Mat - Dynamic Menu

This is a floating tab and not present in the top ribbon by default. When a mat is selected, this tab appears in top ribbon. Various options for mat editing, analysis, design, review etc are available under this tab and are explain in detail.

Alter-

It provides various options to edit an existing mat geometry or adding multiple mats. This first group features simple transformations that treat the mat as an integral unit-

a) Move

b) Clone

c) Repeat

d) Mirror

e) Rotate

All these transformation tools can be accessed by selecting the mat/mats and right clicking.

Simple Transformations-

1. Move-

“Move” shifts the entire mat by translation. The three options are

1. Move With Reference
2. Move By Distance
3. Move Edge

1. Move With Reference- You can shift the Mat graphically by clicking the starts and end points in the schematic area or enter their coordinates in the “Move With Reference” window. Click “Apply” to execute the operation. In the snap below, the existing mat is being shifted from reference point (3,0,-1)m (as shown in “Move With Reference” Window) to another point (5,0,8) (as shown in the view window. User may shift by direct input of source and destination coordinates at “Move with Reference” window, or by picking source and destination coordinates through mouse click at view area. If these two points are picked by mouse click, the coordinates at “Move With Reference” Window would get automatically updated.

2. Move By Distance-

You can enter the shift in the X and Z directions in the “Move” window. As before, click “Apply” to execute the operation.

If you click the arrow next to “By Distance”, two further options are shown. The second option is to move by angle, as shown below.

Note that by default setting, the “Move” windows and any windows corresponding to any operation are displayed at the lower right corner of the main window, but you can change this setting.

3. Move Edge-

The above two options shift the entire mat without changing its shape. This third option shifts one edge of a mat and thereby changes its shape. When you select the edge to be moved, the “Move Edge” window is displayed. In the ’Distance’ field, a default value is shown, and in the schematic, the direction in which the edge will be moved. If you enter a positive value in distance field, then the edge will be moved in the direction of the arrow and if you enter a negative value in distance field then the edge will be moved in the opposite direction of the arrow. As before, click “Apply” to execute the operation.

2. Clone-

The Clone transformation works in the same way as “Move With Reference”. You either click and select where to copy and paste the mat or enter the parameters in the “Clone” window. If you prefer to use your mouse, the table in the “Clone” window would be automatically updated. You can copy loads together with the mat. As before, click “Apply” to execute the operation.

3. Repeat-

The Repeat transformation creates multiple mats a single operation by copying one original mat at any angular direction at a user-defined offset. In the screenshot below, three new mats are created (drawn with broken lines) at an angle of 30 degrees and an offset of 20 m. The “Copy Load” option allows you to copy the mat geometry with or without loads. As before, click “Apply” to execute the operation.

4. Mirror-

The Mirror transformation copies a mat into a mirror image of it. You pick two points on the mirror line either by clicking in the drawing area, or by entering the coordinates of the points in the “Mirror” window. When you click the two points, their coordinates automatically updated in the “Mirror” window. The new mat, which is a mirror image of the original mat reflected at the mirror line, is drawn with broken lines in the figure. As before, click “Apply” to execute the operation.

5. Rotate-

The “Rotate” operation rotates a mat at an angle about a center of rotation. You define that point by clicking it on the drawing area or entering its X and Z coordinates in the “Rotate” window. When you click the point, its coordinates are automatically updated in the Mirror window. In the example shown in the screenshot, the mat is rotated at an angle 30 degrees (counterclockwise is positive) about a point with X, Z coordinates (4, -2). As before, click “Apply” to execute the operation.

Modify-

These options are for Further Transformations and this second group features further transformations to the shape of the mat:

a) Delete

b) Stretch

c) Resize (Expand/Shrink)

d) Merge (Not available right now)

e) Add Point (to Edge)

f) Convert (Not Available right now)

 

1. Delete-

You can select and delete any mat. Select the mat and click the “Delete” button on the keyboard or select the mat, right click, and then click “Delete”.

2. Stretch-

The Stretch tool is purely graphical—only the mouse is used. You click on the schematic to select an edge of the mat, hold and drag it to stretch the mat as desired.

 

3. Resize (Expand/Shrink)-

The “Resize” or “Expand/Shrink” tool expands or shrinks a mat by a given offset at all sides. Enter the offset in the “Expand/Shrink” window; a negative offset denotes shrinking. As before, click “Apply” to execute the operation.

