Limitations of Structural Models

“All models are wrong, but some are useful”. This aphorism coined by George Box for statistical models may also have a grain of truth about structural models. Often in telecoms structural analysis, assumptions are made to simplify the calculation process or fill in for missing data. A good engineer will ensure that these assumptions are based on sound theory and perhaps even well-established industrial design codes. However, engineers must take care to be aware of the limitations of the any assumptions employed.

As an example, analysis of telecoms structures is based on a static model, that is, checking that the structure survives under the action of an extreme load e.g., a 50-year wind event. Implicit in this design methodology is that fatigue failure is not an issue. Fatigue is the failure of a material under repetitive or cyclic loads at load significantly below loads that would cause yield: think about bending a paper clip back and forth, eventually it will snap.

There are certainly cyclic loads to consider for telecom structures: the wind is not constant; it changes direction and strength. So why do we not perform fatigue analysis for these structures? Well, the steel sizes used for telecoms structures would take a very long time to fail under fatigue for the typical cyclic stresses that they experience so fatigue is not a practical consideration. But is this true for all the components?

Consider a wall mounted antenna fixed to a brick wall by a chemical anchor (these terms should now be familiar to you from our previous blogs 😊). There are several components in that system that can experience rapid fatigue failure. Currently, it may not be practical to conduct fatigue analysis for these components, but this is where it is important that an engineer understands the limitations of the analysis model used.

For these wall anchors, we recommend that site providers and operators have a clearly defined integrity monitoring procedure for inspecting the anchors to ensure that they are still fit for purpose. The consequence of not doing this is that a day will come when you may simply be able to remove the anchor by hand! Even worse still, you may find the EMA on the ground which does not bear contemplating in a busy town centre.

Contact our expert team at: info@ka-engroup.com to learn more and discuss how we can best serve your needs.

 

Rigger Safety in Telecom Structural Design

A common pitfall in telecoms structural design is to solely consider the proposed structure from the viewpoint of the ancillary (antennas/dishes) operability. This is natural, after all, functioning ancillaries are what make money. However, it is very important to not forget the human element. These ancillaries must be installed/rigged by real people who need to return home safely.

A rigger anchoring to a piece of telecom steelwork effectively puts their lives in the hands of the structural designer. This responsibility should not be taken lightly. Accidental loads in all their various forms must be carefully considered throughout the design phase. Engineers can uphold their ethical responsibility and help to create a safer working environment for employees who construct and maintain these essential telecommunications facilities by prioritising safety during the design phase.

At KAEG, safety is part of our core values, it is a philosophy that underpins everything we do. Our structural teams have real site/ climb experience which allows us to put ourselves in the rigger’s position so we can even sense check “attractive nuisance” steelwork that the rigger is not “supposed” to anchor to.

Stay safe out there and reach out to our expert team at: info@ka-engroup.com to see how we can best serve your needs.

Drone Surveys: Taking Telecoms Structural Engineering to New Heights

Drone surveying is the use of unmanned aerial vehicles (UAV) equipped with specialized cameras to capture aerial data. It has had a positive impact on the way telecoms structural engineers now approach design, maintenance, and optimisation of telecoms structures from previous traditional methods. Here are some intriguing benefits of this innovation:

  • Seamless Integration with Data Analysis tools: With modern advances in technology and the abundance of data collected during drone surveys, captured images can be transferred to data analysis and modelling tools. Engineers can then create accurate simulations to anticipate the effects of loads on the structural integrity of telecoms infrastructure.
  • Cost-Saving: Drone surveys can reduce manual labour costs and can result in more efficient resource allocation.
  • Virtual Inspections: 3D models can be constructed from sensors like UAV LiDAR sensors, enabling more immersive inspections and minimising safety risk for the engineers on site

In essence, drone surveying is likely to become a quintessential technique for inspecting modern telecoms structures. We are sure the conversation around there use will continue to grow, At KA Engineering Group, we take a responsible approach to considering, advising, and optimizing each site, ensuring cost-effective design, installation, and maintenance for build contractors and efficient utilization for operators. Contact our expert team at: info@ka-engroup.com to learn more and discuss how we can best serve your needs.

Mastering the Craft

Last week, we shared with you a glimpse into the diverse range of structural solutions that KAEG offers; from rooftop scanning to tower mapping. Our mission is to simplify and remove barriers, providing you with comprehensive structural services. As we continue our journey, let us delve deeper into the importance of specialisation and how it defines our approach at KAEG.

