GEOTECHNICAL INFLUENCE OF UNDERLYING  SOILS TO PAVEMENT FAILURE  IN SOUTHWESTERN PART OF NIGERIA

Roads in Nigeria are usually constructed without in-depth knowledge of the subsoil that serves as the foundation for the road elements. Road failures are often associated to poor construction materials or inadequate design without cognisance of the underlying soils. Engineering properties of ten bulk soil samples collected from the subgrade of Arigidi/Oke-Agbe highway were investigated to determine their suitability for highway pavement. Results show that all the subgrade soils below the failed locations have higher plasticity indices, which is an indication of their high swelling potential, and they are classified as A-7-6 clayey soils with high-water adsorption capability (16.1 – 22.4%) compared to subgrade soils from the stable locations. Low compacted density (1325 – 1928 Kg/m3), extremely poor CBR values; 8 – 31% (unsoaked) and 3 – 8% (soaked) which indicate percentage reduction in strength of the soils up to 77% on exposure to excessive moisture and the predominance of fines (> 59%) in the soils are responsible for the degree of instability. Furthermore, soft to low stiffness (49 – 131 kN/m2) and poor permeability of the subgrade materials underlying the pavement result to the failure characteristics witnessed. This study shows that the suitability and behaviour of subgrade soil is dependent on its engineering properties.

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Use of Road Stabilizers in Sensitive Environments

Regular issue - International Journal of Management and Humanities ◽

10.35940/ijmh.j0986.0641020 ◽

2020 ◽

Vol 4 (10) ◽

pp. 168-189

Keyword(s):

Rural Areas ◽

Construction Materials ◽

Road Construction ◽

Engineering Properties ◽

The Road ◽

Polymer Binders ◽

Traffic Loads ◽

Environmental Properties ◽

Environmentally Sensitive ◽

Maintenance Requirements

Road infrastructure is key for any developing country to enable its expansion such as those in Africa. Natural road construction materials can become depleted and increasing traffic loads produce higher maintenance requirements, leading to research to develop additives that can be used to enhance the engineering properties of available pavement soils. Providing all weather roads for large vehicles in rural areas, such as Northern Namibia, are often based only on the available soils, involving compaction and use of stabilizers, is required to both provide a suitable load bearing road surface and maintain the road network. The region is also environmentally sensitive to any potentially adverse impacts of chemicals that may be released into the environment during construction or as breakdown products. A number of road stabilizer products are available and the choice of stabilizer must take into account both its specific properties and the sensitivity of the environment where it is to be used to any environmental impacts. The main stabilizer types are cementitious, bituminous and chemical, with the latter broken down in a range of materials including synthetic polymer binders, organic and ionic compounds, salts, enzymatic products and combinations thereof. Twenty available stabilizer products were considered in terms of their environmental properties and assessed against the published literature and the general findings reported in terms of the overall ranking of the environmental impact of stabilizer types.

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Influence of Subgrade Soil on Pavement Perfomance: A Case Study of Ago-Iwoye - Ilishan Road, Southwestern Nigeria

International Letters of Natural Sciences ◽

10.18052/www.scipress.com/ilns.38.86 ◽

2015 ◽

Vol 38 ◽

pp. 86-92

Author(s):

J.O. Fatoba ◽

A.O. Sanni ◽

A.B. Ayantunji

Keyword(s):

