Rules-of-Thumb are often dismissed as the lazy man’s route to design, but it’s worth remembering that in ancient times, structures were built according to form and proportion, the builders knew and understood the relationships between span and depth, together with height and cross-sectional area, and this understanding enabled them to build structures, which were not […]
Welded beam splices come in many forms, but generally, as mentioned earlier, unless there are compelling reasons otherwise, they are usually considered to be ‘shop’ welded. The welded joint usually has to develop the full strength of the beam or girder which means that the welds (of at least the flanges) must be prepared, full
Welded Beam Splice Read Article »
Sometimes it’s necessary to join together two beams in order to extend its length, this may be necessary when the required beam length exceeds that which is commercially available, or for reasons of transportation and/or erection issues. Beam splices typically resist large Bending Moments and shear forces and it is typically assumed that the flange
Bolted Beam Splices Read Article »
There are two welding symbols in common use – American Welding Society (AWS) which until 1992 was the general standard – then ISO presented ISO 2553 which has largely been adopted by the EU and affiliate countries. The Basic ISO Welding Symbol The basic weld symbol comprises of: The full reference line The dashed reference
ISO Weld Symbols Read Article »
Fillet welds, as a rule do not require any special end preparation, whereas with groove welds it is generally necessary to prepare the edges of the joints to be joined so as to provide space for the weld metal to be deposited during welding. The depth of preparation depends on the loading on the joint
Weld Preparations Read Article »
Most steel detailers are already familiar with AutoCAD or BricsCAD, which reduces training investment. Structural steel objects can be modified through the standard commands or using the Object Property Manager, all Parabuild objects are integrated as if they are native AutoCAD/BricsCAD objects. For those not familiar with these platforms, we offer some links to Learning
Learning Resources Read Article »
Butt Welds with Basic Symbols Note! See Weld Preparation Details Tee Welds with Basic Symbols Other Welds with Basic Symbols Supplementary Weld Symbols
Butt, Tee and Other Welds with Basic Weld Symbols Read Article »
One should keep in mind the distinction between ‘Joint’ and ‘Weld’ types, the former describes the configuration of the steel parts relative to each other, while the latter refers to the type of weld employed to hold the parts together. Joint Types There are 5 basic joint types, they include: Butt, Tee, Corner, Lap, and
Weld and Joint Types Read Article »
BricsCAD may have started out as an AutoCAD work-alike long ago, but in recent years it has grown to become a very capable CAD platform in its own right. It has many unique features that set it apart from the rest while still staying fully DWG compatible. With Bricsys, the company that develops BricsCAD, acquired
Learning BricsCAD Read Article »
AutoCAD is a very popular and versatile CAD application that is used by most drafting offices worldwide. However there are too many parts in a typical steel structure, and too many drawings to be made to make it an efficient solution for steel detailing by itself. Parabuild can run inside AutoCAD, it helps to automate
Learning AutoCAD Read Article »
Due to visual input, high degree of automation, instant feedback and intuitive design Parabuild needs only a short training period so the steel detailer can become productive quickly. Our experience is that 2 full days of training is sufficient for learning Parabuild if you are familiar with AutoCAD or BricsCAD. Those experienced with 3D CAD
Learning Parabuild Read Article »
General Settings Before beginning with the creation of the structural model you should address the Settings – These cover 3 main areas: Global – Where you can preset global standards and settings – these settings will override all AutoCAD and BricsCAD settings The bottom buttons allow you to edit the various libraries and filters, and clash control settings 3D Model – These settings will determine
Parabuild General Settings Read Article »
Under this heading, we’ll look at how Parabuild automatically generates Workshop Drawings, these include: General Arrangement Drawings Detail and Assembly Drawings at the single click of a button.
Prepare Workshop Drawings with Parabuild Read Article »
About BIM The key idea behind BIM (Building Information Modelling) is to have all information related to a facility organized in one application-independent model. Ideally, this model is started at concept stage and expanded during each phase of construction and operation of the facility. While BIM is centred around a 3D model, it is not
BIM (Building Information Modelling) with Parabuild Read Article »
A Bill of Materials is a comprehensive list of parts, items and assemblies – each item should be identified with its item/part number, length, weight, materials and quantities, plus any special considerations such as surface treatment, corrosion protection etc… All this to be done to conform with the General Arrangement and Detail + Assembly Drawings.
