
9.10		2009-01-14 (build number MStab 9.10.8.6) Zone circles for method uplift Van in combination with more the 1 tangent line were not always the correct ones. In Spencer the point of application from the interslice forces lies sometimes outside the slice geometry. To check this the intersection points are drawn in the result plots.


9.10		2008-06-12 (build number 9.10.7.900) Horizontal Balance was not correctly calculated 2008-01-12 (build number 9.10.7.1) The PCRing files (.pcr) were not written correctly (see Known bugs for details) An error in calculation of the minimum profile is solved The convergetion criteria in form are improved 2007-12-05 (build number 9.10.6.2) New in MStab: Trees: A new option in the Loads menu. It is now possible to model a tree. The wind force against the crown of a tree is modelled as a force and a moment on the surface. The stability calculation takes this force and moment into account Pseudo values: A new shear strength model choice. In a calculation, often the 5% lower limit estimate of the local average value of the shear strength per layer is used. This can lead to a pessimistic estimate of the soil strength when a subsoil consists of several layers. With Pseudo values an estimate is determined for the whole package cut by a slip circle. Zoneplot: When the zoneplot option is used, an embankment is divided into various zones. The idea behind this is that stability loss on the land side of the dike not necessarily means that the retaining capacity of the dike is affected. For each zone different requirements can be made to the stability factor. MStab determines the minimum stability factor per zone. As a result, pictures can be seen with stresses per zone and the safety factor per zone. Horizontal balance: The horizontal balance is considered for a piece of soil loaded by water to the left and to the right. Several tangent lines model Uplift Van: For the Uplift Van model, now several tangent lines can be input. There is also a possibility to create automaticalyy tangent lines at the layer boundaries. Display of slope: Clicking on a line in the graphic input, the slope can be displayed as a percentage. Smaller wmf files: The Exported wmf files are smaller Materials:POP, Ratio Cu/Pc Passive and Ratio Cu/Pc Active extended for Reliability analysis. Note. This is only used for shear strength model Cu calculated. (module Reliability) Geotextiles is now available in the Reinforcements menu. Geotextiles can be hidden in the Model screen. In Uplift Van sometimes the pore pressure was not determined correctly when the middle point was exactly above a vertical layer boundary. (Uplift Van module) The calculation with External waterlevels is slightly improved. (Model Bishop probabilistic Random Field and module Reliability) Module Reliability depends no longer on module Uplift Van. It can be used now in combination with the base module only. A resisting moment from water in soil is added to the moment equilibrium in the uplift Van method. Solved Known bugs: POP at Cu calculated Reliability Analysis with design values and multiple water levels (module Reliability). Besides, a number of small bugs are solved and several wishes were implemented.


9.9		2006-03-18 (build number 9.9.1.11) Fixed several known bugs (see known bugs) Apart from Cu calculated and Cu measured it is know possible to supply a Cu-ratio For calculation using the Spencer method it is now possible to define two slip surfaces. The stability factors of multiple slip surfaces lying between these two slip surfaces are calculated


9.8		2004-04-02 (build number 9.8.7.1) The option “Reliability analysis” (before Probabilistic) has been extended and tested considerably. A great number of defaults have been entered to make this method easier to use. When mean values are entered, MStab can convert these to design values or the other way round. The old DOS program MProstab (without the posteriori analysis) has been added to MStab by the name: Bishop probabilistic random field approach. Besides the already defined shear strength models (c-phi, stress tables and Cu-measured), there is now also the model Cu-calculated available. A different shear strength model can be chosen now for each layer, instead of just one model for the whole calculation. In the option "move grid", now also the tangent lines of the circles will be moved when the minimal circle touches the upper or lower tangent line. It is now possible to enter a minimal depth for a circle. In this way it can be prevented that a very shallow circle will be found as the minimal circle.


