Tuesday, August 9th, 2022
CECR
Use Of Drones In Urban Construction

Use Of Drones In Urban Construction

 Ms. Mattea Jacobs
 Freelance Writer & Green Activist,
 Los Angeles.

The popularity of drones has skyrocketed in the recent years, and so has the market for them. From taking photos and videos for personal use, to their scientific applications and uses in many spheres of life and business, their importance and utilization are constantly growing.

Although many may be familiar with them simply due to their fun and recreational purposes, drones, above all, have very important and practical uses in different industries. One of them is home construction, where drones have significantly contributed to the industry’s efficiency and general development.

 

Construction vs. Technology

When it comes to the construction industry, it has generally been one that is somewhat averse to technology and technological advancements. It is an industry that relies mostly on traditional, manual labour and heavy machinery, and does not always welcome change very easily. Moreover, it is one of the least digitized and technologically advanced areas, which can often reflect on its productivity.

Fortunately, construction has also begun opening its doors to new technology – slowly but surely. With BIM, smart devices and gadgets, 3D modeling and now drones, it is welcoming change into its very core, and becoming a part of the digital revolution. We no longer have to talk about construction vs. technology, but about construction and technology.

Drones, specifically, have the potential to integrate various aspects of the project, simplify it, connect people from different parts of the country who are working on it together, improve the gathering of information, and provide better insight and overview of the project.

 

Saving Time and Money

To keep the project successful and on track, it is important to always have all the necessary data on the site and the building at hand. The traditional methods of surveying, research, and data collection would usually take a lot of time – days or even weeks. And making sure that every minor change in the site or the data is updated and recorded is another part of that strenuous task.

Drones can change all of it and revolutionize the way a site is researched and monitored. They can collect all the necessary data and information in a matter of minutes and update it regularly. They input the data into the BIM (building information modeling), a project management software, and keep you updated at all times. This can save the industry significant amounts of money by decreasing the time spent researching and the amount of labour that is put in.

 

New and Improved Inspection

Using drones for inspection purposes can also help stay on top of your projects, as well as save you a lot of time and money. One of the greatest advantages of drones is that they show you data in real time, so you can act on time. This can help in avoiding unnecessary and costly mistakes or making changes to your plans, and all without wasting time, money or labour.

With drones, the risk of your project going off-track is much smaller and allows you to make some crucial decisions or changes before it’s too late, or before the project has advanced too far. Apart from that, you can also inspect the aesthetics of the building, receive the images and see how they compare to the blueprints and the model.

 

Presenting the Project’s Progress

Many clients and homeowners like to stay informed and keep track of how their house is coming along. That is not always convenient for the architects, the construction company, and the workers, nor for the clients themselves. It would usually involve making trips to the jobsite, which can be time-consuming or showing photos to the clients, which is not a real enough representation of the progress.

This is another aspect where drones help significantly to keep clients well-informed and involved in the project. They allow the architects to show the live progress of the project, present it from all angles and give a better and innovative overview of it to the clients. And clients can then express their (dis)satisfaction, which can be addressed in time.

 

Improving Safety

Construction is known to be one of the most hazardous fields. Many injuries and even deaths occur precisely at constructions worksites, and it has many safety risks. One of the great and very important benefits of the use of drones is also improving this factor and decreasing safety risks.

Inspecting roofs, locations or areas that are hard or too dangerous to reach, working on heights, and similar hazardous tasks can all be done with the help of a drone. This way, accidents,and injuries can be prevented and significantly reduced, making this field of work much safer.

 

Conclusion

Applying new technologies, such as using drones in your construction work, can benefit both you and your clients in great proportions. Technology is shaping and changing our world, so why shouldn’t you be a part of it as well.

Drones can not only save time and money on your project, but they can also provide better results and more successful projects. They are an innovation with many applications and benefits and are surely on their way to become the standard of the industry.

Pragmatic Approach For Development Of Urban Infrastructure

Pragmatic Approach For Development Of Urban Infrastructure

 Er. Satander Kumar
 Consultant,
 Delhi

India has undertaken the most comprehensive and planned urbanization. Between now and 2030, 700-900 million sqm of urban space is to be developed every year to accommodate 40% of the total Indian population that is expected to be based out of the urban areas. By 2030, cities may contribute to around 66% of the country’s GDP and close to 90% of tax collection. Planned urbanization shall be decided by the Centre and urban local bodies as well. The pertinent issues regarding the development is not only of smart city, smart roads, smart bridges, with smart design and smart monitoring, but also other components of the urban infrastructure development such as mall, toll plazas, hospitals, community centres, gardens, parking facilities with stringent securities, industries for sufficient job creation, safety measures/fire station, communication, electrification, drinking water, local transport system, smart facilities for kids, children, ladies, senior citizens and disabled persons, domestic and all kinds of animals having habitation in the cities with proper care and settlements, proper factual treatment of patients and their travel.

Last but not the least, simple rules and practically being enforced in public life including proper and working CCTV camera installation at critical locations at least. All old/accident and dumped unrepairable vehicles lying in public places not allowing to utilize the rare available space shall be removed at least within one year of accidents or disputes. Any court/disputed cases shall not take more than 1-2 years for its final judgments. This is the basic demand of the public particularly senior citizens, disabled persons and ladies for having developed infra structure at the time of the need.

