What is Structural Design Engineering?
The principles behind structural engineering have been around since the beginning of time. These principles are essential in understanding how bridges form, buildings stand up, and skyscrapers stay upright. It mainly involves the use of physical and mathematical laws combined with material science to analyse and design building elements that can resist loads and stresses without failing. In simple words, every building and structure has a skeleton that needs to be strong enough to withstand physical forces and loads throughout its design life. Structural engineering is a set of methods and principles to ensure that all loads are safely transferred from the topmost section of the structure to the lowest part of the building, which is the foundation and the soil.
What is the aim of structural design engineering, and why is it important?
Structural engineering is important because it’s a big part of the building process. It deals with everything from how big the footing needs to be to how the structure will hold up in strong winds. Designing structures is a complicated process, which can be difficult to understand for people who are not in the industry. When you design a structure like a building or a bridge, you need to balance many factors like cost, functionality and ease of use. However, the health and safety of the public is the top priority of any structural engineering project. It’s not only a legal requirement but also an ethical one. There are many structures and buildings around us that we use daily. Houses, hospitals, offices, warehouses, and bridges are all intended for human use and should be designed using structural engineering principles. When it comes to buildings and infrastructure, it is vital to make certain that they will not collapse or impose a risk to public health and safety, even during catastrophic events such as earthquakes.
What do Structural Engineers do?
Every structure and building is exposed to certain conditions and loads throughout its life. For example, a residential house in a bushfire prone area must have structural frames with appropriate fire ratings, or a high-rise building in Melbourne city must be able to withstand strong winds and earthquakes. Structural engineers have to anticipate the loads that are being placed on a structure and design it so that it can resist them. Engineers use their technical and analytical skills to determine all the forces that can affect the structure’s performance during its lifetime. They will then design the structure with suitable materials and building elements to guarantee the structure’s safety and stability.
In many ways, structural engineers are the unsung heroes of construction. They are mainly problem solvers. Every design project has its own set of challenges and complications that the design engineer must thoroughly think about and skilfully consider. These challenges present themselves either during the design phase or, at the construction phase or after completion. During this process, a structural engineer needs to be very alert and should be able to follow any change in the design in a short time. Only an experienced structural design engineer can foresee most of the complications that can arise during the construction phase and proactively provide a practical solution for them during the design phase. In other words, the more experienced the structural engineer is, the less hassle and problems builders will have during the construction. This can have a massive positive impact on the overall cost of a project and delivery time. Not to mention that the building owners will experience fewer issues with the structure throughout its service life.
It is not just new buildings that require careful design and engineering; older structures, especially those showing signs of damage or aging, also need the expertise of a structural engineer. In these cases, forensic structural engineers are the ones who play a crucial role in identifying damage to older buildings, whether caused by disasters, wear and tear, or neglect. They have the necessary skills to assess a building’s structural integrity and determine if they can restore the building and how.
What is the difference between a Structural Engineer and a Civil Engineer?
The difference between a structural engineer and a civil engineer can be a bit of a blur sometimes. There are several similarities, of course, but some key areas differentiate the two professions. Structural engineering is a sub-discipline of civil engineering. It deals with the design, analysis and performance of structures to give them strength, stability and serviceability. Structural engineers are responsible for the structural integrity of all structures around us. On the other hand, civil engineers tend to work on major infrastructure projects, such as bridges, dams, highways, rail systems, and other structures used for transportation and public works. They also design water, sewer, and drainage systems on both small and large scales.
Civil engineering is a broad field that encompasses many different types of engineering disciplines:
Structural Engineering
Structural engineering deals with designing and analysing structures to resist forces and deformations. Structural engineers study the behaviour of materials under stress and how structures can be designed to support various loads.
Water Resources and Hydraulics Engineering
Water resources engineering deals with the management of water supplies essential to everyday life, including the supply of water for drinking and sanitation, industry, agriculture, recreation, and other uses.
Geotechnical Engineering
Geotechnical engineering is the science of studying soil and rock properties that determine the loads, deformations, and stability of the foundations and sub-surface materials. The field deals with the physical properties of materials on the earth’s surface.
