scholarly journals Experimental Investigation on Efficiency Factor of Pile Groups Regarding Distance of Piles

2019 ◽  
Vol 5 (8) ◽  
pp. 1812-1819
Author(s):  
Mojtaba Pashayan ◽  
Gholam Moradi
Keyword(s):  
Axial Loading ◽  
Pile Group ◽  
Group Behavior ◽  
Efficiency Factor ◽  
Diameter Ratio ◽  
Efficiency Coefficient ◽  
Continuous Change ◽  
Pile Groups ◽  
Shaft Resistance ◽  
The Impact

There are a lot of the parameters which affect pile group behavior in soil. One of these factors is the distance of piles from each other. The impact of distance on pile groups in sand has been investigated through some researches, whereas most of them have not represented an exact estimation according to the continuous change of the distance in sand. Moreover, most of previous investigations have considered two piles as a perfect group. Since two-pile group has the least interaction effect among piles, it cannot suitably demonstrate the influence of spacing. In this lecture, several 4-pile groups modeled with different spacing were subjected to axial loading in laboratory. The pile groups were free-head with length to diameter ratio of 13.5. The piles are designed in a way which the shaft resistance of piles can be completely mobilized through the test. Then, the bearing capacities of pile groups are measured and compared with the single pile's resistance in order to calculate the efficiency coefficient of the groups. It is revealed that the distance is noticeably effective in efficiency factor and this effectiveness, non-linearly decreases by increase of spacing. The results show that the efficiency coefficient is changing between almost 1 and 1.4.

scholarly journals Investigating the Effect of Distance and Diameter Ratio of Elliptical Piles on the Amount of Force Exerted by Waves in the Pile Groups with Regular Layout

2018 ◽  
Vol 8 (1) ◽  
pp. 37-46
Author(s):  
M. Ghatarband ◽  
M. Behdarvandi Askar
Keyword(s):  
Numerical Modeling ◽  
Safety Factor ◽  
Pile Group ◽  
Offshore Structures ◽  
Diameter Ratio ◽  
Pile Groups ◽  
Distance Ratio ◽  
Offshore Area

Abstract Today, advanced countries compete enormously for further exploitation in the offshore area, for its enormous fresh resources and space. Therefore, these competitions will double the importance of these types of structures. As it is known, the most important part in the design of the offshore structures is the design of the piles on which the structure will be placed. Engineers have always been trying to build these types of structures with the least cost and the highest safety factor. In this research, the effect of distance and the ratio of the elliptical pile diameters on the strength of the pile group was evaluated using numerical modeling. Five different states of diameter ratios including: 1.2, 1.4, 2, 2.5, 3 and five different distance ratios were investigated. The results demonstrate that with the increase in the diameter ratio, the amount of force decreases while it increases as the distance ratio rises.

Modeling of Piled Foundations

1982 ◽  
Vol 22 (05) ◽  
pp. 775-783
Author(s):  
Glenn A. Kriger
Keyword(s):  
Linear Models ◽  
Pile Group ◽  
Group Behavior ◽  
Model Construction ◽  
Single Pile ◽  
Pile Groups ◽  
Model Synthesis ◽  
Construction Methods ◽  
Single Piles ◽  
Piled Foundations