The disputed cases must be settled preferably with in one year as compared to the court /police cases, which are being settled and dealt with in a week or so in many countries. The paper describes some realistic/ practical problems and their remedial measures/solution.

 

Introduction

There is significant amount of momentum in urban areas and things may work with either due to simple design or its implementation in making smart cities, roads, bridges etc: liveability, employability and productive use of public spaces. Progress is being made for making Smart urban infra structure at the level of government & local bodies to pursue cities to become smart for infrastructure developments (Figure 1).

Fig. 1: Development of Infrastructures – Smart Cites, with Smart Roads, Bridges and Buildings

Today, the attachment of word ‘smart’ to any noun has become synonymous with thinking, connected and mobile technologies, as well as the Internet of Things. Smart phones, smart watches, smart cars, smart cities, smart roads … it’s an ever-increasing list of ingenuity.

 

Smart Roads

Smart roads mean that roads that think, feel, and predict the needs of the people and the vehicles that travel on them. Roads that have an environmental conscience, charge our vehicles with fitted sensors in the roads using solar energy and help to improve our safety. Roads that make a difference to the world. Presently, roads are a simple science. They help us get to and from places in the safest, most efficient manner. They connect us to other people, cities and towns. Roads are the literal bedrock of future transport. On the other hand, smart road is a well-planned, animated, beautiful system and incorporated with warning system, with multilevel parking and multilevel roads. (Figure 2.)

Fig. 2: Smart Road

Smart Cities

On the other hand, creating smart cities is to improve the quality of living of all sections of the society living in urban areas for fast development of urban infrastructure. Quality of Physical Infrastructure is first and foremost in creating smart cities. In the absence of quality infrastructure any amount of effort will not yield desired results. For creating smart cities, maximum focus should be on improving the quality of existing & developing new physical infrastructure with proper monitoring. This may include:

  1. The most pressing problem of urban areas is the ever-growing undeveloped number of private colonies and clusters and non-availability of quality housing for all needy people.
  2. The problem is aggravated by increasing number of shifting population. There shall be well planned private housing colonies and clusters as per standard municipal drawings in the cities.
  3. There shall be appropriate very easy to use rules and regulations and building bye laws for Private Colonies and clusters and the enforcement of the existing rules whatsoever.

2,855 projects worth Rs 1,35,459 crore are in various stages of implementation while 147 projects worth Rs 1,872 crore have been completed and 396 projects with a cost of Rs 14,672 cores are currently under implementation.

(Ref: Central Chronical News 2 Jan 2018, E paper: Agencies, New Delhi)

 

Smart Bridges In Action

This tragedy may have been prevented had the bridge been equipped with a network of smart bridge sensors providing continuous monitoring of various properties. For instance, the six-lane, 2.9 km Charilaos Trikoupis Bridge (Rion-Antirion Bridge) in Greece has 100 sensors (300 channels) that monitor its condition. Soon after opening in 2004, the sensors detected abnormal vibrations in the cables holding the bridge, which led engineers to install additional weight to dampen the cables.

  Fig. 3a, 3b, 3c, 3d: Smart Bridges with Smart Design

Only a handful of other smart bridges across the globe incorporate sensors of various types, including accelerometers, strain gauges, anemometers, weigh-in-motion devices, and temperature sensors. The Tsing Ma Bridge in Hong Kong, the world’s seventh longest suspension bridge, is equipped with more than 350 sensor channels. The bridge, which can handle wind speeds up to 341 km per hour, uses GPS sensors mounted on the towers and cables to measure wind speed.

 About 100 photonic sensors are used to monitor the strain on the bridge’s cables. Signature Bridge (Cable Stayed Bridge) under construction is being fitted with such types of sensors in Delhi near ISBT by MEGEBA Kolkata. Additional smart bridges in action include the following:

  • Geumdang Bridge, South Korea: Low-cost wireless sensors monitor the bridge’s response to speeding and overloaded trucks.
  • Gi-Lu Cable-Stayed Bridge, Taiwan: Wireless sensors and accelerometers monitor its structural health.
  • Brooklyn Bridge, New York City: Fibre optic sensors measure displacement and temperature.
  • Bill Emerson Memorial Bridge, Cape Girardeau, Missouri: Strong-motion sensors, at a cost of $15,000 per sensor, acquire and transmit data via Ethernet (Figure 3 and Figure 4)
Fig. 4: Bridge Component with Sensors
for Smart Monitoring
Global Views on Urban Infrastructure

Steffen Sorrell, focuses on two over-arching benefits of smart cities – sustainability and efficiency. To that end, he identified following five essential components of a smart city or intelligent infrastructure developments:

  1. New Technologies
  2. Buildings
  3. Utilities
  4. Transportation with Intelligent advance system & road infrastructure
  5. The smart city itself

One of the first countries to implement roads (with inbuilt facility of charging vehicles) that charge electric vehicles was South Korea. In 2013, the Korea Advanced Institute of Science and Technology (KAIST) installed the first electronically charged bus route in the city of Gumi that was able to charge the electric buses that drove on it.

In the UK, trials started in 2015 for similar technology after a feasibility study commissioned by Highways England highlighted the need for more charging points for electric vehicles. Not only will this improve journeys, it’ll also “create a more sustainable road network”.

