Journal of Science, Engineering, Technology and management Vol. 02, No. 03, (2020), pp. 1-7 https://doi.org/10.46820/JSETM.2020.1104 Engineering and Geological Investigation of Afe-Babalola Matthew Junction in Ado Ogar Rita Onwu 1, Adebayo Victor Babafemi 2, Samuel-Soma M. Ajibade3 Adediran Anthonia4 1,2, 3 Dept of Civil Engineering, Afe Babalola University, Ado Ekiti, Nigeria Dept of Computer Science, The Federal Polytechnic, Ado Ekiti, Nigeria 4 Dept of Real Estate, Universiti Teknologi Malaysia, Johor, Malaysia adebayovb@abuad.edu.ng2, ajibade_ms@fedpolyado.edu.ng3, oaanthonia2@live.utm.my4 Abstract Integrated geophysical investigation, involving the electrical resistivity and magnetic methods was carried out along ABUAD-Matthew roadway in Ekiti State. This was with a view to investigating the cause(s) of the persistent pavement failure recorded over the years along the road. The resistivity survey utilized 1-D Vertical Electrical Sounding (VES) with the Schlumberger array was employed for this research. Total field data were acquired along the identified segments of the road at 5 m intervals. The data were inverted into resistivity structures and were used to constrain the location of the five (5) VES stations. The VES curves were interpreted quantitatively and the results were used to generate 3-D geoelectric sections. The geoelectric sections were characterized by the presence of sedimentary rocks whose materials can either be sandstone, Shale or Limestone with a resistivity value of 41.7-354.1 Ωm, the hardpan layer has a resistivity value of 41.7Ωm which indicates the presence of clay at 4.7 m depth. The fractured basement has a resistivity value of 354.1 Ωm which indicates the presence of rocks which can either be sandstone, Shale or Limestone for VES 1. Also, Alluivium, soils and water at 80 Ωm and 126.8 Ωm at VES 2. VES 3 indicates the presence of metamorphic rocks which can either be basalt, marble, quartzite at a resistivity value of 4815.3 Ωm. It can be seen from the research that clay was found at every depth ranging from 1.4 to 3m which isnt a good material for construction. Geophysical survey should not be neglected as it gelps us to know the geological properties of the underlying soil structure. Keywords: Geophysical Survey; Pavement Failure; Geoelectric 1. Introduction Highways, could literally be referred as the public roads, are subject to deterioration due to constant use, and if they are to give the standard of service to which they are designed and built, maintenance must begin as soon as the roads are constructed and commissioned (A stitch in time saves nine). The poor situation of our roads in many parts of Nigeria today is due largely to long and persistent neglect, particularly by Federal Government (The Federal Roads) [8]. The reason attributed to this neglect is inadequate funding. Ideally, maintenance would ensure that the roads always function as efficiently as when they were newly constructed, and so in planning maintenance, due regards must be paid to limitations or resources such as funds, manpower and machineries. Therefore, maintenance is adjusted to control the rate of deterioration and to ensure that ISSN: 9989-7858 JSETM Copyright ⓒ 2020 JSETM 1 Journal of Science, Engineering, Technology and management Vol. 02, No. 03, (2020), pp. 1-7 https://doi.org/10.46820/JSETM.2020.1104 serviceability of the road does not fall below minimum standards, depending upon available resources [1], [2]. With increase in traffic loads due to increased economic and developmental activities, the road network in Nigeria is being overstressed while the maintenance needs have been rising sharply, the matching fund allocation and other infrastructural requirements have been found wanting. The situation has resulted in fast deterioration of road pavements in the network [3], [4]. Maintenance should be considered of paramount importance in every spheres of construction of roads and must commence immediately after such construction of roads and must commence immediately after such construction is completed to always keep it in shape, save cost and prevent jeopardizing the purpose for which the construction was made [5], [6]. 