Design of Long Span Steel Structures and Hangars [With Eave Bracing Concept]

Pre-engineered building (PEB)
Amit Bharana, President, ERA BUILDSYS Ltd.

The majority of industrial buildings are made out of steel for obvious reasons of high strength/weight ratio. A study, on the Efficient Design of Large span hangars/structures, ensuring lighter foundations is presented.

Introduction

Structure with Span larger than 40 m can be regarded as long span structures and need to be carefully designed keeping a balance of all the aspects like its weight, deflections (sway) and foundation forces. There are many combinations of designing large spans, like conventional truss & RCC column combination, truss & steel columns, Pre-engineered building (PEB) etc.

Design of Long Span Steel Structures and Hangars

These days with the concept of PEB, the major advantage we get is the use of high strength steel plates (usually Fe 350), lighter but high strength cold form purlins, and 550 Mpa Galvalume profiled sheets. The use of PEB not only reduces the weight of the structure because high tensile steel grades are used but also ensures quality control of the structure. In the following study, we have designed a hangar using this modern concept of PEB.

Design Philosphy

The design under discussion is a 42 meter clear span hangar for aircrafts maintenance. We have designed this Hangar in 3D on STAAD software, for proper simulation of the load distribution uniformly in three co-ordinates system i.e. X, Y and Z. All the Basic loads i.e. Dead, Live, Wind, Temperature, seismic etc have been taken into consideration for designing of the frames. The structure has been designed under enclosed as well as open condition for application of wind loads, because of the opening & closing of the large sized Hangar Door.

Design of Long Span Steel Structures and Hangars

The basic philosophy of rigid frame design is by adopting 'FIXED' or 'PINNED' column base conditions. A fixed column base is always a sturdy frame and helps in controlling allowable deflection (side sway) in the frames. Steel designers always prefer fixed base to pinned base frames. On the contrary, for foundation designers the design of foundations becomes a nightmare particularly in large span buildings. In fixed base design, the frame is rigid, but transfers heavy moments to the foundations. On weak soil, designing foundations becomes tedious task. Likewise for pinned support, the frame does not transfer any moment to the foundation and only vertical & horizontal reactions affect the design of foundation. It looks simple but in case of large spans, controlling deflections of frame in pinned base condition is a challenging task.

Design of Long Span Steel Structures and Hangars

To control this deflection, the simplest way is to increase the Geometrical properties/sectional sizes of frame, but it is not advisable as it adds to the tonnage of the whole building, adding not only to the seismic forces but also adding to the cost subsequently. We need a solution wherein the sway of the frame can be controlled and the section sizes are also not increased.

The best way we could find is to 'BRACE' the frame to control the excess deflection. In the present case we have provided bracing at eave level (braced eave) on both sides of the structure along the length for this purpose. Span of this Eave bracing is taken approximately L / 10 of each side. We can observe in the following example that eave bracing is of a great help in controlling Horizontal deflections and leading to lighter foundation design.
This is a premium article available exclusively for our subscribers.
If you are already a subscriber, please Login
If not, subscribe now and get access to well researched articles & reports on infrastructure construction, equipment & machinery, innovations & technology, project reports, case studies, and more. All this by simply paying just ₹200/- for a month of complete portal access, or a discounted rate of ₹1000/- for a full year of access.
NBM&CW January 2011
Cold Form Steel Building: A Sustainable Development

Cold Form Steel Building: A Sustainable Development

Cold form steel is a dry construction system that reduces the risk of moisture problems and sick building syndrome; every material used can be recycled, and there is less energy consumption during production, ultimately leading to reduced

Read more ...

Reuse of Structural Steel Yields Significant Environmental Savings

Reuse of Structural Steel Yields Significant Environmental Savings

Reusing structural steel yields significant environmental savings compared to recycling; in fact, structural steel is seen as an obvious candidate for reclamation and reuse as opposed to the current, common practice of recycling by remelting.

Read more ...

Use Of Steel In Construction of Buildings & Infrastructure

Use Of Steel In Construction of Buildings & Infrastructure

Use of steel in construction accounts for about 65% of the overall consumption of steel in India. It, therefore, plays a major role in the fast growing construction industry of India, which is slated to reach $1.4 trillion

Read more ...

Skeleton: Consultant at Accommodation Facility for MES in New Delhi

Skeleton: Consultant at Accommodation Facility for MES in New Delhi

Skeleton Consultants successfully tackled a unique project – accommodation facility for MES, Shankar Vihar, New Delhi – involving three Y-shaped, G+3 prefabricated buildings.

Read more ...