4. Merge (Not available right now)-

You can merge several mats. Select the mats. In the “Merge” window, check the mat properties to be retained in the new mat and click “Merge” to execute. A new mat will be generated by adding the old mats. You can only merge mats that share a common boundary.

5. Add Point (On Edge)-

You will need to use this tool to split an edge by a new point. Here, the edge is selected, and the distance is given as entered in the Add Point on “Edge” window. As before, click “Apply” to execute the operation.

This tool is especially useful when the basic shape of a mat is being changed. The following figure shows how two new nodes are added to one edge, after which those nodes are shifted to create a C-shaped mat.

The Reference Vertex and Distance options are explained in the figure.

 

6. Convert (Not available right now)-

This option is not applicable to mats.

Example-

The transformation tools are very powerful. In the figure below, we show how they can be used to change the basic shape of a mat.

Click “View Elements” , a page named “View Elements” would pop up. It provides tick option for different objects. Tick any object off or on to deactivate or activate in view.

Action-

It covers four items-

1. Perform Meshing
2. Perform Analysis
3. Post Analysis
4. Perform Design

All these options are available under different tabs and already explained in details. So, only a very brief description is added.

1. 1. Perform Meshing-

This feature is available under “Meshing” tab, and also can be accessed through right click, and explained in detail in Meshing document under Application Page Layout. Here same feature is available and explained very briefly. Click “Perform meshing” and the selected mat would be meshed.

If no subgrade soil is already defined, then SFA would pop up a page “Perform Meshing” and ask for soil input to defined and assign a subgrade soil.

Click “Create and Assign” to handle subgrade soil quickly and then another page “Perform Meshing” would pop up, asking for meshing criteria inputs- Mesh Type (Quad, Triangle, or Quad with Triangle), Max Element Size, Optimization Level and Tolerance. Input and hit “Create Assign and Mesh” button to perform meshing.

 

Once “Create, Assign and Mesh” is hit, the selected mat would be meshed as per the meshing criteria. Intermediate nodes would be generated, and Plates would be created to generate analytical model for the meshed slab accordingly.

Note- if Subgrade soil and meshing criteria are already created and assigned, above two pop up pages would not come and direction the surface would be meshed. If the mat is already meshed, SFA asks for confirmation to delete old data and re-mesh.

 

2. Perform Analysis-

This feature is available under “Analysis” tab, and also can be accessed through right click, and explained in detail in Analysis document under Application Page Layout. Here same feature is available and explained very briefly. This button gets activated when meshing is already performed. Click “Perform Analysis” and the selected mat would be analysed. For this, the analytical model is used and STAAD Pro engine fired. The following snap shows stress contour of an analysed mat and the analysis progress window used by STAAD Pro displayed when a STAAD Pro model is analysed.

If no concrete grade is created or assigned, then the following pages would pop up sequentially for quick addition and assignment of Concrete type. Select Country code and Concrete Grade ,Click “Add Concrete Grade” and then in the next pop up page click “Assign and Analysis”.

If soil load is not as already generated and associated with dead load, then the following page appears for quick generation of soil load and associated with dead load.

If no “Analysis Criteria” is defined, then another page “Perform Analysis” would appear. To include /exclude Load combinations for analysis and for handling different soil/ buoyancy effect, click “Select” (as shown in the snap below) to open “Load Combination” page. Click “OK” to finalized load combinations and click “Create Assign and Analysis” button to perform analysis. These pages are explained in detail in  Analysis document under Application Page Layout.

3. Post Analysis-

This button gets activated once analysis is performed successfully. Hit this button to perform post analysis or service checks like sliding, overturning, bearing capacity, partial out of contact, pile capacities, soil and pile settlement etc.

To perform this task, post analysis criteria should be created and assigned to the mat. If that is not already available, then SFA would pop up the following page for quick creation and assignment of post analysis criteria. This is explained in detail in Post Analysis Checks and Design document under Application Page Layout.

4. Perform Design- This button gets activated once analysis is performed successfully. Hit this button to perform Design checks (Flexure, Punching, shear, reinforcement calculation etc.). To perform this task, Design Criteria, Detailing Criteria and Design Envelope should be created and Design Envelope should be assigned to the mat. If that is not already available, then SFA would pop up the following page for quick creation and assignment of Design Criteria, Detailing Criteria and Design Envelope. This is explained in detail in the Post Analysis Checks and Design document available under the Application page layout.

For analysis, Concrete grade is mandatory, which is already created and assigned. For design, along with Concrete grade, Steel grade is also needed. If no steel grade is created and assigned SFA would pop up following page and quickly create and assign steel grade.

