Yerzhanov S.Е.
Yerzhanov S.Е.

Ержанов С.Е. Yerzhanov S.Е.
Ph.D. in Engineering Science, Adviser to Director General for Science, Corresponding Member of NEA RK and IEA,KazNIISA JSC, Republik of Kazakhstan, Almaty


Publications


Issue: №4 2018
read more


Issue: №3 2018
read more

Dynamics of the Object of Polygon of Seismic Isolation: Building with Supports on Fluoroplastic Gaskets
Issue: №6 2019
read more

To study the seismic insulating properties of buildings in Almaty there is a special polygon. It includes buildings with conventional strip foundations with a system of cross-belts, seismic kinematic and supports with PTFE gaskets. The buildings are equipped with stations of engineering and seismometric service (seismic stations 20,21,22). The results of experimental studies of the house on fluoroplastic gaskets, performed in the late 80s, are analyzed. The results are compared with the instrumental records of the earthquakes of May 31, 2012 and August 16, 2014. The period of maximum spectrum coincides with the resonance in the initial stages of vibration tests-0.44-0.47 seconds. Using a single-mass calculation scheme taking into account the presence of dry friction forces, the dynamic model of the building was calculated for the impact of an unsteady random process. The median acceleration values at the base correspond to the “Seismic Zoning Map of the Republic of Kazakhstan” for earthquakes with a frequency of 475 years and 2475 years. Probabilistic estimates of displacement values at the support level are obtained.

Object Dynamics of the Seismic Isolation Site: Analogous Building
Issue: №3 2019
read more

The results of reference building (analogous building) research at the seismic isolation site is presented in the study. A system of cross-strips foundations, seismic insulating kinematic foundations and pillars with fluoroplastic gaskets were utilized in building construction. There are stations of engineering seismological measurement services installed on the buildings. It is analyzed the experimental studies for analogous building performed in the late 80s. The results are compared with the earthquake instrumental records happened on August 16, 2014. According to the seismological measurement services the building oscillation period is 0.40 sec, that fully corresponds to data vibration test with a minimum load of unbalances - 0.39-0.42 sec. It has been established that the floor distortions decrease with building height. Mainly the building is deformed by shear scheme. Taking into account the experimental data, a piecewise linear diagram of the deformation of a single-mass dynamic model of a building is constructed.

Dynamics of the Object of Polygon of Seismic Isolation: Building at Kinematic Foundations
Issue: №2 2019
read more

To study the seismic insulating properties of buildings in Almaty there is a special polygon. It includes buildings with conventional strip foundations with a system of cross-belts, seismic kinematic and supports with PTFE gaskets. The buildings are equipped with stations of engineering and seismometric service. The results of experimental studies at home on KF, performed in the late 80-ies. The results are compared with the instrumental records of the earthquakes of May 31, 2012 and August 16, 2014. The period of maximum spectrum coincides with the resonance in the initial stages of vibration tests-0.45-0.51 seconds. It is established that floor distortions of floors of the building decrease with height. With the use of a one-mass calculation scheme, taking into account the nonlinear deformation diagram, the dynamic model of the building is calculated for the impact in the form of accelerograms of the specified earthquake at the Foundation level.

Spectral Analysis of Non-Canonical Representation of Random Process in the Earthquake Action Modeling Problems for Proportioning of Buildings and Structures
Issue:
read more

Model of earthquake effect in the form of combination of simple functions with random parameters is analyzed. Random process simulating earthquake effect is given by non-canonical representation. Method of generation of artificial accelerograms of local earthquakes is proposed based on presentation of correlation function as a sum of cosine exponential summands. Approximation parameters of correlation function were defined earlier on the basis of least square method by using MATLAB package with the application of methods of nonlinear approximation. Coincidence of initial and generated spectral curves is used as a quality criterion. Selections of random process realizations from 20 to 10000 accelerograms are used. Algorithms are simply implemented in present day systems of computer mathematics MATLAB, SCILAB. Mathematical model of accelerogram of earthquake in El Centro, 1940, has also been considered. Algorithms application area — computations with the use of Eurocode 8 and standards ISO 2394, ISO 8930, including with the application of probabilistic methods, reliability assessment of buildings and constructions based on the method of statistical testing.

Generating Artificial Accelerograms of Local Earthquakes
Issue:
read more

Approaches to proportioning of buildings and structures, based on direct numerical integration of dynamic equations, continue to be relevant. For this purpose realistic or artificial accelerograms are used. Probabilistic methods of calculation are based on generation of artificial accelerograms as random-process realizations. There is proposed method of generation of artificial accelerograms, based on representation of correlation function as sum of cosine-exponential summands. Approximation parameters are defined on the basis of least squares method through the use of Curve Fitting Toolbox CKM MATLAB package. Artificial accelerograms are generated by utilizing design formula of autoregression (moving average). Accuracy of generation is illustrated by computation of spectral curves. 

