scholarly journals INVESTIGATION OF SHALLOW FOUNDATION SOIL BEARING CAPACITY AND SETTLEMENT CHARACTERISTICS OF MINNA CITY CENTRE DEVELOPMENT SITE USING PLAXIS 2D SOFTWARE AND EMPIRICAL FORMULATIONS

2017 ◽  
Vol 36 (3) ◽  
pp. 663-670
Author(s):  
AB Salahudeen ◽  
JA Sadeeq
Keyword(s):  
Soil Properties ◽  
Bearing Capacity ◽  
Average Energy ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Analytical Models ◽  
City Centre ◽  
Foundation Soil ◽  
Development Site ◽  
Allowable Bearing Pressure

This study investigated the soil bearing capacity and foundation settlement characteristics of Minna City Centre development site using standard penetration test (SPT) data obtained from10 SPT boreholes at 0.6, 2.1 and 3.6 m depths to correlate soil properties. Evaluation of foundation bearing capacity and settlement characteristics for geotechnical preliminary design of foundations was carried out using some conventional empirical/analytical models and numerical modelling. The aim was to investigate and determine the geotechnical parameters required for adequate design of Physical structures of the proposed Minna City Centre, at Minna the capital of Niger state. The SPT N-values were corrected to the standard average energy of 60% (N60) before the soil properties were evaluated. Using the corrected N-values, allowable bearing pressure and elastic settlement of shallow foundations were predicted at 50 kN/m2 applied foundation pressure. The numerical analysis results using Plaxis 2D, a finite element code, shows the analytical/empirical methods of estimating the allowable bearing pressure and settlements of shallow foundations that provided acceptable results. Results obtained show that an average bearing capacity value of 100 – 250 kN/m2 can be used for shallow foundations with embedment of 0.6 to 3.6 m on the site.  http://dx.doi.org/10.4314/njt.v36i3.1

scholarly journals STRENGTH CHARACTERIZATION OF FOUNDATION SOILS AT FEDERAL UNIVERSITY LOKOJA BASED ON STANDARD PENETRATION TESTS DATA

2017 ◽  
Vol 36 (3) ◽  
pp. 671-676
Author(s):  
JA Sadeeq ◽  
AB Salahudeen
Keyword(s):  
Soil Properties ◽  
Estimation Method ◽  
Average Energy ◽  
Standard Penetration Test ◽  
Analytical Models ◽  
Penetration Test ◽  
Strength Characterization ◽  
Penetration Tests ◽  
Allowable Bearing Pressure

Strength characteristics of foundation soils in the Permanent site of the Federal University Lokoja in Kogi State were evaluated based on standard penetration test (SPT) results using some conventional analytical models proposed by different researchers. The study was carried out in order to take precise engineering decisions on the type of foundations suitable for the proposed structures and to determine the optimal depth of foundation embedment.  The SPT N-values were first corrected to the standard average energy of 60% (N60) before they were used to correlate soil properties. Evaluation of the soil properties were done at foundation embedment depths of 0.6, 2.1 and 3.6 m. Results show that bearing capacity generally increased with boring depth. Based on the Meyerhof allowable bearing pressure estimation method, foundation pressures in the range of 150 – 600  kN/m2 were evaluated for use in the study area at shallow depths (depths in the range of 0.6 - 3.6 m).http://dx.doi.org/10.4314/njt.v36i3.2

scholarly journals GEOTECHNICAL PROPERTIES AND STRENGTH CHARACTERIZATION OF NIGERIAN SOILS

2019 ◽  
pp. 85-96
Keyword(s):  
Soil Properties ◽  
Bearing Capacity ◽  
Average Energy ◽  
Standard Penetration Test ◽  
Internal Resistance ◽  
Strength Characteristics ◽  
Analytical Models ◽  
North West ◽  
North East ◽  
Nigerian Soils

