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| dc.contributor.author | Yoseph, Mekonen Getahun | |
| dc.date.accessioned | 2022-03-04T06:55:58Z | |
| dc.date.available | 2022-03-04T06:55:58Z | |
| dc.date.issued | 2021-08 | |
| dc.identifier.uri | http://ir.bdu.edu.et/handle/123456789/13133 | |
| dc.description.abstract | Self-supported, directly-embedded wood and concrete poles are widely used by the Utility Service of Ethiopia to support low to high-voltage transmission lines. This study deals with examining the effect of backfill and embedment depth on the stability of transmission poles built on Bahir Dar red clay soils. In this research, three approaches; namely, rule of thumb, analytical and finite-element software are used to assess the soil-pole interaction problem. A finite-element software, Abaqus is employed to simulate the soil–pole interaction behavior of a self-supported, directly-embedded concrete pole in a clay soil under undrained condition. A short-term static (Pseudo-static) loading mainly from a 3-second gust wind pressure is considered. Since the loading is of transient nature, the pressure independent Tresca soil failure criterion is adopted for the soil in the numerical analysis. A parametric study using Abaqus shows that a change in the modulus of elasticity of the soil from 7MPa to 30MPa reduces the groundline deflection by 80%. Whereas, a change in the undrained shear strength from 70 kPa to 120 kPa, reduces the lateral groundline deflection only by 27%. The lateral groundline deflection of the transmission pole at the ground surface is greatly improved by providing a radial support (concrete jacket) around the embedded portion of the pole. For a 5kN lateral load applied at the top of the transmission pole, a 20cm thick concrete jacket improves the groundline deflection by about half (50%) for the low undrained shear strength values. In addition, providing a 30cm thick jacket improves the deflection by about 61%. From the numerical analysis, it is found that increasing the depth of embedment significantly improves the groundline lateral deflection of the transmission pole. For Bahir Dar non-expansive red clay soils; increasing the depth of embedment by about 11% (20cm) can improve (reduce) the lateral deflection at the ground surface on average by about 50%. The influence of increasing the depth is small after 2.0 meter embedment depth. Especially for soils having a modulus of elasticity 50 MPa, increasing the depth of embedment has no any effect after a depth of 2.2 meter. | en_US |
| dc.language.iso | en_US | en_US |
| dc.subject | CIVIL AND WATER RESOURCE ENGINEERING | en_US |
| dc.title | The Effect of Backfill and Embedment Depth on the Stability of Transmission Pole Built on Red Clay Soils Found in Bahir Dar City | en_US |
| dc.type | Thesis | en_US |