9.7		2003-01-09 (build number 9.7.3.1) An error in the "new security" has been solved: working with two dongles now no longer causes problems because the program no longer checks the serial number. The ‘About’ box has been redesigned in the Delft GeoSystems house style. In the Support dialog, email is now automatically sent to support@delftgeosystems.nl, and no longer to support@geodelft.nl. 2002-12-3 (build number 9.7.2.1) Calculation time shortened. The calculation time is now mush shorter. Do not use points for both layer boundary and pn-line. A point may not be used by both a layer boundary and a pn-line. In this version, it is no longer possible to use the same point for both. If this was possible in an old project, when that file is being imported a new point is now created for the pn-line. Do not use points for both layer boundary and pn-line. A point may not be used by both a layer boundary and a pn-line. In this version, it is no longer possible to use the same point for both. If this was possible in an old project, when that file is being imported a new point is now created for the pn-line. 2002-11-5 (build number 9.7.1.8) Uplift Van and Spencer modules. MStab now has a modular structure. The basic module contains the Bishop and Fellenius methods. Spencer and Uplift Van are now modules. When the Spencer and Uplift Van modules are both available, calculations can be made using the Uplift Spencer method calculated. Safety factor Uplift Van. The ‘Safety with model factor’ for the Uplift Van method is also displayed (in parentheses) in the report and in the 'Stresses' plots. Display geometry with ‘File, Open’ and ‘File, Save As’. When opening and saving projects, an example of the geometry of the selected file is now displayed. Geometry in input file. In the past, the geometry was stored in the .geo file. Now it is stored in the input file (.sti file). A geometry can still be imported from the .geo file and exported to a .geo file. The geometry can also be imported from the new input files of MStab 9.7 (.sti), MSeep 6.7 (.sei), MDrill 3.7 (.dri) and MSettle 6.7 (.sli). Use of the +/- keys in graphical input. When a point, boundary or pl-line has been selected on the Geometry tab of the graphical input window, the +/- keys can be used to select the next/previous. Excess pore pressure in graphical output. In the graphical output, no excess pore pressure was displayed for a temporary load in "Degree of consolidation pore pressures". This problem has been solved. Calculation time shortened. The calculation time is now much shorter. Do not use points for both layer boundary and pn-line. A point may not be used by both a layer boundary and a pn-line. In this version, it is no longer possible to use the same point for both. If this was possible in an old project, when that file is being imported a new point is now created for the pn-line. Input and zooming. Both the graphical input and the input windows have been improved, thanks to the solving of a number of minor errors. Particularly the zoom functionality has been improved. Negative stresses when using MSeep Net. ‘Use MSeep Net’ includes an option to set negative stresses to zero. However, this option did not work. The problem has now been solved. Moment water for vertical wall not included. For a vertical wall, the moment as a consequence of water against that wall was not included in the calculation. It is now included. X- and y-coordinates in output plots. In all output plots, the x and y coordinates of the mouse are now visible when you activate the ‘Infobar’ option in ‘Project Properties’.


9.1		28-11-2001 Reading future MSeep files MStab is modified so it can read files that are made by the next version of MSeep. Geometry improved The geometry part is improved. Short report The 'short report' is shortened even more.


9.0		Geometry You can create and adjust the geometry directly from MStab. You do not need the program MGeo anymore. Interpolation pl-lines When 99 is chosen as pl-line, MStab searches in the layers above and below for a pl-line with a 'real' value and interpolate between those values. Contrary to the DOS version, the Windows version of MStab did not check if the layer thickness was larger than zero. This has been corrected in this version. Stresses in Geometry The option 'Stresses in Geometry' has been added to the 'Result' menu. Here you can view the total stress and the pore pressure graphically for a given x co-ordinate.


8.2.2		Uniform loads When using temporary uniform loads, now it is possible to choose the option "use under/over pressure above phreatic line". Before, MStab always calculated with pore pressures above the phreatic line regardless of the choice that was made.


8.2.1		Project Properties 'Save as Default' in the 'Project Properties' did not work correctly, just as going to the 'Project Properties' by a right-mouse click from within some of the result plots. Both problems are solved. Zoom into critical circle As the result plot 'Stresses' is opened, there will be zoomed automatically into the critical circle. Force equilibrium By double clicking a slice in 'Stresses' a force equilibrium plot will be shown. This option was made for the Spencer method. For the Bishop or Fellenius method also a force polygon will be shown, but this one is not closed because Bishop only takes the moment equilibrium and the vertical equilibrium (not the horizontal equilibrium) into account and Fellenius the moment equilibrium only. Cu-measured An error in the 'cu-measured' calculation is solved. This error occurred when a material number was not equal to the corresponding layer number. Geotextiles It is now possible to work with oblique geotextiles. Furthermore, the next problems are solved: - When the y co-ordinate of a geotextile was changed in the input screen, in the calculation part it was only assigned to the starting point of the geotextile and not to the end point. Therefore calculation took place with an oblique geotextile. In the input view this was not visible since in the drawing part of the program the y co-ordinate was ascribed correctly to the end point. When the input file was read the y co-ordinate of the end point was made equal to the starting point. So the problem was over as soon as a project was opened again. - The value of the 'Mobilized embedded tensile strength' written to the output file was not correct when the distance from the circle to the starting point of the geotextile was larger than the distance from the circle to the end point of the geotextile. The calculation itself was performed with the proper value. Result plots Several problems concerning opening of result plots were solved. Interpolation bottom pl-line When the 'pl-line at top of layer 1' in the geometry file was 99 (to enforce interpolation) then the MStab calculation was interrupted. MStab presumes that the bottom layer is infinitely deep (in contrast with e.g. MSettle). Therefore the interpolation went wrong because no value was found at the bottom. Now, after reading the geometry in MStab the value of the 'pl-line at bottom of layer 1' is used. Reading DOS-files Several problems concerning reading of some old DOS-files were solved. Requested number of slices It is now possible to choose the 'requested number of slices'. This option can be found in the 'Calculation Options'. See the help file for more information. Copy to clipboard With 'copy to clipboard' now for all the figures the accompanying text is copied too. Multi-language output All output plots can be shown in both English and Dutch. For now, the report is only available in English. Working directory It is now possible to specify a working directory. Zoom option for graphical output If a geometry picture is zoomed in and then printed, exported or copied to clipboard, only the visible part will be printed. Internet links In the help menu a link is added to the Software Plaza at the GeoDelft website. Via 'Support', you can now send your question directly by email to the support group of GeoDelft.