Influence of the Long-Term Loading on the Strength and Rigidity of the Annular Section Poles

Introduction. The modern methods of analysis and conducting the numerical experiments referring to calculation and design of constructions are mostly aimed at a deeper study of parameter changes of different structures exposed to the influence of the certain loads. Due to the course of time and upon obtaining and analysing the new results of the numerical studies, there arises the need to revise and update the normative documents developed in the past in the frame of studying the certain modes of structures’ operation. Bearing in mind the above-mentioned objective, the numerical study presented in this article has been carried out.

Materials and Methods. It should be mentioned, that most of the previously conducted research was based on the results of the short-term exposure of the structures to the loads, but not enough attention was paid to the study of the influence of the long-term loading on the structures' operation. This paper presents the results of the numerical experiments investigating the load-bearing capacity, flexural rigidity and maximum force of the power transmission line poles exposed to the short-term and long-term loads. The specimen under study is the cylindrical power transmission line pole complying with the GOST 22687.2 “Centrifugal cylinder reinforced concrete posts for high-voltage transmission lines”.

Results. The paper presents the results of studying the behaviour of the cylindrical reinforced concrete poles, serving as the supports for the electrical power transmission lines, under the short-term and long-term loading. The work provides the results of numerical experiments investigating the strength and rigidity parameters of the above-mentioned structures under different types of loading, as well as upon changing the eccentricities of the application of these loads. The assessment of the rigidity parameters change under the long-term exposure of the poles to the loads is carried out.

Discussion and Conclusion. Based on the results, obtained during the numerical experiments, the strength and rigidity parameters of the annular section power transmission line poles were analysed, and proposals for improving the design codes were made that could become a basis for the further research on this issue.

1. Akhverdov IN. Reinforced Concrete Pressure Centrifuged Pipes. Moscow: Stroyizdat; 1967. 164 p. (In Russ.).

2. Batashev VM. Strength, Crack Resistance and Deformations of Reinforced Concrete Elements with Multi-Row Reinforcement. Kiev: Budivelnik; 1978. 121 p. (In Russ.).

3. Batashev VM, Androsov ST, Lebedev VN, Nagornaya TF. Strength Calculation of Bending and Eccentrically Compressed Reinforced Concrete Elements of Annular and Circular Section. Concrete and Reinforced Concrete. 1971;5:31–34. (In Russ.).

4. Dmitriev SA, Bataschev VM. Deformations (Deflections) of Reinforced Concrete Elements of Annular Crosssection and Crack Opening in Them. In: Proceedings of the Research Institute of Concrete and Reinforced Concrete "Features of Concrete and Reinforced Concrete Deformations and the Use of Computers to Assess Their Influence on the Behavior of Structures". Moscow: Stroyizdat; 1969. P. 157–189. (In Russ.).

5. Kudzis AP. About Strength Calculation of Eccentrically Compressed Elements of Circular Section at Small Eccentricities. In: Proceedings of KPI "Studies on Reinforced Concrete Structures". Vilnius: Mintis; 1969. С. 29–35.

6. Kudzis AP. Reinforced Concrete Structures of Circular Section. Vilnius: Mintis; 1975. 224 p. (In Russ.).

7. Shchutskiy VL, Nasevich AS, Chubarov VE, Blyagoz AM. The Research on Bearing Capacity of Supports with Annular Section. IOP Conference Series: Materials Science and Engineering. 2019;698(2):022089. https://doi.org/10.1088/1757-899X/698/2/022089

8. Nasevich AS, Shchutskiy VL, Stelmakh SA, Antipov OV. Crack Strength and Deformability of Power Transmission Line Conical Poles. Materials Science Forum. 2018;931:304–310. https://doi.org/10.4028/www.scientific.net/MSF.931.304

9. Dedukh DA, Shchutskiy VL, Kuzmenko AA. Spun Concrete Properties of Power Transmission Line Supports. Magazine of Civil Engineering. 2017;7(75):37–51. https://doi.org/10.18720/MCE.75.4 (In Russ.).