In the past, we have been asked why we do not dabble in CAD drawings or other related areas. As the saying goes, “Jack of all trades, master of none.” At KAEG, we firmly believe that true expertise comes from a dedicated focus. Just as our previous blog highlighted our commitment to solving structural challenges, specialisation has been our guiding principle to achieve mastery in our field.

While we specialise in structural services, we also recognise the value of collaboration. Instead of trying to cover all bases, we have forged partnerships with experts in various fields. We embrace the concept of tapping into the strengths of others when it complements the vision and objectives of a project. This strategic approach allows us to deliver exceptional results by harnessing the collective expertise of our extended network. These collaborations also enable us to offer you a complete and seamless package, maintaining the highest standards throughout the project lifecycle.

At KAEG, specialisation is not just a buzzword; it is a philosophy that underpins everything we do. Our commitment to mastering structural-related services and building a network of experts has proven to be the cornerstone of our success. As we embark on each project, we remain dedicated to the art of specialisation, ensuring that we deliver solutions that are unparalleled in quality. We invite you to continue on this journey of excellence with us, where specialisation meets collaboration, and expertise knows no bounds.

For further insights or to discuss your unique project needs, please reach out to our expert team at: info@ka-engroup.com. Together, let us build a future that is not only structurally sound but also truly extraordinary.

Chemical fasteners

A short discussion on chemical fasteners, continuing our series of posts on fastening technology. Chemical fasteners transfer tension load to the borehole mainly via adhesion. The components are connected to one another to form an adhesive bond.

Advantages:

  • ​​​​​​​High load-carrying capacities
  • No expansion forces (ideal for fastenings near the edge)
  • Suitable for anchoring in solid and hollow building materials (hollow building materials require a mesh sleeve)
  • Sealing function

Limitations:

  • ​​​​​​​No immediate load-carrying capacity (curing times)
  • Special assembly requirements:
  • Thorough borehole cleaning (prevent high load-bearing capacity losses)
  • Components must be mixed completely
  • Processing and ambient temperatures affect the curing time
  • ​​​​​​​Special storage requirements:
  • Storage period
  • Heat sensitivity

We will discuss more on failure modes of fasteners in subsequent blogs. Stay tuned.

At KA Engineering Group, we leverage on our extensive experience to design and recommend most efficient fastening solutions for new as well as existing systems in telecom construction.

Contact our expert team at info@ka-engroup.com to learn more and discuss how we can best serve your needs.

Bamboo to Replace Telecom Steel?

Assuming that we can keep the Pandas at bay, should we be looking at replacing steel with bamboo? Can bamboo telecommunication towers be sustainable and economical? Telecom towers are usually fabricated using steel because steel has very good strength. However, due to its tightly packed fibres, bamboo has superior tensile strength over steel. Producing steel also has a lot of drawbacks like high costs, atmospheric pollution, and environmental degradation. Bamboo, on the other hand, can be produced at very low costs and has various environmental benefits.

So far so good! Unfortunately, tensile strength alone is not sufficient. Bamboo is prone to insect attacks and will degrade until sustained exposure to water which is an issue for any towers not installed in the Sahara!

Perhaps the future of bamboo will depend on its use as a composite material or more resistant strains will be cultivated to remove some of the limitations. Either way, we are excited to see what the future holds.

At KA Engineering Group, we like to think of ourselves as a solution independent structural consultancy. We leverage our extensive engineering experience to accurately design the most suitable telecom structure for your needs. We take responsible steps to consider, advise, and optimise each site, ensuring cost-effective design, installation, and maintenance for build contractors and efficient utilisation for operators. Contact our expert team at: info@ka-engroup.com to learn more and discuss how we can best serve your needs.

Don’t Forget Primary Structure Check for Rooftop Stub Towers

Rooftop stub towers, a solution that has gained popularity for its ability to overcome space constraints and improve connectivity in urban environments. When performing structural analysis on stub towers, it’s easy to focus solely on the tower structure, headframe and secondary steelworks. However, it’s crucial not to overlook the primary structure of the building itself.

