"Perhaps the most
sophisticated analysis and design software for pile groups is Repute
(Geocentrix 2017) ... based on the calculation algorithm PGROUPN (Basile
effective means of carrying out a Category 3 analysis is to employ a pile
group analysis program that considers non-linear pile-soil response and
pile-soil-pile interaction, and is capable of handling all six components of
loading simultaneously, e.g. the commercially available programs Repute or
see more commendations here....
Repute by Geocentrix is the leading software for the design of single piles and pile groups under any loading conditions.
The software is being used for the design of pile foundations in thousands of major projects worldwide, including: Burj Khalifa (the world's tallest building, Dubai), Nakheel Tower (Dubai), Pentominium Tower (Dubai), Opera Grand tower (Dubai), London Wembley Stadium (UK), Crossrail (UK), Channel Tunnel Rail Link (UK), Incheon Tower (South Korea), Dubai Towers (Doha, Qatar), Milan-Naples motorway (Italy). Repute is market leader in the UK and is used by all top 10 engineering consultants, namely, Atkins, Mott MacDonald, Arup, WSP, Mouchel, Jacobs, Halcrow, URS, Hyder and Capita Symonds (as taken from the New Civil Engineer Consultants File, published by Emap Construct Ltd, UK). Repute is adopted by top engineering companies worldwide including Aecom, Arcadis, Arup, Atkins, CH2M Hill, Costain, COWI, Fugro, Geotechnical Consulting Group, Golder, Halcrow, Hyder, Jacobs, Keller, Mott MacDonald, Mouchel, Parsons Brinckerhoff, Tetra Tech, and URS.
In version 2.5, Repute's design capabilities have been extended to cater for ultimate and serviceability limit state design of single piles and pile groups, according to Eurocode 7 and other design standards. Designs can be fine-tuned by changing the algorithms used in the calculations and factors applied to ensure reliability and suit local practice.
The main technical feature of Repute lies in its capability to account for the continuous nature of pile-soil interaction while retaining a computationally efficient code. Other key features, such as soil nonlinearity effects, multilayered soil profiles and 3D effects, make Repute the most powerful tool to design pile groups in a rigorous yet cost-effective fashion.
Repute incorporates the latest boundary-element calculation engine (PGroupN, designed and written by Dr Francesco Basile of Geomarc) and has been developed by Geocentrix with the support of Corus, Atkins and Stent Foundations.
Why using Repute?
There are many advantages in using Repute for pile group analysis and design, including:
• Analysis method - the Repute analysis method is the most rigorous of the pile-group design programs currently available. It is based on a complete boundary element (BEM) solution of the soil continuum, thereby overcoming the approximations which occur with the traditional interaction factor or load-transfer approaches (e.g. the t-z and p-y curve methods). Use of the above methodology leads to a more realistic prediction of the deformation behaviour and load distribution of the individual piles of the group. To find out more about the theory behind Repute, click here (PDF format, size 35KB) or read the paper by Basile (2003).
• Economies in contruction costs - use of Repute non-linear soil model avoids exaggeration of stresses at pile group corners (a common limitation of linear elastic models), and reduces consequent high loads and moments. This reduction is significant even at typical working load levels. Benefits of this include an improved understanding of pile group behaviour and thus more effective design techniques. Our case studies show how use of Repute can bring substantial saving of materials and therefore reduce construction costs.
• Versatility - the ability of Repute to deal with multilayered soil profiles gives the designer an invaluable tool resulting in a more realistic picture of the group deformation response and the load distribution between the piles. Other features including variable moduli, lengths, rakes, and shaft/base diameters per each pile enhance the flexibility of the program and offer the designer a comprehensive tool for the analysis of a wide range of practical problems. To view a summary of Repute technical features and a comparison with other software, click here.
• Selection of soil paramaters - by taking into account the continuous nature of pile-soil interaction, Repute makes the choice of input soil parameters simple and direct: for a linear analysis, it is only necessary to define two soil parameters whose physical interpretation is clear, i.e. the soil Young’s modulus and Poisson’s ratio. If the effects of soil non-linearity are considered, the strength properties of the soil need also to be specified, i.e. the undrained shear strength for cohesive soils and the angle of friction for cohesionless soils. These parameters are routinely measured in soils investigation. This aspect represents a significant advantage over Winkler approaches (such as the t-z and p-y curve methods) which disregard soil continuity and have therefore to rely on empirical parameters (e.g. the modulus of subgrade reaction) that can only be determined by backfiguring from the results of pile load tests. Indeed, the modulus of subgrade reaction is not a fundamental soil parameter, but is dependent on the dimensions of the pile. As stated by Poulos (2000), "given the potential for unreliable and unrealistic results and the enduring problem of assessing an appropriate modulus of subgrade reaction, the time has come for the Winkler concept to be consigned to history, and not to be perpetuated in modern-day structural and geotechnical analyses".
• Group effects - the t-z and p-y curve methods (widely adopted in current commercial software) treat the soil as a series of independent springs. Such a model oversimplifies the problem and makes it impossible to find a rational way to quantify the interaction effects between piles in a group. Consequentially, group effects between piles can only be considered by making use of empirical parameters (e.g. the "p-multipliers") which are difficult to derive. It has been shown that such approaches can produce nonconservative estimates of pile group behaviour (Rollins et al., 2005; Mandolini et al., 2005; Basile, 2003). Repute, by taking into account the continuous nature of pile-soil interaction, removes the above limitation and provides a more realistic representation of the problem.
• Speed of use - one of the main features of Repute is its capability to provide a complete 3D non-linear BEM solution of the soil continuum while retaining a computationally efficient code. This represents a considerable advantage over similar BEM solutions (eg PGROUP) which are limited by the large amount of computing time required to analyse practical pile group problems. In principle, a complete three-dimensional analysis of a pile group can be carried out by finite element or finite difference analyses; however, the complexity and high computational costs involved preclude the use of such techniques in routine design of pile groups, particularly if non-linear soil behaviour is to be considered (see note on "Repute vs 3D FEM-FDM analyses").
• Ease of use - the amount of input data required by Repute is minimal and handled through a state-of-the-art user interface. This is in notebook style for easy entry of your pile, soil, and loading data, and has extensive reporting capabilities via its in-built web browser, rich text viewer, and graph control. XML and XSLT technology allows reports to be customised.
• Pedigree - the development and testing of Repute's boundary-element calculation engine is part of a research programme which began in 1994 under the leadership of Dr Francesco Basile. Contributors include the late Dr Ken Fleming of Cementation Foundations Skanska Ltd. Repute is based on the boundary element algorithm of the well-established program PGROUP (UK Department of Transport, 1975) which has been extended in order to increase computational efficiency and to include multilayered soil profiles, 3D effects, non-linear soil behaviour and other features.
• Publications - use of Repute is documented in over 100 international publications.
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