By: Javier Encinas, PE | July 30, 2019
ASDIP CONCRETE is a structural engineering software for design of concrete members. It includes the design of CMU bearing walls subject to gravity loads and out-of-plane wind pressures, based on the latest TMS 402 provisions.
The design of masonry walls involves the calculation of shears and moments for the factored load combinations, and then the slenderness effects to finally design the reinforcement accordingly. But what happens if the wall is not solid, but it has door and window openings? This document shows a new feature on wall opening design, and how to reinforce the members using ASDIP CONCRETE.
How do you model a wall opening in ASDIP CONCRETE?
This feature includes a graphical user interface to model a wall opening and the reinforcing members, as shown in the screen shot below. To create an opening, click and drag on the canvas. The software will show the dimensions in elevation view. To resize the opening, drag a corner. To move the opening, just drag with your mouse. Note that the table immediately below the canvas shows the opening dimensions and the pressure distribution type, which can be Top / Bottom, Left / Right, or 4-Sides.
To add a lintel or sill, click on the top or bottom of the opening. To add a jamb click on the sides of the opening. The software will show the members as red lines and will assign a unique number to each member. ASDIP CONCRETE generates two tables below the canvas, one for the lintels and sills, and another table for the jambs.
In the Lintels table enter the dimensions and reinforcement of a concrete lintel or sill. In the Jambs table specify the jamb material, either concrete or masonry. If concrete, enter the dimensions and the number and size of rebars. If masonry, enter the number of reinforced cells and the rebar size.
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How do you design the lintel and jambs?
Based on the geometric information, ASDIP CONCRETE determines whether to consider the arching effect in the lintel design, and calculates the gravity loads accordingly. The software distributes the lateral pressure according to the tributary area to the lintel and jamb. In addition, the lateral reactions of the lintel and sill are applied to the jambs as concentrated loads.
With these loads the software calculates the maximum moments and shears at each element and compares them versus the structural strengths. If the lintel is precast, then the calculated load should be used to select the required lintel size in the load tables by the manufacturer.
To complete the wall opening design, a new section has been added in ASDIP CONCRETE to the Condensed and Detailed tabs and reports, with the calculations of lintels and jambs for the controlling load combination, as shown below.
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ASDIP CONCRETE includes the design of bearing walls, with multiple options to optimize the design easily. A new feature allows the design of CMU wall openings, which includes the design of reinforcing members such as lintels and jambs.
Detailed information is available about this structural engineering software by visiting ASDIP CONCRETE. For engineering background, see the post Bearing Walls Under Out-of-Plane Loads: A Design Overview.
Javier Encinas, PE
ASDIP Structural Software