INSDAG: Creating Sustainable Rural Housing in Steel

INSDAG: Creating Sustainable Rural Housing in Steel

In view of the need for Sustainable Rural Structures in India, INSDAG has developed different modules of rural buildings which are mainly steel intensive and have the benefits of being robust, functional, comfortable, low-maintenance

Read more ...

AM/NS India promotes steel for construction equipment

AM/NS India promotes steel for construction equipment

Specialized steel producer ArcelorMittal Nippon Steel India (AM/NS India) is keen to increase its foothold in the infra construction sector which has led to a growing demand for construction equipment and pre-engineered buildings systems.

Read more ...

Tubular Construction Revolutionizing Construction Industry

Tubular Construction Revolutionizing Construction Industry

Tubular construction is a structure-building technology in which parts are fabricated off-site and brought to the construction site for final assembly. The tubular steel structures are strong, long-lasting, and, most importantly, customizable. Because

Read more ...

APL Apollo's ready-to-build 500 x 500 mm box section A revolution in PEB structures

APL Apollo's ready-to-build 500 x 500 mm box section A revolution in PEB structures

Tubular Construction is one of the latest technologies and is growing rapidly. APL Apollo is the first company in India to produce ready square box sections of 500x500mm and 20mm thickness, which make tubular construction faster, better, and more

Read more ...

Composite Construction in Pre-Engineered Buildings

Composite Construction in Pre-Engineered Buildings

Dr. Padmaja Gokaraju, AVP- Designs, Kirby Building Systems and Structures shares insights on the evolution of Pre-Engineered Buildings, their design concepts, materials, section profiles, manufacturing, erection methods, and code provisions.

Read more ...

Pre-Engineered Steel Buildings

Pre-Engineered Steel Buildings

PV Rao, Director, Pennar Industries, Hyderabad, elaborates on the concept of Pre‐Engineered Steel Buildings and their advantages over conventional buildings. The pre-engineered building technology, which entered the Indian construction

Read more ...

Everest Industries Executes PEB Project for Godrej Agrovet

Everest Industries Executes PEB Project for Godrej Agrovet

Everest industries delivers a very complex 34.8m high G+6 multi-storey processing plant for Godrej Agrovet under difficult site conditions and with full safety compliance. Godrej Agrovet Ltd is among the largest oil palm producers

Read more ...

Dr. Fixit introduces revolutionary building envelope solutions for roofs & walls

Dr. Fixit introduces revolutionary building envelope solutions for roofs & walls

The building envelope refers to the external walls, windows, roof and floor. A building's envelope, especially roofs and walls, contribute to as much as 28% and 45% of the energy loss in buildings. Good thermal insulation for

Read more ...

Importance of Cold-Formed Steel in Seismic-Resistant Design of Structures

Importance of Cold-Formed Steel in Seismic-Resistant Design of Structures

Cold Formed Steel is a product made by rolling steel or pressing steel in to semi-finished or finished goods at relatively low temperatures. Manufacturing of Cold Formed Steel (CFS) occurs at room temperature.

Read more ...

Fire Resistance of Steel Structures

Fire Resistance of Steel Structures

Structural steel frames are widely used in virtually all types of buildings and industrial installations. Fire-resistant design of structural steel framing is often required, depending on the fire risks

Read more ...

Roof Insulation

Study on Temperature and Heat Flow Reduction Through Insulated Industrial Roof Building

The paper presents a case study to investigate the delay, causes and its implications on the management & development of a steel plant project. Delay and cost overruns are common in construction projects and

Read more ...

Underdeck insulation

Underdeck insulation – heat reducing technique in industrial process or plant

Underdeck insulation in an industrial process or plant is often neglected but is one of the most important techniques to reduce the heat inflow. Underdeck insulation ensures low consumption of energy

Read more ...

Atul Khanna General Manager Thermal Insulation Division The Supreme Industries Ltd

Supreme Industries' Thermal Insulation Division offers cutting edge technology

Founded in 1942, Supreme Industries Ltd. pioneered path-breaking plastics products by offering advanced solutions for various industries. Atul Khanna, General Manager, Thermal Insulation Division

Read more ...

Progress Group Furnishes Complete Solution for New Bending Shop in Singapore

Progress Group Furnishes Complete Solution for New Bending Shop in Singapore

Consisting of five different plants and machines, SC Ferrotech’s new rebar shop will enable the company to supply mesh, stirrups, rebars and reinforcing cages to all projects of its parent company, Straits

Read more ...

Reflective Insulation

Reflective Insulation

The radiant heat is invisible and has no temperature, just energy. When this energy strikes another surface, it is absorbed and increases the temperature of that surface. In summer, radiation from the Sun

Read more ...

To get latest updates on whatsapp, Save +91 93545 87773 and send us a 'Saved' message
Click Here to Subscribe to Our eNewsletter.