scholarly journals Effect of perforations on the bearing capacity of shallow foundation on clay

2019 ◽  
Vol 56 (5) ◽  
pp. 746-752 ◽  
Author(s):  
Run Liu ◽  
Meng-meng Liu ◽  
Ying-hui Tian ◽  
Xinli Wu
Keyword(s):  
Shear Strength ◽  
Bearing Capacity ◽  
Three Dimensional ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Two Dimensional ◽  
Element Analysis ◽  
Dimensionless Ratio ◽  
Undrained Strength ◽  
Strength Gradient

As a type of shallow foundation, a mudmat serves as the seabed support structure for subsea wells, pipeline manifolds, and pipeline terminations. The shallow foundations are usually designed with perforations to facilitate installation and removal, but the influence of these perforations has not been fully understood. This paper presents a method to analyze the bearing capacities of both two-dimensional (2D) and three-dimensional (3D) perforated shallow foundations using finite element analysis. The soil was idealized as a Tresca material, with the undrained strength increasing linearly with depth. The outcome indicates that perforations have nonnegligible effects on the bearing capacity of shallow foundations. The bearing capacity decreases with increasing perforation ratio, R, and the degree of reduction increases with the increase of the dimensionless ratio kB/Suo, where k is the shear strength gradient, B is the width of the foundation, and Suo is the shear strength at the mudline. For 2D shallow foundations, there exists a critical perforation ratio, Rc; when the perforation ratio is lower than the critical perforation ratio, the perforated foundation does not lose its bearing capacity. For 3D shallow foundations, the bearing capacity decreases directly with the increase of perforation ratio, R.

PROBABILISTIC ANALYSIS OF BEARING CAPACITY OF SHALLOW FOUNDATIONS USING THREE-DIMENSIONAL LIMIT ANALYSES

2014 ◽  
Vol 11 (02) ◽  
pp. 1342008 ◽  
Author(s):  
JOÃO T. SIMÕES ◽  
LUÍS C. NEVES ◽  
ARMANDO N. ANTÃO ◽  
NUNO M. C. GUERRA
Keyword(s):  
Bearing Capacity ◽  
Three Dimensional ◽  
Latin Hypercube Sampling ◽  
Shallow Foundations ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Upper Limit ◽  
Heterogeneous Soil ◽  
Small Set ◽  
Undrained Conditions

Strip shallow foundations on random heterogeneous soil responding in undrained conditions are analyzed using three-dimensional upper limit analysis and Latin Hypercube sampling. The results obtained considering the three-dimensional variability of soil are compared with results using plane models, showing significant differences in terms of both mean and standard deviation of bearing capacity. An averaged two-dimensional model fitted to a small set of three-dimensional samples is shown to yield accurate predictions of the bearing capacity distribution.

scholarly journals Composite hollow truss with multiple vierendeel panels

2013 ◽  
Vol 66 (4) ◽  
pp. 431-438
Author(s):  
Augusto Ottoni Bueno da Silva ◽  
Newton de Oliveira Pinto Júnior ◽  
João Alberto Venegas Requena
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Three Dimensional ◽  
Analytical Calculation ◽  
Two Dimensional ◽  
Shear Forces ◽  
Vertical Displacements ◽  
New System ◽  
The Ideal

The aim of this study was to evaluate through analytical calculation, two-dimensional elastic modeling, and three-dimensional plastic modeling, the bearing capacity and failure modes of composite hollow trusses bi-supported with a 15 meter span, varying the number of central Vierendeel panels. The study found the proportion span/3 - span/3 - span/3, as the ideal relationship for the truss - Vierendeel - truss lengths, because by increasing the proportion of the length occupied by the central Vierendeel panels, the new system loses stiffness and no longer supports the load stipulated in the project. Furthermore, they can start presenting excessive vertical displacements and insufficient resistance to external shear forces acting on the panels.

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.

