scholarly journals Marine transportation-technological systems safety and development

2018 ◽  
Vol 2 (51) ◽  
pp. 45-49
Author(s):  
Konstantin Iegupov ◽  
Sergey Rudenko ◽  
Oleksiy Nemchuk
Keyword(s):  
Hydraulic Structures ◽  
Seismic Resistance ◽  
Seismic Loads ◽  
Marine Transportation ◽  
Balanced Development ◽  
Regulatory Documents ◽  
Scientific Support ◽  
Design Loads ◽  
Zone Development ◽  
Planning Development

The article deals with marine hydraulic structures design and operation, considering the influence of various superstructures and reloading equipment. The analysis of seismic resistance of the hydraulic structures erected in the seismic regions of Ukraine has shown that the actual seismic loads on the structures significantly exceed the design loads being determined by regulatory documents prior to 2006. In the era of globalization, transformation of cargo flows, changes in their structure, the issue of ports planning development, implying port capacities balanced development, namely: sea zone port zone, and land zone development, becomes particularly important. The design of hydrotechnical structures should be carried considering the transshipment complexes at the quay with proper scientific support.

scholarly journals Dynamic Calculation of the Pile Supported Wharf

2018 ◽  
Vol 2 (51) ◽  
pp. 37-44
Author(s):  
Konstantin Iegupov ◽  
Gennady Meltsov ◽  
Vyacheslav Iegupov ◽  
Denys Bezushko
Keyword(s):  
Hydraulic Structures ◽  
Seismic Resistance ◽  
Seismic Load ◽  
Dynamic Calculation ◽  
Influence Analysis ◽  
Normative Documents ◽  
Scientific Support ◽  
Seismic Regions ◽  
Ship Repair

The article deals with the issues of designing and operating marine pile supported wharf in the seismically hazard areas considering various superstructures and overload equipment influence. Analysis of hydraulic structures seismic resistance erected in seismic regions of Ukraine shows that the actual seismic load on buildings significantly exceeds the estimated loads that are determined by the normative documents before 2006. Design of hydraulic structures should be done considering berths of reloading complexes, with proper scientific support. Berth construction calculationsof the ship repair yard No. 2 of the «Ilichevsk Ship Repair Plan» are given.

scholarly journals Analysis of Seismic Resistance of Large-Sized Electrical Equipment by the Method of Computational Analysis

2021 ◽  
Vol 21 (2) ◽  
pp. 17-27
Author(s):  
A. S. Koshmak ◽  
◽  
V. B. Krytskyi ◽  
V. O. Kurov ◽  
Y. O. Oborskyi ◽  
...  
Keyword(s):  
Experimental Method ◽  
Electric Motor ◽  
Computational Analysis ◽  
Electrical Equipment ◽  
Computational Method ◽  
Seismic Resistance ◽  
Seismic Loads ◽  
Seismic Action ◽  
Electric Motors ◽  
Regulatory Documents