Environmental Engineering
Environmental engineering is a field that focuses on the design, construction, and operation of engineered systems to protect the environment while meeting human needs.
Transportation Engineering
Transportation engineering is the study of how to get things from one place to another. This includes how to move goods safely and efficiently. Transportation engineers design a variety of transportation systems, including airports, public transportation, and roadways.
Municipal and Urban Engineering
Municipal and urban engineering is the process of designing, planning, building, and maintaining cities as well as the infrastructure that supports them. Municipal engineers design public works projects such as roads, bridges, airports, and railroads.
Coastal Engineering
Coastal Engineering is the science of designing and managing human-made structures on the coast, such as harbours, ports, marinas, and lighthouses.
Materials Engineering
Materials engineering is the study of the various materials that make up everyday objects. Engineers in this field can apply their knowledge of thermodynamics, strength, and other physical properties to create new materials for various applications.
Construction Engineering and Management
Construction engineering is the science of designing, planning, and coordinating a construction project. It is concerned with all stages of planning, design, building, inspection, and management.
Forensic Structural Engineering
Forensic structural engineering is a specialised field that involves the investigation of structures that have failed or do not perform as intended. It aims to determine the causes of failure or poor performance, which can include design flaws, material failures, or unforeseen stresses. This discipline helps to improve the safety and reliability of structures by applying lessons learned from past failures to future projects.
What is the difference between a Structural Engineer and an Architect?
There is a lot of confusion when it comes to the difference between a structural engineer and an architect. The key difference between these two industries is that the structural engineer designs buildings from a safety and serviceability point of view, while the architect creates a vision for the structure. Architects design buildings from an aesthetic point of view, focusing on the layout of different rooms, accessibility, locations of windows for optimum light and view, outdoor spaces such as balconies, and the building’s look from both inside and out. Architects ensure that the building is comfortable, inviting, and, most importantly, easy to use for its intended purpose.
Structural Engineers, on the other hand, work closely with architects to turn their visions into reality while ensuring that the building will stand the test of time. They calculate all the loads that the structure is expected to support, given the architect’s layout of the building. They will then design the footings, beams, columns, and the entire structural system to hold up the building. Structural engineers ensure that the building does not shake when it is windy, or the roof does not fall when it snows.
Do I need an architect or structural engineer?
If you are building a new home or making an alteration and addition to the existing one, you will need both. The architect will help you with the design of your new house and will also be able to make changes to the plan if necessary. A tasteful architect will carefully listen to your ideas and needs and incorporate them into the design with style whilst considering your budget. However, the dream will not come true without the skills of a structural engineer. You will need to engage an experienced structural engineer to provide a logical structural foundation for your architectural design. The structural engineer will make sure that your dream house is safe to use, and you will enjoy it throughout its service life without encountering significant structural problems.
What is the structural engineering design process?
Structural design is the backbone of any building, ranging from a simple house to a world-class museum. There are many types of structures, but the design process of all structures is somewhat the same. Here, we will tackle the basics of structural design in an easy-to-understand format, providing an overview of the process and how structural engineers can provide solutions for different building types:
Architectural Plan and Design
Before a construction project can get off the ground, all parties involved must have a good understanding of what to build, how to build it, and what is expected of the final product. This starts with a detailed architectural layout and plan. Architects are responsible for setting the function and layout of the structure and building. An excellent architectural plan will include the building’s size, location of every room, parking, stairwells, entrances, wiring, fire protection, and other details.
Geology and Soil Test
The next step is to test the soil on which the building and structure will be built. It is essential to determine whether or not the soil is stable enough to build on and if there are any underlying problems. A geotechnical investigation is a process of obtaining information about the soil’s physical and mechanical properties, such as soil characteristics, water content, and rock types. Some key points that the engineer needs to know before starting to design are:
- Existing layers of the soil on-site and the depth of each layer. There are four main classifications of soil: sandy soil, Clay soil, Silty soil, and loam. Geotechnical engineers identify the soil types by drilling boreholes at each given site. Depending on the size of the site, the number of required boreholes can vary. Geotechnical engineers are responsible for analysing the site’s geology and then deciding how many boreholes should be drilled and at what locations. It is crucial to get the data right. It is recommended for residential sites to have a minimum of 3 boreholes taken from different locations across the site.