Negative Impact ◽

Construction Materials ◽

Liquid Limit ◽

Primary Objective ◽

Engineering Properties ◽

Major Road ◽

Southwestern Nigeria ◽

The Road ◽

Ogun State ◽

Grade Material

Ago-Iwoye –Ilisan road is the major road that links Abeokuta the state capital of Ogun –state to Ijebu towns. The road has always been experiencing pavement failure, which occurs inform of cracks and potholes. Being the major road, the effect of the failure has negative impact on the soico-economic growth of Ijebu –areas. The primary objective of the study was to determine the influence of the geotechnical properties of the sub-grade materials on the pavement performance of Ago-Iwoye – Ilishan Road. Eleven (11) soil samples were collected at eight (8) different locations with the aid of hand auger and were air-dried before taken to the laboratory for determination of engineering properties. The Liquid limit and the Plastic limits ranged from 13.9 – 46.2% and 8.1 – 32.7%, with the Plasticity index from 10.6 – 15.9% and Shrinkage limit from 6.2 – 27.7% respectively. The soaked CBR values of the subgrade materials is between 67% and 75% compared with 30% minimum specified by FMWH, 1997.The soils were classified by ASSHTO under the A-6 and A-7 category which shows that the soils are fair to poor as a sub-grade material and USCS classification shows that the soil falls into the SM and SC group.The comparison of all the results with the Nigeria specification (Federal Ministry of Works and Housing general guidelines) for the sub grade materials along the Ago-Iwoye-Ilisian road show that the materials underlain the pavement do satisfy the Nigeria standard. Therefore, the perennial failure frequently experience along the road route is not significantly influenced by subgrade materials. Hence, influence of other factors such as poor drainage courses, level of groundwater table, variation of geologic materials along the road route and poor construction materials should be thoroughly addressed before embarking on future rehabilitation of the highway.

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Impact of subgrade soils on pavement roughness

Canadian Geotechnical Journal ◽

10.1139/cgj-2015-0131 ◽

2016 ◽

Vol 53 (4) ◽

pp. 687-695

Author(s):

Michel Vaillancourt ◽

Daniel Perraton

Keyword(s):

Road Construction ◽

Soil Variability ◽

International Roughness Index ◽

Long Wavelength ◽

The Road ◽

Subgrade Soils ◽

Road Section ◽

Pavement Roughness ◽

Subgrade Soil ◽

The Impact

To highlight the impact of subgrade soil variability on the pseudo-profile and roughness at the end of road construction, a research program has been carried out at the Laboratoire sur les chaussées et matériaux bitumineux at École de technologie supérieure (ÉTS). The analysis is intended to highlight the variability of materials’ characteristics according to the longitudinal and vertical axes of the road. The proposed approach aims to calculate potential settlement variations through a global numerical simulation of a road section, in a bid to identify the expected pseudo-profile and to quantify the roughness quality by calculating the international roughness index (IRI). The proposed methodology was tested at a new road construction project in Québec. Here, the results of the simulations are compared to the details of the actual pseudo-profile obtained at the end of road construction for the project under study. It is shown, through the finite difference modeling of the mechanical behavior of the subgrade soil (FLAC calculation code), that the long wavelength pseudo-profile of the road at the end of construction can be determined, and that it is strongly influenced by subgrade soil variability. This article presents a second analysis carried out by Vaillancourt and Perraton in 2015 as part of a study of the impact of subgrade soils on pavement roughness.

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Improvement of Subgrade Characteristics Using Waste Plastic Bottle

Civil Engineering Beyond Limits ◽

10.36937/cebel.2021.004.001 ◽

2021 ◽

Vol 2 (4) ◽

pp. 1-7

Author(s):

Damilola A. Ogundare

Keyword(s):

Low Cost ◽

Sieve Analysis ◽

Waste Plastic ◽

The Road ◽

Subgrade Soils ◽

Plastic Bottle ◽

Subgrade Soil ◽

Stabilized Soil ◽

Ucs Test ◽

Strength And Durability

The need to improve the strength and durability of subgrade soil in recent times has become imperative using stabilizing materials that can be sourced locally at no/or very low cost in other to reach their design life span before a major repair is required. This necessitates the improvement that could be achieved by stabilizing subgrade soil along Ede-Abeere road in Ede, Osun State with the Waste Plastic Bottle (WPB). The soil samples were collected at 1m depth at different portions along the road and stabilized with varying percentages of WPB. Laboratory tests conducted were sieve analysis, natural moisture content, specific gravity, Atterberg limit, compaction, California Bearing Ratio (CBR), and Unconfined Compressive Strength (UCS) Test. The CBR of the stabilized soil ranges from 1.28% to 12.20% with 2.5% WPB having the highest CBR value of 12.20% meeting the recommended value for unsoaked CBR of subgrade soils. However, the statistical model reliably adjudged that there is a significant relationship between the CBR values of subgrade soil-WPB mixture obtained. Thus, it is recommended that WPB at 2.5% can serve as a stabilizing material as it increases the CBR of the subgrade soil and as an effective method of disposing of WPB.