At the more innovative end of the spectrum is the work of Studio Roosegaarde, which is utilising the power of the ‘SUN’ to help cyclists and motorists navigate at night with colourful, reflecting lighting, as well as temperature-controlled paint that lights up to warn drivers of dangers such as ice on the roads.

Juniper Research, USA recently compiled its list of top-five ‘smart cities’ listed below:
Chandigarh, designed by the French Architect Le Corbusier half a century ago as a model city, is spread across 114 sq.km and the urban infrastructure and green belt of the city provide it a distinguished status among India’s planned cities.

Fig. 5: Top Five Cities

 

Ways And Means For Improvement

To improve the quality of living conditions in existing authorized colonies and Govt. developed sectors in urban areas following actions are proposed for infrastructure development:

  • An effective system of regular and continual monitoring
  • Removal of encroachments without delay
  • Action to be taken where the rules are non-existing or are ambiguous
  • Action to improve the condition and quality of roads, buildings, bridges etc, rainwater drainage system, sewerage system (SWACH BHARAT).
  • New technologies like concrete cloth, lacquered paver block, thin white topping, use of construction and demolition including recycled asphalt pavement (RAP) wastes in lower layers, precast prestressed roads, bridges and building components, use of waste plastics, use of carbon black, and waste rubber and milled material in hot mix asphalts, micro surfacing as per IRC:SP:81, cold mix technologies, self-compacted concrete like in Japan and China, ultra-high performance concrete etc.
  • Free and regular supply of clean drinking water and water in toilets and gardens.
  • Sufficient number of toilets to be made available
  • Effective system of collection of garbage
  • Proper banking facilities
  • Free public transport system at least during hazardous weather

 

General Observations

Efforts shall be made for filling gaps between infrastructure and expanding urban population. Focus shall be on drinking water supply, sewerage management, storm water drainage, roads, solid waste management, urban housing, urban greenery and smart LED street lighting, smart bridges etc.

Amaravati: The Andhra Pradesh government has been adopting a focused approach to fill the widening gaps in infrastructure across the state and to meet the challenges posed by a fast-expanding urban geography and demography. The government has drawn up a two-pronged action plan to build up the requisite urban infrastructure and fulfil the citizens’ needs, with the first phase expected to be completed in the next two years. “The prime focus is to meet the National Service-Level Benchmarks (SLBs) by improving the key service-level indicators for delivering the desired outcome to the public.

Full protection with proper justice shall be provided to the Farmers, whose land is being acquired. His consent shall be paramount importance. Considering steep rise in population, more jobs will have to be generated in the next quarter century, at the rate of ~8 million new jobs every year. In recent years of the reform era, the net rate of job generation in the organised sector, relying on the government’s own data, is under 0.5 million per year. Pertinent here is the fact that this is the era of disruptive robotization across all industries: governments boast of jobs that get created, not of jobs lost to automation.

The reigning vision also implies that our cities will be able to provide the enormous infrastructure — of clean air and water, sanitation and power, roads and communication, housing and social security.

Typically, there is very little technology that goes into roads. They tend to be made from asphalt or concrete including white topping or cell fill pavement, which is compacted into a smooth, solid surface and painted upon to indicate certain restrictions, routes and information. The real development of urban infrastructure means a smart city with a smart road/smart bridges, which can provide citizens with smart mobility”.

For now, the focus shall be on the re-imagining and adapting existing roads and cities and their immediate environment to ensure that the promise of smart mobility is delivered upon. Cities have developed over the past 100-200 years. A few suggestions: i) Beautify these Roads. Put similarly designed boards. ii) All establishments must not encroach upon the footpath with their goods or vehicles. All Shops/offices etc on these roads should have a frontage made using vernacular techniques and materials. iii) No customer should stand on the footpath to transect the business.

 

Conclusion

Traffic congestion is acute problem in all cities. With time it is going to worsen further. Some of the main roads shall be identified to improve them to ease the traffic with proper installation of sensors indicating which route is better and which rout is having less pollution. Electric buses could be charged automatically by the sensors fitted in the roads. Efforts shall be made to keep the smart roads and bridges free of all commercial activity. Smart design standards must also adopt a barrier free design for citizens with disabilities and who are physically challenged.

 

References
  1. https://static.mygov.in/rest/s3fs-public/mygov_14822351221494241.pdf
  2. https://www.mygov.in/group-issue/draft-standards-smart-cities-india
  3. http://www.business-standard.com/article/economy-policy/france-will-partner-india-to-build-three-smart-cities-116012500034_1.html
  4. https://www.forbes.com/pictures/54fe2629fcd7da7ddff45018/2-new-york-city/#94697161b0d6
  5. https://www.inmotionventures.com/smart-roads-future-transport.
  6. Aseem Shrivastava and Ashish Kothari, ‘Churning the Earth: The Making of Global India’ (Penguin Viking, 2012) and ‘PrithviManthan’ (Rajkamal, 2016)
  7. http://buildipedia.com/aec-pros/public-infrastructure/innovative-infrastructure-smart-bridges.
  8. SME Times News Bureau | 11 Apr, 2018
  9. www.smetimes.in/smetimes/news/top-stories/2018/Apr/11/urban-local-body37875.html
  10. HANS INDIA, Fri Apr 13, 2018 Hyderabad, India
  11. http://www.thehindu.com/todays-paper/tp-opinion/facing-the-future-of-development/article23507239.ece,
Constructability Hazard For High Speed Rail Project