Abstract A comprehensive set of guidelines for constructing linear models of single piles and pile groups for foundations of offshore structures is presented. These models are used as boundary conditions at the base of the superstructure, thus permitting independent analysis of the superstructure from its supporting foundation.This paper is a "how-to" text for piled foundation modeling. It is also of value to those in related disciplines, such as geotechnical specialists, who will gain insight into how their data is applied in analyzing structures supported by piled foundations. Discussions include the behavior and modeling of single piles and pile groups. Construction methods are presented for pile groups. Construction methods are presented for three types of pile models-matrix, springs, and equivalent pile. The advantages and disadvantages of each model type are described. Linear and nonlinear foundation behavior characteristics are treated in depth. Factors that influence the approach to a modeling problem are outlined. Emphasis is placed on providing the problem are outlined. Emphasis is placed on providing the reader with an understanding of the physical behavior of piled foundations and model construction. A step-by-step piled foundations and model construction. A step-by-step procedure for model synthesis is provided in an example. procedure for model synthesis is provided in an example. Introduction In a fixed offshore platform, the steel jacket superstructure and its supporting piled foundation are more conveniently analyzed if treated separately. There are major structural and behavior-al differences between the jacket and foundation, and the two do not lend themselves to similar analytical methods. This paper presents basic techniques for constructing linear models that simulate the foundation behavior at the superstructure/foundation boundary. Use of these models permits independent superstructure analyses. Selection of the model type and its degree of refinement are described from a global overview of the structure, available data, and ramification of analytical results. Construction of the foundation simulation model follows routine procedures using results of an independent foundation analysis. Single Pile Behavior The load-deflection behavior of a single pile crown is of key importance in model construction. Analysis of a pile embedded in soil is extremely difficult because of pile embedded in soil is extremely difficult because of the infinite dimensions, nonhomogeneity, and nonlinearity of the soil. As a practical necessity, the problem usually is simplified by treating the pile as a beam-column supported by nonlinear axial and lateral soil springs. Details of these analytical procedures are beyond the scope of this work, although application of the techniques presented here will require the availability of such an analytical tool. Although this material pertains to single piles, it forms the basis for understanding pertains to single piles, it forms the basis for understanding pile group behavior discussed later. pile group behavior discussed later. Fig. 1 depicts a right-hand orthogonal coordinate system, which is used throughout this paper. Displacements, s, and forces, F, are shown in each of the six degrees of freedom (DOF). The pile behavior is studied by observation of the force(s) required to produce displacement in each of the six DOF while all other displacements are held at zero. Of utmost importance is the effect of coupling-the interaction of forces (and displacements) in different DOF.First consider linear pile behavior, which is characteristic of small-magnitude loadings. Force and displacement are directly proportional; therefore, stiffness (force divided by displacement) remains constant for all values of displacement (Fig. 2).Fig. 3a shows that an axial displacement is produced by an axial force. This axial displacement requires no other forces in each of the remaining five DOF. Therefore, linear axial pile behavior is uncoupled. Similarly, a torsional displacement (Fig. 3b) requires only a torque along the same DOF and therefore is also lineally uncoupled. SPEJ p. 775

scholarly journals Assessing the Effects of Length, Slope and Distance between Piles on the Bearing Capacity of a Pile Group under Axial Loading in Granular Soil

2017 ◽  
Vol 7 (5) ◽  
pp. 1894-1899
Author(s):  
A. Firoozfar ◽  
A. Rostami ◽  
H. Ghaderi ◽  
H. Zamani ◽  
A. Rostamkhani
Keyword(s):  
Bearing Capacity ◽  
Axial Loading ◽  
Pile Group ◽  
Granular Soils ◽  
Deep Foundations ◽  
Pile Groups ◽  
Finite Element Software ◽  
Bedrock Depth ◽  
Exact Effect ◽  
Technical Capacity

Piles are usually made of steel, concrete, reinforced concrete or wood, used to enhance the ground’s bearing capacity in order to enable the construction of deep foundations, also called pile foundations. However, the exact effect of the complex interaction between the piles and the surrounding soil has not adequately been investigated yet. Considering the increased application of the technique recently, further analysis is essential for achieving the highest economic and technical capacity. Using fewer piles or shorter piles and allowing greater distances between pile groups, results to reduced construction. However, other restrictions such as high groundwater level, bedrock depth and the limited size of the foundation are also to be considered. The issue of optimal pile layout is further investigated in the current paper employing Plaxis, a finite element software, for modeling purposes and considering axial loadings in granular soils. Results are shown and further discussed.

scholarly journals Prediction of pile group scour in waves using support vector machines and ANN

2010 ◽  
Vol 13 (4) ◽  
pp. 609-620 ◽  
Author(s):  
Samaneh Ghazanfari-Hashemi ◽  
Amir Etemad-Shahidi ◽  
Mohammad H. Kazeminezhad ◽  
Amir Reza Mansoori
Keyword(s):  
Data Mining ◽  
Support Vector Machines ◽  
Back Propagation ◽  
Pile Group ◽  
Diameter Ratio ◽  
Support Vector ◽  
Scour Depth ◽  
Empirical Methods ◽  
Pile Groups ◽  
Vector Machines

