scholarly journals Investigation into Erosion induced Highway Structural Failure along Ifon—Benin Highway, Southwestern Nigeria

2020 ◽  
Author(s):  
Olumuyiwa Olusola Falowo
Keyword(s):  
Traffic Load ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Natural Soil ◽  
Stream Channels ◽  
Southwestern Nigeria ◽  
The Road ◽  
The Earth ◽  
Clayey Silt ◽  
Limit Test

Abstract Geotechnical investigation was carried out at two failed segments along Ifon-Benin Highway, with the aim of determining cause, nature, and extent of the road failure. Eight in-situ cone penetration tests was carried out to a depth of about 20 m with a lateral spacing of 20 m. This was complemented by collection of eight soil samples at different depths within the failed segments and analyzed in the laboratory. The laboratory tests conducted were grain size analysis, Atterberg limit test, compaction test, California bearing ratio, undrained unconfined triaxial test. The failure that existed in both locations are around the embankment, shoulder/edge and wearing course of the highway, due to ingression of water into the subgrade since the earth (natural soil) embankment structure had been eroded by rain water. The laboratory geotechnical results revealed that all the parameters could not meet up with the federal ministry of works and housing specification of Nigeria, with plasticity index greater than 20 %, % fines greater than 35 %, CBR values less than 80 % minimum recommended, shear strength parameters; angle of friction and cohesion are less than minimum of 30° and 50 kPa respectively. The CPT revealed predominant sandy silt to clayey silt topsoil and clay substratum with an inferred compressive strength of 20 – 40 KN/m2. At both failed segments, the clayey substratum is seriously affected within the upper 6 m. The ingression of water into these foundation structures was due to compromise of the design/construction engineer, since a bridge was supposed to be erected across these two locations. Hence the stream channels across the highway were blocked by the earth-fill embankment. Therefore during wet season, pool of water that supposed to flow across the road through bridge system, continue to dissolve the embankment, and consequently infiltrate into the subgrade. This makes the highway to settle largely under traffic load. In addition, incessant heavy flooding around the embankment/shoulder of the highway might have induced the failure since a bridge was supposed to have been constructed across the two failed segments. This flooded water might have infiltrated into the pavement structural material leading to looseness, and less-cohesion of the layers which invariably reduces subgrade support and weakens various pavement layers.

scholarly journals GEOENGINEERING INVESTIGATION OF AN EROSION INDUCED HIGHWAY STRUCTURAL FAILURE ALONG IFON – BENIN HIGHWAY, SOUTHWESTERN NIGERIA

2020 ◽  
Vol 4 (1) ◽  
pp. 51-60
Author(s):  
Olumuyiwa Olusola Falowo ◽  
Adekunle Aliu
Keyword(s):  
Soil Analysis ◽  
Cone Penetration Test ◽  
Traffic Load ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Soil Parameters ◽  
Penetration Test ◽  
Cone Penetration ◽  
Clayey Silt ◽  
Limit Test

Road infrastructural is one of the most important economic indices for development of a country. Therefore in-situ cone penetration test and laboratory soil analysis were performed at two failed segments along Ifon-Benin highway, with the aim of determining cause(s) and extent of the failure. The cone penetration test was carried out to a depth of about 20 m with a lateral spacing of 20 m along the roadway. The laboratory tests conducted were grain size analysis, Atterberg limit test, compaction test, California Bearing Ratio, and undrained unconfined triaxial test. The results revealed that all the soil parameters fell short of the federal ministry of works and housing specification of Nigeria, with plasticity index (>20%), % fines (>35%), CBR values (<80%) recommended, angle of friction and cohesion are less than minimum standard of 30° and 50 Kpa respectively. The CPT revealed predominant sandy silt to clayey silt topsoil and clay substratum with compressive strength of 20 – 40 KN/m2. The water level is higher than 3 m, consequently far below the road foundation baseline. Findings showed that the upper 6 m of the failed segments has been seriously affected by erosion and flooding. Subsequently the process resulted into excessive settlement of the silt/clayey-subgrade soil underneath the pavement structure. This makes the highway to settle largely under traffic load. In addition, incessant heavy flooding around the embankment/shoulder of the highway might have induced the failure, leading to looseness, and less-cohesion of the layers which invariably reduces subgrade support and weakens various pavement layers.

scholarly journals Compositional and industrial assessment of Isua-Akoko, Akure, Ayadi and Lafe (Ode Aye) clay deposits of Ondo state, Nigeria

