Analysis and Design of Offshore Pile Foundation

2014 ◽  
Vol 891-892 ◽  
pp. 17-23 ◽  
Author(s):  
Sudip Basack
Keyword(s):  
Pile Foundation ◽  
Complex Loading ◽  
Offshore Structures ◽  
Laboratory Model ◽  
Element Analysis ◽  
Analysis And Design ◽  
Theoretical Investigations ◽  
Experimental Laboratory ◽  
Combined Action ◽  
Ocean Environment

The ocean environment necessitates the pile foundation supporting the offshore structures to be designed against cyclic load, moments and torques initiated by a combined action of waves, wind, tides, currents, etc. Such a complex loading condition induces progressive degradation in the pile-soil interactive performance introducing significant reduction in bearing capacity with increased settlement and displacements. The Author has carried out extensive experimental (laboratory model tests) and theoretical investigations (boundary element analysis) to study the salient features of this degradation and developed a design methodology for offshore pile foundation. The works conducted and the major conclusions drawn are highlighted in this paper.

Offshore Pile Foundation Subjected to Lateral Cyclic Load in Layered Soil

2014 ◽  
Vol 891-892 ◽  
pp. 24-29 ◽  
Author(s):  
Sudip Basack ◽  
Abhik Kumar Banerjee
Keyword(s):  
Numerical Model ◽  
Pile Foundation ◽  
Loading Condition ◽  
Cyclic Load ◽  
Complex Loading ◽  
Offshore Structures ◽  
Layered Soil ◽  
Interactive Performance ◽  
Parametric Studies ◽  
Combined Action

The pile foundations supporting offshore structures are required to be designed against cyclic load, moments and torques initiated by a combined action of waves, wind, tides, currents, etc. Such a complex loading condition produces progressive degradation in the pile-soil interactive performance which is likely to introduce significant reduction in bearing capacity with increased settlement and displacements. This paper is based on a numerical model developed by the Authors to study the response of pile foundation under lateral cyclic load in layered soil. The model is validated with a field test data and thereafter, parametric studies have been carried out. A brief description of the works conducted and the major conclusions drawn are highlighted in this paper.

Experimental and theoretical studies of laterally loaded finned piles in sand

2014 ◽  
Vol 51 (4) ◽  
pp. 381-393 ◽  
Author(s):  
Ahmed M.A. Nasr
Keyword(s):  
Pile Foundation ◽  
Numerical Study ◽  
Scale Model ◽  
Laboratory Model ◽  
Small Scale ◽  
Lateral Loads ◽  
Pile Head ◽  
Element Analysis ◽  
Fin Efficiency ◽  
Lateral Resistance

Large lateral loads may act on pile foundation supporting structures, such as bridge abutments, retaining walls, and structures subjected to wind–earthquake loads. A pile with fins is a newly developed type of pile foundation that is capable of supporting large lateral loads. In the present study an attempt is made to evaluate the improvement in lateral capacity of a pile with fins mounted close to the pile head. Small-scale model tests and a numerical study using finite element analysis were performed on regular piles without (fins) and piles with fins. These piles were installed in sand of different relative densities (Dr = 35% and 78%). The investigations were carried out by varying the length, width, and shape of the fins, and type of pile. Results reveal that there is a significant increase in lateral resistance of the piles after mounting the fins close to the pile head. The increase in lateral resistance gained by placing fins on a pile varies with geometries of the pile and fins. The lateral resistance increases with the increase in length of the fins until the fin’s length is equal to 0.4 of the pile length. Based on the results of the laboratory model and numerical analysis, critical values of fin parameters for maximum improvement are suggested. The agreement between observed and computed results is found to be reasonably good in terms of ultimate lateral load and fin efficiency. A comparison between the model results and the prototype-scale results is also studied.

Composite Design Methodology: Design of Composite Trails for the U.S. Army’s M198 Howitzer, A Case Study

1996 ◽  
Vol 118 (2) ◽  
pp. 286-293
Author(s):  
E. Sancaktar ◽  
M. West ◽  
K. R. Miner
Keyword(s):  
Finite Element ◽  
Design Methodology ◽  
Adhesive Bonding ◽  
Complex Loading ◽  
Material Design ◽  
Element Analysis ◽  
Finite Element Program ◽  
Analysis And Design ◽  
The U.S

Analysis and design of a fiber reinforced organic composite trail pair for the U.S. Army M198 Howitzer is presented as a case study in composite material design methodology. For this purpose mechanics analysis is performed using the computer program: MIC-MAC composites design and ANSYS 4.4A finite element analysis. The analyses includes composite lamination, material optimization, adhesive bonding, buckling, deflection, stress and failure analysis and validates the practicability of the proposed constant cross-section graphite/epoxy trail. The use of PC based spreadsheet MIC-MAC program, initially, allows efficient and inexpensive evaluation of several alternative designs including different geometries and materials before the finite element program is employed with the few final design choices to rule out failure in stress, deflection and buckling modes. However, superposition principles need to be used to describe the complex loading configuration as a collection of mechanically equivalent individual load modes such as midspan loaded beam, cantilever beam under torsion, in-plane loaded plate etc. in order to be able to utilize the MIC-MAC program initially. Fabrication plans are also proposed for the trail pair.

