Basic IFC Concepts for Revit users

Basic IFC Concepts for Revit users

 

What is IFC and why it is often misunderstood ?

 

IFC is developed by the buildingSMART association and it is an open standard for the BIM Data exchane.

IFC stands for the Industry foundation classes and it’s not a file format, but actually a semantic schema which defines the way the building related data is described and inherited.

This also means that you can open an IFC file in a simple Texteditor and view its content.

The foundation of IFC are as its name already says the classes, which can describe anything, from a physical object like a wall to abstract concept like a task.

Unfortunately the buildingSMART documentation is very complicated and even scary, because it is actually meant for software developers and not for us mortal Revit users. But the good thing is that you don’t need to get that deep into the theory in order to be able to uses IFC correctly.

 

Using the IFC documentation

 

Now let’s have a look you can find and navigate the IFC documentation. You can always access the latest version through the buildingSMART wbsite at https://technical.buildingsmart.org/

As you can see here, IFC4 is the latest development and it is also still being updated.

IFC2x3 is also still often used, but we will stick with IFC4 in this video series, because it is the latest development and 2×3 will become more and more obsolete in the next years.

The best way to find the IFC classes is to select alphabetical listing from the main page sinc IFC4 we can also browse the list in other languages like German, or also in plain English.

Keep in mind that there are a lot more IFC classes that Revit categories for two reasons : the first one is that IFC classs are often more granular and the second one there are many classes which don’t describe physical elements or don’t have a representation in a BIM modeling software like Revit.

Another important point are the predefined property sets – all of the common property sets are mapped automatically when exporting from Revit.

These are very important because they provide the most important element information in a standardized way, and are always structured and named in the same way, no matter from which software the model has been exported.

Same goes for the Quatity sets, which are a special kind of the property sets are used for QTO workflows.

 

IFC Mapping table in Revit

 

You can find the mapping table if you go to Revit -> Export Settings -> IFC. This table displays the Revit Categories matched to IFC classes and types.

Note that this table is already filled out by default and it should cover the most common usecases but of course you can always change it if needed.

For this, you will need to copy and paste the exact name from the IFC documentation. Certain Revit categories can also be excluded from the export by simply inserting Not Exported.

This is just the starting point, as in most BIM Projects you will need a more granualar mapping on the object level. The mapping table is saved as a simple textfile and can be easily shared.

If you ever want to revert the default settings or of the mapping table gets messed up by switching between different Revit languages, you can reset it very easily select Load, delete the default file and then hit « Standard ». This will regenerate the file you just deleted with the default, hardcoded settings.

Once we have set up the mapping table, you can launch the Export dialog. Here y ou can select between several already pre-defined setups or also modify these.

 

Model View Definitions (MDV)

 

Note that the IFC schema is always combined with a Model View Definition or MVD, which defines a subset of the IFC schema. You can compare an MVD with a 3D view in Revit, where all elements from all phases, all analytical models and calculations are all displayed at the same time.

Model View Definitions help to extract the data in a meaningful way, like a dedicated view of the model.

This is very simplified explanation, but you get the point !

If you use IFC2x3, your choice will usually be the Coordination View 2.0, and for IFC4 the Reference View. These are the default MVDs defined by the buildingSMART for BIM coordination.

 

Open source Revit IFC

 

The client of the BIM Manager should always define which IFC version and which MVD is to be used in a project in order to keep this consistent.

Otherwise, just use IFC4 Reference View for your specific discipline. It is important to keep in mind that Autodesk offers an open source Revit Toolset and regularly updates IFC for Revit independantly from Revit Updates.

This way the developers can react much faster and publish updates whenever needed. Therefore you should keep an eye on the version number and check back on apps.autodesk.com for updates.

The easiest way is to just search for revit IFC and you will be presented with the apps for the four most current Revit versions.

Often you will find these updates a week or two earlier on github, where the developers are also publishing the sourcecode, but you can also download the most current installers here.