- Soil Reactivity. Different soil types have different levels of clay, sand, and silt in them. The amount of these minerals in the soil determines how they behave when they absorb or lose water. The more clayey the soil, the more reactive it is, and hence, the expected level of ground movement is high. The engineer needs to be confident that the site has been correctly classified to design a foundation that will perform satisfactorily even when subjected to substantial movements of the underlying reactive soil. For more information, read our blog on soil reactivity.
- Soil bearing capacity. In simple words, soil bearing capacity refers to the maximum weight that the soil can support before it starts to break down. If the ground is too soft, the foundation may sink or not be able to support the weight of the structure. This information is of the utmost importance to the structural engineer. Structural engineers need to learn about the soil’s bearing capacity to design and build structures that will not collapse or topple over. Read a case study about a footing failure caused by inadequate soil bearing capacity.
- Presence of any adverse site factors: The site’s condition can significantly be affected by adverse site factors such as trees and high groundwater table. The geotechnical investigation should highlight these factors for the structural engineer to consider and account for them in the foundation’s design.
Structural Design
The structural design preparation begins once the architectural drawings have been finalised, and the soil report is completed. Structural design typically includes plans for the foundation and basement, beams, columns, trusses, and other support structures. There are five main steps to structural designing:
- Conceptual design: Firstly, the structural engineer decides on the locations and orientations of beams and columns throughout the building to match the architectural layout. This is done either by hand sketching or computer modeling, depending on the complexity of the design.
- Load calculations: Structural engineers like to use loads to evaluate how much a structure can bear. Loads are stresses that a structure will be exposed to, and the calculation of these stresses requires knowledge of the structure’s shape and stiffness. The engineer will calculate the loads that must be applied to each element of the structure. These loads are specified in design codes and standards and are based on the structure’s type and occupancy. For example, the load considerations for a residential building are different from those of a commercial project. The four main load categories are dead load, live load, wind load, and earthquake loads.
- Framing system: The framing system is comprised of a footing type, posts, beams, joists, and roof type to form a structure. The framing system is one of the most critical parts of the structural design. It plays a key role in determining the sizes and types of the structural elements to provide overall safety of the structure. Also, it will determine how much material will be needed for the building. In this stage, the engineer, with the help of the geotechnical investigation’s information, decides on the type of footings for the structure. The footing is the largest, most important, and heaviest part of a building. It has to be strong enough to support the weight of the entire building. There are different types of footings such as waffle slab, stiffened raft slab, strip and stumps, and deep bored piers. Furthermore, based on the load calculation results, the engineer chooses the proper materials for the beams and columns. The selected materials should be strong and stiff enough to transfer the loads to the footings safely. The most common building materials in today’s construction are concrete, steel, and timber.
- Structural modelling: Structural modelling is a powerful tool used to verify the adequacy of structural framing design. It enables engineers to see how the structure would perform in a variety of building scenarios, including seismic events. The technique involves high-precision finite element analysis of the elements of a structure subject to loads. However, the engineer may choose to design manually or use spreadsheets and simpler tools for less complicated projects. In any case, with today’s technology, these analyses can be done in a matter of a few minutes. Based on this analysis, the engineer designs connections, checks the adequacy of the structural elements, and modifies them where necessary. For example, bigger beams may be specified due to over deflection results, or more concrete reinforcement may be considered essential to prevent cracking under load.
- Structural drafting: Structural drafting is the process of drawing a building or any other type of structure on paper before building it. To ensure that the project will be completed on time and within budget, it is important to have accurate information on the drawings. It has been proven time and again that if a technical drawing is not clear enough, the builders will struggle to put it together. Therefore, structural drawings should be clear, precise, and detailed enough to describe all the construction works’ details. The clearer the structural drawings are, the more easily they can be interpreted by the builders who will be making the actual physical structures. Also, proper drafting will avoid unnecessary and costly delays. While drafting is a required skill for engineers, it is usually done by a draftsperson trained in using drawing software such as AutoCAD.