Generate Bills of Material with Parabuild Read Article »
An NC file is a data file containing numerical control instructions for directing a CNC machine tool for automated drilling, marking and cutting. Parabuild can create NC files in DXF or DSTV formats. DXF Files DXF files are meant for plate table machines (laser, plasma, jet) that only have 2D capacity. These DXF files can
Generate CNC NC Files with Parabuild Read Article »
As with General Arrangement Drawings, Parabuild generates workshop detail and assembly drawings directly from the 3D model Complete with dimensions and tags. All generated detail drawings are stored in the DWG format, the most common and widely used format for 2D drawings. You can choose to keep the shop drawings in the same drawing as
Prepare Workshop Detail and Assembly Drawings with Parabuild Read Article »
General arrangement drawings (GA’s) present the overall composition of a structure such as a floor plan, elevation. or section through the building, depending on its complexity this may require a number of different drawings. Enlarged views or details may also be required to provide additional detailed information such as specific complex connections or assemblies. As a minimum, they
Preparing General Arrangement Drawings with Parabuild Read Article »
The model is not just a pretty picture, it is in fact a digital representation of the completed structure and contains all the information necessary to fabricate, erect, plan and execute the entire project. This information includes all the mathematical and property data relating to the section profiles used, including all connections and their individual
3D Modelling with Parabuild Read Article »
Fillet Welds Fillet welds are usually applied when welding Tee joints where the plates are located at between 60 and 120 degrees to each other, 90 degrees being the most common. A Fillet weld is created when the weld forms a fillet between the faces of the adjoining parts, known as the fusion faces. The
Electric arc welding as applied to structural steel fabrication is almost invariably carried out by one of the following processes: Manual Metal Arc Where the electrode is hand-held and manually fed into the weld pool. No shielding gas is used, but a flux is incorporated as a coating to the electrode. This is one of
Welding Processes Read Article »
Best Practice could be defined as saying “This is the way it should be done” it’s not taught at university or technical college, it’s poorly documented, it’s not officially sanctioned, and yet, it’s recognized by all those in the steel construction industry. These principles go back to time when structural detailers were recruited into apprenticeship
Best Practice – in a Nutshell Read Article »
The steel detailer has a critical role to lay in the steel construction industry. It is he or she that has the responsibility to accurately interpret the design intent, and from that, prepare a full set of detail documents enabling the fabricator to fabricate and the erector to erect the completed structure. The design intent
The Structural Detailer – Role and Responsibility Read Article »
About BIM The key idea behind BIM (Building Information Modeling) is to have all information related to a facility organized in one application-independent model. Ideally, this model is started at concept stage and expanded during each phase of construction and operation of the facility. While BIM is centered around a 3D model, it is not
Building Information Modelling (BIM) Read Article »
Straight-Cut Connection to a Steel Floor Top connections require a little more thought. If an accident happens on a stairway, it’s likely to be at the top during a descent. It’s important that the principle of ‘goings’ and ‘risers’ is observed here, particularly with regards to the top step. The approach to the stair should
Stairways – Top Connection to a Steel Floor Read Article »
Connecting to a Concrete Floor – Straight-Cut Connection Using the straight cut connection can present the same problems as with connecting to a steel floor. The Foot-Fall may be limited and, depending on the thickness of the concrete, the last stair tread may impede the concrete. Then there’s also the problem of the concrete itself
Stairways – Top Connection to Concrete Floor Read Article »
Connecting to a Steel Floor – Bottom Seating-Connection Stairways connecting to steel floors are commonly found in emergency fire escapes and industrial environments where they would provide access between floors, and to and from platforms and walkways. The specific application will determine the most suitable connection type, of which there are 2 principal options: The
Stairways – Base Connections to a Steel Floor Read Article »
Probably the easiest way to connect a stair to a concrete floor is to sit it on top and fasten it directly to the concrete. The limiting factor here is that the concrete floor must be in place before the stair can be installed. This generally doesn’t present a problem if the stair is to
Stairways – Base Connections to a Composite Concrete Floor Read Article »
Connecting to a Concrete Floor – Direct-Fixing When connecting to a ground floor, which in most instances would represent the first flight, the stair may be connected directly to the floor. The connection should be somewhat flexible using an adjustable bolted cleat with vertical slotted holes to make up any difference in elevations, the cleat
Stairways – Base Connections to a Concrete Floor Read Article »
Stair treads are usually a bought-out item, though some fabrication workshops make their own, it’s generally not cost effective. There are numerous suppliers whose products conform to the necessary codes and specifications which means they can be used with confidence. The key dimensions for stair treads include – the tread depth (a) / side-plate depth
Stairways – Stair Treads and Risers Read Article »
The tube, as opposed to the core moves the lateral load resisting system to the perimeter of the steel structure rendering the internal structure secondary thus maximizing the lateral stiffness of the structure while maximizing the available floor space. The construction of tube structures will differ from that of core structures in that the steel
Braced and Framed Tubes Read Article »
The internal core comprises of a stiff rigid frame which may be either braced or framed, this core is effectively a vertical cantilever truss, anchored at the base by means of the foundation. The outer, or perimeter structure may be straightforward beam to column connections without the need for moment resisting connections. The outer columns
Internal Core Stabilizing Systems Read Article »