1970 ◽  
Vol 21 (1) ◽  
pp. 41-49
Author(s):  
O Adegbuyi ◽  
GP Ojo ◽  
AJ Adeola ◽  
MT Alebiosu
Keyword(s):  
Chemical Properties ◽  
Fine Sand ◽  
Coarse Sand ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Medium Sand ◽  
Southwestern Nigeria ◽  
Firing Test ◽  
Clay Deposits ◽  
Ondo State

The physical and chemical properties of clay deposits around Isua-Akoko, Akure, Lafe and Ayadi in Ondo State southwestern Nigeria have been examined. The results have shown that Isua-Akoko, Akure and Lafe Clays are plastic fire clays while Ayadi clay is kaolinite. Grain size analysis reveals that Isua Akoko Clay contains 45% of clay, 18% silt, 12% fine sand,14% medium sand and 11% coarse sand and no gravel; Akure clay contains 42% clay, 14% silt, 13% fine sand, 20% medium sand and 8% coarse sand with 1% gravel. Lafe Clay contains 21% clay, 8% silt, 25% fine sand, 37% medium sand and 8% coarse sand with 1% gravel while Ayadi clay contains 83% clay and 17% silt. The liquid limits of these clay samples range from 41% to 73%% and plastic limits range from 18% to 26% respectively. The chemical analysis reveals that the most abundant mineral is silica (60.97%) and aluminum was next in abundance (23.69%) while other oxides are low. The results show that Isua-Akoko and Akure are residual while Lafe and Ayadi are sedimentary and transported Clays. The firing test, PH, and bleaching tests of the clays are also discussed. The chemical and physical characteristics of the clay deposits are strongly indicative of their industrial importance in the production of ceramics, refractories, paving bricks, paint and pharmaceutical products.KEYWORDS: Kaolinite, fire clay, gravel, ceramics and alumina.

scholarly journals Geochemical, Mineralogical and Biological study of Holocene deposits in Almuthana province, southern Iraq

2019 ◽  
pp. 1521-1529
Author(s):  
Sattar Jabar Al-Khafaji ◽  
Maher Mandeel Mahdi
Keyword(s):  
Grain Size ◽  
Clay Minerals ◽  
Flood Plain ◽  
Grain Size Analysis ◽  
Biological Study ◽  
Size Analysis ◽  
Clayey Silt ◽  
High Concentrations ◽  
Recent Sediments ◽  
Southern Iraq

Fifteen samples were collected from recent sediments grouping at 80 km east Samawa City, southern Iraq. Three selected samples for grain size analysis and twelve samples for chemical and biofacies analysis. Grain size analysis indicated that the sediment is mainly composed of the silt and clay with a small amount of sand. Most of the samples considered to be as clayey silt. The dominated non clay minerals are Quartz, Calcite, and Dolomite, while the clay minerals are composed of mixed Montmorillonite- Chlorite, Palygorskite, Illite and Kaolinite. Chemical analysis showed that all samples have high concentrations of SiO2 and CaO in comparison with Al2O3, MgO, Fe2O3, K2O and N2O. The identified faunas consist of a number of groups such as Mollusca, Ostracoda and Charophyta, all diagnosed genera indicated of fresh water environments. The results from all collected data are indicated that the sediments belong to flood plain deposits which deposited in fluviatile environments.

scholarly journals Magnitude and frequency of debris and slush flows in the Khibiny mountain valleys, Kola Peninsula, NW Russia

2019 ◽  
Vol 381 ◽  
pp. 37-47
Author(s):  
Ekaterina V. Garankina ◽  
Vladimir R. Belyaev ◽  
Fedor A. Romanenko ◽  
Maxim M. Ivanov ◽  
Natalia V. Kuzmenkova ◽  
...  
Keyword(s):  
Kola Peninsula ◽  
Extreme Event ◽  
Remote Sensing Data ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Future Research ◽  
Last Deglaciation ◽  
Stream Channels ◽  
14C Dating ◽  
Sediment Delivery