Constructability Hazard For High Speed Rail Project

 Mr. Om Prakash Singh
 Senior Alignment Engineer,
 High Speed Rail KL-SG and MRT2,
 Kula Lumpur, Malaysia

 

Introduction

As part of the Economic Transformation Plan, there is ongoing High-Speed Rail (HSR) project of Ahmedabad-Mumbai, Kuala Lumpur – Singapore, and Thailand. HSR connects the southern region of Malaysia and Singapore in 90 minutes with a speed of 300km/h. With a total length of approximately 335km within the Malaysian section, the high-speed rail service connects 7 major towns with stations at Bandar Malaysia, Putrajaya, Seremban, Ayer Keroh, Muar, Batu Pahat and Iskandar Puteri. Mumbai-Ahmedabad high speed rail has operation speed of 320km/h.

This Constructability Hazard is prepared with due consideration for health and safety and to impose better standards of HSR management in design by avoiding, reducing and controlling HSR hazards faced by workers on construction site. The design has taken reasonable steps to address HSR hazards and associated risks to ensure that the project is capable of being constructed to be safe, can be maintained safely and complies with all relevant safety and health legislation.

 

Construction Safety

Based on the recent development of construction safety research, the concept of construction safety both at the policy level and implementation is needed. In this case, the safety of the construction should be seen not only of occupational safety but the safety of the total system of construction (total safety of construction systems). Thus, the safety of the construction will have dimensions of (i) safe for people, (ii) safe for the public, (iii) safe for the property, and (iv) safe for the environment. Safety for people to understand including safety from danger (hazard), which can lead to accidents and occupational diseases. In addition, construction safety should be viewed throughout the life cycle of the building woke up (built assets), starting from conception, planning, design, procurement, implementation, operation and maintenance, deconstruction and reconstruction.

 
Purpose of Hazard Log
  • Recording identified hazards and causes of the hazards
  • Recording the hazard consequences and affected group
  • Recording the appropriate actionee (Hazard Owner) and mitigation measures in place
  • Classifying hazard based on the likelihood of occurrence (accident frequency) and consequences of the accident (accident severity) to arrive at a level of risk (initial risk)
  •  Assessing residual risk after considering mitigation measures proposed and relevant disciplines
  • Tracing hazard status
  • Recording hazard closer as endorsed by Hazard Owner, Head of Department, and Project Management
Hazard Risk Identification

Hazard Risk Management is a continuous process where the project team will identify risks and develop strategies to mitigate or avoid those risks. The pertinent Hazard risk items are identified from each relevant Department head of this section.

 

Risk Frequency

The Risk Frequency is the qualitative rate of occurrence (probability range) of that Risk. In other words, it is the range of probabilities that the Risk occurs (Table 1).

 
Risk Severity

The Risk Severity is the qualitative category of the level of harm caused by that Risk once it occurs (Table 2).

 
Risk Evaluation

Risk evaluation will be performed by combining the frequency of occurrence of a hazardous event with the severity of its consequence to establish the level of risk generated by the hazardous event. For the HSR project, the ’frequency-consequence’ matrix shown in Fig. 1 will be used.

 
Risk Acceptance

Table 2, defines qualitative categories of risk and the actions to be applied against each category. The Railway Authority will be responsible for defining the principal to be adopted (in this case the ALARP principal) and the tolerability level of a risk and the level that fall into the different risk categories.

 

 
Preliminary Hazard Analysis (PHA)

The first hazard identification process will be the production of a Preliminary Hazard Analysis (PHA) for each of the systems that make up the HSR project. The PHA is a semi-quantitative initial risk study carried out in the early stages of the project that is performed to identify potential hazards that may lead to an accident. The PHA will rank each identified accidental event according to the severity and frequency. The PHA will also identify potential safeguards and mitigations to be considered for implementation to reduce the risk to an acceptable level.This can have two parts. i.e., Design and construction stage.

 
Interface Hazard Analysis (IHA)

The IHA shall identify and assess existing or potential hazards between systems and/or subsystems and the inter-relationships of each subsystem to determine the cause and effect of possible independent, dependant and simultaneous failures that could present a hazardous condition.

 

Operation and Support Hazard Analysis (OSHA)

OSHA shall consider tasks and human actions including acts of omission and commission by persons interacting with the system, subsystems and assemblies at any level, including the public. All human factors and ergonomic aspects of the design and its operation shall be considered. When the OSHA indicates a potential safety hazard, it shall be made known to HSR immediately.

 

Risk Close-Out

The objective of the Risk Close-Out process is to identify residual project risks for handover to the project owner or contractor at completion of the Handover Phase of the project. Residual Close-Out Risks are defined as those project risks that have a probability of occurrence greater than zero and could impact operations. These risks are detailed in the Hazard Risk Close-Out Register, which is handed over to the project owner to ensure risk management continuity.

 

Conclusion

The Hazard risks are very important issues in construction. Not only this is important for High Speed Rail and Light Rail only it can be applied to every construction field like road construction and Building construction etc. Hazard log for a year was made and risks were analysed. Based on the risk analysis, the following safety measures have been provided:.

Fencing provided for operational area. Fencing overlaps onto viaduct ramp or runs under viaduct ramp (viaduct crosses fence at high level). Automatic area is fenced within depot, and depot has security perimeter fence. Hand rail along raised platform runs along the length of train allowing access anywhere. Fall arrest system to be fitted for all high-level platforms.