Scour around pile groups is rather complicated and not yet fully understood due to the fact that it arises from the triple interaction of fluid–structure–seabed. In this study, two data mining approaches, i.e. Support Vector Machines (SVM) and Artificial Neural Networks (ANN), were applied to estimate the wave-induced scour depth around pile groups. To consider various arrangements of pile groups in the development of the models, datasets collected in the field and laboratory studies were used and arrangement parameters were considered in the models. Several non-dimensional controlling parameters, including the Keulegan–Carpenter number, pile Reynolds number, Shield's parameter, sediment number, gap to diameter ratio and number of piles were used as the inputs. Performances of the developed SVM and ANN models were compared with those of existing empirical methods. Results indicate that the data mining approaches used outperform empirical methods in terms of accuracy. They also indicate that SVM will provide a better estimation of scour depth than ANN (back-propagation/multi-layer perceptron). Sensitivity analysis was also carried out to investigate the relative importance of non-dimensional parameters. It was found that the Keulegan–Carpenter number and gap to diameter ratio have the greatest effect on the equilibrium scour depth around pile groups.

The impact of stirrups on the composite action of concrete-filled steel tubular stub columns under axial loading

Structures ◽  
2021 ◽  
Vol 30 ◽  
pp. 786-802
Author(s):  
De-ren Lu ◽  
Wen-jun Wang ◽  
Fa-xing Ding ◽  
Xue-mei Liu ◽  
Chang-jing Fang
Keyword(s):  
Axial Loading ◽  
Composite Action ◽  
The Impact ◽  
Stub Columns

Some data on long term large screw pile group behavior

ce/papers ◽  
2018 ◽  
Vol 2 (2-3) ◽  
pp. 113-134
Author(s):  
William F. VAN IMPE ◽  
Peter O. VAN IMPE ◽  
Alice MANZOTTI
Keyword(s):  
Pile Group ◽  
Group Behavior ◽  
Screw Pile

POST-INVESTMENT REVIEW OF TECHNOLOGICAL PROJECTS IN OIL AND GAS: GAZPROM NEFT UPSTREAM APPROACH

2020 ◽  
pp. 73-80
Author(s):  
V.R. Filimonova ◽  
A.V. Shushkov ◽  
D.S. Zmienko ◽  
M.U. Rabaev ◽  
G.S. Kuzmin ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Economic Benefits ◽  
Continuous Change ◽  
General Process ◽  
Technology Project ◽  
Technology Readiness Level ◽  
Readiness Level ◽  
Impact Of Technology ◽  
The Impact ◽  
A Company

In the world of continuous change and volatility, benefits and results of investments made by companies into research and development (R&D) projects have to be transparent for management of a company in order to make timely and appropriate investment decisions. The paper discusses prospects of post-implementation review of R&D projects, process complications the company faced and its interaction with key related processes of the technology strategy: diffusion among affiliated companies, education and commercialization. Any technology project strives to deliver both technological and economic benefits to a company. While technological success is usually the focus of a project manager, the economical results are overseen by the management of a company and used as a source for action. An overview of best industrial practices is given, later compared to the approach employed by the upstream division of Gazprom Neft company. The latter presents general process and key principles, including process initiation triggers, stages and KPIs used for the monitoring. The importance of technology diffusion is discussed, specifically the impact of technology readiness level on the success of a project is considered as well as necessity to develop “fail fast” culture in the company in order to have higher success ratio. Interconnection between the diffusion of a technology and the amount of intellectual property created by the technology is studied. The need for alignment to the company’s strategies by the project teams is revealed as well as continuous education methods are presented. The conclusion contains results and ways for improvement of the postimplementation review process in the company.

Seismic Response of Pile Groups Improved with Deep Cement mixing Columns in Liquefiable Sand: Shaking Table Tests

2021 ◽  
Author(s):  
Dingwen Zhang ◽  
Anhui Wang ◽  
Xuanming Ding
Keyword(s):  
Seismic Behavior ◽  
Lateral Displacement ◽  
Bending Moment ◽  
Pile Group ◽  
Shaking Table ◽  
Excess Pore Pressure ◽  
Shaking Table Tests ◽  
Pile Groups ◽  
Acceleration Response ◽  
Table Model