Strength characteristics of foundation soils in the six geo-political zones of Nigeria were evaluated based on standard penetration test (SPT) results using some conventional empirical/analytical models and the bearing capacity was predicted by numerical analysis using Plaxis 3D, a finite element application package. The SPT N-values were first corrected to the standard average energy of 60% (N60) before they were used to correlate soil properties. Evaluation of the soil properties were done at foundation embedment depths of 0.6, 2.1, 3.6, 5.1, 6.6, 8.1, 9.6, 11.1 and 12.6 m. The results of overconsolidation ratio, rigidity index, relative density, angle of internal resistance, undrained shear strength and unconfined compressive strength show that the strength characteristics of Nigerian soils is lowest on the average in the South South (SS) geo-political zone, followed by South West (SW), South East (SE), North East (NE), North West (NW) and the North Central (NC) geo-political zone has the highest prediction of strength characteristics. Bearing capacity generally increased with boring depth and having its lowest values in the SS geo-political zone and increased for the remaining zones in the order of SW, SE, NE, NW and the NC geopolitical zone.

scholarly journals Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand

Geosciences ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 392
Author(s):  
Maurizio Ziccarelli ◽  
Marco Rosone
Keyword(s):  
Bearing Capacity ◽  
Mechanical Behaviour ◽  
Failure Mechanisms ◽  
Shear Bands ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundations ◽  
Foundation Soil ◽  
Weak Layer ◽  
Geotechnical System ◽  
The Difference

The presence of minor details of the ground, including soil or rock masses, occurs more frequently than what is normally believed. Thin weak layers, shear bands, and slickensided surfaces can substantially affect the behaviour of foundations, as well as that of other geostructures. In fact, they can affect the failure mechanisms, the ultimate bearing capacity of footings, and the safety factor of the geotechnical system. In this research, numerically conducted through Finite Element Code Plaxis 2D, the influence of a horizontal thin weak layer on the mechanical behaviour of shallow footings was evaluated. The obtained results prove that the weak layer strongly influences both the failure mechanism and the ultimate bearing capacity if its depth is lower than two to four times the footing width. In fact, under these circumstances, the failure mechanisms are always mixtilinear in shape because the shear strains largely develop on the weak layer. However, the reduction in the ultimate bearing capacity is a function of the difference between the shear strength of the foundation soil and the layer. The presence of a thin weak layer decreases the ultimate bearing capacity up to 90%. In conclusion, this research suggests that particular attention must be paid during detailed ground investigations to find thin weak layers. Based on the obtained results, it is convenient to increase the soil volume investigation to a depth equal to four times the width of the foundation.

scholarly journals Comparative Analysis of Kazakhstani and European Approaches for the Design of Shallow Foundations

2020 ◽  
Vol 10 (8) ◽  
pp. 2920
Author(s):  
Assel Shaldykova ◽  
Sung-Woo Moon ◽  
Jong Kim ◽  
Deuckhang Lee ◽  
Taeseo Ku ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Summation Method ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Design Procedures ◽  
Geological Conditions ◽  
Elastic Settlement ◽  
Geotechnical Design ◽  
The Difference ◽  
Design Calculations

The design of shallow foundations is performed in accordance with different building regulations depending on geotechnical and geological conditions. This paper involves the design calculations applying Kazakhstani and European approaches. The design of shallow foundations in Nur-Sultan city in Kazakhstan was implemented by the calculation of bearing capacity and elastic settlement in accordance with the design procedures provided in SP RK 5.01-102-2013: Foundations of buildings and structures, and Eurocode 7: Geotechnical design. The calculated results of bearing capacity and elastic settlement for two types of shallow foundations, such as pad foundation and strip foundation, adhering to Kazakhstani and European approaches are relatively comparable. However, the European approach provided higher values of bearing capacity and elastic settlement for the designed shallow foundation compared to the Kazakhstani approach. The difference in the results is explained by the application of different values of partial factors of safety for the determination of bearing capacity and different methods for the calculation of the elastic settlement of shallow foundations (i.e., elasticity theory and layer summation method).

