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.

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 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.

Modelling the applied vertical stress and settlement relationship of shallow foundations in saturated and unsaturated sands

2011 ◽  
Vol 48 (3) ◽  
pp. 425-438 ◽  
Author(s):  
Won Taek Oh ◽  
Sai K. Vanapalli
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Characteristic Curve ◽  
Friction Angle ◽  
Vertical Stress ◽  
Shallow Foundations ◽  
Surface Settlement ◽  
Soil Parameters ◽  
Finite Element Analyses ◽  
Unsaturated Sands

The bearing capacity and settlement of foundations are determined experimentally or modelled numerically based on conventional soil mechanics for saturated soils. In both methods, bearing capacity and settlement are estimated based on the applied vertical stress versus surface settlement relationship. These methods are also conventionally used for soils that are in an unsaturated condition, ignoring the contribution of matric suction. In this study, a methodology is proposed to estimate the bearing capacity and settlement of shallow foundations in unsaturated sands by predicting the applied vertical stress versus surface settlement relationship. The proposed method requires soil parameters obtained under only saturated conditions (i.e., effective cohesion, effective internal friction angle, and modulus of subgrade reaction from model footing test) along with the soil-water characteristic curve (SWCC). In addition, finite element analyses are undertaken to simulate the applied vertical stress versus surface settlement relationship for unsaturated sands. The proposed method and finite element analyses are performed using an elastic – perfectly plastic model. The predicted bearing capacities and settlements from the proposed method and finite element analyses are compared with published model footing test results. There is good agreement between measured and predicted results.

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

Exact probabilistic solution of two-parameter bearing capacity for shallow foundations

1992 ◽  
Vol 29 (5) ◽  
pp. 867-870 ◽  
Author(s):  
Said M. Easa
Keyword(s):  
Bearing Capacity ◽  
Random Variable ◽  
Friction Angle ◽  
Shallow Foundations ◽  
Cohesionless Soil ◽  
Unit Weight ◽  
Previous Solution ◽  
Probabilistic Solution ◽  
Two Parameter ◽  
Soil Unit

An exact probabilistic solution of the ultimate bearing capacity of cohesionless soil for shallow strip foundations is presented. The solution incorporates two random variables: effective friction angle [Formula: see text] and soil unit weight γ. This solution is an extension of a previous solution in which only [Formula: see text] is considered as a random variable. The exact solution is verified using Monte Carlo simulation and the sensitivity of the solution to the coefficient of variation of the soil unit weight is examined. Key words : probability, reliability, bearing capacity, shallow strip foundations, friction angle, soil unit weight.

scholarly journals ANALISIS CARA PENINGKATAN DAYA DUKUNG FONDASI DANGKAL PADA KONSTRUKSI GEDUNG BERTINGKAT

2020 ◽  
Vol 3 (3) ◽  
pp. 897
Author(s):  
Feric Antonius ◽  
Alfred Jonathan Susilo
Keyword(s):  
Bearing Capacity ◽  
Friction Angle ◽  
Shallow Foundation ◽  
Soil Reinforcement ◽  
Crushed Stone ◽  
Unit Weight ◽  
Stone Column ◽  
Deep Foundation ◽  
High Rise ◽  
Crushed Limestone

ABSTRACTThe construction of high rise buildings requires a strong foundation. High rise building construction usually requires a deep foundation which requires a large cost. Therefore, shallow foundation can be used as an alternative to replace deep foundation. The main problem that arise is the low bearing capacity of the foundation which unable to carry the load. This research conducts is to find out how to increase the bearing capacity of a square footings with several reinforcement materials for high rise buildings. The analysis bearing capacity of shallow foundation is carried out manually using the Terzaghi method and the Meyerhof and Hanna method. The results of the analysis using these two methods show that soil reinforcement materials such as stone column, crushed stone, crushed limestone, construction and demolition can increase the bearing capacity of shallow foundations. The conclusions of this research with Terzaghi method obtained that the greater the value of the friction angle and unit weight of soil from the reinforcement materials, the bearing capacity of the foundation will be even greater, while the Meyerhof and Hanna method obtained that the stronger material does not always get the greatest value of bearing capacity because it depends on the type and consistency of the soil under the reinforcement layer.Keywords: bearing capacity; stone column; crushed stone; crushed limestone; construction and demolitionABSTRAKDalam perencanaan pembangunan seperti gedung bertingkat tentunya memerlukan sebuah fondasi yang kuat. Pembangunan konstruksi gedung bertingkat biasanya memerlukan fondasi dalam tetapi memerlukan biaya yang besar. Oleh karena itu, fondasi dangkal dapat digunakan sebagai alternatif untuk menggantikan fondasi dalam. Masalah utama yang timbul dari penggunaan fondasi dangkal untuk gedung bertingkat adalah daya dukung fondasi yang rendah sehingga tidak mampu memikul gaya luar. Penelitian ini dilakukan untuk mengetahui cara peningkatan daya dukung fondasi telapak persegi dengan beberapa material perkuatan tanah untuk gedung bertingkat. Analisis daya dukung fondasi dangkal dilakukan secara perhitungan manual menggunakan metode Terzaghi dan metode Meyerhof dan Hanna. Hasil analisis menggunakan kedua metode tersebut menunjukkan bahwa material perkuatan tanah yaitu stone column, crushed stone, crushed limestone dan construction and demolition yang digunakan dapat meningkatkan daya dukung fondasi dangkal. Kesimpulan dari penelitian ini antara lain menggunakan metode Terzaghi didapatkan bahwa semakin besar nilai sudut geser dalam dan berat jenis tanah dari material perkuatan yang digunakan maka nilai daya dukung fondasi akan semakin besar sedangkan metode Meyerhof dan Hanna didapatkan bahwa semakin kuat material belum tentu berpengaruh untuk mendapatkan nilai daya dukung yang paling besar karena dipengaruhi dengan jenis dan konsistensi tanah yang berada dibawah lapisan perkuatan tersebut.Kata kunci: daya dukung; stone column; crushed stone; crushed limestone; construction and demolition

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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