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

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.

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CORE LOG AND CONE PENETRATION TEST APPROACH FOR BEARING CAPACITY ANALYSIS OF QUATERNARY DEPOSIT AND ITS CORRELATION TO FACIES DISTRIBUTION IN SOUTHERN BALI

Rudarsko-geološko-naftni zbornik ◽

10.17794/rgn.2020.4.1 ◽

2020 ◽

Vol 35 (4) ◽

pp. 1-14

Author(s):

Nugroho Aji Satriyo ◽

Eko Soebowo ◽

Imam Achmad Sadisun

Keyword(s):

Bearing Capacity ◽

Depositional Environment ◽

Cone Penetration Test ◽

Shallow Foundation ◽

Grain Size Analysis ◽

Size Analysis ◽

Capacity Analysis ◽

Penetration Test ◽

Cone Penetration ◽

Quaternary Deposit

Area development deals with optimal land use and the reduction of the risk of geological disasters. The coastal area of South Bali is prone to land settlement hazards. In order to mitigate the risk, it is important to understand the depositional environment of the area related to its bearing capacity and geological hazard risks. The aim of this research is to understand the subsurface depositional environment and quantifying its bearing capacity. Quantitative modeling was carried out to obtain the sediment-bearing capacity of the Pendungan area in Bali, Indonesia. The methods used in this research were the observation of borehole cores, the identification of the cone penetration test (CPTu) curves pattern, the sediment index property test, the soil strength laboratory, and bearing capacity analysis. Based on lithologic association, the CPTu curve pattern, and grain size analysis, there are three facies developing in the study area with different bearing capacity values. Generally, beach ridge sand has a higher bearing capacity (N-SPT value of 8 – 52) for shallow foundation than fluvial clay. Meanwhile, floodplain facies has the lowest bearing capacity (N-SPT value of 2 – 20).

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

10.21203/rs.3.rs-16191/v1 ◽

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.

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Calibration of a Miniature Cone Penetrometer for Highway Applications

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1614-02 ◽

1998 ◽

Vol 1614 (1) ◽

pp. 8-14 ◽

Cited By ~ 4

Author(s):

Pradeep U. Kurup ◽

Mehmet T. Tumay

Keyword(s):

Ground Improvement ◽

Cone Penetration Test ◽

Test System ◽

Soil Parameters ◽

Cone Penetrometer ◽

Penetration Test ◽

Cone Penetration ◽

Tip Resistance ◽

In Situ Investigation

The electronic cone penetrometer is an important in situ investigation tool of choice for site characterization. Application of this proven concept of the cone penetration test (CPT) to highway design and construction control by miniaturization is described. A miniature cone penetrometer with a projected cone area of 2 cm2 has been developed and implemented in a continuous intrusion miniature cone penetration test system (CIMCPT). This device may be used for rapid, accurate, and economical characterization of sites and to determine engineering soil parameters needed in the design of pavements, embankments, and earth structures. The miniature cone penetration test (MCPT) gives finer details than the standard 10-cm2 cross-sectional area reference cone penetrometer. This makes the MCPT attractive for subgrade characterization, quality-control assessment, compaction control of embankments, and assessment of ground improvement effectiveness for transportation infrastructure. In situ calibration of the CIMCPT system was conducted at a highway embankment site in Baton Rouge, Louisiana. MCPT penetration profiles were compared with those obtained by using the standard cone penetrometer at the same site. The tip resistance of the MCPT was 10 percent higher than that of the reference CPT. The sleeve friction and friction ratio of the reference CPT were higher than that of the MCPT by 12 and 23 percent, respectively. Calibration was also performed to determine empirical cone factors required for estimating undrained shear strength from MCPT data.