Analysis of Friction Vibration in Sliding Model of Double Rough Surfaces

2014 ◽  
Vol 926-930 ◽  
pp. 52-55
Author(s):  
Lian Feng Lai ◽  
Cheng Hui Gao ◽  
Jian Meng Huang
Keyword(s):  
Finite Element Analysis ◽  
Shear Strength ◽  
Friction And Wear ◽  
Rough Surfaces ◽  
Three Dimensional ◽  
Frequency Component ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Element Analysis ◽  
The Finite Element Analysis

A three-dimensional W-M fractal sliding model of double rough surfaces was established, and the factors of interface shear strength influenced the whole sliding process was considered. The velocity in Z direction of sliding processes was analyzed using the finite element analysis and taking into account of adhesion factors in the process of contact. The numerical results showed that the velocity in Z direction's fluctuation is larger, and the higher-frequency component is more with the decrease of the interface shear strength. Compared with experimental results and related documents, it is concluded the rationality of the results. The contact model between two rough solids will lay a foundation to further research on the substance of the process of friction and wear.

Three-dimensional deformations in a single-lap joint

1994 ◽  
Vol 29 (2) ◽  
pp. 137-145 ◽  
Author(s):  
M Y Tsai ◽  
J Morton
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
Stress Distributions ◽  
Lap Joint ◽  
Displacement Fields ◽  
Element Analysis ◽  
Linear Elastic ◽  
Non Linear ◽  
Linear Effects ◽  
Peel Stress

The three-dimensional nature of the state of deformation in a single-lap test specimen is investigated in a linear elastic finite element analysis in which the boundary conditions account for the geometrically non-linear effects. The validity of the model is demonstrated by comparing the resulting displacement fields with those obtained from a moiré inteferometry experiment. The three-dimensional adherend and adhesive stress distributions are calculated and compared with those from a two-dimensional non-linear numerical analysis, Goland and Reissner's solution, and experimental measurements. The nature of the three-dimensional mechanics is described and discussed in detail. It is shown that three-dimensional regions exists in the specimen, where the adherend and adhesive stress distributions in the overlap near (and especially on) the free surface are quite different from those occurring in the interior. It is also shown that the adhesive peel stress is extremely sensitive to this three-dimensional effect, but the adhesive shear is not. It is also observed that the maximum value of the peel stress occurs at the end of the overlap in the central two-dimensional core region, rather than at the corners where the three-dimensional effects are found. The extent of three-dimensional regions is also quantified.

THREE DIMENSIONAL FINITE ELEMENT SIMULATION OF THE FRETTING WEAR PROBLEMS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3890-3895 ◽  
Author(s):  
CHOON YEOL LEE ◽  
JOON WOO BAE ◽  
BYUNG SUN CHOI ◽  
YOUNG SUCK CHAI
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Fretting Wear ◽  
Symmetric Model ◽  
Two Dimensional ◽  
Element Analysis ◽  
Inconel 690 ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The structural integrity of steam generators in nuclear power plants is very much dependent upon the fretting wear characteristics of Inconel 690 U-tubes. In this study, a finite element analysis was used to investigate fretting wear on the secondary side of the steam generator, which arises from flow-induced vibrations (FIV) between the U-tubes and supports or foreign objects. Two-dimensional and three-dimensional finite element analyses were adopted to investigate the fretting wear problems. The purpose of the two-dimensional analysis, which simulated the contact between a punch and a plate, was to demonstrate the validity of using finite element analysis to analyze fretting wear problems. This was achieved by controlling the value of the wear constant and the number of cycles. The two-dimensional solutions obtained from this study were in good agreement with previous results reported by Strömberg. In the three-dimensional finite element analysis, a quarterly symmetric model was used to simulate tubes contacting at right angles. The results of the analyses showed donut-shaped wear along the contacting boundary, which is a typical feature of fretting wear.

Finite-element analysis of axi-symmetric rotors

1969 ◽  
Vol 4 (3) ◽  
pp. 163-168
Author(s):  
H Stordahl ◽  
H Christensen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Engineering Problems ◽  
Symmetric Rotor ◽  
Practical Engineering ◽  
Element Method

The finite-element method (1) (2)∗ is increasingly used in the stress analysis of mechanical-engineering problems. It is the purpose of this paper to described how the finite-element method can be used as an effective tool in the design of rotors. Up to the present time this method has mainly been used in the analysis of two-dimensional problems. However, a special class of three-dimensional problems, namely axi-symmetric rotors, can be treated as a nearly two-dimensional problem. This paper summarizes the development of the finite-element method as applied to the analysis of the axi-symmetric rotor. A computer programme is then briefly described, and the application of the method to the solution of three examples taken from practical engineering experience are presented.

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