2. Materials and Methods 2.1. Materials Materials used for carrying out this survey include, Terrameter, Electrodes, GPS device, Current Source, Hammer, Multi-Conductor Wires. The base map of the research area where the VES points were taken is shown in Figure 1 below Figure 1. Base Map of the Study Area 2.1. Methods Method of study for the geophysical investigation employed was the resistivity method. The method of array employed was the Schlumberger array and the campus omega type terrameter was used for the purpose of this research. The VES data were represented as sounding curves and interpreted using a 1-D computer aided modeling software called WinResist [7]. The VES interpretation results were used to generate geoelectric sections along each traverse. The geoelectric sections along each traverse were used to establish the persistent failure along the invesigated roadway. 3. Result and Discussion ISSN: 9989-7858 JSETM Copyright ⓒ 2020 JSETM 2 Journal of Science, Engineering, Technology and management Vol. 02, No. 03, (2020), pp. 1-7 https://doi.org/10.46820/JSETM.2020.1104 The Vertical Electrical Sounding modeling carried out at five (5) VES stations was used to derive the geo-electric sections of various profiles. The interpretation of the measurements can be performed based on the apparent resistivity values. The depth varies with the distance of the electrodes [9], [10]. The area of study consists of four geo-electric layers successions in 1-D. The first layer is represented by Top soil, the second layer is represented by Sandy clay/ Hardpan material, the third layer is represented by a fractured basement and the fourth layer is represented by Fresh basement. Figure 2. Sounding Curve for VES 1 Figure 2 represents the sounding curve for VES 1 which was gotten by plotting Apparent resistivity values against current Electrode Distance, the resistivity value ranges from 41.7-354.1 Ωm at depth ranging from 1.4m to 14.3m. The top material indicates the presence of sedimentary rocks at 1.4m depth whose materials can either be sandstone, Shale or Limestone. The hardpan layer has a resistivity value of 41.7Ωm which indicates the presence of clay at 4.7 m depth. The fractured basement has a resistivity value of 354.1 Ωm which indicates the presence of rocks which can either be sandstone, Shale or Limestone. The last layer has a resistivity value of 296.7Ωm. The current terminated at this point showing no value for thickness and depth. ISSN: 9989-7858 JSETM Copyright ⓒ 2020 JSETM 3 Journal of Science, Engineering, Technology and management Vol. 02, No. 03, (2020), pp. 1-7 https://doi.org/10.46820/JSETM.2020.1104 Figure 3. Sounding Curve for VES 2 The top material has a resistivity value of 80 Ωm which indicates the presence of soils and water at 1.2m depth. The hardpan layer has a resistivity value of 45.8 Ωm which indicates the presence of clay at 5.0 m depth. The fractured basement has a resistivity value of 126.8 Ωm which indicates the presence of alluvium at 14.2 m depth. The last layer has a resistivity value of 250.2 Ωm. The current terminated at this point showing no value for thickness and depth. Figure 4. Sounding Curve for VES 3 The top material has a resistivity value of 18.7 Ωm and which indicates the presence of clay materials at 2.2m depth. The hardpan layer has a resistivity value of 46.6 Ωm which also indicates the presence of clay at 3.0 m depth, The fractured basement has a resistivity ISSN: 9989-7858 JSETM Copyright ⓒ 2020 JSETM 4 Journal of Science, Engineering, Technology and management Vol. 02, No. 03, (2020), pp. 1-7 https://doi.org/10.46820/JSETM.2020.1104 value of 4815.3 Ωm which indicates the presence of metamorphic rocks which can either be basalt, marble, quartzite at 26.3 m depth. The last layer has a resistivity value of 679.5 Ωm. The current terminated at this point showing no value for thickness and depth. Figure 5. Sounding Curve for VES 4 The top material has a resistivity value of 18.7 Ωm which indicates the presence of clay materials at 1.7m depth.The hardpan layer has a resistivity value of 88.5Ωm which also indicates the presence of clay at 1.5m depth, The fractured basement has a resistivity value of 1532.8 Ωm which indicates the presence of