Ottosha B. Sabirova
Ottosha B. Sabirova

Сабирова Оттоша Бурхоновна Ottosha B. Sabirova
engineer, Emperor Alexander I St. Petersburg state transport university, "Industrial and civil construction" department. Russian Federation, St. Petersburg


Estimating Combination Coefficients of Seismic and Ice Loads
Issue: №1 2019
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Abstract: Combination coefficients of ice and seismic loads for earthquakes of different frequencies have been considered. As the density function of the ice load distribution, the Weibull law, supplemented by a delta function at the origin was used, which allowed us to take into account the absence of ice in the warm season. The interval between earthquakes was taken according to the Poisson law. It has been shown that the magnitude of the design loads significantly depends on the frequency of earthquakes, and the combination coefficients are practically independent. Combination coefficients determine equally probable pairs of actions, which in their term determine the dependence of the combination coefficient to ice loads on the combination coefficient to seismic ones.
An example of calculations for the region respectively with situational seismicity of 9, 10 and 10, using maps A, B and C of general seismic zoning maps of the territory of Russia is given

The Combination Coefficients of Seismic and Wind Loads
Issue: №6 2018
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The combination coefficients of seismic and wind loads for multilevel designing buildings and structures in high seismic regions are considered. For design and maximum design earthquakes equiprobable pairs of seismic and wind loads are determined.  Correspondingly, these pairs are iven coupling coefficients for the loads under consideration, which determine the dependence of one combination coefficient on the other. In constructing the equiprobable pairs, the wind load is described by Weibull law and seismic load is described by Poisson’s law. It is shown that for the seventh wind zone with high seismic intensity in calculating structures under the action of the esign earthquake, the combination coefficients are close to 1, and in calculating structures under the action of the maximum design earthquake they are less than 1, and therefore it becomes necessary to choose the most dangerous pair of seismic and wind loads.

Multi-level designing structures in tsunami-prone areas
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The paper proposes a two-level approach to the calculation of structures for the tsunami effect. The concept of the design tsunami and the maximum design tsunami and their corresponding limit states is introduced. The estimated loads on the bridge piers from the design and maximum design tsunami are estimated, depending on the territory danger and the bridge responsibility. At the same time, bridges, in accordance with the approach adopted in transport construction, are divided according to their degree of responsibility into four categories. A formula is obtained to estimate the design splash value for the design and maximum design tsunami, depending on the bridge category. In addition, graphs are provided showing the frequency of the tsunami and the calculated wave height corresponding to this frequency. To estimate the combination coefficient of wind and tsunami loads, their equally probable pairs are considered. At the same time, the Weibull distribution is used to set the wind load, and for the tsunami load, the distribution given in the Code of Rules for Ensuring Tsunami Safety is used. Taking into account such load pairs is relevant for bridges with high piers, when the height of the splash does not exceed the pier height and there is a high probability of a simultaneous combination of wind and tsunami loads. The paper presents the calculations of surges for two types of tsunamis: the design one with a repeatability of once in 50 years and the maximum design one with a repeatability of once in 500 years for the Kamchatka region and the Kuril Islands for bridges of the first and second categories. Studies show that for the design tsunami and the maximum design tsunami, the coefficients of combinations with wind load differ significantly.