In the framework of this article, the problem of confirming the seismic resistance of large-sized electrical equipment is raised using the example of large asynchronous electric motors. The analysis of regulatory documents for the assessment of the seismic resistance of such equipment showed that confirmation of seismic resistance should be performed by an experimental method and other methods can be applied only with sufficient justification of the correct functioning of products. At the same time, rather stringent requirements are established for the test conditions, which in many cases are rather difficult to implement or cannot be met at all. The analysis of the possibility of testing the ASVO 15-23-34M1 electric motor, which is used as fan drives for seismic resistance by an experimental method, under the conditions of specialized organizations accredited in Ukraine, has been carried out. It was found that the existing test installations, due to their characteristics of carrying capacity, cannot be used to carry out tests for seismic resistance of electric motors weighing more than 600 kg. Considering the above, we can conclude that the justification of the seismic resistance of such equipment by experimental methods in Ukraine today is impossible. The analysis of current standards and special normative documents for seismic testing has been carried out. In these documents, clarifications are established on the separation of electrical equipment according to their design features, which make it possible to confirm the seismic resistance of certain groups of equipment by calculation methods. The requirements for the assessment of seismic resistance by the computational method and the evaluation criteria are established. The main purpose of such an assessment is to confirm that the engine retains its structural integrity and performance during and after the passage of seismic action. An assessment of the seismic resistance of the ASVO 15–23–34M1 electric motor was carried out by the method of computational analysis using the method of limiting seismic resistance. A finite element model of an electric motor has been built taking into account all the necessary operational and seismic loads. Strength analysis was carried out using the APM Structure 3D code. Taking into account the results of the performed calculations, it can be concluded that the seismic resistance of the engine during an earthquake with an intensity of up to 8 points according to the DSTU BV.1.1–28:2010 scale is confirmed. The engine withstands seismic loads and remains operational during and after the passage of an earthquake. The minimum value of the ultimate seismic resistance of the engine is determined by the seismic resistance of the stator HCLPF = 0.142 g. Based on the results of the analyses carried out, it can be concluded that the use of the computational method for assessing the seismic resistance of large-sized electrical equipment does not contradict the requirements of the current regulatory documents and can be used as a replacement for the experimental method in cases where tests are impossible or impractical. Modern computer simulation and calculation technologies allow for a comprehensive assessment of the equipment seismic resistance and obtain high reliability results.

On the question of setting the level of calculated impact and reliability of high-rise construction

2021 ◽  
pp. 43-56
Author(s):  
Dmitry M. Zhemchugov-Gitman ◽  
Lyubov V. Mozzhukhina ◽  
Alexander M. Uzdin
Keyword(s):  
Seismic Design ◽  
Earthquake Engineering ◽  
Seismic Loads ◽  
Seismic Action ◽  
Seismic Zoning ◽  
Reliability Factor ◽  
High Rise ◽  
Regulatory Documents ◽  
Reduction Coefficient ◽  
Damage Risk

The question of setting the seismic design input on high rise buildings is considered. The existing approaches to accounting for increased responsibility of high rise buildings in Russia are described. The proposal to reduce the probability of an acceptable building failure in proportion to the number of floors and Guideline proposals to increase the reliability factor and using maps of general seismic zoning are analyzed. The main disadvantages of methods described are indicated. It is shown that the current regulatory documents in the field of earthquake engineering do not provide the same reliability of designed structures in general and high-rise buildings in particular. The influence of seismic dangers in according with seismic zoning maps on the reliability of the designed objects is noted. An approach to generating the design input based on the permissible probability of its exceeding is considered using the example of five five-storey buildings and one 25-storey buildings. The probability of the admissible damage value included in the normative calculations is estimated. An estimate of the allowable failure probability on the value of acceptable damage (risk) is proposed under the assumption of a normal distribution of damage caused by earthquake. It is shown that the allowable failure probability decreases with decreasing acceptable damage only in the area of small damages. An approach to the assignment of seismic action based on an assessment of seismic risk has been formulated. The system of design coefficients used to calculate seismic loads on high-rise buildings is analyzed. It is noted that along with an increase in the design level of seismic acceleration, it is necessary to increase the coefficient, taking into account the low damping of high-rise buildings oscillations. At the same time, it is possible to significantly reduce the reduction coefficient by regulating the strains between the building floors.

scholarly journals SEISMIC STABILITY OF THE MOORING WALL ACCORDING TO THE RESULTS OF NUMERICAL SIMULATION

2019 ◽  
pp. 2-2
Author(s):  
Victor A. Esinovsky
Keyword(s):  
Numerical Simulation ◽  
Spectral Theory ◽  
Strain State ◽  
Dynamic Theory ◽  
Seismic Stability ◽  
Hydraulic Structures ◽  
Seismic Loads ◽  
Stress Strain ◽  
Stress Strain State ◽  
Seismic Forces