Transition slabs installed (by depot / civil contractors). Concrete apron in front of buildings. Fixed concrete end stops in workshop and stabling provided by Civils. Fill the gap with inserts.

Clearly demarcated walking route clear of pit (and clear of train on pittrack). Anti-climb fencing provided around track area. No catenary outside fenced area. Security fencing provided around depot operational area. No public access to depot operational areas. Dedicated loading / unloading area provided at stores. Loading / unloading inside workshops. P-way unloading at dedicated hardstand. Floor areas will be marked to segregate fork lift and pedestrian movements.

Provide separate pedestrian access at gate. Dangerous goods’ store well away from occupied buildings. Guardhouse and perimeter fence to prevent unauthorised access to depot. Clearly demarcated walking route Road has barrier, which can only be opened under Depot Controller’s permission, segregation of Traffic with Road Barrier.

As far as practicable, keep manholes out of footpaths, roadways (also trip hazard from raised manhole covers). Manhole cover is seated and double sealed on the manhole.

 

References
  1. EN5016 “Railway applications-The Specification and Demonstration of Reliability, availability, Maintainability and Safety”
  2. Occupational Safety and Health Act 1994 (ACT514)
  3. Universal Design Standard dated 26 April 2017 Rev P01 (Document Reference No: KLSG-C001-CH2-SA-ST-00-000-000001)
  4. Engineering Safety Management Plan (KLSG-MHSR-CH2-SA-PL-00-000-000005)
  5. Interface Management Procedure
  6. ISO 14001 Environment Management Standard and the Occupational Health & Safety System OHSAS 18001
Benefits Of Steel Construction

Benefits Of Steel Construction

 Dr. R Kuberan,
 Editor
 Civil Engineering and Construction Review

In the multi-storey building sector, the benefits of steel construction are largely related to the fast-track nature of the construction process, which leads to a wide range of financial and process benefits. Many innovations associated with the construction process have further improved these inherent benefits and have increased efficiency and productivity. This is very important in inner city projects where lack of space for storage of materials and other facilities, limitations on deliveries and logistics, and planning constraints, mean that a higher proportion of work should be done in the factory and less on site.

The benefits of steel in multi-storey construction arise mainly from its prefabricated nature, its lightweight and the ability to phase the various activities in series rather than in parallel.

 
Speed of Construction

Speed of construction is the most important benefit offered by steel construction, which leads to financial, management and other logistical benefits, many of which can be experienced in economic as well as sustainability terms. For an eight-storey office building, it is found that steel construction is up to 20% faster than reinforced concrete. But, importantly, the construction of the primary frame and floors is up to 40% faster and allows for early start in building services, installation, cladding and other activities. The fast construction process is based on a synergistic use of steel frames, steel decking and in some cases, concrete or braced steel cores.

The financial Benefits of Speedy Construction Includes:

  • Early completion, which leads to reduced interest on the borrowed capital and to early return in terms of revenue
  • Lower cash flow
  • Reduced management costs on-site, primarily due to the shorter construction period, but also due to the fewer personnel employed
  • Reduced hire costs of site facilities
  • Greater certainty and less risk in the construction process

 

Construction Process

Speed of construction is achieved by ‘just-in-time’ delivery of components and by rapid assembly of the steel framework. It is estimated that a single tower crane can install up to 20 steel elements per day, which corresponds to a floor area of approximately 300m2. Secondary benefits in steel construction arise from:

  • Decking, in ‘bundles’ on the beams and installation of decking at a rate of up to 500m2 per day
  • Avoidance of temporary propping by using steel decking spans of 3-4m for profiles of 50-80mm depth
  • Fire protection by intumescent coating that is applied in the factory and, therefore, eliminates the time required for this process on-site
  • Opportunities for reduction in the amount of fire protection by use of fire engineering analysis
  • Use of mobile installation platforms to improve construction safety and speed up the installation process
  • Prefabricated stairs that are installed as part of steel construction package
  • Safety barriers can be attached to the perimeter steel beams
  • Rapid concrete placement
  • Light steel infill walls and partitions that are installed rapidly and can be prefabricated
  • Modular service units that may be installed with the steelwork package

 

Lightweight Structures

Steel construction of all types is lightweight, even when including concrete floors. The self-weight of a typical composite floor system is typically only 40% of that of a RC flat slab. When the total building weight is considered, a steel framed structure is up to 30% lighter than the equivalent concrete building, which leads to an equivalent saving in foundation costs. Further, steel construction is the preferred solution for building on:

  • Post-industrial or former built-on sites, often with pre-existing foundations
  • Building over underground services and tunnels
  • Building on railway lines and other ‘podium-type’ structures

Steel construction virtually eliminates waste by the nature of its manufacturing process and all steel waste is recycled. Synergistic materials such as plasterboard can also be recycled.

 

Benefits of Adaptability

General expectations for all multi-storey buildings change substantially during their design lives. A building’s occupancy is also likely to change several times during its life. Increasingly, the nature of the occupancy may change. In the 1960s and 70s, many buildings we reconstructed to minimise cost without any allowance for future adaptation. These structures have not proved capable of responding to occupant’s changing needs, leading to their early demolition.

