Economic Efficiency of Debris-flow Control

Debris-flow is one of the most formidable manifestations of nature. A debris-flow moving along the bed of the debris-flow-carrying river on its way destroys bridges, roadways, roads, hydro-technical and other facilities, causes significant damage to agricultural land, residential buildings, social infrastructure, poses a serious danger to the life and health of the population. A possible way to solve this problem is the construction of engineering structures that ensure the protection of the population living in the area at risk of debris-flow passing, the preservation of both natural and man-made material assets. It is determined that the dependence of the Net Present Value (NPV) on the frequency of the debris-flow passage has a hyperbolic character. The value of NPV reaches its maximum with the annual passage of the debris-flow. With a decrease in the frequency of debris-flow passing, the efficiency of capital investments in a protective structure decreases sharply

Efekty zwartego przepływu gruzowego przez pół cylindryczną konstrukcję antyosuwiskową

Counteracting the phenomenon of debris flow is implemented in various ways. As international practice has shown, hydrotechnical constructions occupy a special place among structures regulating debris flow . Despite the large variety of constructions, each of them has a strictly defined purpose. The specifics associated with the hazards of debris flow in a given area are taken into account when selecting such a construction The work indicates the expediency of applying semicylindrical open-web constructions to regulate debris flow. The methodology of selecting the design elements is presented. A specific example of the construction calculation and graphic illustrations are presented.Przeciwdziałanie zjawisku przepływu gruzowego jest realizowane na różne sposoby. Jak pokazała praktyka międzynarodowa, konstrukcje hydrotechniczne zajmują szczególne miejsce wśród struktur regulujących przepływy gruzowe. Mimo dużej różnorodności konstrukcji każda z nich ma ściśle zaznaczony cel. Specyfika związana z niebezpieczeństwem przepływu gruzowego w danym obszarze jest brana pod uwagę przy ich doborze. W pracy wskazano celowość zastosowania półcylindrycznych konstrukcji w otwartych kanałach stosowanych w celu regulowania przepływu gruzowego. Przedstawiono metodologię doboru elementów konstrukcyjnych. Przytoczono konkretny przykład obliczeń konstrukcyjnych oraz ilustracje graficzne

Estimation of breaking risks of Zhinvali Earth Dam taking into consideration the “CAPRA”

Г. В. Гавардашвили, Э. Г. Кухалашвили, Т. Г. Супаташвили, И. Р. Иремашвили, И. А. Купарашвили, К. Г. Бзиава, Г. Т. Натрошвили. ОЦЕНКА РИСКОВ ПРОРЫВА ЖИНВАЛИЙСКОЙ ПЛОТИНЫ С УЧЕТОМ МЕТОДА «CAPRA»Georgia is one of the most vulnerable countries to natural disasters within South Caucasus Region. In recent years, the disaster risk has increased due to faulty land-using. Outstanding building codes lead to inadequate building construction. There is a lack of real data on natural disasters and the impact of mudflows, floods, debris flows etc. on land-use planning and prompt actions after above mentioned catastrophes. Therefore, it is important task to carry out assessments of critical structures sensitive to natural threats such as dams and reservoirs. In order to be able to improve the resistance of hydraulic engineering structures it is necessary to utilize a formal risk analysis framework, such as the Critical Asset and Portfolio Risk Analysis (CAPRA) method. The scientific article examined the creation of a framework for the condition of the earth dam and risk management using the analysis of the critical state and the risk portfolio, which was developed by Professor Billal Ayyub who represents Maryland University in USA, to examine human-caused threats, such as terrorism events, and natural hazards, such as flooding due to dam failures, with focus on potential failure modes due to deterioration. For this purpose, based on the field and theoretical studies, the regulation of hydrological (floods, debrisflows, snow avalanches), geological (erosion, mudflows), and seismic (earthquake), as well as those natural disasters formed in the water area of Zhinvali Reservoir, which determines the stability and reliability of the Zhinvali Earth Dam, is estimated using existing statistical data and theory of reliability and risk. Special attention is paid to the safety of the population living in the risk zone, as well as the development and evaluation of methods and principles of the impact of expected disasters