 

Current download links for Revit IFC (sidebar): https://bim-me-up.com/​

Autodesk App Store: https://apps.autodesk.com​

Revit IFC on Github: https://github.com/Autodesk/revit-ifc​

Wiki OS with useful tips around openBIM, not only for Revit: ​ https://wiki.osarch.org/index.php?title=Category%3AAutodesk_Revit

Recommended freeware IFC Viewers:

Open IFC Viewer, very fast and supports latest IFC Versions: https://openifcviewer.com/​

BIM Vision, powerful viewer, offers additional features for measurement or easy display of classifications: https://bimvision.eu/download/​

BIMcollab IFC Viewer, popular viewer, offers direct connection to the BIMcollab platform: https://support.bimcollab.com/en/zoom…%E2%80%8B

FZK Viewer, a bit oldschool, not good with big models, but very accurate display of properties: https://www.iai.kit.edu/1302.php​

 

 

BlenderBIM: An open source solution for BIM projects?

BlenderBIM: An open source solution for BIM projects?

 

If you’ve never heard of Blender, it’s only a matter of time! In short, this is freely accessible graphics software, which offers, for example, 3D modeling, simulation, rendering, composition, motion tracking, video editing and animation pipeline functionalities. Created in 1998, it is currently being developed by the Blender Foundation.

Since 2019, the software has been increasingly recognized by companies in the graphics industry, such as Epic Games, Ubisoft or NVIDIA.

 

What’s new for us:

 

The BlenderBIM add-on has been around for some time: a specific add-on for Open BIM processes that rely on the BuildingSmart IFC format. It is built by volunteers from the IfcOpenShell project, still in development mode, and constantly evolving.

 

A new free BIM tool, on software recognized in the world of graphics, and capable of understanding the IFC format. What more ? This is how we focused our attention on the possibilities of this add-on. Is it possible to analyze and modify the data contained in an IFC for example? We summarize everything:

 

By default, in Blender, collections contain objects that have location, materials, etc. With BlenderBIM, we get several additional properties and functionalities: durability, price, description, globalID, assignment of IFC classes, assignment of attributes and sets of properties to elements, calculations of quantities from the geometry of objects, etc.

 

Taking into account the ability of this add-on to interpret the IFC format, we therefore asked ourselves the following question: can we think that Blender, technical and cutting-edge software in the field of graphics, can represent a help for stakeholders? of a construction project? Since BlenderBIM allows you to make modifications to an IFC mockup, it can be a solution in a BIM project, especially in the operation-maintenance phase.

In fact, during this phase, we start by using the model of the work executed “as built” in IFC format. In order to identify the functionalities this sotftware can offer to a project today, several tests were carried out on blender 2.92.0 (BlenderBIM addon blender28-bim-210404-py37-win, IFC2x3)

So here are examples of options we can obtain quite simply with the help of BlenderBIM:

  • The ability to view IFC models,
  • to be able to delete objects (and therefore by extension to divide IFC models by a new save),
  • To be able able to move objects, and change the values ​​of their properties
  • To be able to add new attributes to objects from Blender.

This is possible: but the IFC models we can export from Blender do not seem to keep the new properties, we consider that this option is still limited to a concrete deployment on a BIM project.

In short, from our point of view, IFC export remains difficult to master, and still seems to limit the possibilities of modifying the IFC format thanks to Blender.

To take a step back, it is also necessary to consider that this is a software whose technique is quite advanced and whose handling represents several years of practice.

However, we are counting on the meteoric progress of the BlenderBIM add-on to allow us to manipulate IFCs with more freedom in the future.

 

 

What is the difference between Formwork and Shuttering?

What is the difference between Formwork and Shuttering?

 

Introduction

 

Both formwork and shuttering are used to describe the procedure of making moulds in construction projects. In this process, the concrete gets poured & contained until it gets hardened. To simply put, shuttering formwork is used in concrete construction. While shuttering is a method of foaming moulds using the plywood, formwork creates moulds using a range of materials. Both shuttering and formwork accomplish more or less a similar task.

The primary difference between the two processes is the use of materials to accomplish this constructional job. In many cases, shuttering formwork is described as one form of formwork.

Let’s explore how different these processes are from one another.

 

Times When Shattering is More Significant than Formwork

 

Projects ranging in different sizes might require employing both the methods of formwork as well as shattering. The large-scale projects use a range of formwork types. But in almost all cases, shuttering is a popular option, given that the process is more straightforward and allows significant concrete amounts to be used at a single go.

