Safety analysis of shallow foundations towards the bearing capacity: Effect of the soil parameters spatial variability

1988 ◽  
Vol 6 (1) ◽  
pp. 68
Author(s):  
J-L. Favre ◽  
B. Genevois
Keyword(s):  
Spatial Variability ◽  
Bearing Capacity ◽  
Safety Analysis ◽  
Shallow Foundations ◽  
Soil Parameters

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 PLANNING OF FLOATING FOUNDATION FOR SOFT SOIL IN GLAGAH AGUNG, BANYUWANGI CITY

2019 ◽  
Vol 3 (2) ◽  
pp. 154
Author(s):  
Dora Melati Nurita Sandi ◽  
Erna Suryani ◽  
Ayu Wanda Febrian
Keyword(s):  
Bearing Capacity ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Soft Soil ◽  
Soil Samples ◽  
Shallow Foundations ◽  
Soil Parameters ◽  
Floating Foundation

Soft soil in construction often creates a problem. Soft soil which has the characteristics of low bearing capacity and high shrinkage properties becomes a problem for construction. One of the efforts to overcome these problems is by planning building foundations that are following soft soil characters. A floating foundation is planned that adopts the concept of lightweight concrete. The lightweight concrete used is an innovative concrete that uses styrofoam as a substitute for coarse aggregate. So that this concrete does not require broken stone or gravel as a concrete filler. Initial planning for floating foundations was carried out in the Purwoharjo area. Soil samples are taken and analyzed their characteristics to get the soil parameters. Then the dimensions of the foundation are planned by using the terzaghi formula for shallow foundations. The decrease or settlement of the soil was analyzed using the help of PLAXIS 2D software. Tanah lunak dalam konstruksi seringkali menjadi sebuah kendala. Tanah lunak yang memiliki karakteristik daya dukung rendah dan sifat kembang susut tinggi menjadi sebuah permasalahan dalam mendirikan bangunan di atasnya. Salah satu upaya untuk mengatasi permasalahan tersebut adalah dengan merencanakan pondasi bangunan yang sesuai dengan karakter tanah lunak. Direncanakan sebuah pondasi apung yang mengadopsi konsep beton ringan. Beton ringan yang digunakan merupakan beton inovasi yang menggunakan styrofoam sebagai pengganti agregat kasarnya. Sehingga beton ini tidak memerlukan batu pecah atau kerikil sebagai bahan pengisi beton. Perencanaan awal untuk pondasi apung, dilakukan di daerah Purwoharjo. Sample tanah diambil dan dianalisis karakteristiknya untuk mendapatkan parameter-parameter tanahnya. Kemudian direncanakan dimensi pondasi dengan menggunakan rumus terzaghi untuk pondasi dangkal. Penurunan atau settlement tanah dianalisis menggunakan bantuan software PLAXIS 2D.

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.

Bearing capacity improvement of shallow foundations using a trench filled with granular materials and reinforced with geogrids

2021 ◽  
Vol 14 (15) ◽  
Author(s):  
Mohammad Mahdi Hajitaheriha ◽  
Davood Akbarimehr ◽  
Amin Hasani Motlagh ◽  
Hossein Damerchilou
Keyword(s):  
Bearing Capacity ◽  
Granular Materials ◽  
Shallow Foundations ◽  
Capacity Improvement

scholarly journals Application of Artificial Neural Networks for Predicting the Bearing Capacity of Shallow Foundations on Rock Masses

2021 ◽  
Author(s):  
M. A. Millán ◽  
R. Galindo ◽  
A. Alencar
Keyword(s):  
Bearing Capacity ◽  
Analytical Solutions ◽  
Shear Failure ◽  
Numerical Models ◽  
Computational Effort ◽  
Shallow Foundations ◽  
Geological Strength Index ◽  
Rock Masses ◽  
Ann Model ◽  
Artificial Neural

AbstractCalculation of the bearing capacity of shallow foundations on rock masses is usually addressed either using empirical equations, analytical solutions, or numerical models. While the empirical laws are limited to the particular conditions and local geology of the data and the application of analytical solutions is complex and limited by its simplified assumptions, numerical models offer a reliable solution for the task but require more computational effort. This research presents an artificial neural network (ANN) solution to predict the bearing capacity due to general shear failure more simply and straightforwardly, obtained from FLAC numerical calculations based on the Hoek and Brown criterion, reproducing more realistic configurations than those offered by empirical or analytical solutions. The inputs included in the proposed ANN are rock type, uniaxial compressive strength, geological strength index, foundation width, dilatancy, bidimensional or axisymmetric problem, the roughness of the foundation-rock contact, and consideration or not of the self-weight of the rock mass. The predictions from the ANN model are in very good agreement with the numerical results, proving that it can be successfully employed to provide a very accurate assessment of the bearing capacity in a simpler and more accessible way than the existing methods.

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