the level of sediment that culvert is filled with. The relationship between occurrences of overtopping and peak runoff value was defined using the runoff hydrograph transformation model in the accumulation on the upstream side of the road. In addition to the calculation of overtopping occurrence probability for the existing culvert condition, the CMOOP algorithm was used to analyze the impact of rehabilitation and reconstruction works from the perspective of legally based safety criterion for road overtopping occurrence probability (SCROOP). The CMOOP algorithm was appled to 67 concrete culverts located in a mountain road section in the Republic of Serbia. The results show that the application of rehabilitation works on selected culverts will increase the percentage of culverts that satisfy SCROOP from 49.25% to 89.55%, which confirms that the accumulated stone sediment is the main reason for the SCROOP unfulfillment.

In recent years, there has been increasing interest in the use of recycled concrete aggregate (RCA) as a sustainable alternative to natural aggregates in construction. RCA is obtained by crushing and reusing old concrete, which contains both the original aggregate and a cement mortar layer. However, the quality of RCA can vary depending on the characteristics and quantity of the leftover mortar. In this study, we aim to investigate different methods for improving the chemical, physical, and mechanical features of RCA, with a focus on untreated RCA, RCA exposed to a presoaking treatment in HCl, and RCA exposed to rapid carbonation. The overall results show that if RCA is obtained by crushing compact, high-quality concrete, the procedures for improving aggregate quality are not necessary.

The selection of optimal solution for road construction mechanization has been presented on the case of access road construction. For selection between possible alternatives the Promethee method of multicriteria decision analysis has been used. The alternatives were evaluated through the several criteria (number of machinery, total cost, time, machinery reserve, practicle effect, number of people, price of effective working hour) and the impact of each criteria on the final ranking of alternatives has been analyzed. The optimal solution was determined by comparing the two different scenarios (with different relative weights for criterias) in the multicriteria decision analysis model. Conclusions on each criteria influence on final ranking were presented in this paper.

This paper investigates the influence of soil idealization on stress distribution and settlement beneath isolated footings of building structures. Two basic soil models commonly used in geotechnical engineering practice are analyzed: the elastic half-space model and the finite-thickness soil layer model resting on a rigid base. Stress and settlement analyses were performed for square isolated footings of different dimensions subjected to a constant uniformly distributed surface load, while varying the mechanical properties of the soil. Particular attention is devoted to comparing the soil deformation response at characteristic points along the footing-soil interface. The obtained results indicate a significant influence of the selected soil model, soil deformability (soil stiffness, E), and footing geometry on settlement values, confirming the necessity of a careful choice of the calculation model in geotechnical design.