GGU-RETAIN: Capabilities

GGU-RETAIN has the following characteristics and maximum capabilities

• Up to 50 soil layers

• Transfer of soil properties from GGU-CONNECT

• Up to 40 berms on the active earth pressure side

• Up to 40 berms on the passive earth pressure side

• Analysis with active and increased active earth pressure and with at-rest earth pressure

• Coefficients of active earth pressure pursuant to DIN 4085

• Coefficients of passive earth pressure pursuant to DIN 4085, Streck, Caquot/Kerisel

• Additional calculation of active and passive earth pressure after Culmann possible.

• Classical water pressure approach for impermeable retaining walls and, alternatively, by means of flow conduits parallel to the wall in accordance with potential theory (analysed using finite-element methods). Inconsistencies in subsurface hydraulics apparent when using the classical approach are avoided when using flow conduits, and varying permeabilities are correctly considered as far as the approach allows. User-defined potentials can be applied at any point along the flow conduit. This allows correct, problem-free consideration of systems with several groundwater storeys and/or aquifuges, or with artesian conditions.

• Optional consideration of hydraulic gradients on the active and passive earth pressure sides

• Verification of safety against deep-seated failure with optimisation of anchor lengths

• Analysis of hydraulic heave 'classical' or after Aulbach/Ziegler

• Verification of buoyancy safety

• Verification of base heave safety

• Verification of pull-out resistance of driven steel tubular piles and injection piles

• Verification of sum H

• Analysis of mobilised passive earth pressure

• Analysis of vertical capacity

• Convenient interface to the stability analysis application, GGU-STABILITY, for quick determination of safety factor against general failure

• Up to 50 additional earth pressure distributions

• Up to 20 area loads at any depth

• Structural analysis of the retaining wall by means of a two-dimensional rod construction module based on finite-element methods. In contrast to many other retaining wall analysis applications, the influence of inclined anchors or struts and their interactions are thus directly considered in the analysis approach. Analysis can even be performed using 2^nd order theory, making the generally onerous buckling length investigation of struts and retaining wall unnecessary. In addition, it is possible to consider loads on the struts (e.g. for auxiliary bridges additionally acting as struts) during analysis.

• Buckling analysis to DIN EN 1993-1-1 using 2^nd order theory

• Elastic subgrade reaction at the wall toe with user-defined values. Option for automatic selection of an elastic modulus of subgrade reaction profile consistent with the specified passive earth pressure distribution

• Specification of up to 5 displacement boundary conditions (rotation, displacement in x or y directions) at any location

• Specification of up to 5 action boundary conditions (moment, shear force and normal force) at any location

• 20 anchor and strut sets; in defining the anchors and struts, axial stiffness and bending stiffness can be specified, so that, for example, passive anchors can be incorporated.

• Consideration of prestressing of anchors and struts possible

• Definition of up to 20 additional potentials by the calculation of flow conduits to the left and right of the wall for complex groundwater conditions

• Expandable database of default sections for soldier piles, sheet piles, combined sheet piles and tubular sections with which automatic design, including automatic searches for the optimum section, can be carried out.

• Reinforced concrete design to EC 2 for circular and rectangular cross-sections

• Modelling corrosion for all sections

• Design of horizontal lagging for soldier pile walls

• Automatic computation of section weights for analysis of sum V

• Variable bending resistance of the retaining wall

• Automatic computations of earth pressure redistributions according to the EAB Recommendations

• Other earth pressure distribution options:

  • no redistribution

  • rectangle

  • 2 rectangles

  • triangle (maximum can be optionally placed at top, middle or bottom)

  • trapezoidal

  • quadrilateral with maximum at anchor locations or any other location

  • user-defined polygon

  • EAU 2012

• Soil pressure can be redistributed either to the wall toe or to the transition point.

• Passive earth pressure can be superimposed or located in front of the wall.

• Calculation of the transition point with or without porewater pressure

• Structural analysis can be performed in 4 different ways:

  • section length determined automatically after entering degree of fixation for the wall toe

  • determination of degree of fixation for fixed section length

  • section length automatically determined with elastic bedding of wall toe

  • bedding of wall toe with fixed section length

• Following computation of the system, earth pressure, porewater pressure, moment, shear, normal force and bending line are displayed on the screen. The visualisation can be varied within wide limits. For example, the distribution of the modulus of subgrade reaction as well as the distributions of the potential and the gradient, etc. can also be displayed.

• For soldier pile walls it is necessary to demonstrate the equilibrium of horizontal forces below the excavation level. This is carried out by the application. If necessary, the section length is automatically increased.

• At anchor points, existing predeformations can be defined as boundary conditions.

• Previously calculated datasets can be combined to investigate the additive deformation of individual advancing and retreating states. A Mohr's envelope showing the distribution of moments, shear and normal forces can also be depicted. Visualisation of the reinforcement envelope is also possible for diaphragm walls, bored pile walls and bored soldier pile walls.

• Legends can be displayed on screen showing soil properties and general computation data. Thus, virtually all the raw data necessary for the computation and the results are shown on screen.

• GGU-RETAIN's user interface is based on WYSIWYG (What You See Is What You Get), which means that what you see on the screen is virtually identical with what is printed. It also means that you can print out what you see on the screen at any point during the analysis.

• The use of true-type fonts guarantees excellent layout.

• Colour presentation of virtually all system geometries. Colours can be freely determined by the user. Soil strata can also be coloured according to the German DIN 4022 conventions.

• Zoom function

• Mini-CAD system (additional text, lines, rectangles, circles, graphics, etc).

• GGU-RETAIN includes virtually all the examples contained in the Krupp Hoesch Stahl "Piling Handbook" ("Spundwand-Handbuch") and in Weißenbach's "Excavations" III ("Baugruben III", 1977) as datasets.

• By clicking the "Copy/print area" icon on the toolbar you can copy any part of the graphics to the clipboard, save it as an EMF file (Enhanced Metafile Format) or print it directly on your printer. Using the "Mini-CAD toolbar" or "Header toolbar" modules, you can insert EMF files into your graphics. Thus, the results of a slope stability analysis or of a grading analysis, for example, can easily be imported into the current graphics.