A Simplified Design Model for Modular Steel Buildings Subject to Vapor Cloud Explosions (VCEs)

2020 ◽  
Vol 14 ◽  
Author(s):  
Osama Bedair
Keyword(s):  
Dynamic Response ◽  
Minimum Cost ◽  
Design Parameters ◽  
Front Wall ◽  
Steel Buildings ◽  
Element Analysis ◽  
Analysis And Design ◽  
Vapor Cloud ◽  
Building Components ◽  
Analytical Expressions

Background: Modular steel buildings (MSB) are extensively used in petrochemical plants and refineries. Limited guidelines are available in the industry for analysis and design of (MSB) subject to accidental vapor cloud explosions (VCEs). Objectives: The paper presents simplified engineering model for modular steel buildings (MSB) subject to accidental vapor cloud explosions (VCEs) that are extensively used in petrochemical plants and refineries. Method: A Single degree of freedom (SDOF) dynamic model is utilized to simulate the dynamic response of primary building components. Analytical expressions are then provided to compute the dynamic load factors (DLF) for critical building elements. Recommended foundation systems are also proposed to install the modular building with minimum cost. Results: Numerical results are presented to illustrate the dynamic response of (MSB) subject to blast loading. It is shown that (DLF)=1.6 is attained at (td/t)=0.4 for front wall (W1) with (td/T)=1.25. For side walls (DLF)=1.41 and is attained at (td/t)=0.6. Conclusions: The paper presented simplified tools for analysis and design of (MSB) subject accidental vapor cloud blast explosions (VCEs). The analytical expressions can be utilized by practitioners to compute the (MSB) response and identify the design parameters. They are simple to use compared to Finite Element Analysis.

Numerical Investigation of Ultimate Strength of Stiffened Plates With Various Cross-Section Forms

2018 ◽  
Author(s):  
Huilong Ren ◽  
Yifu Liu ◽  
Chenfeng Li ◽  
Xin Zhang ◽  
Zhaonian Wu
Keyword(s):  
Aluminum Alloy ◽  
Ultimate Strength ◽  
Cross Section ◽  
High Performance ◽  
Lightweight Design ◽  
Offshore Structures ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
Element Analysis ◽  
Hull Structure

There is an increasing interest in the lightweight design of ship and offshore structures, more specifically, choosing aluminum alloys or other lightweight high-performance materials to build structure components and ship equipments. Due to its better mechanical properties and easy assembly nature, extruded aluminum alloy stiffened plates are widely used in hull structures. When the load on the hull reaches a certain level during sailing, partial or overall instability of stiffened plate makes significant contribution in an event of collapse of the hull structure. It is very necessary to investigate the ultimate strength of aluminum alloy stiffened plate to ensure the ultimate bearing capacity of large aluminum alloy hull structure. Most of studies of the ultimate strength of stiffened plates deal with stiffened plates with T–shaped stiffeners. Stiffeners of other shapes have seldom been explored. In this research, the ultimate strength of six different cross–section aluminum alloy stiffened plates and one steel stiffened plate was studied based on the non–linear finite element analysis (FEA). Taking into account stiffness, weight and other issues, the new cross–section aluminum stiffener has finally been concluded for replacing the original steel stiffener in upper deck of a warship.

scholarly journals A Numerical Analysis on the Behavior of Single Battered Pile under Pullout Loading

2021 ◽  
Vol 318 ◽  
pp. 01010
Author(s):  
Mais S. Al-Tememy ◽  
Mohammed A. Al-Neami ◽  
Mohammed F. Asswad
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
Offshore Structures ◽  
Pullout Capacity ◽  
Element Analysis ◽  
Dense Sand ◽  
Dimensional Finite Element ◽  
Pullout Load ◽  
Three Dimensional Finite Element ◽  
3D Software

Batter or raker piles are piles driven at an inclination with a vertical to resist large inclined or lateral forces. Many structures like offshore structures and towers are subjected to overturning moments due to wave pressure, wind load, and ship impacts. Therefore in such structures, a combination of the vertical and batter piles is used to transfer overturning moments in compression and tension forces to the foundation. This paper presents a three-dimensional finite element analysis using PLAXIS 3D software to study the battered pile's behavior under the effect of pullout load. Several variables that influence the pile tension capacity embedded in sandy soil are investigated. The pile models are steel piles embedded in the dense sand at different batter angles (0, 10, 20, and 30) degrees with two embedment ratios, L/d (15 and 20). To clarify the pile shape's influence on a pullout capacity, two shapes are used, a circular pile with a diameter equal to 20 mm and a square pile with a section of 15.7×15.7 mm. These dimensions are chosen to achieve an equal perimeter for both shapes. The numerical results pointed that the pile pullout capacity increases with the increasing of the batter angle and embedment ratio, and the maximum values are marked at a batter angle of 20o. The shape of the bending moment profile is a single curvature, and the peak values are located approximately at the midpoint of the battered pile, while a zero value is located at the pile tip and pile head.

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