scholarly journals Reliability Analysis of Bearing Capacity of Shallow Foundation on c- φ Soil

2019 ◽  
Vol 5 ◽  
pp. 71-78
Author(s):  
Mahesh Acharya ◽  
Indra Prasad Acharya
Keyword(s):  
Bearing Capacity ◽  
Reliability Analysis ◽  
Design Method ◽  
Order Approximation ◽  
Shallow Foundation ◽  
Unit Weight ◽  
Multiple Sources ◽  
Systematic Analysis ◽  
Reliability Based Design ◽  
Taylor’S Series

Bearing capacity of shallow foundation is a challenging problem for geotechnical engineers. The difficulty comes from multiple sources of uncertainty. Only the uncertainties in Soil properties; unit weight (γ), cohesion(c), and angle of friction (φ) are taken in this study. The Reliability Based Design method is used for the assessment of bearing capacity of shallow foundation by First-and second-order approximation using Taylor’s series expansion and Mathcad Computer program which provide systematic analysis of uncertainties and allow the designer how reliable are their designs. The Terzaghi Bearing capacity equation is used for the analysis along with the certain range of variability (CV %) associated with the variables. For the reliability analysis, to become more realistic two real cases of shallow foundation on c-φ soil has been taken as a sample case.

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

Reliability Analysis of Circular Footing by Using GP and MPMR

2021 ◽  
Vol 12 (1) ◽  
pp. 1-19
Author(s):  
Rahul Kumar ◽  
Pijush Samui ◽  
Sunita Kumari ◽  
Yildirim Hüseyin Dalkilic
Keyword(s):  
Bearing Capacity ◽  
Reliability Analysis ◽  
Unit Weight ◽  
Variable Parameters ◽  
Angle Of Internal Friction ◽  
First Order ◽  
Moment Methods ◽  
First Order Second Moment ◽  
Minimax Probability Machine Regression ◽  
Circular Footing

Circular footings are designed to bear a load of super structures. Studies have been done on the influence of soil properties on bearing capacity of shallow foundations. The use of circular foundation is practical in geotechnical engineering. During the design of circular footing, bearing capacity of soil is taken into consideration, and cohesion (c), unit weight (γ), and angle of internal friction (ϕ) are the most variable parameters. Reliability analysis is used frequently for the design of circular footing. Most of the authors have used first order second moment methods (FOSM). However, FOSM is a time-consuming method. Drawbacks of FOSM have been overcome by genetic programming (GP), minimax probability machine regression (MPMR). This article gives a distinct analysis between the developed MPMR based FOSM and GP-based FOSM.

Reliability analysis of the bearing capacity of a shallow foundation resting on cohesive soil

2006 ◽  
Vol 43 (2) ◽  
pp. 217-223 ◽  
Author(s):  
G L Sivakumar Babu ◽  
Amit Srivastava ◽  
D SN Murthy
Keyword(s):  
Random Field ◽  
Bearing Capacity ◽  
Autocorrelation Function ◽  
Cohesive Soil ◽  
Shallow Foundation ◽  
Soil Variability ◽  
Statistical Parameters ◽  
Random Field Theory ◽  
Reliability Based Design ◽  
Tip Resistance

In recent years, there have been considerable advances in the characterization of soil variability and its application in geotechnical designs. It is recognized that in using reliability-based design it is necessary to consider all sources of uncertainty in the analysis and incorporate them in the geotechnical design. It is also necessary to examine the reliability-based approach in relation to deterministic approaches. In this study, cone tip resistance (qc) data obtained from a static cone penetration test on a stiff clay deposit are analyzed by using random field theory; and statistical parameters, such as the mean, variance, and autocorrelation function, are estimated in evaluating the reliability of the allowable bearing capacity of a strip footing founded on the above deposit.Key words: reliability-based design, soil variability, random field, variance, autocorrelation function, bearing capacity.

Load and resistance factor design of shallow foundations against bearing failure

2008 ◽  
Vol 45 (11) ◽  
pp. 1556-1571 ◽  
Author(s):  
Gordon A. Fenton ◽  
D. V. Griffiths ◽  
Xianyue Zhang
Keyword(s):  
Bearing Capacity ◽  
Limit State ◽  
Resistance Factor ◽  
Shallow Foundation ◽  
Ultimate Limit State ◽  
Full Potential ◽  
Design Codes ◽  
Reliability Based Design ◽  
Factor Design ◽  
Load And Resistance Factor

Shallow foundation designs are typically governed either by settlement, a serviceability limit state, or by bearing capacity, an ultimate limit state. While geotechnical engineers have been designing against these limit states for over half a century, it is only recently that they have begun to migrate towards reliability-based designs. At the moment, reliability-based design codes are generally derived through calibration with traditional working stress designs. To take advantage of the full potential of reliability-based design the profession must go beyond calibration and take geotechnical uncertainties into account in a rational fashion. This paper proposes a load and resistance factor design (LRFD) approach for the bearing capacity design of a strip footing, using load factors as specified by structural codes. The resistance factors required to achieve an acceptable failure probability are estimated as a function of the spatial variability of the soil and by the level of “understanding” of the soil properties in the vicinity of the foundation. The analytical results, validated by simulation, are primarily intended to aid in the development of the next generation of reliability-based geotechnical design codes, but can also be used to assess the reliability of current designs.

Design and Research of Double-Drum Winch with Anti-Pressure Wheel

2012 ◽  
Vol 479-481 ◽  
pp. 1709-1713
Author(s):  
Kai An Yu ◽  
Tao Yang ◽  
Chang Zhi Gong
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Finite Element Methods ◽  
Design Method ◽  
New Method

In view of the problems of large stress and severe bearing heating in double-drum winch at present, this paper adopted a new method to enhance bearing capacity for double-drum winch by adding anti-pressure wheels between two drums. Finite element methods were used to analyze the strength of 4000kN-traction double-drum winches with anti-pressure wheels and without anti-pressure wheels respectively. The results of the analysis revealed that the stress of the cylinder bearing decreased from 264MPa to 167MPa. The new method by adding anti-pressure wheels had remarkably improved the endurance of the bearing. Therefore, the design method can be widely used in large-traction double-drum winch.

scholarly journals Influence of the groundwater level on the bearing capacity of shallow foundations on the rock mass

2021 ◽  
Author(s):  
Ana Alencar ◽  
Rubén Galindo ◽  
Svetlana Melentijevic
Keyword(s):  
Rock Mass ◽  
Bearing Capacity ◽  
Groundwater Level ◽  
Sensitivity Study ◽  
Shallow Foundations ◽  
Unit Weight ◽  
Geological Strength Index ◽  
Strength Index ◽  
Mass Type

AbstractThe presence of the groundwater level (GWL) at the rock mass may significantly affect the mechanical behavior, and consequently the bearing capacity. The water particularly modifies two aspects that influence the bearing capacity: the submerged unit weight and the overall geotechnical quality of the rock mass, because water circulation tends to clean and open the joints. This paper is a study of the influence groundwater level has on the ultimate bearing capacity of shallow foundations on the rock mass. The calculations were developed using the finite difference method. The numerical results included three possible locations of groundwater level: at the foundation level, at a depth equal to a quarter of the footing width from the foundation level, and inexistent location. The analysis was based on a sensitivity study with four parameters: foundation width, rock mass type (mi), uniaxial compressive strength, and geological strength index. Included in the analysis was the influence of the self-weight of the material on the bearing capacity and the critical depth where the GWL no longer affected the bearing capacity. Finally, a simple approximation of the solution estimated in this study is suggested for practical purposes.

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