Although difficult to quantify at the proposal development stage, there are clear qualitative benefits in specifying a structure that is inherently adaptable to changes in requirements during its design life. Key issues on adaptability are:

  • Specifying longer spans, permitting greater flexibility of layout
  • Providing space for additional services
  • Specifying floor loadings that permit change of occupancy

Some examples of steel buildings are given below.

 

Office Building, Bishop’s Square, London

The Bishop’s Square Project near London’s Broadgate area comprises a composite steel structure of 18m span and only 650mm depth. There is an almost fully glazed façade and a ‘green’ roof space on three levels. The 12-storey building of close to 80,000 m2 floor area comprised approximately 9,500 tonnes of steelwork and was erected in only 30 weeks out of an overall 20-month construction programme. Fire protection, in the form of intumescent coatings, was applied to off-site in a single operation by the steelwork contractor, which speeded up the following trades.

The highly glazed façade was designed to satisfy onerous thermal requirements, which led to the use of triple glazing with integral louvres. Photovoltaic panels were installed on the roof to provide an energy source for lighting, thereby reducing running costs and CO2 emissions.

The floor-to-floor height was only 3.9m, which necessitated a beam depth of only 650mm as part of a 1050mm overall floor zone. The 9m span heavily loaded primary beams had large rectangular openings and were tapered in depth close to the concrete cores to allow for distribution of large ducts.

Secondary beams were designed as fabricated steel sections with a series of 425mm diameter circular openings of 425mm depth x 750mm length close to mid-span. An imposed load deflection limit of only 30mm was specified, which was achieved by beams of 138 kg/m weight with no stiffening.

 

Luxembourg Chamber of Commerce

The headquarters of the chamber of commerce of the Grand Duchy of Luxembourg was designed by Vasconi Archietcts and comprises an existing building and 20,000m2 of new office space. A conference centre of approximately 8,000m2 was provided together with 650 underground parking spaces on four levels. The total building area is 52,000m2 including car parking.

The four and five storey composite structure consists of hot rolled steel sections and concrete floor slabs with integrated IFB sections (a rolled asymmetric section with a wide bottom flange). The integrated steel beams are stiffened using a lightweight truss below the beams, leading to a 40% increase in span. Services are passed below the beams and through the truss to minimise the floor depth.

The structure was assessed by a fire engineering analysis, which demonstrated that 60 minutes fire resistance could be achieved without additional fire protection. The IFB beams are particularly protected by the concrete slab and support the reduced load in fire despite the loss of the exposed truss.

 

Kings Place, Kings Cross, London

Kings Place in north London provides seven floors of office space, a 420-seat concert hall, are galleries and restaurants. The basement levels house the auditorium and other facilities. The flexible use structure is designed as a steel composite frame consisting of 12m span fabricated beams with multiple circular openings and supporting a 130m deep composite slab. In some areas, the composite floor is supported on a shelf angle.

A novel part of the design was the fire engineering strategy, which demonstrated that the fire resistance of 90 minutes could be achieved by intumescent coatings only on the beam connecting directly to the columns; other beams were unprotected. The columns were protected by two layers of boards. The long span fabricated beams are typically 600mm deep and consist of multiple 375mm deep openings. The 130mm deep composite slab is reinforced according to fire engineering principles, which permit development of membrane effects in fire.

The primary and secondary beams connecting to the columns are protected by 1.6mm thick intumescent coating that was applied off-site to speed up the construction process. The coating was applied in a single layer, which was achieved by designing slightly heavier steel sections to reduce the load ratio in fire conditions. This holistic approach was justified using a finite element model in which the properties of the steel and concrete were modified for the temperatures in both a standard fire and natural fire concept using the fire load and ventilation conditions established for the building use.

A.M. Steel Centre, Liege

The five-storey Steel Centre in Liege, Belgium is an innovative office building designed to achieve a high level of energy efficiency. It is 16m x 80m on plan and consists of an off-centre line of internal columns to create beam spans of 9m and 7m. The longer span secondary members are 500mm deep and are placed at 3m spacing, which support a composite floor. The secondary members use IPE330/IPE300 sections to create cellular beams with regular 400mm diameter openings. The 9m span primary cellular beams are the same depth and use HEB320/HEA320 sections.

A fire engineering analysis was carried out to demonstrate that the composite beams could be unprotected except for those connected to the columns. The columns are concrete filled circular hollow sections, which are unprotected and achieve the required fire resistance, leading to a considerable reduction in fire protection costs.

The building is supported on piles because of the poor ground conditions. The self-weight of the structure (<350 kg/m2) and of the curtain walling system was important in minimising the loads on the piles.