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Evaluation of excess pore pressures and drainage conditions around driven piles using the cone penetration test with pore pressure measurements

Canadian Geotechnical Journal ◽

10.1139/t90-029 ◽

1990 ◽

Vol 27 (2) ◽

pp. 249-254 ◽

Cited By ~ 2

Author(s):

P. K. Robertson ◽

D. J. Woeller ◽

D. Gillespie

Keyword(s):

Pore Pressure ◽

Large Diameter ◽

Cone Penetration Test ◽

Pressure Measurements ◽

Penetration Test ◽

Cone Penetration ◽

Pore Pressures ◽

Clayey Silt ◽

Excess Pore Pressures ◽

Excess Pore

Large-diameter steel pipe piles were driven as part of the foundations for the Alex Fraser Bridge near Vancouver, British Columbia. The piles penetrated through a normally consolidated marine clayey silt. As part of the geotechnical studies a multipoint piezometer was installed close to the pile group. A cone penetration test with pore pressure measurements (CPTU) was performed adjacent to one of the piles shortly after driving. During the CPTU through the clayey silt deposit, dissipation tests were performed to evaluate the pore pressures around the nearby pile. The CPTU results are compared with the pore pressures recorded at the multipoint piezometer, allowing for differences in radial distance from the piles. Excellent agreement was obtained between the CPTU and multipoint piezometer data, both showing large excess pore pressures around the piles. The CPTU dissipation data were also analyzed to evaluate the time required for dissipation of excess pore pressures around the piles. The upper half of the clayey silt deposit was inter bedded with thin sand and silt layers. The CPTU data showed that the thin sand layers were sufficiently large in extent to allow rapid dissipation of the pore pressures due to cone penetration but were not of sufficient extent to allow dissipation of the excess pore pressures from the much larger diameter piles. Key words: in situ, piles, pore pressures, CPT.

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Study on the Correlation between Cone Resistance and Soil Density Using Centrifuge Robot CPT

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.831.336 ◽

2013 ◽

Vol 831 ◽

pp. 336-340

Author(s):

Qing Lei Sun ◽

Yu Jing Hou ◽

Xue Dong Zhang ◽

Ren Peng

Keyword(s):

Relative Density ◽

Cone Penetration Test ◽

Soil Parameters ◽

Test Results ◽

Soil Density ◽

Penetration Test ◽

Cone Penetration ◽

Cone Resistance ◽

Centrifuge Tests ◽

Relative Density Of Sand

Density is one of the most important soil parameters. However, it is difficult to measure the density of soil model during centrifuge in flight. The cone penetration test (CPT) with robot provides a useful tool to determine the soil density of different models, as the cone resistance is closely related to soil density. This paper presents the correlation between cone resistance and relative density of sand, by doing centrifuge tests with robot CPT. Based on the test results, a formula that describes the correlation between cone resistance and sand relative density of Fujian standard sand is proposed for IWHR CPT attached to centrifuge robot.

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Simplified geostatistical analysis of earthquake-induced ground response at the Wildlife Site, California, U.S.A

Canadian Geotechnical Journal ◽

10.1139/t02-089 ◽

2003 ◽

Vol 40 (1) ◽

pp. 16-35 ◽

Cited By ~ 20

Author(s):

Tamer Elkateb ◽

Rick Chalaturnyk ◽

Peter K Robertson

Keyword(s):

Spatial Variability ◽

Stochastic Analysis ◽

Surface Damage ◽

Cone Penetration Test ◽

Soil Parameters ◽

Penetration Test ◽

Cone Penetration ◽

Damage Potential ◽

Deterministic Analysis ◽

Mean Values

Almost all natural soils are highly variable and rarely homogeneous. In this study, the seismic response of the Wildlife Site, Imperial Valley, California, U.S.A., has been analysed to assess the effect of ground heterogeneity on liquefaction assessment in a probabilistic analysis framework. Cone penetration test (CPT) data recorded at the site have been used to identify different lithologies and to estimate elements of soil inherent spatial variability. Monte Carlo simulation has been utilized to obtain several realizations of CPT data that were then implemented into empirical approaches to examine the liquefaction susceptibility of the site. In addition, stochastic analysis of liquefaction-induced surface damage has been carried out through the application of these realizations into damage criteria, such as total liquefaction damage potential and surface settlement. These stochastic analyses have indicated that using mean values in deterministic analysis can be on the unsafe side. As a result, attempts have been made to obtain meaningful representative soil parameters that can be used in simplified deterministic analysis, while continuing to honor detailed ground heterogeneity. In addition, an empirical technique has been developed to compare ground variability of potentially liquefiable sites on a qualitative basis.Key words: liquefaction, spatial variability, stochastic analysis, cone penetration test, damage, characteristic parameters.

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