The primary structure of a building supports the weight of the entire structure, including the added load of a rooftop stub tower. Conducting a load-bearing capacity assessment is crucial to ensure that the building’s structure can safely accommodate the additional weight and forces imposed by the tower and its equipment. This assessment involves evaluating the roof slab, columns, beams, and other structural elements to determine their ability to bear the load without compromising structural integrity. A thorough structural analysis can also help to determine how the additional weight and forces from the rooftop stub tower are distributed within the primary structure. By assessing load distribution, engineers can identify areas that may require reinforcement or modifications to maintain the stability of the primary structure under varying conditions.

Also, adhering to building codes and regulations is of utmost importance when designing rooftop stub towers. Building codes often outline specific requirements for structural integrity, load capacities, and safety factors. KA Engineering Group possess extensive knowledge and experience during the completion of hundreds of stub tower projects to assess the stub tower and building’s structural capacity.

Contact our expert team at: info@ka-engroup.com to learn more and discuss how we can best serve your needs.

EMA Strengthening Solutions

EMA Poles are common telecom structures in city centres. EMA poles are usually held by standoffs attached to a plate and connected to a wall through anchor bolts. The forces generated causes the anchors to want to pull out from the wall. Historically, these anchors are held by chemical resins injected into the wall. Click here for description of chemical resin anchors. Usually, where the pull out load is excessive, the resin anchors become unsuitable to resist pull out and strengthening solutions needs to be adopted where the EMA is existing. There are two possible strengthening solutions

Back plating: This involves using a bolt that passes through the wall to the other end held by a back plate. In this case, pull out of the bolt is resisted by the rigid connection of the plates and nuts at the back. For the bolts to pull-out, the entire wall will have to cave in. Hence, the proposal of a back-end plate negates the need to pull test the anchors.

Over plating: This involves increasing the number of bolts and spacing of the existing anchors. A small Equal angle (EA) steel section is placed over the existing front plate and new bolt holes are drilled at the top and bottom of the EA for new bolts to pass through the wall. This increases the number of bolts and hence reduces the pull-out force as the forces are shared by 6No. bolts as opposed to 4Nos as shown in the fig 2b below.

Lattice Tower Braces

Lattice towers can be braced in various configurations (see image) but have you ever wondered why a particular configuration is selected?

Braces are needed to keep a structure stable and prevent it from swaying or drifting since most towers act as a cantilever system. They transfer lateral loads from the tower to the ground and they also prevent the tower legs from buckling. There are various types of brace configurations but can be broadly simplified to 3 groups.

Configuration 1 is called a Single brace and they are good for resisting light loads for instance near the top of a tower.

Configuration 2 is called a Cross Brace and is capable of withstanding both tensile loads and drifts.

Configuration 3 is called a Chevron/K- Bracing and it is used for controlling deflection and resisting lateral loads.

Other brace configurations are made from a combination of these basic configurations.

At KA we ensure that the right brace configuration is selected to new tower design or applied for strengthening scheme to increase capacity to withstand lateral loads. We also take responsible steps to consider, advise, and optimise each site, ensuring cost-effective design, installation, and maintenance for build contractors and efficient operator utilisation. Contact our expert team at: info@ka-engroup.com to learn more and discuss how we can best serve your needs.

Diversifying Your Skillset

As a structural engineer, it is easy to become so focused on design and analysis that you neglect other valuable skills that can help you excel in your field. While knowledge of codes, standards, and structural theory is essential, it is equally important for engineers to have a diverse range of skills and well-rounded knowledge that can help them stand out in the workplace.

One such skill that can be extremely useful for a structural engineer is the ability to code. This is because quite often, we come across repetitive tasks that require some form of automation through coding. By having the ability to write code, engineers can streamline their workflow, reduce errors, and increase efficiency, allowing them to focus on more complex and creative aspects of their work. Coding also opens up opportunities to work on cutting-edge projects and to develop custom solutions to complex engineering problems. It broadens your perspective, and this can be particularly valuable in the field of structural engineering where new materials, construction methods, and design techniques are constantly emerging.

An example is having some knowledge of Python or VBA that allows you to automate a process and create useful tools that help in your structural calculations.

It is not just structural engineers who can benefit from diversifying their skills, we at KAEG are encouraging all working professionals, regardless of their discipline, to never be so straight-narrowed in their profession and should instead learn complementary skills and diversify. In today’s fast-paced, rapidly changing world, it is more important than ever to be versatile and flexible. Contact our expert team at: info@ka-engroup.com to learn how we can bring our diverse skills to best serve your needs.