ALGORITHMS FOR DETERMINATION OF SEISMIC RISK FOR BUILDINGS AND STRUCTURES IN THE REPUBLIC OF KAZAKHSTAN WITH DUE CONSIDERATION OF SEISMIC ZONING DATA
Issue:
read more

The paper studies the matters of quantitative estimation of seismic risk values for buildings and structures with due consideration of new seismic territorial zoning maps of the Republic of Kazakhstan. On the example of seismic risk value calculation for 2 experimental fragments of skeleton-type industrial buildings, influence of occurrence frequency of earthquakes is assessed. Non-linear deformation of indicated building fragments is taken into consideration. There is also provided an example of risk value calculation for buildings at the local site. Importance of availability of necessary legalized
seismologic information for seismic risk assessment for RK inhabited localities is noted.

Studies of instrumental records of the engineering seismometric service at the Kapchagay HPP
Issue:
read more

Instrumental records of accelerations at the Kapchagay HPP facilities (soil, HPP building and channel dam) at the intensity 5 earthquakes are given for the first time. Spectral curves ? are built. It has been established that under the effects of two earthquakes, the least spectral curves differ for the case of a channel dam, the most – for the recording point on the soil. Recommendations are given for expansion in the number of recording points.

Studying the dynamics of seismically isolated buildings with the aid of the stations of engineering seismometric service
Issue:
read more

In KazNIISA JSC studies of seismic isolating properties of buildings equipped with special earthquake protection systems are carried out at the special field test site. Displacement, velocity and acceleration measuring sensors were installed on three houses constructed with the same above-foundation part (9-storey large-panel houses of series 158), but with different foundations: conventional strip foundations with the system of crossstrips, seismically isolating kinematic foundations and supports with PTFE gaskets. On these buildings instrumental records of the earthquake were received in the transverse direction on August 16, 2014. The resulting accelerograms were used to construct spectral curves ?. The possible effect of seismic isolation, as well as the influence of foundation constructions on the dynamics of buildings with foundations of conventional type and seismically isolated ones is assessed.

Change Research of Dynamic Characteristics of High-rise Building According to Data from Engineering Seismometric Stations

read more

Analysis of instrumental records made by stations of Engineering and Seismometric Service on buildings has been performed to assess changes in dynamic characteristics of the 25-storeyed building of the “Kazakhstan” hotel in Almaty. The building is located near tectonic fault. During two earthquakes, representative instrumental data were obtained at the seismic station No. 16 (“Highrise hotel”) equipped with digital instrumentation system. The building is twenty-five storied with a stiffening core, was built in 1976. Using ADXL accelerometers and RSM-8 recorder, qualitative instrumental records of accelerations were received in the basement, on the floors and on the roof of the building, and spectral curves ? were also built. The features of the dynamics of this building during the earthquake are noted. Under the impact of remote earthquake, building oscillation periods were revealed on the first and second oscillation modes. Dynamic characteristics of the house were compared according to the measurements of 1977 and 2018. Significant increase in the magnitude of oscillation period on the first mode by 25-48% as compared with the measurements of 1976-1977 over the 40-year period of operation was established.

Methodological fundamentals for using stations of engineering seismometric service on buildings

read more

Methodological fundamentals for application of the network of stations of Engineering Seis-mometric Service of KazNIISA JSC are described. Based on the type of problems being solved, all stations are divided into groups (polygons). Buildings located in close proximity to tectonic faults are gathered separately. Buildings equipped with seismic protection and analog house systems are situated at one site. Instrumental records processing means are analyzed – adjustment of zero baseline of the accelerogram according to the type of correlation function, building of accelerations distribution on azimuthal plane. Capabilities to process instrumental records over a long recording interval are analyzed. Recommendations are given for further development of Engineering Seismometric Service of KazNIISA JSC.

Peculiar Features of Building Footing Oscillation During Local Earthquakes
Issue: №6 2018
read more

The stations of the engineering seismometric service of KazNIISA JSC recorded more than 15 lo-cal earthquakes with the foci in Almaty and Almaty region in 2018. Accelerograms recorded on rigid and flexible buildings during 3 sensible earthquakes were selected from the obtained instru-mental records. These are accelerograms recorded in the basement parts of a four-storeyed frame building and an 11-storeyed steel-framed building. In one instance, the instrumental rec-ords registered in the basement of a 17-storeyed building are used. Flexible buildings are locat-ed near tectonic faults. The spectral curves characterizing the frequency content of the seismic effect are built. It has been established that the frequency response characteristics of the foundation composed of soils of the 2nd category by seismic properties are high-frequency with prevailing periods of 0.1-0.20 sec. Resonance phenomena for flexible buildings under the influence of local earthquakes are not observed. Instrumental records are included into the accelerogram database of KazNIISA JSC.