Introduction. New building codes provide for a significant increase in the magnitude of seismic loads that should be perceived by hydraulic structures. In this regard, even in areas with low seismic activity, there may be a problem of ensuring the seismic stability of hydraulic structures. This is particularly acute in berthing facilities. As a rule, they are not so massive to withstand seismic loads. The issue of seismic stability of berthing facilities has not yet been properly considered. The results of numerical simulation of the seismic stability of the mooring-dividing wall during a 7-point earthquake are considered. A structure about 24 m high located on a non-rock base was investigated. Materials and methods. The seismic stability of the mooring structure was estimated by calculating its stress-strain state under the action of seismic forces. Calculations were carried out by the finite element method. Seismic loads on the structure were determined in two ways — by linear-spectral theory and by dynamic theory. For the calculation of seismic loads, 30 lower frequencies and the natural mode of the structure were determined together with an array of its base. When calculating according to the dynamic theory, the seismic effect was specified in the form of an accelerogram adopted for similar conditions. The direction of seismic impact was assumed horizontal. Results. According to the dynamic theory, seismic loads turned out to be lower than according to linear-spectral theory. However, the results of the calculation of the stress-strain state of the mooring structure were close. It was found that the seismic forces on the mooring wall will reach about a quarter of the weight of the structure. Under the influence of such forces, the mooring wall will lose its stability. Conclusions. To ensure seismic stability, it is recommended to combine the mooring wall and the base plate into a single monolithic structure, as well as to strengthen the lower part of the structure and facilitate the upper one.

Structural Analysis of Rigid High-Pressure Risers for Seismic Loads

2021 ◽  
Author(s):  
Mahesh Sonawane ◽  
Rohit Vaidya ◽  
Hunter Haeberle
Keyword(s):  
High Pressure ◽  
Offshore Structures ◽  
Mitigation Strategies ◽  
Seismic Loads ◽  
Wave Loading ◽  
Design Data ◽  
Final Design ◽  
Design Loads ◽  
Offshore Risers ◽  
Low Probability

Abstract Typically, the design of all offshore risers focuses on environmental loads i.e. wave loading, wind loads and currents. While these loads are ubiquitous in an offshore environment, accidental loading in the form earthquake induced seismic loads is an important criterion in the design of offshore structures. API RP 2A recommends site-specific studies as a basis for developing the ground motion specification of the design criteria, particularly for sites in areas of high seismicity (Zones 3–5). Seismic loads are low probability events in most cases and there isn't enough data in the initial pre-FEED / FEED phase of project to conduct seismic studies on the riser systems. Designers have to rely on past experience, code guidance, and assumptions for design data. In this paper through the means of two (2) case studies for a region prone with high seismic activities, we will demonstrate the challenges of designing rigid High-Pressure Riser Systems for seismic loads. A comparison will be provided for assumed loads based on code guidance and loads derived from preliminary seismic studies. In addition, comparisons will be provided for the final design loads achieved after the detailed platform design. The results will show the risks of relying solely on one source of data in the design process that can imperil the fabrication / procurement process with redesign due to unforeseen loads. Design optimization through proper centralization and other mitigation strategies will be presented for the benefits of future concrete based fixed platform projects.

scholarly journals Calculated Determination of the Seismic Resistance of Nuclear Power Plant Equipment

2021 ◽  
Vol 24 (2) ◽  
pp. 24-36
Author(s):  
Serhii A. Palkov ◽  
◽  
Ihor A. Palkov ◽  
Keyword(s):  
Calculation Method ◽  
Three Dimensional ◽  
Seismic Intensity ◽  
Normal Operation ◽  
Seismic Resistance ◽  
Seismic Loads ◽  
Design Basis ◽  
Turbine Condenser ◽  
Steam Turbine Condenser