Abstract. Available results for five studied valleys of the Khibiny Mountains, Kola Peninsula, suggest that slush flows and, possibly for some valleys, typical debris flows with lower frequency, are a leading mechanism for downstream sediment delivery and valley floor topographical formation. Typical fluvial topography in slush flow-affected basins is extremely suppressed or nonexistent, since under such conditions, stream channels are unable to rework slush flow deposits. The recovery phase of fluvial topography can serve as an indicator of the magnitude and time passed since the last extreme event. A combination of grain size analysis, radionuclide fingerprinting with the 232Th content in the finer-grained sediment matrix (size <10 mm) and 14C dating, were applied to reveal the age and common structure of debris and slush flow environments and to investigate the main factors in their lithodynamics. Those helped to estimate transportation distances and capacities of the flows and the amount of fluvial reworking of its deposits with time. Application of radiocarbon dating to determine absolute ages (about 30 dates) of stabilization periods for the colluvial cones, mountain fans and valley bottoms and integration with other available chronological data provided a basis for distinguishing several stages of decreased activity of debris and slush flows and extreme slope failures through the second half of the Holocene. Field mapping and remote sensing data interpretation revealed spatial distribution patterns of debris and slush flows. Geomorphic analysis of large relic landforms in valley bottoms confirms, in general, the case for a significant reduction of debris flow magnitude since the last deglaciation and distinct shift to slush flow processes with much lower clastic content. A reliable chronology of the early events is yet to be obtained representing a challenging problem for future research.

L'utilisation de matériaux naturels pour la construction du barrage OA-5 sur la rivière Opinaca

1983 ◽  
Vol 10 (4) ◽  
pp. 614-626
Author(s):  
Michel Massiéra ◽  
Claude Pelchat
Keyword(s):  
Electrical Potential ◽  
Glacial Till ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
James Bay ◽  
River Sand ◽  
River Diversion ◽  
The Earth ◽  
Earth Structures ◽  
Three Rivers

The OA-5 Dam is one of the earth structures of the EOL (Eastman–Opinaca–La Grande) project within the 'La Grande' hydro-electric complex at James Bay, Quebec. Three rivers were diverted to the La Grande River to increase the hydro-electrical potential of the LG-2 power plant. Dam OA-5 (32.3 m high and 385.6 m long) has a zoned section with an impervious central core, and rests on bedrock.The paper describes the different construction phases of the dam, i.e., Opinaca River diversion and closure, foundation treatments, earth and rockfill placement, quality control of materials, and the behaviour of the dam during and after filling of the reservoir. Keywords: closure, compaction, construction, dam, diversion, earth and rockfill, glacial till, grain size analysis, gravel, river, sand.

scholarly journals Geoengineering Assessment of Subgrade Highway Structural Material along Ijebu Owo – Ipele Pavement, Southwestern Nigeria

2020 ◽  
pp. 57-69
Keyword(s):  
Shear Strength ◽  
Clay Mineralogy ◽  
California Bearing Ratio ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Southwestern Nigeria ◽  
Kaolinite Clay ◽  
Static Water ◽  
Under Construction ◽  
Geotechnical Tests

Geochemical, geotechnical, and geophysical investigations were carried out along Migmatite gneiss underlain Iyere – Ipele pavement (under construction) in order to assess the suitability of the imported subgrade soil. Also static water level (SWL) was obtained from five open wells along the highway. The geotechnical tests include specific gravity, grain size analysis, consistency limits, consolidation, compaction, and California Bearing Ratio (CBR), and shear strength; while geochemical tests were analyzed using X-ray fluorescence and Atomic Absorption Spectrophotometer (AAS). The results show that SiO2, Al2O3 and Fe2O3 constitute an average of 46.2%, 23.30% and 26.54% respectively of the soils chemical composition. The silica- sesquioxide ratio of the samples ranges from 0.89 to 0.96 and classified as true laterite. The topsoil along the highway is made of moderately competent/competent soil with resistivity ranging from 298 – 924 ohm-m and thickness of 3.1 - 8.2 m. The SWL varies from 3.3 - 5.5 m with an average of 4.3 m (moderately low). The soils are characterized by high California Bearing Ratio values, moderate shear strength (150 – 200kpa), and unconfined compressive strength (300 – 420kpa) with predominant kaolinite clay mineralogy group. The AASHTO and USCS classification system rate the soils as good and fair/good respectively.

scholarly journals Geotechnical Evaluation of Road Pavement Failure along the Awotan-Akufo Road, Oyo State Southwestern Nigeria