Wall Form Shuttering

Making the right use of plywood to make shuttering becomes more inexpensive, especially when plywood is a recycling medium. Nonetheless, when it is about shuttering & formwork, not all plywood can serve the purpose. A special water-resistant plywood type is used for outdoors.

Wall Formwork

Falsework Support

 

Both shuttering and formwork will need the falsework support, that too in their various forms. Falsework, as a matter of fact, denotes stabilizers and poles, besides other units used to keep theme in place as the concrete dries.

Not all of these elements are permanent; some come as temporary ones too. So, this means that it can also be taken down right after the concrete sets. For permanent ones, the falsework gets removed as soon as the concrete sets in. This makes shuttering and formwork to remain in place permanently.

Basically, the difference between them is very little. But a definite example of formwork that does not use shuttering is in constructing concrete sidewalk. Rather than using timber for creating the mould, roadform (metal beams) can get used. It features a flat face right against which the concrete setting gets poured to create a clean edge. Connecting grooves and tongues are featured at either end of roadforms.

Modeling and Understanding Floor Diaphragms in STAAD Pro Tutorial

Modeling and Understanding Floor Diaphragms in STAAD Pro Tutorial

 

In this video, you will learn how to model and understanding floor diaphragms in STAAD.Pro.

00:00 Introduction to Floor Diaphragms
03:08 Modeling Floor Diaphragms in STAAD.Pro
08:51 Modeling Diaphragm Masses in STAAD.Pro
16:12 Printing the Center of Rigidity for Floor Diaphragms in STAAD.Pro
18:46 Specifying the Floor Diaphragm Options in STAAD.Pro
25:55 Printing the Floor Diaphragm Story Stiffness in STAAD.Pro
27:10 Specifying the Seismic Eccentricity for Floor Diaphragms in STAAD.Pro

  1. Rigid Floor Diaphragm which assumes that the floor is very rigid to experience any in-plane and out-of-plane deformation. The rigid diaphragm action of floors
    assumes that the floor is stiff enough to undergo rigid body movement.
  2. Semi Rigid diaphragm which assumes that the floor is very rigid to experience any in-plane deformation but no out-of-plane deformation.
  3. Flexible diaphragms which assumes that the floor has no rigidity to resist lateral loads.

The rigid floor diaphragm assumption may not be appropriate if a relatively narrow building has closely spaced shear walls (i.e. the shear walls are stiffer than the floor diaphragm). In the case of a low rise building, the floor diaphragms may be flexible compared to the shear walls as in light wood framed construction.

For long narrow buildings with deep beams the rigid floor diaphragm assumption has to be evaluated carefully. The presence of a slab opening for elevators or stairs can weaken the floor diaphragm action.

Wood and metal decks without concrete fills may not be modeled as rigid diaphragms unless the floor system is braced properly. Hence, the use of these options in STAAD.pro requires good engineering decision making based upon the actual site conditions.

 

Video Download Link

Design of Water Tank Structure using RCDC, STAAD Advanced Concrete Design

Design of Water Tank Structure using RCDC, STAAD Advanced Concrete Design

 

Water tank design in RCDC can now be done using British Standard and European Standard code. The walls and slabs of the water tank must be modelled as parametric model in STAAD.Pro and analyzed using finite element modelling.

Create the water tank model and transfer it to RCDC after analyzing in STAAD.Pro to generate the detailed calculation, drawing and detailing.

Design of Water Tank Structure – This video covers entire workflow of designing the Water Tank Structure with in #RCDC #SACD — STAAD Advanced Concrete Design. It gives insights of the Design of different Structural Elements like Tank Walls, Tank Slabs, Column-Beam arrangement as part of the Water Tank structure.

Also, discussion is done about various Design and Detailing options / settings available and how it can be used to meet your requirements.

All you should Know about Surveying and Its Classifications

All you should Know about Surveying and Its Classification

 

Here is everything you need to know about surveying and its different classifications.

Surveying is a fundamental element of civil engineering since it is the initial stage in initiating a new civil engineering project.
A student must master the fundamentals of surveying in order to fully understand the procedures.
To begin learning surveying, one must first understand what surveying is and why it is important.

So first of all :

What is surveying ?