 

References
  1. https://www.steelconstruction.info/Concept_design
Effect Of Green Construction In The Urban Environment

Effect Of Green Construction In The Urban Environment

 Er. Sumeet Agarwal
 HOD Recovery & Consulting Services,
 Sustainable Environment and Ecological Development Society,
 New Delhi

Increasing urbanization has resulted in a spurt in construction activities which, in addition to providing jobs and spaces for living and working, have also created many problems like generation of waste during construction and demolition, spike in demand for water and energy, emissions from materials like paints. Construction industry is estimated to be responsible for 18% of carbon emissions. Cities cover 2% of the world’s land area but account for 70% of greenhouse gas emission, 30% of which are caused by buildings. In view of the issues it is imperative to re-examine the construction practices and try at greening the construction practices to reduce adverse impacts on environment and to reduce living and maintenance costs. It has been reported that compared to traditional construction, green buildings have reduced CO2 emissions by as much as 34%. Green buildings are designed to use less water and energy and improve indoor environment including air quality. Different rating systems are used for green construction, the commonest being the LEED (Leadership in environment and energy design) system. India also has a rating system for green buildings known as Green Rating for Integrated Habitat Assessment (GRIHA). The rating system consists of 31 criteria categorized under various sections such as Site Planning, Construction Management, Occupant Comfort and Wellbeing, Sustainable Building Materials, Performance Monitoring and Validation, and Innovation. All buildings, which are in the design stage and have built up area more than 2,500 m2, are eligible for certification under GRIHA. Building types include, but are not limited to offices, retail spaces, institutional buildings, hotels, hospital buildings, healthcare facilities, residences, and multi-family high-rise buildings.

As seen from the above initiatives, the interest and awareness in Green building systems has been growing in various countries as they face greater environmental issues and find it advantageous to adopt green building systems to address these. However, considering the scale and severity of issues in a rapidly urbanizing world, a more widespread adoption of green building practices at city level would help to develop a sustainable built environment through inherent positive impacts of green construction practices. Such buildings would form an integral part of the smart cities, which are coming up in various countries across the world. Considering the need for green development at a larger scale, beyond the building envelope, a concept of “Green Districts” is emerging, which envisages a densely populated and geographically cohesive area located within and city that employs technology and design elements to reduce resource use and pollution. In general, green districts deploy design principles that lead to dense, transit oriented, mixed use developments and renewable energy sources. The US Green Building Council, which developed the LEED rating system, has also introduced a system known as LEED for Neighbourhood Development (LEED- ND). According to the council the system aims to integrate ideas of New Urbanism, Smart Growth and Green Buildings. The concept of green districts is being widely supported by a number of organizations worldwide and is already being used to revitalize a number of North American cities.

Green districts use various technologies and design elements such as:

Design Elements
  • Dedicated bus/ car pool lanes
  • Pedestrian friendly streets and streetscapes
  • Bike infrastructure
  • Trees/ urban forestry
  • Permeable pavements and green alleys
  • Green roofs
Technologies
  • Energy- efficient street lighting
  • Pneumatic waste transport system
  • Combined heat and power systems
  • Grey water recycling systems
  • Composting
  • Anaerobic digestion
  • Rain water harvesting
  • Renewable energy systems
  • Smart grids
  • Waste to e- nergy systems

Many above mentioned elements and technologies are also part of India’s smart city concept. It has been seen that though the initial cost of development using the above-mentioned technologies and elements is high, these are recovered over a period, making use of these technologies and elements not only viable, but also profitable. However, advantage of green district development should not be seen only in terms of economic costs since they provide significant environmental and health benefits also. They are known to reduce wastes being moved to landfills by as much as 25%, reduce energy consumption by 20-25% and use of freshwater and waste water generation by as much as 60-65%. Such benefits would address many urban issues that Indian cities are grappling with in modern times. Solutions to address issues like scarcity of landfill sites can be implemented on priority to conserve valuable urban land and to reduce the adverse impacts on environment. Green district developments could also contribute to reduction in air pollution, which have been plaguing cities like Delhi, through development of environment friendly and pedestrian friendly transport modes. Such developments can form part of the system of Local Area Plans introduced into planning practices of many cities since many elements, technologies and actions would be required at the local level to ensure development of green districts. Development of such districts can also be integrated into redevelopment or revitalization plans of parts of cities, such as old city areas. However, integration of such concepts would need a shift in emphasis from financial viability of development to environmental and health impacts of planned development since, though the cost of adverse impacts on environment and health are not immediately apparent, the long-term cost in terms of increase in impacts of natural hazards due to environmental degradation and stress on health infrastructure would be very high.

In recent years the city of Vancouver, Canada has figured prominently in green building and green city development. It has developed a Greenest City Action Plan, which would help it develop as a major Green city by 2050. The citizens and the city government are working jointly towards green transformation of the city. As a part of the initiative, the city plans to reduce greenhouse gas emissions of new homes by 33% by 2020 with the aim of making all new buildings carbon neutral by 2030. Greenhouse gas emissions from existing buildings will also be reduced by 20% over 2007 levels. The vision of the green action plan is to develop opportunities while building:

  • A strong local economy
  • Vibrant and inclusive neighbourhoods
  • Internationally recognized city that meets the needs of generations to come

The city action plan is divided into 10 goal areas addressing three overarching areas of focus, which are:

  • Zero carbon
  • Zero waste
  • Healthy ecosystems

Each goal has at least one measurable target for 2020. Each of the goals and their targets are as under.

 
Climate and Renewables

The target is to reduce community based greenhouse gases by 33% from 2007 levels by 2020. Some of the initiatives that are helping to meet the goal are:

  • Neighbourhood energy strategy which aims to i) Cut carbon emissions, ii) Reduce our dependence on fossil fuels, iii) Keep energy affordable in the long term, and iv) Achieve 100% of our energy needs from renewable sources before 2050. Neighbourhood renewable energy systems supply central heating, hot water and cooling using renewable energy systems like heat generated from sewage waste. Such systems, besides reducing the use of fossil fuels also obviate the need for individual boilers in buildings.
  • Zero emissions building plan, which will eliminate emissions from new buildings by 2030. The plan mandates that all new buildings may be constructed to produce little or no Green House Gas (GHG) emissions by: i) Being built to a zero-emission standard like the Passive House standard (which essentially reduces energy demand), ii) Connecting to a neighbourhood energy utility (increasing renewable energy supply), iii) Building all future city facilities to a zero-emission standard, and iv) Developing tools to catalyse private sector leaders to do the same.