sedimetary rocks which can either be sandstone, shale or limestone at 17.1 m depth. The last layer has a resistivity value of 462.3Ωm. Figure 6. Sounding Curve for VES 5 The top material has a resistivity value of 72.8 Ωm which indicates the presence of clay materials or presence of groundwater at 1.5m depth .The hardpan layer has a resistivity ISSN: 9989-7858 JSETM Copyright ⓒ 2020 JSETM 5 Journal of Science, Engineering, Technology and management Vol. 02, No. 03, (2020), pp. 1-7 https://doi.org/10.46820/JSETM.2020.1104 value of 24.2 Ωm which also indicates the presence of clay or groundwater at 6 m depth, The fractured basement has a resistivity value of 236.1 Ωm which indicates the presence of sedimentary rocks which can either be sandstone, shale or limestone at 14.6 m depth. The last layer has a resistivity value of 281.5Ωm. The current terminated at this point showing no value for thickness and depth. The geoelectric section shows the 3-D representation of the underground soil condition. It can be seen that at a depth ranging from 1.2 m. 1.4 m, 2.2 m, 1.7 m and 1.5 m which are the top materials, the materials found at this layer mainly contains clayey materials because their resistivity values ranges from 1-100 Ωm which aren't good for highway construction. Figure 7. Representation of the Underground Soil Condition 4. Conclusion This project discusses factors believed to have contributed to failures of ABUADMATTHEW road. The objective of the study has been achieved through geophysical investigation analysis and it was found that clayey materials exist from the base course to sub base course. As a result of inadequate knowledge of the characteristics and behavior of our soils, designs and construction has taken place without due considerations of the consequent changes the soil will undergo. The soil sample used are mostly A-2-6 and A2-4 soils for the sub grade, the Plasticity index of the soil samples had low swelling potential meaning they have less amount of clay in them which can make them swell during rainfall and the Linear shrinkage of the soil samples are within non- critical degree of expansion. ISSN: 9989-7858 JSETM Copyright ⓒ 2020 JSETM 6 Journal of Science, Engineering, Technology and management Vol. 02, No. 03, (2020), pp. 1-7 https://doi.org/10.46820/JSETM.2020.1104 References [1] Heggie, I. G. (2003). Commercializing management and financing of roads in developing and transition countries. Transport Reviews, 23(2), 139-160. [2] Tawalare, A., & Raju, K. V. (2016). Pavement performance index for Indian rural roads. Perspectives in Science, 8, 447-451. [3] Niroula, G. S., & Thapa, G. B. (2005). Impacts and causes of land fragmentation, and lessons learned from land consolidation in South Asia. Land use policy, 22(4), 358-372. [4] BANDA, T. (2018). INVESTIGATING THE CAUSES OF FREQUENT FAILURES ON MAINTAINED ASPHALT PAVEMENT FEDERAL ROADS IN ETHIOPIA (Doctoral dissertation, ADDIS ABABA SCIENCE AND TECHNOLOGY UNIVERSITY). [5] Okigbo, N. (2012). Causes of highway failures in Nigeria. International Journal of Engineering Science and Technology (IJEST), 4(11), 4695-4703. [6] Ajibade, S. S., & Adediran, A. (2016). An overview of big data visualization techniques in data mining. Int J Comput Sci Inf Technol Res, 4(3), 105-113. [7] Ebhohimen, V. O. (2017). Geophysical Investigation of Road Failure Using Electrical Resistivity Imaging Method, A Case Study of Uhiele–Opoji Road Edo State (Doctoral dissertation). [8] Abdullahi, M. G., Toriman, M. E., & Gasim, M. B. (2014). The application of vertical electrical sounding (VES) for groundwater exploration in Tudun Wada Kano state, Nigeria. International Journal of Engineering Research and Reviews, 2(4), 51-55. [9] Samuel, M., Samuel-soma, M. A., & Moveh, F. F. (2020). AI Driven Thermal People Counting for Smart Window Facade Using Portable Low‐Cost Miniature Thermal Imaging Sensors. [10] Ogungbe, A. S., Olowofela, J. A., Da-Silva, O. J., Alabi, A. A., & Onori, E. O. (2010). Subsurface characterization using electrical resistivity (Dipole-Dipole) method at Lagos State University (LASU) Foundation School, Badagry. Advances in Applied Science Research, 1, 174-181. ISSN: 9989-7858 JSETM Copyright ⓒ 2020 JSETM 7