If no “Design Criteria” is defined, then another page “Perform Design” would appear.  It helps to select country code. Hit “Create Design Criteria” and next, SFA would quickly create a detailing criteria through pop up page with the already available detailing criteria (If no detailing criteria is available). Hit “Create Detailing Criteria” and Next pop-up page would quickly create a design envelope for the available design and detailing criteria. Hit “Create Assign Design Envelope” button to perform design the mat for this particular envelope.

Before final execution, one last page would pop up asking for different Mat Design data (MF). Input design inputs and finally hit “Create and Design” to perform design of the mat. If you perform the task from post processing tab, then design inputs are asked for during design criteria. Post Analysis and Design document under Application Page Layout explains in detail about the design process.

Analysis results-

This provides different tools for viewing analysis results-

1. 1. Contour
   2. Analysis Output
   3. Cut Line

1. Contour-

This is also available under “Analysis” tab and explained in detail. It shows different analysis results like bearing stress, node translation in different directions, Shear stresses, shell moments, global moments etc. in contour form with color scale.

You need to pick up the Load Combination and the type of output you want to see and click upon “Contour” to generate the particular contour for that particular output and for that particular load combination.

In the snap below, vertical deflection contour is being frown for load combination 107.

 

Critical- Critical is also a part of contour facility but it depends upon the load combination envelope (Service or Ultimate) , not upon any particular load combination. It takes all critical at each node among all load combinations and present in contour form.

Export- This helps users to export contour data in csv file format and open in excel. Still under development.

 

2. Analysis Output -  It opens the ANL file which is generated as the output from the STAAD Pro analysis of the analytical model.

3. Cutline- This is a powerful feature to draw a line on a mat and generate stress values along that line using it as a cut -section. It’s explained in details in another document named Cutline.

Post Analysis Check Results-

This option displays a few Post Analysis result in contour form. So, this would be effective only when Post Analysis Check is executed successfully. If you expand this drop down, you will observe four options, -

 

1. Soil Capacity Envelope
2. Pile Compression Capacity Envelope
3. Pile Tension Capacity Envelope
4. Pile Shear capacity Envelope

Click “Soil Capacity Envelope” and Click on “View result” Button. The contour would be generated for Capacity Envelope.

Suppose we have run post analysis for service cases only and service case envelope covers 14 SLS load combinations, then SFA is having stress datasets for 14 SLS cases each of which contains stresses at each node. Now for each load combination, for each node, we can calculate capacity ratio as Factored Bearing Capacity/ Soil Stress. So, for each node, we can calculate critical capacity ratio for this SLS envelope (minimum capacity ratio at this point among these 14 SLS load combinations). If we perform this task for all nodes, then the SLS capacity envelope would be available. The snap below is showing the same data in contour format.

For Mat over Soil only, “Soil Capacity Envelope “is the only valid option, other three pile capacity envelops are valid only for mat on piles. Service check of mat over piles, covers three checks-

Compression capacity check of pile

Shear Capacity Check of Pile

Tension Capacity Check of Pile

Compression capacity check of pile, the capacity ratio = Factored Compression capacity of Pile / Compressive load on that Pile. Critical capacity ratio can be calculated for the whole envelope for each pile and displayed graphically as shown in the snap below-

Design results-

It provides various options to view results after design.

a) Strip X/Y

b) Strip Forces

c) Punching

d) TX/TY/BX/BY Design results

1. Strip X/Y- This is available after successful design of a mat. SFA breaks the total mat into small strips at X and Y (Local) directions. For each strip, the width is kept 1000 mm for metric models and 1ft for English unit system models. Click on “Strip X” or “Strip Y” to activate corresponding strips in view area. Select any strip and “Properties- Design Strip” would appear in place of “Properties” window, which displays various information of the strip like total steel, reinforcement etc.

By default, The strip width is 1000 mm or 1 ft (until the size and shape of the mat forces to compromise at last strip). SFA keeps the strips continuous, until any change of depth, is observed (in that case SFA automatically slices those parts of that strip as separate strips.) Please observe the snap below, where differences in depth are observed due to presence of thickened regions and SFA automatically considers those parts as separate strips.

1. Strip Forces-

It shows Moment and Shear (M and V) for any strip in graphical form. In other words, it provides us the SF and BM diagram of this strip, if we consider this strip as if an independent combined footing, or if we draw a cutline along the center-line of this strip, the SF and BM diagram effective for this 1m (or 1 ft) strip along this line is being displayed here.

