RAM | STAAD | ADINA - RAM Elements Masonry Wall [FAQ]

	Product(s):	RAM Elements
	Version(s):	10.00 or later
	Area:	Modeling; Analysis; Design

Which surface of the shell is the "Front"?

Whichever way the shell local 2 axis points, that's the "front" of the wall, i.e. the elevation you "see" when you pull the shell into any integrated wall module. The 2 axis can be flipped using the "Flip shell orientation" tool under Shells - Local axes, but this also affects the 3 axis direction, opening placement and sign convention for shell pressures.

On the FEM tab of the stand-alone masonry wall module the Front is denoted as the Top surface, while the back is the Bottom surface.

How does partial grouting affect the Masonry Wall design?

Partial grouting versus full grouting affects:

The self weight of the wall*.
Effective concrete area considered in checking the major axis shear for shear wall design (lateral in-plane loads). The center area of the blocks are ignored when partial grouting is used.

* Wall self weight is derived from NCMA TEK 14-13B. Material properties for masonry are still used in the analysis of walls. Also note, the program reports masonry wall "Effective unit weight" in force per unit volume (density) units, not force per unit square area of wall. To convert this into the area weight of the wall you must multiple by the thickness of the block (i.e. * 7.625/12 for 8" block).

Partial grouting does not affect out-of-plane deformation shown on the FEM screen or the Diagram screen. These are based on the solid, prismatic, uncracked properties of the wall.

Can I check other block dimensions?

Regretfully the only block dimensions that can be checked are 4", 6", 8", 10" and 12" thick blocks. Other block dimensions, rotated block layouts, and multi-wythe layouts are not possible at this time due to the available published data for partially grouted block properties. In the main Ram Elements module one can still analyze shells of any thickness, however.

Why doesn't the module optimize a wall with any horizontal reinforcement?

Make sure that you have “Shear walls” selected under Elements to Design.
Make sure you have the desired joint reinforcement type selected too.

But, the program will only optimize a wall with horizontal reinforcement when it’s needed (otherwise it will be treated as an unreinforced wall). If the shear forces are too small to require horizontal reinforcement then you can only add it in manually.

Why does stacked bond produce the same capacity as running bond?

The bearing wall checks are based on a width of wall that matches the code prescribed effective compressive width per bar. This width is different for stacked bond (when bond beams are not spaced 48" oc) and running bond walls (see TMS 402-13 5.1.2). The problem is that RAM Elements only uses the effective compressive width requirements for running bond walls. The prescriptive horizontal reinforcement requirements are also not checked.

If you can justify using the same effective compressive width for your stacked bond wall and detail the prescriptive reinforcement, then you can safely use the RAM Elements design. RAM Elements should not be used to design reinforced, stacked bond walls when the effective compressive width is not the same as a running bond wall.

How are masonry lintels designed?

Currently, the wall above an opening can be designed as a lintel beam if the Home – Design data – "Elements to design" includes the Lintels option.

The user can specify the design depth for the lintel, it need not be the full depth of the wall above the opening. The user can also limit the range of bar sizes used.

The lintel and the wall are all part of the same finite element mesh, visible on the FEM tab in the stand-alone version of the module. From the FEM screen, it is clear that the elements are all connected and inseparable, analogous to a continuous bond beam or fully doweled lintel. To determine the demand, the program slices vertical section cuts through the lintel at 10 points along the length and integrates the shell internal forces to determine an envelope of bending moment demand. The critical demand is then reported under Results: Bending as “M” in the Lintel Design portion of the report. The critical force along the cuts is reported as V. The bending moment and shear does not include forces associated with bending of the lintel out-of-plane of the wall.

The program tries to optimize longitudinal and shear reinforcing, placing top reinforcement when negative bending requires it and bottom bars just above the opening for positive bending. The program will extend or develop these bars as required. For user defined reinforcement, warnings will be given when the flexural strength of development is insufficient.

Design of a pinned-ended type lintel or one with control joints is not possible at this time.

How is shear friction evaluated?

We are calculating the shear friction for ASD and SD methods as follows:

There is an issue in version 16.03 that is being fixed for version 16.04 for the linear interpolation equations above that causes a NPC (not possible to calculate) error for some cases. In v 16.04 we will furthermore limit the check to base sections.

What sections of ACI 530-08 are checked?

Here is a table of the provisions checked for Strength design, LRFD.

Chapter	Section	Notes
1. General Design requirements for masonry	1.8 Materials 1.8.2 Elastic moduli 1.8.2.1 Steel reinforcement 1.8.2.2 Clay and concrete masonry
	1.9 Section properties 1.9.1 Stress computations 1.9.2 Stiffness 1.9.3 Radius of gyration 1.9.5 Bearing area 1.9.6 Effective compressive width per bar
	1.13 Beams 1.13.3 Deflections 1.13.3.1 1.13.3.2
	1.14 Columns 1.14.1 General column design 1.14.1.1 1.14.1.2 1.14.1.3 (a and b)
	1.15 Details of reinforcement and metal accessories 1.15.1 1.15.2 Size of reinforcement 1.15.2.1 1.15.2.3 1.15.3 Placement of reinforcement 1.15.3.1 1.15.3.2 1.15.4 Protection of reinforcement and metal accessories 1.15.4.1	The masonry cover is set by the user
	1.17 Seismic requirements.	All implemented related to ASD and SD (chapter 2 and 3)
3. Strength Design of Masonry	3.1.3 Design Strength
	3.1.4 Strength – reduction factors 3.1.4.1 3.1.4.2 3.1.4.3
	3.1.8 Material properties 3.1.8.1
	3.2.2 Flexural and axial strength of unreinforced masonry 3.2.2.1 3.2.2.2 3.2.2.3 3.2.2.4
	3.2.3 Axial tension
	3.2.4 Nominal shear strength
	3.3.2 Design assumption for reinforced masonry
	3.3.3 Reinforcement 3.3.3.3 3.3.3.5	The maximum flexural reinforcement can be calculated considering or not the reinforcement in compression
	3.3.4 Design of beams piers and columns 3.3.4.1 Nominal strength 3.3.4.1.1 Nominal axial and flexural strength 3.3.4.1.2 Nominal shear strength 3.3.4.2 Beams 3.3.4.2.2 Longitudinal reinforcement 3.3.4.2.2.2 3.3.4.2.2.3 (c and d) 3.3.4.2.4 3.3.4.2.5 3.3.4.4 Columns 3.3.4.4.1 3.3.4.4.2
	3.3.5 Wall design for out of plane loads 3.3.5.3 3.3.5.4
	3.3.6 Wall design for in plane loads 3.3.6.2 3.3.6.3 3.3.6.4

How to apply different out-of-plane load for parapet?

By default on the parapet the same load is applied as of the last level. But under advanced option, we can uncheck the box against "Parapet load equal to the last level" and it will provide option to input different load value for parapet level.

RAM Elements Masonry Wall [FAQ]