2019 ◽  
pp. 1-11
Author(s):  
Apanpa, A. Kazeem ◽  
Olayiwola, Hameed ◽  
Anjonrin, Ademola
Keyword(s):  
Moisture Content ◽  
Asphalt Pavement ◽  
Optimum Moisture Content ◽  
Traffic Load ◽  
California Bearing Ratio ◽  
Engineering Properties ◽  
Southwestern Nigeria ◽  
The Road ◽  
Road Pavement ◽  
Natural Moisture Content

In order to access the cause(s) of road failure and proffer preventive measures for the future reconstruction of the Awotan-Akufo road, southwestern Nigeria, the geotechnical engineering properties of the subgrade soil, asphalt pavement thicknesses, drainage and traffic load were evaluated. Soil samples were collected from test pits 1 m deep and at an interval of 50 m and subjected to geotechnical analyses in accordance to AASTHO specification. The grain size distribution revealed that 70% of the entire samples from Awotan-Lifeforte and Adaba failed sections along Akufo road contain amount of fines more than 35% passing through sieve No. 200. The Natural Moisture Content range from 5.73 - 20.21% (Awotan-Lifeforte section) and the entire samples from Adaba failed sections have high natural moisture content ranging from 16.20 - 23.20%. From Atterberg limit test, the Liquid limit of 12 - 56% (Awotan-Lifeforte section) and 26.00 - 40.00% (Adaba Section) were obtained. The Plastic Limit and Plasticity Index of the soils ranges from 8.43 to 49.10% and 1.01 to 7.0% (Awotan-Lifeforte section), and 23.10 - 35.50% and 1.50 - 7.10% (Adaba Section) respectively. Linear shrinkage varies from 0.80 to 9.60% and from 3.10 to 8.80% for Awotan-Lifeforte and Adaba sections, respectively. The Maximum Dry Density of the soils ranged from 1.625 - 1.835 mg/m3 at Optimum Moisture Content of 13.4 - 17.3% (Lifeforte-Awotan section), and MDD of 1.752 - 1.975mg/m3 at Optimum Moisture Content of 13.4-17.3% (Adaba section). The unsoaked California Bearing Ratio are 30.08, 70.14, 39.08%, and the soaked California Bearing Ratio values are 26.17, 11.41, 33.41% (Lifeforte-Awotan section) respectively. At Adaba section of the road, the unsoaked California Bearing Ratio is 3.46, 87.70, 70.14%, and soaked California Bearing Ratio values are 3.42, 32.56, 39.83%. The average asphalt pavement thicknesses around Awotan-Lifeforte section range from 0.60 - 1.10 inches, and that of Adaba section range from 0.57 to 1.46 inches. The study concluded that the road pavement subgrade is silty clay and the geotechnical properties rated below the specifications of the Federal Ministry of Works and Housing at some failed portions. Asphalt pavement thicknesses are grossly inadequate and far below NAPA 2007 recommendation. As such the road cannot withstand the heavily loaded trucks that ply it on regular basis. All aforementioned contributed to the untimely failure of the road.

scholarly journals Grain size analytical and geochemical data of sediments from Ishakare and Alatan streams in Akungba-Akoko, Southwestern Nigeria

2021 ◽  
Vol 6 (2) ◽  
pp. 44-50
Author(s):  
Olumuyiwa A. Odundun ◽  
Keyword(s):  
Grain Size ◽  
Mean Value ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Dispersal Pattern ◽  
Southwestern Nigeria ◽  
Elemental Concentrations ◽  
Major Oxide ◽  
Geochemical Analyses

The identification of anomalous elemental concentrations and the prediction of their dispersal pattern play a key role in geochemical exploration. Stream sediments are important focus in this aspect. Nine (9) sediment samples collected from Ishakare and Alatan Streams in Akungba-Akoko were subjected to grain size and inorganic geochemical analyses in order to determine their grain sizes distribution, travel distances, elemental concentrations and origin. Results of grain size analysis show that streams sediments are mostly medium-grained, poorly-moderately sorted and ranged from fine to strongly coarse skewed suggesting that they have been transported relatively not too far away from their sources under high to low energy. SiO2 is a dominant major oxide with concentration values ranging between 64.81 and 71.59 wt.% with a mean value of 68.07 wt.%. Abundance of Al2O3 indicates that samples are from Aluminum-rich source bed rock. The weights of Fe2O3 and TiO2 also point to gneissic rocks as a probable source. Generally, concentrations of trace elements were found to be low indicating that the contamination statue of the sediments ranges from unpolluted to moderately polluted

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