What are the structural elements of a building?
The structural elements of the buildings are the foundation, walls, columns, floors, and roof. These elements are load-bearing and are crucial to ensuring that the structure is safe and will continue to hold up under heavy loads. The essential elements that form the structure of a building are:
Footings
Footings are the lowest component of the structure and provide support and stability to the building. Footings are responsible for transferring all the loads to the foundation soil. Therefore, it is important to know that each site requires its unique footing design compatible with the site’s soil condition. Structural engineers should thoroughly study the ground conditions of the proposed site and the soil’s bearing capacity before designing the footing. The type of the building and the site’s soil characteristics dictate whether the footing should be shallow or deep. Examples of shallow foundations are concrete slabs or strip footing system. Deep foundations such as bored piers are usually designed for large buildings or buildings on unstable soils.
Walls
Walls are either load-bearing or non-load bearing. Load-bearing walls carry the loads from the upper floor or roof to the footings and are a critical part of the structural components. Double studs or double masonry walls of buildings are examples of load-bearing walls. Non-loadbearing walls, on the other hand, carry their own weight and do not provide support to any other structural elements of the building. Internal non-load bearing walls are known as ‘partitions’. Nowadays, particularly in single-story houses, interior walls are non-loadbearing as roof trusses span between the external walls. However, if you plan to remove a wall within your house, be sure to consult with an engineer first. Distinguishing a load-bearing wall from a non-loadbearing one might be tricky. Most people will probably not be able to tell the difference just by looking at them. An engineer will advise you on any potential risks and the safest ways to remove the wall. Tall buildings that are exposed to earthquake and wind loads have another type of wall known as “shear walls”. Shear walls provide diagonal bracing against earthquake or other large horizontal forces. If a shear wall fails, it doesn’t just fail as an isolated element. The entire building can come down.
Columns
The word column comes from the Greek word kolpos, which means pillar and is the building’s primary structural element. Columns are found in every type of structure, from homes and offices to bridges and skyscrapers. They run the length of a building and transfer the weight of the upper floors to the lower floors without buckling or collapsing. A column has two basic types, rectangular and round, and it is independent of the wall. The columns that are attached to the full height of the load-bearing walls are called piers. They are engaged with the walls to provide monolithic actions and increase the stiffness of the walls. This type of wall and pier system is commonly used in the construction of garages in Melbourne.
Floors
Floors are used to divide different building levels whilst transferring loads from one level to another. Common types of floor structures in Australia consist of long-span timber beams such as joists and bearers or PosiStruts, or concrete slabs such as raft slabs and suspended slabs.
Beams
Beams are horizontal members of the structure and are an essential part of the roof framing or floor framing. The bottom chord of a truss in the roof or lintels above windows and doors are examples of beams. Depending on the amount of load they need to support, they are made of wood, reinforced concrete, or steel. Beams span between supports and need columns/piers to transfer their loads to the footings.
What is a holistic forensic view, and why is it important in design engineering?
A building project’s success heavily depends on its structural design engineer’s skill, experience, and creativity. But that’s not all! The design outcome gets even better if the structural engineer is well familiar with past building damages and failures, their causes, and how to avoid them. Humans have been using structural engineering principles since the beginning of time. The origin of Structural Engineering can be traced back to the first instance when the early man and woman realised the need for shelter and built one using tree branches. Since then, engineers have been designing and building ambitious and innovative structures across the world. However, not all buildings and structures were designed and constructed perfectly. There have been and still are many buildings and structures that suffer from poor designs and detailing or from construction shortcuts and poor workmanship. Every structural engineer must be aware of what has been done right and what hasn’t, so they can avoid the mistakes of others. Minor design flow issues can be a big issue in the long-term performance of a building. That is why having forensic experience and knowledge is a big plus for the structural engineer. Forensic Structural Engineering is the application of engineering principles to determine the causes of structural damage and failure. It helps engineers to design in such a way as to prevent any future damage, big or small, to the building. With forensic knowledge, the engineer can foresee all the things that could go wrong with the structure, either during construction or post-construction. A combination of sound structural engineering knowledge and extensive forensic experience leads to the design of a home and a structure that lasts for generations.
