Sustainable High-Performance Hydraulic Concrete

Concrete has always been indispensable as a material for the engineering and construction of hydraulic structures (e [...]

1 to 10 days extreme rainfall studies for Kerala state

The daily rainfall data for 80 years from 98 stations in Kerala region have been analysed to arrive at the Probable Maximum Precipitation (PMP) estimates for rainfall durations or 1 to 10 days. Hershfield's statistical technique has been adopted for the estimation of PMP from annual maximum data. The study will be useful in the estimation of extreme precipitation for computation of design floods, required for design of spillways of dams and other major hydraulic structures in the Kerala state.

THE HYDRAULICS OF NATURE-LIKE FISHWAYS

Nature-like fishway arrangements are commonly used because these structures imitate the characteristics of natural rivers and effectively allow fish to migrate past river sections blocked by hydraulic structures. In this paper, physical models were analyzed, and the velocity distributions of two different fishway structures (Types I and II) were compared. Results showed that the maximum mainstream velocity of the Type I structure was 5.3% lower than that of the Type II structure. However, the average mainstream velocity of the Type I structure was 21.1% greater than that of the Type II structure. The total per-cycle length of the mainstream path in the Type II structure was 2.1 times greater than that of the Type I structure, which indicated that the length of the mainstream path was somewhat proportional to the average velocity of the mainstream. When the flow rate was kept constant, increases in the velocity of the main flow associated with changes in the internal structure of the fishway decreased the average velocity of the main flow, while decreases in the total length of the flow path led to increases in the average velocity of the main flow. Due to frictional head loss along the fishway and local head loss, as well as the overlaps between these factors, the overall flow rate gradually decreased every cycle, despite periodic fluctuations.

CONTROL AND METHODOLOGY OF MODELING HYDROLOGICAL PROCESSES IN THE DESIGN OF HYDRAULIC STRUCTURES IN THE ESTUARIES OF RIVERS

The article presents the methodology of hydrological modeling of water flows for constructing flow plans in the design of hydraulic structures. On the basis of these calculations, both the specific costs of bottom and suspended sediments in each flow stream and the deformation of the riverbed at various points in time can be determined. The results of experiments with spatial models of river sections are considered. The developed technique makes it possible to calculate the deformation of the bottom and shores and form a flow organization scheme, which, due to an increase in velocities in some section of the channel, ensures sediment transport to more remote areas of the seashore, up to the open sea.

STRESS-DEFORMED STATE OF THE FOUNDATION OF HYDRAULIC STRUCTURES AT CONTROLLED COMPENSATION DISCHARGE

Nnumerical simulation of the process of injection of mortar into the thickness of the sandy base during the work on lifting and leveling the structure by the method of compensatory injection is carried out. An author's program has been developed that implements the finite element method (FEM) in a spatial formulation, taking into account the elastic-plastic nature of soil deformation, in which a special element in the form of a spheroid has been developed to describe the expanding area at the location of the injector, which changes its volume during the injection of mortar. During the verification of the program, the results of mathematical modeling were compared with the data of a physical experiment conducted by PhD Luca Masini from the University of La Sapienza (Rome, Italy). Numerical modeling of the stress-strain state of the base of the structure during repair work is considered by the example of lifting the foundation plate of the Zagorskaya PSPP-2. A number of tasks are being solved related to minimizing the number of injection columns, their location, the pitch of the cuffs, the selection of portions of the injected solution, taking into account the requirements for uniform lifting of the foundation plate in order to avoid additional cracking.

Assessment of the resource formation of truck tires in mountainous conditions during the construction of the Rogun hydro power plants

In the harsh mountainous conditions of the operation of trucks during the construction of hydraulic structures, the car tire is the most vulnerable element that determines the efficiency of the transport process and the cost of transportation. Due to a significant decrease in the resource of truck tires in the harsh mountain conditions, the cost of operating a vehicle increases significantly. The purpose of the study is related to the assessment, adjustment and regulation of the resource, as well as planning the costs of purchasing and the entire life cycle of truck tires operated in mountainous conditions. The work is devoted to the assessment of the formation of the resource of truck tires in the mountainous conditions of the construction of the Rogun HPP, taking into account the influence of the most significant factors. To assess the formation of the resource of truck tires in the mountainous conditions of the construction of the Rogun HPP, an integrated scientific approach was used, taking into account the most significant factors. The assessment of the influence of fluctuations of external influences on the object of research, depending on the conditions and nature of the process of formation of the tire resource was carried out by the probabilistic-statistical method, and the empirical characteristics of the distribution of the above factors were calculated by the method of V.I. Romanovsky. The simplified mathematical model presented in the article can be recommended when adjusting the tire resources of trucks in mountainous conditions during the construction of hydraulic structures (for example, the construction of the Rogun HPP). The practical significance of the work is associated with the selection and planning of the need for automobile tires, operated in mountain conditions. The research results can be recommended for assessing the resource of tires of various standard sizes and designs mounted on trucks of various modifications, operated in various road and climatic conditions during the construction of hydraulic structures.

Biological Attacks on Underground Hydroelectric Pump Storage Power Stations

Studies have shown the unconditional danger of biological attacks on underground hydroelectric pumped-storage power stations. A hypothetical list of biological damage to water conduits and dams is determined. Relevant predictions are given, as well as accident events of hydraulic structures are described. A universal scheme for the application of hazard protection measures, which can be comprehensive, has been developed. Praemonitus praemunitus – precautions should be taken.

Devastating rainstorm of June-2013 in Uttarakhand

The state of Uttarakhand is prone to floods and landslides due to its topographic location. The state of Uttarakhand and neighbouring states experienced heavy to very heavy rainfall during 15-18 June, 2013. The analysis of this rainstorm is important because it caused severe floods, landslides, loss of thousands of lives, property etc. During this period, many stations reported very heavy rainfall with a few extremely heavy rainfall (more than 24.5 cm in a day) in Uttarakhand and also in the neighbouring states of Himachal Pradesh, Haryana and Punjab. Most part of the state of Uttarakhand lies in the Greater Himalayan region. For safety from floods, one of the methods is to store water in hydraulic structures. For planning and designing of hydraulic structures, the estimation of design storm is the primary and the basic input for the computation of design flood. In the estimation of design storm, all the heavy rainstorms occurred over or near the area have to be analysed. In this paper, this rainstorm and other heavy rainstorms over a wide area has been analysed for the purpose of computation of Design storm estimates of hydraulic structures in that area. The rainstorm of June 2013 is compared with the earlier historical heaviest rainstorm of 28th to 30th September, 1924 at Lansdowne and it is observed that the rainstorm of June 2013 has contributed more rainfall than the rainstorm of September 1924 rainstorm for an area up to 5000 km2 for 1-day duration, while the DAD estimates for two day and three duration of rainstorm of September 1924 are higher than the rainstorm of June 2013 for area up to 20,000 km2.