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Appraisal on Different Sustainable Road Stabilization Techniques for Different Road Condition and Materials

Materials Science Forum ◽

10.4028/www.scientific.net/msf.975.208 ◽

2020 ◽

Vol 975 ◽

pp. 208-213

Author(s):

Mohd Idrus Mohd Masirin ◽

Halina Abdul Hamid ◽

Raha Abdul Rahman ◽

Abdullah Wagiman ◽

Mohammad Sukri Mustapa ◽

...

Keyword(s):

Soil Stabilization ◽

Ground Improvement ◽

Surface Condition ◽

Road Surface ◽

Engineering Properties ◽

The Road ◽

Subgrade Soil ◽

Road Condition ◽

The Difference ◽

Ground Condition

Road condition in term of road surface condition depends on the subgrade soil strength. Therefore, a weak subgrade condition requires improvements in stabilization. Soil stabilization is the alteration of one or more geotechnical properties to create an improved soil material possessing the desired engineering properties. The main purpose of the soil stabilization is to increase the shear strength of an existing ground condition to enhance its load-bearing capacity, achieve a desired improved permeability and enhance the durability of the soil to resistance to the process of weathering, and traffic usage among others. Three method in soil stabilization considered in this study are chemical admixture, mechanical and geosynthetics methods. The difference in soil stabilization methods depends on the different road surface conditions. Road condition with weakness subgrade is more appropriate and economical in used stabilization chemical method. In this paper, discussing the road condition requires the ground improvement through soil stabilization

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ANALISIS DAYA DUKUNG TANAH TERHADAP KERUSAKAN JALAN DI DESA BULUTIGO KECAMATAN LAREN KABUPATEN LAMONGAN

Jurnal Teknika ◽

10.30736/jt.v13i2.616 ◽

2021 ◽

Vol 13 (2) ◽

pp. 53

Author(s):

Miftahul Harits Abdullah ◽

Rio Rahma Dhana

Keyword(s):

Water Content ◽

Carrying Capacity ◽

High Water ◽

High Water Content ◽

Shear Strength Test ◽

The Road ◽

Average Value ◽

Subgrade Soil ◽

Cbr Test ◽

High Plastic

Road damage in Bulutigo Village, Laren District, Lamongan Regency affects access to agricultural mobilization in Lamongan Regency. So the researchers studied the value of the carrying capacity of the soil that caused road damage on the Bulutigo Village road, Laren District, Lamongan Regency. This study also examines the factors that affect the decline in the value of the bearing capacity of the soil. Data processing shows that the road subgrade soil in Bulutigo Village, Laren District, Lamongan Regency has a low carrying capacity value in terms of water content testing with an average value of 16.66% which includes high water content, from the Atterberg limit, it is included in the class of clay soil type. has a high plastic value with a PI value of 34.61%. Meanwhile, in the CBR test, the CBR value was 6.80% which was included in the "enough" category. And in the direct shear strength test, the value of the internal shear angle () is 15.03o.

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Influence of different loading rates on the mechanics and failure characteristics of high-water-content material

Geomechanics and Geoengineering ◽

10.1080/17486025.2021.1889688 ◽

2021 ◽

pp. 1-12

Author(s):

En Wang ◽

Shengrong Xie ◽

Dongdong Chen ◽

Yaohui Sun ◽

Pengyu Qi

Keyword(s):

Water Content ◽

High Water ◽

High Water Content ◽

Failure Characteristics ◽

Loading Rates

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An investigation into the cause of road failure along Sagamu-Papalanto highway southwestern Nigeria

Geoenvironmental Disasters ◽

10.1186/s40677-020-00174-8 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Ubido Oyem Emmanuel ◽

Igwe Ogbonnaya ◽

Ukah Bernadette Uche

Keyword(s):

Construction Materials ◽

Road Construction ◽

Linear Shrinkage ◽

Liquid Limit ◽

Dry Density ◽

Maximum Dry Density ◽

Southwestern Nigeria ◽

Low Resistivity ◽

The Road ◽

Cause Of Failure

AbstractInvestigation into the cause of road failure has been carried out along a 60 km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12 to 61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1–52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2–35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17–43.9%, maximum dry density ranges from 1.51–1.74 g /cm3, specific gravity ranges from 2.52–2.64 and CBR between 3 and 12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20–138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20 m – 240 m along the profile to a depth of 7.60 m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m − 120 m along the profile to a depth of 15 m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.

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