Structural Engineers with a holistic forensic view can provide the following:
- Sound and lasting structural design based on years of forensic experience.
- Unique structural design rather than duplicating the same design over and over.
- Detailed engineering solutions and designs from footings to framing to minimise building issues that usually arise after project handover.
- Innovative, efficient, and cost-effective methods for structural design mixed with passion.
- Progressive design solutions by continuously challenging and disrupting conventional thinking.
What types of structures does MFS Engineering design?
At MFS Engineering, we take a stand for proper building processes. We never get manipulated into designing a structure that will perform poorly just because it’s less expensive to create. That goes against everything that we stand for. However, that’s not to say that we aren’t budget-conscious. We provide the best services possible at the most reasonable cost- without skimping on design. We are not the cheapest in the market due to the time, effort and experties we put into every project. For this reason, we only provide our design services to private sectors, such as Homeowners, Architects, and Builders who are not developers.
Our design includes, but is not limited to, the following structures:
Residential Buildings
No matter how big or small the project is, we have the right team for it. Some of the residential building types we design are:
- Timber framed house: Timber is one of the most versatile materials used in the construction industry. Not only timber structures are strong, aesthetically appealing, and unique, but they are also environmentally friendly and sustainable. We believe timber design should be the future of the construction industry, and we are passionate about making this happen.
- Concrete Structures: Concrete is the most widely used construction material in the last century. It’s cheap, strong, and easy to work with. Even though concrete is the basis of all the construction, it should never be used alone because it can crack and crumble over time. Engineers use reinforced concrete instead. Reinforced concrete is known for its durability and resistance to high temperatures, making it an excellent building material.
- Steel structure: Steel is not just for large buildings and warehouses. Many residential buildings can very well benefit from steel structures. They are sustainable, durable, and cost-effective and considered a preferred choice for bushfire-prone areas.
- Conventional roof design: Conventional roof design is a forgotten art that was mastered by building carpenters. Unfortunately, this is not the case anymore, and many modern engineers nowadays do not know how to design a simple conventional roof. However, we are still following the footsteps of our precedents and are very well trained in designing conventional roofs.
Swimming Pools
Whether for visual appeal, health, fitness, or just fun, swimming pools can be very nice additions to any property. We have full expertise to design any swimming pools no matter the type, shape, and size.
Retaining Walls
Proper design of Retaining walls will ensure their durability and the long-term capability to support various loads such as hydrostatic pressure and surcharges. We design concrete retaining walls, split-level retaining walls and more.
Extension to the Existing House
Adding an extension to an existing property might be a very attractive option. However, careful analysis of the building structure is required, especially if the existing building is a very old one. Our forensic structural engineers assess the structural integrity of the existing building and recommend any structural upgrades if necessary. Our structural engineers will then design the structural upgrades, protection works, and the structure of the extension. We will ensure that the building of the extension will not cause any damage to the existing one.
Underpinning
The structural stability of a building can be undermined due to various reasons, with poor design and construction being the most common ones. Thorough knowledge of the nature of the soil, its moisture content and bearing capacity, and drainage are required during the building’s construction to prevent structural instability. However, underpinning may be used as the last resort to repair a structurally undermined footing.
Commercial Structures
Commercial designs are very different from residential designs. While the residential building generally calls for a fairly straightforward design that caters to the need for a living space, the commercial building, on the other hand, requires strict compliance with many standards and regulations. All our team members are highly trained, which means that they apply engineering skills, experience, and a practical approach to each and every project.
Industrial Structures
Industrial structural design varies considerably from both residential and commercial design. The industrial design usually consists of a structure to support and contain a complex technical process. Such complex processes almost always require a structure to endure heavy loads, extreme heat or cold, and toxic conditions.
