Okeniyi, Elizabeth Toyin (2022) ASSESSMENT OF ROAD FAILURE USING GEOPHYSICAL AND GEOTECHNICAL TECHNIQUES: A CASE STUDY OF IDIROKO ROAD, OTA, NIGERIA. Masters thesis, Covenant University Ota..
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Abstract
The importance of road to a nation cannot be overemphasised, therefore, it is necessary to investigate the causes of road failure in order to choose the appropriate technique for maintenance. The aim of this study is to investigate the structures in the subsurface and identity the geotechnical parameters which caused the road failure in Idiroko road, Ota using 2D electrical resistivity Imaging (ERI) and geotechnical analysis. Geophysical investigation and geotechnical analysis were employed for the study. A 2D ERI and vertical electrical sounding (YES) were used for the geophysical investigation, while random soil sampling was used for the geotechnical investigation. Six ( 6) 2D (ERI) traverses of 100m each and 15 VES points were conducted along a unfailed and failed dual-carriage highway using ABEM Terrameter (SASlOOO) along Idiroko road. WinResist software was used to process the acquired apparent resistivity data for the VES to derive geo-electric layer parameters. RES2DINV software was used to process the 2D ERI to derive 2D resistivity inverse model. The geo-electric parameters obtained for the VES and the inverse models resistivity for 2D ERI are integrated for characterisation of the subsurface in order to delineate the lithologic units in the study area. The results reveal that the topsoil composition varies from sandy-clay to clayey-sand, clay, and laterites with the resistivity values varying from 41.9 Qm to 3390.4 nm and the thickness from 0.4 m and 84.8 m. The clay and clayey-sand are representatives of the recent alluvial deposits with resistivity values of 5.2 to 203.6 nm. The geotechnical testing on the soil samples taken from the survey area were carried out to investigate parameters such as liquid limit which varies from 24.0 to 50.6, specific gravity from 2.33 to 2.57, plasticity index from 18.0 to 21.20, plastic limit from 15.05 to 35.4, moisture content from 33.06 to 58.2 using atterberg limit device comprising spatula, weighing balance, micro-iron sieve, wash bottle and sample containers. Moisture content was determined using oven dry techniques. Permeability test was measured with a permeameter. The results showed that the causes of road failures are due to be high moisture content, expansive subgrade soils, poor drainage and usage oflow standard construction materials. Based on the results obtained, it is recommended that qualified road construction engineers should be sought in choosing the right and effective maintenance techniques for road integrity.
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | Geotechnical analysis, Electrical resistivity imaging, Road failure, Subsurface structure |
| Subjects: | Q Science > QC Physics |
| Divisions: | Faculty of Engineering, Science and Mathematics > School of Physics |
| Depositing User: | Mrs Patricia Nwokealisi |
| Date Deposited: | 17 May 2022 12:06 |
| Last Modified: | 17 May 2022 12:06 |
| URI: | http://eprints.covenantuniversity.edu.ng/id/eprint/15846 |
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