Most of the time, STAAD Pro is used to analyze and design steel structures. But add-on parts that come with the program make it a valuable and powerful tool for creating concrete. Engineers have the means to design and build concrete structures, such as STAAD Foundation Advanced and RCDC - FE. Join today STAAD Pro Online Training if you want to learn from home.
In many design offices, slab and basics either:
• Included in the superstructure model and looked at along with the beams and columns; or • Either analyzed separately from the beams and columns.
• Modeled as a separate local structure so that the Finite Element Method can be used to analyze and design it (FEM)
In this article, they look at how STAAD Pro, RCDC-FE, and STAAD Foundation Advanced can be used to handle these "planar" elements, such as floor slabs and foundations.
This article is mainly about the following:
• How slabs and foundations usually work.
• Things to think about when analyzing concrete slabs and foundations
• Discussion on main design requirements
• A talk about rebar detailing
• Making of reports and sketches
How Work Usually Goes: Slabs or Foundations:
Any building project goes through standard steps like:
• Model generation and preliminary assessment
• Improvements to the model and a final look at it
• Concrete design (determination of reinforcement required)
• Rebar detailing
• Drawings being made
• Making reports and bills of quantities and doing the math for them
At each step, different software has to be used. In the same way, there are separate workflow stages for other parts of the structure. This would be the most common way to do things for floor slabs and mat foundations. If you are nearby Noida then join any good institute for STAAD Pro Training in Noida.
Workflow in STAADPro for Modeling and Analysis
1. Make a plan (usually an X-Z plane) model to match the shape.
2. Make the parts that hold the building together, such as beams, columns, shear walls, and floor slabs.
3. Put the allowable loads on the slab and the other parts as needed.
4. Analyze the structure with the right support conditions, which can be (a) idealized as pinned, fixed, and springs, or (b) if you want, you can include the mat foundation in the superstructure model.
5. Look at the analysis results for things like deflection and stability.
Technical Talks About Floor Slabs
The slabs of the building are essential parts of the structure because they support most of the weight put on the building. Most of the time, "flat slabs" are used for this. These slabs are held up by columns directly. Most of the time, beams may be in a few places—these need to be carefully thought out and planned.
Some important things about the model to remember are:
• The slab thickness (and drop panels, if there are any) must match what the design code says.
• The mesh size chosen should be small enough to have good parts of the span but not too small.
• The check for deflection should be done based on the cracked sections.
• For line loads, such as walls, the right "dummy" beams should be modeled to distribute the load better.
• If beams are used, they should be the right size for their weight.
Technical Discussions for Mat Foundations
Most mats are held up by the soil, piles, or both. Soils like clay and sand are flexible, so the best way to model them in a finite element model of a mat is several discrete translational springs at each node. Depending on their size and held up, piles can be thought of as a spring, a pinned support, or fixed support. The physical modeling features of STAAD Foundation Advanced make it easier to do all of these things.
Parts that have been "thickened" to handle higher column loads need extra care. If the forces need to be transferred well, roller-compacted concrete (RCC) pedestals may be required for steel columns. The loads that the superstructure puts on the mat are another factor that needs to be considered. High-stress concentration happens when a large force or moment is sent through a single connection point between the column and the mat. By default, STAAD Foundation Advanced spreads the loads and moments to several points where the column and carpet are supposed to meet. Load combinations can be made in the STAAD Pro How It is Used in Civil Engineering? Foundation Advanced environment if component cases like Dead, Live, Wind, etc., are available or imported from the superstructure model.
One thing that makes STAAD Foundation Advanced stand out is that it can check for stability when sliding or turning over. This check is done with the same methods used for isolated footings or combined footings for each service type combination.
Floor Slabs - Design
For beam-supported slabs, the bottom reinforcement is designed for each panel between the beams, and the top support is based on the analysis of the design requirements for continuity. The deflections of these slabs need to be checked based on the size of the panel.
When building flat slab structures, with or without drop panels, there are some things to think about. Most design codes have an empirical design method that you can use. Most of the time, these are only used to compare. Most of the time, the FE analysis in the software is used to design flat slabs. Some of the most important things to keep in mind when designing a flat slab using FEM are:
• Punching around columns and drop panels to check for shear
• The design is based on the widths of the panels, which are given names like "column-strip," "middle-strip," etc.
• Standard methods of detailing and curtailment, which are based on experience and don't match up with the actual behavior in the analysis, are empirical and don't match up directly.
Here is a small picture of a STAAD Foundation Advanced model of a mat foundation on piles that supports storage tanks in an industrial complex. The tanks were modeled in STAAD with fixed supports for plate and solid elements. Pro and the reactions were put as loads on the mat in STAAD Foundation Advanced. Become a professional by doing STAAD Pro Training in Delhi from any of the top institutes.