In expanding large cities where ground space is at a premium the only real option is to build up and with the need to cater to the requirements of ever expanding populations buildings are getting taller and taller. Tall buildings, particularly those in already built-up areas present a whole new range of difficulties for the
High-Rise Buildings Read Article »
A badly designed stairway is an accident waiting to happen; too often designers do not pay sufficient attention to the geometry that can make a stair access comfortable and safe or perilous and downright dangerous. The geometry of public access stairways and fire escapes are usually determined by regional codes and regulations, but even then,
Stairways – Introduction Read Article »
Columns are stiffened mainly to improve their resistance to bending moments and are often used in conjunction with Moment Connections. Careful selection of the columns and beams will often negate the need for strengthening of the connections, however, there will always be cases where it’s deemed necessary. The method of strengthening is determined by the
Column Stiffening Read Article »
Flexible Beam-To-Beam Connections Just about every beam-to-beam connection will fall into this category and there are a number to choose from. The engineer will rarely dictate which connection type to use, preferring instead to leave it up to the fabricator and his right-hand-man – the detailer. To assist the detailer in analyzing the pro’s and
Flexible Connection-Types Read Article »
Today it’s very rare for the engineer to design each and every flexible connection, often he or she will not even select a connection type, preferring instead to leave it up to the fabricator to select such connections best suited to preference provided they meet the design requirements. The fabricator will often delegate the selection
Connection Selection Read Article »
Shared Bolts One factor to be considered with shared bolts is the thought that must be applied to the site-erection of the beams, where both beams must be held in position until at least some of the bolts have been installed. In most cases, especially with smaller beams this can be accomplished with a skilled
Shared Bolts and Interferences Read Article »
Fin-Plates with a Single Row of Bolts Fin-Plates with a Double Row of Bolts Tables Note that the values given for the number of vertical pitches of the bolt rows in Table 3 – should really only be used for estimating purposes. There are numerous variables affecting these values including bolt diameters, and of course
Standard Fin-Plate Connections Read Article »
Welded Fin-Plates, like End-Plates are cut from Plates or standard ‘Flats’ which are then drilled or punched to the required bolt pattern and shop-welded to the web of the supporting beam. The connecting beam web is match-drilled in the workshop to suit. Fin-Plates are not strictly flexible in the vertical plane, and as a consequence
Welded Fin Plates Read Article »
End Plates are probably the most versatile of all the flexible Connection types in that the may be used to connect beam-to-beam and bean to columns, both to the flange and web. They can also be used for skew connections at any angle. End-Plates are cut from Plate or ‘Flats’ which are drilled or punched
Welded End Plates Read Article »
Here we’ll look at standardizing cleats following on from what has been discussed under Bolted End-Cleats. It’s not an accident that the proposed standards align with Welded End-Plates. Though interchangeability is not really recommended, it does have advantages with regards to general Standardization. The standard cleats proposed below all assume a Standard Gauge – however,
Standard Cleats Read Article »
End Cleats are usually used to connect beam-to-beam – they may also be used for beam-to-column connections but there are limitations, which we’ll look at later in this article Cleats are usually fabricated from standard hot-rolled angle sections and may be configured either as ‘Single’ or ‘Double’. Single cleats offer many practical advantages, the most
Bolted End-Cleats Read Article »
The Welded-Tee connection is the most expensive to fabricate of all the connection types, they typically comprise of a flange and web-plate formed into a Tee, which is then welded to the top-flange and web of the supporting beam. The Tee may also be fabricated from a Tee-Cutting of a standard rolled section, usually matching
Welded Tee Connections Read Article »
There are basically 3- types of seating connections in common use, they include: The conventional Beam to Column Seating seat, where the beam is fastened perpendicular to the column. The Corbel, where the beam is fastened parallel to the column. The beam-to-beam crossover, where one beam sits at an angle on top of another. The
Seating Connections Read Article »
Beam-end clearances are necessary to to provide adequate assembly and erection tolerances. They take into account rolling mill and fabrication tolerances. The diagram below indicates the suggested clearance for flexible connections, including: Welded End-Plates Bolted End-Cleats Welded Fin-Plates, and Seating Connections When there are a string of beams erected along a single line, there is
Beam-End Clearances Read Article »
A beam-end notch will be necessary when connecting a beam directly to the web of the supporting beam – the connection itself may be any of the bolted connections including: an end-plate, fin-plate or a bolted cleat. Welded beam-to-beam connections will also need to be notched, but the method will be different from that of
Beam-End Notches (Copes) Read Article »
Standardization is the key to successful, efficient and economic detailing, the benefits of which are incalculable. It will reduce errors in the workshop and on site during erection and speed up the entire process from concept to commissioning. There are two main steps to standardization, the first may be outside of the realm of the
Standardization Read Article »
Anchor Bolts range from those required for normal fixing of concentrically loaded columns to those subject to uplift, shear and moment forces. The standard diameters suitable for use are M20, M24 and M30. These sizes match standard nuts while for bolts M36, M48, M56, M64 and M72 – round bars of the next larger standard
Columns are essentially compression members, but they may be required to resist lateral forces caused by wind and seismic activity. Additionally, they may be required to resist bending, especially in suspension structures where they act as ‘towers’ or ‘masts’ providing support for tension members. Bending may also be the result of eccentricity of the end-reaction
Columns – Introduction Read Article »