 

Green Buildings

The city recognizes the fact that electricity and natural gas being utilised by the buildings are responsible for GHG emissions. Hence, an attempt is being made to improve the performance of buildings through certain initiatives, some of which are:

  • Preparation of zero emissions building plan to eliminate emissions from new buildings by 2030 through energy efficiency and renewable energy.
  • Neighbourhood energy strategy that seeks to develop additional energy systems throughout the city.
  • Building retrofit strategy.

 

Green Transportation

The city aims to provide fast, reliable, frequent and accessible transit. It aims to improve quality of life by making Vancouver a city where moving on foot or by bike is safe, convenient and enjoyable. The city’s targets for green transportation are:

  • Make the majority (more than 50%) of trips by foot, bicycle and public transit.
  • Reduce average distance driven per resident by 20% from 2007 levels.

The initiatives the city is introducing include: i) Public bike share program, ii) Implementing different projects to make streets safer for bikes, resulting in an increase in ridership, and iii) Repurposing an old rail corridor into a greenway.

 

Zero Waste

The city aims to reduce waste going to landfills or incinerator by 50% from 2008 levels.The initiatives that have helped the city achieve its goals are:

  • Diversion of construction waste from landfills: 75% of the solid waste generated from demolition of pre-1940 homes in Vancouver must be reused or recycled.
  • Diversion of food waste from landfill: Many businesses generating food waste have set up an organic recycling program and food and yard waste collected annually from single family homes has increased by 75%.
  • Diversion of electronics from landfills: Many electronics recycling drop-off events were organized in the city and in 2015 about 11,000 electronics and small appliances were diverted from landfills and recycled through drop-off events.

 

Clean Water

Recognizing the possibility of water stresses due to population growth and climate change, the city has taken several steps to reduce water use. It aims to reduce per capita water consumption by 33% over 2006 levels. The initiatives that are being implemented to help meet the target are:

  • Integrated water management plan: In April 2016 the city adopted a target to capture and treat 90% of the city’s average annual rainfall through green infrastructure.
  • Reduced laundry water use: Gathering place community centres have been providing free laundry and shower facilities to some communities since 1995. Volunteers worked with laundry users to ensure that the washing machines were running with full loads, resulting in substantial savings of water and energy.

 

Clean Air

The city is working with businesses, residents and other levels of government to ensure clean air as it is anticipated that air pollution levels would increase with city growth. The city’s target for clean air is to meet or beat the most stringent air quality guidelines from Metro Vancouver, British Columbia, Canada and the World Health Organization. Some initiatives that are helping to meet the goal are:

  • Joining the International zero vehicle emissions alliance: The International Zero-Emission Vehicle Alliance (ZEV Alliance) is a collaboration of national and sub-national governments working together to accelerate adoption of Zero Emission Vehicles. The participants set ambitious, achievable targets for ZEV deployment, take actions to achieve those targets as appropriate in each jurisdiction, act together to achieve individual and collective targets, and encourage and support other jurisdictions in setting and achieving ambitious Zero Emission Vehicles targets.
  • The city completed installation of electric vehicle charging infrastructure. 111 charging stations were installed across the city from 2011. These stations are helping to address public concerns about lack of infrastructure for electric vehicles and help to incentivize adoption of such vehicles.
  • Adoption of neighbourhood energy strategy, which envisages development of neighbourhood renewable energy systems throughout Vancouver city, which is key to meeting greenest city 2020 action plan.

 

Conclusion

The goal of sustainable development can be met only through citywide green development. Green constructions would be a part of the green development plan on a citywide scale to have the desired impact. Cities need to prepare a green development Master plan and set goals for green development to ensure time bound implementation of development processes. Cities like Vancouver can set examples for development. The codes also need to make green development mandatory.

 
References
  1. https://www.nationalgeographic.com/environment/urban-expeditions/green-buildings/benefits-of-green-buildings-human-health-economics-environment/
  2. https://www.nationalgeographic.com/environment/urban-expeditions/green-buildings/benefits-of-green-buildings-human-health-economics-environment
  3. http://www.grihaindia.org/index.php?option=com_content&view=article&id=87
  4. https://www.mckinsey.com/business-functions/sustainability-and-resource-productivity/our-insights/building-the-cities-of-the-future-with-green-districts
  5. http://vancouver.ca/home-property-development/green-building-and-renovating.aspx
  6. http://vancouver.ca/green-vancouver/greenest-city-action-plan.aspx
  7. http://climateinitiativesplatform.org/index.php/International_Zero-Emission_Vehicle_Alliance_(ZEV_Alliance)
  8. http://vancouver.ca/green-vancouver/neighbourhood-energy-strategy.aspx
  9. https://www.nationalgeographic.com/environment/urban-expeditions/green-buildings/benefits-of-green-buildings-human-health-economics-environment/

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