An algorithm to confirm the seismic resistance of equipment by a calculation method is proposed, and the limits of its application are determined. A mathematical model of the equipment is developed, and an example of the determination of natural frequencies and stresses for a three-dimensional structure is given. Two main types of calculation were used – static and dynamic. In the static calculation, the stress-strain state of a structure was determined. The values of the obtained stresses were compared with the allowable ones for the materials used, on the basis of which conclusions were made about the strength of the structure under seismic effects. The dynamic calculation resulted in the determination of the rigidity of the structure. The comparison of the stress values obtained for this equipment allowed us to make a conclusion regarding its resistance to seismic effects. The seismic resistance of the equipment was estimated on the example of the K-1000-60 / 1500 steam turbine condenser, and calculated at a seismic intensity of 6 points on the MSK-64 seismic intensity scale. In the course of solving this problem, results of the stress distribution in the housing and other structural elements of the condenser due to the action of combined normal operation and design-basis seismic loads were obtained. The seismic resistance of the equipment was calculated using the finite element method. This allowed us to present a solid body in the form of a set of individual finite elements that interact with each other in a finite number of nodal points. To these points are applied some interaction forces that characterize the influence of the distributed internal stresses applied along the real boundaries of adjacent elements. To perform such a calculation in CAD modeling software, a three-dimensional model was created. The obtained geometric model was imported into the software package, which significantly reduced complexity. The use of the calculation method allows us to significantly reduce the amount of testing when confirming the seismic resistance of equipment. Results of the assessment of the spatial complex stress state of the steam turbine condenser design due to the action of combined normal operation and design-basis seismic loads are obtained.

scholarly journals Subsidence deformations of the foundations of hydraulic structures

2021 ◽  
Vol 264 ◽  
pp. 03069
Author(s):  
Rustam Хujakulov ◽  
M Zaripov ◽  
U Normurodov
Keyword(s):  
Stressed State ◽  
Strain State ◽  
Stress Redistribution ◽  
Hydraulic Structures ◽  
Physical Processes ◽  
Irrigation Systems ◽  
Stress Strain ◽  
Regulatory Documents ◽  
Stress Strain State

One of the most important tasks in designing and constructing reclamation network structures on loess subsidence soils is to ensure their long-term trouble-free operation. The improvement of methods for the design of hydraulic structures on subsidence foundations requires further study of very complex physical processes occurring in the foundations of structures during their construction and operation. This is confirmed by the fact that even if all the requirements and recommendations of regulatory documents for the design of irrigation systems on subsiding soils are observed, the deformations of the foundations of structures often significantly exceed the calculated ones, which can cause a loss of serviceability of irrigation structures. This determines the need for further study peculiarities of interaction of irrigation structures with their subsidence bases. This article is devoted to this problem, in particular, to the study of the influence of stress redistribution in wetted subsidence foundations of hydraulic structures on the stressed state of their elements and the stress-strain state of loess subsidence foundations on the models of float bets of hydraulic structures in the Karshi steppe.

ASSESSMENT OF THE IMPACT OF CHANGES IN THE CHARACTERISTICS OF EXTREME HEAVY RAINS ON THE RELIABILITY OF HYDRAULIC STRUCTURES

2021 ◽  
pp. 99-105
Author(s):  
N. P. KARPENKO ◽  
◽  
A. A. NAUMOVA ◽  
V. V. ILJINICH
Keyword(s):  
Daily Precipitation ◽  
Accurate Method ◽  
Operational Reliability ◽  
Hydraulic Structures ◽  
Normative Values ◽  
Expert Assessment ◽  
Main Hypothesis ◽  
Regulatory Documents ◽  
Maximum Water ◽  
The Impact

The article on the observations of weather stations in the south-west of the Chernozem (Black Earth) zone of Russia checks the main hypothesis about the increase in the maximum daily precipitation which is the basis for calculating the maximum water consumption when designing reservoirs of hydraulic structures on small catchments. Statistical calculations showed a clear regional trend towards an increase in the maximum daily precipitation over time. Studies have confirmed a significant asymmetry in the distribution of their values, the ratio between the coefficients of asymmetry and variation ranges from 2 to 5. It isnoted that there is currently no sufficiently accurate method for determining the coefficients of asymmetry, therefore, approaches to their expert assessment have been proposed. It isrecommended to estimate the normative values of the maximum daily precipitation for erosion calculations using empirical probability curves. Thus, in the current regulatory documents intended for the design of hydraulic structures, there are shortcomings in the methods for determining hydro meteorological characteristics which leads to a decrease in their operational reliability during the passage of dangerous rain floods. The necessity of appropriate updating of the existing regulatory documents is substantiated.

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