Ultimate bearing capacity of shallow foundations on sand with geogrid reinforcement

1993 ◽  
Vol 30 (3) ◽  
pp. 545-549 ◽  
Author(s):  
M.T. Omar ◽  
B.M. Das ◽  
V.K. Puri ◽  
S.C. Yen
Keyword(s):  
Bearing Capacity ◽  
Key Words ◽  
Model Test ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Laboratory Model ◽  
Critical Depth ◽  
Test Results ◽  
Laboratory Model Test

Laboratory model test results for the ultimate bearing capacity of strip and square foundations supported by sand reinforced with geogrid layers have been presented. Based on the model test results, the critical depth of reinforcement and the dimensions of the geogrid layers for mobilizing the maximum bearing-capacity ratio have been determined and compared. Key words : bearing capacity, geogrid, model test, reinforced sand, shallow foundation.

Study on Effects of the Scouring on Horizontal Bearing Capacity of the Composite Bucket Foundation

2018 ◽  
Author(s):  
Ding Hongyan ◽  
Zhao Xing ◽  
Zhang Puyang ◽  
Le Conghuan
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Shallow Foundation ◽  
Offshore Wind ◽  
Physical Model Test ◽  
3D Fem ◽  
Foundation Soil ◽  
Bucket Foundation ◽  
Loading Mode ◽  
Waves And Currents

Composite bucket foundation is a new kind of wide-shallow foundation for offshore wind turbines, and can be made on land, transported and installed by one step. Compared with other deep pile foundations, the erosion caused by waves and currents is more obvious and this would cause more risks for the overall safety of the wind turbine. In order to know more about it, a 3D FEM composite bucket foundation - soil model is established using Abaqus in this paper. In this study, the lateral bearing capacity of composite bucket foundation in different situation is analyzed by FEM and the results of FEM have been compared with that of physical model test. And through anther model test, the size parameters of scouring pit are obtained. Then the emergence and development of scouring pits are simulated by continuously excavating soil. The horizontal bearing capacity of a practical project is calculated considering the influence of scouring on the CBF by the displacement loading mode. The calculation results show that the horizontal bearing capacity of the bucket foundation is significantly reduced after scouring, and the influence of scour depth is more significant than the scouring extent.

Reliability evaluation of shallow foundation bearing capacity on c' ϕ' soils

2000 ◽  
Vol 37 (1) ◽  
pp. 264-269 ◽  
Author(s):  
C Cherubini
Keyword(s):  
Bearing Capacity ◽  
Probabilistic Models ◽  
Correlation Coefficients ◽  
Friction Angle ◽  
Reliability Evaluation ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Probabilistic Methods ◽  
Deterministic Models ◽  
Modus Operandi

As our understanding of soils has been steadily improving, the characteristics of its variability can now be highlighted. This has practically changed our geotechnical modus operandi from strictly deterministic models to semiprobabilistic or even strictly probabilistic models. The latter are still to be regarded as experimental and cannot, for the time being, be used routinely in practical working applications. However, the ongoing, continued research and study of these methods combine to develop their worth and bring out any drawbacks. This paper proposes a possible application of probabilistic methods to the study of shallow foundations reliability with respect to their bearing capacity. The study concerns a foundation on a soil characterized by effective cohesion c' and friction angle ϕ', considering possible values of correlation coefficients between them and taking into account the effects of vertical fluctuation scale. The results show that higher reliability indexes are found when correlations between c' and ϕ' are negative and when the fluctuation scale has a minimum value.Key words: reliability, bearing capacity, shallow foundations, friction angle, cohesion.

Experimental Study of Compressive Bearing Capacity of Pile-Bucket Foundation

2011 ◽  
Vol 261-263 ◽  
pp. 1851-1855
Author(s):  
Wen Bai Liu ◽  
Ye Li ◽  
Da Shan Wang
Keyword(s):  
Bearing Capacity ◽  
Soil Surface ◽  
Shallow Foundation ◽  
Length Variation ◽  
Obvious Effect ◽  
Foundation Soil ◽  
Bucket Foundation ◽  
Circular Shape ◽  
Pile Length ◽  
Surrounding Soil