It picks up a number of points on the strip along the centerline, calculates Shear and moment at those points (for the current load combination) and draws the graph.

If a strip is aligned parallel to the global X axis, then this moment would be MZ moments at the control points (as shown in the snap below) and the shear would be the shear on this strip in global YZ-plane.

Activate strips first and then click upon any strip to display the graph for this strip. “Strip Forces” graph view would appear showing M and V for current load combination.  In “Strip forces” graph view window, click the first icon to expand the load combination and select the load combination as current, for which M and V graphs would be displayed. Expand the second icon to tick untick M and or V for display. Third and fourth icons are for activation of horizontal and vertical grids respectively. The fifth icon is for switching between line segment graph or smooth curve graph. Sixth item is for saving the graph for future access. Seventh icon is for popping up “setting” options. The snap below explains each icon. At top of “Strip Forces” window, current load combination is also displayed.

Advance Options- It contains three items-

1. Segment length
2. Calculation Point Count-
3. Calculate for Section Width

 

2. Segment length- This is the distance between two consecutive control points. Lesser value would generate more control points on the centerline of the strip and the graph would be smoother and more accurate.
3. Calculation Point Count- This is the number of points in transverse directions of the strip. For each control node (aligned along the centerline of the strip), SFA draws a line at right angle with the strip direction. A few points are taken at equal internal on this transverse segment, which is on this strip. Now shear force and bending moment calculated at each of these points and an average of them is taken as the strip shear or strip moment at that node for current load combination. This actually takes into account the variation of shear and moment along the strip width and averaged out values are obtained. This parameter (Calculation Point Count) controls the number of points on this transverse segment. Increase number of points to get denser data which leads to more accurate results. Five points for a metric model (1000 mm strip) means each point is at 200 mm gap.

3. Calculate for Section Width- If you keep it ticked, it will give total moment and shear for the strip width at the control points. So, for the snap above, which is a metric file, and having 1m strip, SFA is calculating Shear and moment for the whole 1m strip width and reporting values in kN and kNm units. If you keep it unticked, it will provide the values in per meter, i.e. shear would be reported as kN/m and moment as kNm/m.

 

Note- Whether you untick or tick it, units would change, but values would mostly remain same.or Metric files, strip width is 1 m. So, here, whether you tick or untick Section Width, values would not change (as 5 kNm/m is same with kNm moment for 1 meter width). In the same manner,  for English unit files, strip width is 1 ft and the values would either be reported in kip/ft or kip.ft /ft. So , in English unit files also, values would remain same.

2. Punching-

Click “Punching” button to display the search radius into view window.  Check whether Program defined search radius is not sufficient to identify the correct punching width and if found insufficient, user can change punching radius and instruct SFA to recalculate.

User can click at the model element in properties window (follow the path –Design Model > Models >Default >Elements> select the relevant Mat element, as shown in the snap below) to pop up “Properties: Mat Design Option” window. There click at click on “Show” beside “Punching Check” to open “Punching Check” window, where you can tick/ untick any column for checking, define any column as edge, interior or corner column or change search radius is needed. Click “Check” button to execute punching check with modified information or click “Close” button to close this window.

To see punching result summary, click at Results> Punching> “Show” , this would pop up “Punching Shear Summary” page.

In this document, punching is explained in brief. Punching Shear Check is a major design check and explained in detail in the document named as “Post Analysis Checks & Design”

3. TX/TY/BX/BY Design results-

This is also a major design topic and explained in detail in “Post Analysis Checks & Design” document. Here only a brief discussion is available.

SFA performs flexure check and provides flexure reinforcement in four layers- Top X (TX), Bottom X (BX), Top Y (TY) and Bottom Y (BY). Once design is successfully performed, these options can be used to view reinforcement, moment capacity and various other design outputs. Click on “TX” and select and design result from drop down arrow. Suppose let’s look at “design” (default item). Modelling window would graphically show the design result.

In the picture below, we can see that SFA has broken the whole mat into small design stations and designed each station. Now reinforcement is optimized accordingly. In the picture we can see, for top reinforcement, only #10 @ 150 mm c/c reinforcement is sufficient everywhere.

Another snap below shows, reinforcement detailing along Bottom Y.

In the same manner, other options like Ast required, Ast Provided, Moment Capacity, Extra Rebar, Zone can also be used to view design results. For more details, please refer “Post Analysis Checks & Design” document.