A series of shaking table model tests were performed to examine the effects of deep cement mixing (DCM) columns with different reinforcement depths on the seismic behavior of a pile group in liquefiable sand. Due to the DCM column reinforcement, the fundamental natural frequency of the model ground increases noticeably. The excess pore pressure of soils reduces with the increase of reinforcement depths of the DCM columns. Before liquefaction, the acceleration response of soils in the improved cases is obviously lower than that in the unimproved case, but the acceleration attenuation is greater after liquefaction in the unimproved case. Moreover, the lateral displacement of the superstructure, the settlement of the raft, and the bending moment of the piles in the improved cases are significantly reduced compared to those in the unimproved case, and the reduction ratios rise with the increase of reinforcement depth of the DCM columns. However, reinforcement by the DCM columns may result in the variation of the location of the maximum moment that occurs in the pile.

scholarly journals Comparison of Induced Deflection and Forces in Piles Adjacent to Tunnelling and Deep Excavation in 2D and 3D Problems

2018 ◽  
Vol 203 ◽  
pp. 04011
Author(s):  
Ong Yin Hoe ◽  
Hisham Mohamad
Keyword(s):  
Bending Moment ◽  
Pile Group ◽  
3D Models ◽  
Deep Excavation ◽  
Pile Groups ◽  
Out Of Plane ◽  
National University ◽  
Plane Direction ◽  
2D And 3D ◽  
2D Model

There is a trend in Malaysia and Singapore, engineers tend to model the effect of TBM tunneling or deep excavation to the adjacent piles in 2D model. In the 2D model, the pile is modelled using embedded row pile element which is a 1-D element. The user is allowed to input the pile spacing in out-of-plane direction. This gives an impression to engineers the embedded pile row element is able to model the pile which virtually is a 3D problem. It is reported by Sluis (2014) that the application of embedded pile row element is limited to 8D of pile length. It is also reported that the 2D model overestimates the axial load in pile and the shear force and bending moment at pile top and it is not realistic in comparison to 3D model. In this paper, the centrifuge results of single pile and 6-pile group - tunneling problem carried out in NUS (National University of Singapore) are back-analysed with Midas GTS 3D and a 2D program. In a separate case study, pile groups adjacent to a deep excavation is modelled by 3D and 2D program. This paper compares the deflection and forces in piles in 2D and 3D models.

scholarly journals Competitive Advantage Based on Human Capital and its Impact on Organizational Sustainability: Applied Study in Jordanian Telecommunications Sector

2017 ◽  
Vol 7 (1) ◽  
pp. 64 ◽  
Author(s):  
Abdul Azeez Badir Alnidawi ◽  
Abdul Sattar Husien Alshemery ◽  
Manal Abdulrahman
Keyword(s):  
Human Capital ◽  
Competitive Advantage ◽  
Capital Investment ◽  
Organizational Sustainability ◽  
Business Organizations ◽  
Continuous Change ◽  
Business World ◽  
The Creation ◽  
The Impact ◽  
Telecommunications Companies

The current situation facing business organizations is characterized by diverse work environments with continuous change and development. Todays organizations seek to keep pace with this continuous development and operate to maintain their current business through the ability to effectively respond to change, and to create competitive advantage based on the existence of qualified human capital that contribute to the creation of organizational sustainability in the business sector. Talented human capital, with special skills, has the potential to create confidence and integration among the staff and top management, leading to organizational growth and continuation (Kurucz, 2013). The emergence of a set of challenges in the knowledge economy has had a clear reflection on business organizations which have begun to search for new mechanisms to compete and insure their existence in the business world. Hence, the importance of the concept of competitive advantage, based on human capital, as a necessary requirement to deal with the challenges faced by local, regional or international organizations (Global Institute, 2011). Where competitive advantage based on human capital is the main generator of new ideas, development of old ideas, and contribution to aid in organizational abilities to expand their current market share as well as maximizing value. Competitive advantage based on talented human capital allows organizations to be able to seize new opportunities and achieve permanence and future continuity (Thomas, 2014). This study aimed to look at the impact of competitive advantage through intellectual capital investment as one of the elements in the creation of organizational sustainability in the Jordanian Telecommunications Companies sector. Simple and Multiple regression was used for data analysis and testing the hypotheses of this research .This study has reached a set of results that previous studies reinforced in this area such as: Competitive advantage based on a distinct capital is the optimum method that should be used in telecommunications companies since it contributes to the optimal investment of human capital. This leads to optimum organizational sustainability for companies in various fields and also contributes to the achievement of a company’s mission and vision of the future. 

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