Surveying is simply the process of using direct or indirect measurements to determine the relative positions of various features on, above, or beneath the earth’s surface, and then putting them on a sheet of paper known as a plan or map.

Surveying skills are helpful in various of engineering processes. Any engineering project necessitates the use of surveying.
Below are some of the most important aspects of surveying.

You’re just about to know why surveying is that important , keep reading :

Why is it important ?

The first phase in surveying is to draw out a plan and a portion of the region that will be surveyed.
Based on the nature of the project, the best potential alignment, quantity of earthwork, and other relevant information can be computed using these prepared maps and sections.

Surveying measurements are used in the planning and design of all Civil Engineering projects, including railways, highways, tunneling, irrigation, dams, reservoirs, waterworks, sewage works, airfields, ports, enormous structures, and so on.

So, to conclude, any project of any size is built along the lines and points specified by surveying during its implementation as an initiation to its success and full achievement in the best possible ways.

 

Surveying most common classifications:

 

In order to get more in depth with surveying, you need to know that its most common classifications are:

  • Plane surveying
  • Geodetic surveying.

Let’s start with the first one :

Plane surveying :

Plane surveying refers to surveying in which the earth’s mean surface is treated as a plane and the spheroidal shape is ignored.
Plane triangles include all triangles created by survey lines. All plumb lines are parallel and the level line is deemed straight.
We are only concerned with a small portion of the earth’s surface in everyday life, and the above assumptions appear reasonable in light of the fact that the length of an arc 12 kilometers long lying on the earth’s surface is only 1cm greater than the subtended chord, and that the difference between the sum of the angles in a plane triangle and the sum of those in a spherical triangle is only one degree.

And that was all you need to know about plane surveying for now.
Now, let’s jump into the second type of surveying which is « the geodetic surveying ».

Geodetic surveying :

 

Geodetic surveying the second method of surveying that takes into consideration the shape
of the earth.
The lines on the surface are all curved, and the triangles are all spherical.
As a result, spherical trigonometry is required to be able to master the different phases of
this kind of surveying.
All geodetic surveys entail labor at a bigger scale and with a high level of precision.
We can say that the goal of a geodetic survey is to identify the precise location on the earth’s surface of a set of widely separated sites that serve as control stations for less precise surveys.

To conclude, there are two types of surveying : the plane surveying and the geodetic one.
As a matter a fact, it’s up to the civil engineer to choose the best type based on each project he’s asked to accomplish.

The question now is :

Are there other ways to classify surveying ?

The answer is a massive YES and you’re about to discover some other ways of classifying surveying.

 

Classification based on nature of field:

There are three categories of surveying that are classified depending on the nature of the field:

  • Land surveying : which is divided into three categories: topographical survey, cadastral survey, and city survey.
    It is concerned with natural and man-made characteristics on land such as rivers, streams, lakes, wood, hills, highways, trains, canals, towns, water supply systems, buildings and properties, and so on.
  • Marine surveying : This classification of surveying is also known under the name of hydrographic surveying, is simply the species and elements related to the water for the purposes of navigation, water supply, harbor construction, and mean sea level determination.
    Measurement of stream discharge, topographic survey of coasts and banks, taking and locating soundings to establish water depth, and recording ocean tidal fluctuations are actually all part of the job we’re talking about.
  • Astronomical Surveying: This type of surveying allows a surveyor to determine the absolute location of any point on the earth’s surface, as well as the absolute location and direction of any line.
    This entails making observations of celestial bodies like the sun or any fixed star. (this one is quite interesting).

 

Classification based on instruments used :

Surveying can be split into six groups based on the different types of instruments employed :

  • Surveying in a chain
  • Surveying using a compass
  • Surveying on a plane table
  • Surveying using a theodolite
  • Tacheometric surveying is a method of measuring the distance between two points.
  • Surveying using photographs

Methods used for classification: Or in other words, classification based on the method used .
Surveying can be classified into the following categories based on the methodologies used:

 

  • Surveying via triangulation
  • Surveying in a straight line

And … the last surveying classification , and my favorite one is :
Object-based classification:
There are four different forms of surveying based on the object:

  • Surveying of the Earth
  • Surveying of Mines
  • Surveying archaeology
  • Military reconnaissance
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