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MWK | Basement Masonry Wall | Update Information


Version 02/17


Addition

The material database for the products of Schlagmann Poroton GmbH & Co. KG has been updated.


Version 01/17


Correction

The internal force graphs for the output document are scaled correctly now.


Version 02/16


Addition

Divergent wall thicknesses can be entered flush with the outer surface.
ÖNORM EN 1996: For partially superted ceilings the rules from the German Annex can be applied.
The material databas for the products of "Wienerberger GmbH" and the "Schlagmann Poroton GmbH & Co. KG" are updated.


Version 01/16


Addition

Wall overhang: An overhang beyond the edge of a plate or strip foundation can be defined. The design is done like for partial supported slabs according to DIN EN 1996.
Data exchange: Loads and wall geometry can be transfered to foundation programs FDS+ and FDR+.


Version 02/15


Eurocodes

With the selection of DIN EN 1996:2015 new adjustments for the National Annex (A1 + A2) Part 1-1 and Part 3 are implemented. Main adjustments are the correction for compressive strength of masonry recipe.

Material update

The material database with material parameters for Germany has been updated according to the product approvals 2015.


Version 01/15


Internal

Technical adjustment


Version 01/14C


Material selection updated

The material selection form for masonry based on technical approvals and user definied masonry acc. to DIN 1053 and DIN EN 1996 have been updated. The form for approval based masonry now shows substantially more values for mechanical properties definied in the specific approval as well as verbal hints from the approval.

In case of user defined material a greater selection of derived mechanical properties (e.g. unit weight based on selected bulk density class) are shown.

When defining a standard material acc. to EN 1996 it can now be specified that perpend joints parallel to the wall face shall be assumed. This automatically toggles the neccessary reductions of the masonry compressive strength.


Version 01/14A


Correction

The value of the load bearing capacity underneath concentrated loads in the print out included an unjustified factor of 10. (However, the utilization ratio was printed out correctly.)

Extension of product database

For DIN 1053 and DIN EN 1996 the product database now also contains all products of Schlagmann and HART Keramik.


Version 01/14


Updated material database from Wienberger

The material database has been updated by Wienerberger Germany GmbH in order to include the design values of the material properties for their latest products as well as to provide them for the newly introduced National Annex to Eurocode 6 for Germany.

New: Optional biaxial load transfer for basement walls in the general design method

The parameters property sheet was extended by an option to – approximately – take into account the positive effects of a possible biaxial load transfer of earth pressure loaded basement walls in the context of the general design method.
Basement wall which do not comply with application conditions of the simplified design check have to be checked as if they were ordinary walls using the general design method. Thus, even if all four edges of the wall are restrained, only a uniaxial load transfer is taken into account. However, depending on the aspect ratio of the wall, the simplified basement wall check without explicit estimation of the earth pressure allows a reduction of the required vertical load. Yet, the theoretical basis of the this design rule is not linked to the application conditions of the simplified design check (see the fundamental paper of Mann/Bernhardt in Mauerwerk-Kalender 1983). It appears therefore reasonable to apply this rule also in the general design method, simply by reducing the acting earth pressure by the same amount (50% for square walls, 100% for aspect ratios greater smaller than 1:2, no reduction for element masonry with reduced overlapping ratios).
Please note that this procedure is not explicitly given in the design code but represents an extension based on engineering reasoning. Therefore, the application must be subject to the special responsibility of the user!

New: Centering bars at the top of the walls

The property sheet as well as graphic context menu for walls (right click on wall in graphics view) now offer the option to specify centering bars and thus to enforce a perfectly centric load application at the top of the wall.
Using the general design method the bending moments due to the floor slab deflection will entirely be introduced into the bottom of wall above. Thus it is important to also define (possibly present) centering bars in walls underneath in order to not underestimate the wall moments. In most cases the introduction of centering bars increases the vertical bearing capacity of a wall; however it will decrease its resistance to lateral loads (e.g. wind and earth pressure perpendicular to the wall), since no fixed end moment can be activated at the top of the wall.
In the simplified design method the definition of centering bars only increase the bearing capacity at the top of the wall. Any other design locations remain unaffected.

New: Eurocode 6 for Germany

Walls can now be designed according to DIN EN 1996 (general and simplified design methods). Background information to the changes in comparison to DIN 1053-1/-100 can be found in Frilo-Magazin 2012 (download available from www.frilo.eu/de/service/publikationen/frilo-magazin.html).
The following facts are worth mentioning:
- partially supported floor slabs are now an integral part of all design checks; this commonly reduces the load bearing capacity
- if partially supported floor slabs are present the resistance to lateral loads exhibits an significant dependency on the load direction; wind pressure is more favorable than wind suction
- due to a reformulation of the set back rule for load eccentricities at the top and the bottom of the wall utilization ratios of 1.0 do not indicate the load bearing limit; only utilization ratios > 1.0 indicate immanent wall failures


Version 02/11B


Internal modifications

Only internal modifications and adoptions were conducted.


Version 02/11D


Correction

For walls supported at the top and the bottom only the effective length was not conservatively estimated if the following conditions were

met: DIN 1053-100, general design method, wall thickness min. 36.5 cm and floor slab supporting length less than half the wall thickness.


Version 02/11C


Correction

After modifiing the slope shape parameters the dimensions in the grafical representation were not updated reliably.


Version 02/11A


Visibility of utilisation ratio panel

The utilisation ratio table at the right screen border is now by default not visible. Its visibility can

now be toggled via the F12-key on the keyboard or the newly added eta-button in the main toolbar.


Version 02/11


Graphical display of load dispersion areas underneath vertical loads

In order to identify differently loaded wall areas more easily a graphical hint of the load dispersion

areas underneath vertical loads of type concentrated load, block load and trapezoidal load has been added.


Version 03/10A


Grafical enhancement

The earth pressure figures have been extended by numerical values of the displayed earth pressure type (active, at rest etc.).

Product database extended

All products of the Porotherm-series by Wienerberger Austria have been inserted into our product database. These also includes the new Porotherm.dryfix-System where a PUR-based adhesive is used instead of common mortar. Only availible in design according to EN 1996, NA Austria.


Version 03/10


Error messages included in text output

In case of errors during the analysis (e.g. load eccentricities exceeding wall boundaries etc) the error messages displayed on screen are now also included in the text output.

User defined material for EC6

In addition to the EN 1996-1-1 material dialog it is now also possible to manually specify all strength parameters. The form is located in a new tab of the material dialog.


Version 01/10


Corrections and improvements in the GUI

This verions comprises several corrections and improvments concerning the graphical display and the funtionality of the GUI.


Version 02/09B


Correction of effective length

Under certain circumstances the effective length of walls supported only at the top and the bottom was evaluated incorrectly. This has been fixed with version 03/09B.


Version 02/09A


Correction: input of vertical wall loads

Under certain circumstances concentrated loads, line-section loads and trapezoidal loads could not properly be defined/showed.

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