Using mass tuning dampers for seismic protection of marine mooring berth
Authors: Areschenko T.S., Uzdin A.M., Frolova E.D., Nesterova O.P., Simkin A.Yu., Us P.V.
Key words: mooring berth, seismic protection, tuning mass dampers, tuning of mass damper parameters
A possibility of using tuning mass dampers for the seismic protection of mooring berth in seismic prone areas is considered. In this case the problem of selecting mass damper parameters has two features. Firstly, a crane can turn out to be on the mooring berth during an earthquake. This situation demands considering two possible tunings of the mass damper: the first one to reduce marine terminal vibrations and the second one to reduce crane vibrations otherwise two dampers can be used. Secondly, it is necessary to ensure the effectiveness of mass dampers both for frequent weak actions (design earthquakes) and for destructive rare impacts (maximum design earthquakes). The paper discusses the tuning of mass damper parameters and their effectiveness. The results are illustrated by calculating the structure under the harmonic excitation and under the action given by earthquake accelerograms. It is shown that the mass damper can reduce the load on the structure during design earthquakes and structure damages at the maximum design earthquake.
Design analysis, design of components, buildings and structures
Application of natural oscillation frequency for evaluation of technical condition category of structures
Authors: Nigmetov G.M.
Key words: danger of collapse of structures, critical force of stability loss of the structure, stiffness structures natural frequency structures, the definition of technical condition of structures
It is proposed to use the square of natural oscillation frequency to determine the category of technical condition of various structural types of structures. Quantitative criteria for assessing the category of technical condition of structures are substantiated. The criteria allowing to draw a conclusion about probability of possible collapse on the basis of data on the measured frequencies of natural oscillations of structures are received.
Safety of earth structures, bases and foundations
Modeling and analysis methods of the system pile foundation – earth foundation in SCAD Office and SMath Studio
Authors: Nuzhdin L.V., Mikhaylov V.S., Rezyapkin V.V.
Key words: pile-and-slab foundation, linearly elastic foundation, Winkler ground base model, SCAD Office, SMath Studio
The article presents a brief review of the main methods for creation of analytical and numerical models of slab-pile foundations in accordance with the applicable technical rules in the structural analysis complex SCAD Office. In order to define the optimal analysis method for pile-and-slab foundation, two analytic methods of piling modeling are considered in accordance with SNiP 2.02.03-85 and SP 24.13330.2011. The analysis of analytic modeling, which is regulated by standards, is carrying out with the mathematical package SMath Studio. The complete analysis technology is supposed to use a standard mathematical package for import and export to and from common data interchange format (DIF) in a structured view, which is acceptable for import and export in the SCAD system. Detailed description of the technology of calculation is presented by authors, indicating the limits of applicability of these methods and recommendations for their use in static conditions.