By combining indoor model experiment and numerical simulation, the analysis of pile-bucket foundation bearing capacity under pressure load was conducted, and the bearing capacity can be enhanced by enlarging the three main dimensions of pile-bucket foundation: diameter of bucket, height of bucket and length of pile. By enlarging the diameter of bucket by 1.5 times while maintaining the two other dimensions, the bearing capacity can be enhanced by 140%;the bearing capacity can be enhanced by 15% when the height of bucket is enlarged by 2 times; the bearing capacity can be enhanced by 14% when the pile length is enlarged by 30% ,that means the variation of bucket diameter affects the pile-bucket foundation bearing capacity most, apart from that the variation of bucket diameter also holds the most obvious effect on the ground foundation soil body in crosswise scope, the bucket diameter of 3# pile-bucket was 1.5 times that of 1# pile-bucket, after the surrounding soil broke, the influence scope on crosswise soil surface was enhanced by the size 3.8 times breadth of bucket diameter; and the pile-length variation keeps the largest effect on surrounding soil body in-depth, the depth of effect on grounding soil of 1#pile-bucket is enlarged by 925mm comparing by 2#pile-bucket (approximately 9 times of bucket diameter) ; By conducting indoor-model pressure bearing capacity experiment on pile –bucket foundation,bucket foundation and circular-shape shallow foundation with same diameter, the limiting bearing capacity of pile-bucket foundation is 3.2 times that of circular-shape shallow foundation and 1.26 times that of bucket foundation, a manifestation of the bearing capacity advantage of pile-bucket foundation.

A closed-form probabilistic solution for evaluating the bearing capacity of shallow foundations

1990 ◽  
Vol 27 (4) ◽  
pp. 526-529 ◽  
Author(s):  
C. Cherubini
Keyword(s):  
Bearing Capacity ◽  
Closed Form ◽  
Closed Form Solution ◽  
Friction Angle ◽  
Form Solution ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Probabilistic Evaluation ◽  
Allowable Bearing Capacity ◽  
Probabilistic Solution

A closed-form solution for the probabilistic evaluation of shallow foundation bearing capacity according to the model proposed by Terzaghi, as modified by Krizek, is described. A numerical example explains the method of computation. Key words: statistics, probability, ultimate bearing capacity, allowable bearing capacity, shallow foundations, friction angle, numerical methods.

scholarly journals Pemodelan Perkuatan Menggunakan Bambu Untuk Daya Dukung Pondasi Dangkal pada Tanah Gambut

CANTILEVER ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 109-114
Author(s):  
Yulindasari Sutejo ◽  
Sutanto Muliawan ◽  
Ratna Dewi ◽  
Febrian Hadinata ◽  
Budi Ariawan ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Peat Soil ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Sampling Location ◽  
Layer Depth ◽  
Number Of Layers ◽  
Percent Increase ◽  
Reinforcing Material ◽  
Effective Layer

Some of the unfavorable characteristics of peat soil are low bearing capacity and high compressibility. The reinforcing material used in this research which functions the same as geogrid are bamboo materials (grids and woven). The bamboo material used aims to determine the carrying capacity and reduction of shallow foundations on peat soil before being reinforced and after being reinforced. Bamboo matting and rectangular patterned bamboo grids. Laboratory scale testing were used as the research methodology. The peat soil sampling location came from the area of Dusun III Banyu Urip, Banyuasin regency, South Sumatra province. The bamboo material is obtained from the Seberang Ulu area, Palembang City and sand  is obtained from the sand depot in the Musi II area, Palembang City. The results of laboratory testing show that the addition of the number of reinforcement layers and the effective layer depth distance will give a greater bearing capacity ratio (BCR) value. The bearing capacity value of the shallow foundation before being reinforced on peat soil using Terzaghi's analysis is 45.232 kpa. Then, after testing the variation in the depth of the layer d = 0b; d = 0.25b; and d = 0.5b with the number of layers 1 layer, 2 layers and 3 layers obtained a variation which gives the highest bearing capacity value of layer depth variations d = 0.25b with the number of layers of 3 layers. The bearing capacity value is 94 kpa with a BCRvalue of 2.08 (percent increase of 107.96 %).

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