on BUILDING CONSTRUCTION By Shamsudheen Kottayil (10 B4)
CERTIFICATE This is to certify that Mr. SHAMSUDHEEN KOTTAYIL has conducted a seminar on: BUILDING CONSTRUCTION by learning the subject from various sources. Overall rating of the seminar preparation, data collection, documentation and presentation is Outstanding Director Dr.Abdul Nazer Dt: 29-10-2010 1
Abstract Building Construction Key words: Building, Construction, Methods, Design, Estimation, Drawing, Planning, Foundation, Structure, As-Built. Building construction is one of the major activities that take place everywhere for residential, governmental and commercials purposes. With the advent of modern technology, building construction methods have been improved to build anywhere on the earth irrespective of the soil and weather conditions. Building construction is a project where lots of man power, equipments and materials are required. This project consists of many activities from foundation to finishing works. Schedule of activities with delivery of materials and manpower will be determined only by a scientific planning. To plan a project detailed design drawings and material specifications should be ready and thus to forecast the cost of the entire project. This seminar illustrates the general features of building construction based on a study conducted in Dubai; including design, drawing and planning aspects. Various parts of a building structure and different methods of construction are also discussed. I hope, this report can be used to learn the basics of building construction, for anyone who are new to this industry. Shamsudheen Kottayil ( Class No:10 B4) 29-October 2010 2
Contents No. Description Page 1. Introduction... 4 2. The crew... 4 2.1 Parties involved... 4 2.2 Authorities... 5 2.3 Construction team... 5 3. Project process... 5 3.1 Construction procedure... 5 3.2 Flow diagram... 6 3.3 Software used... 6 4. Construction... 6 4.1 Drawings... 6 4.2 Site preparation... 7 4.3 Shoring and excavation... 8 4.4 Super structure... 10 4.5 Equipments and materials... 10 4.6 Electrical and mechanical works... 11 4.7 Finishes... 12 4.8 Completion stage... 12 5. References... 13 3
1. Introduction Ancient people were lived in caves and huts. Gradually the mankind started to develop by all meaning like culturally and educationally and it made them to change the total life style. The modern people like to live beside the cities because the 90 percent of the life is connected to the cities. So there should be some convenient place to live beside the cities, and in the cities, it is not practical to have individual houses for all like in villages because lack of space, so the multi story buildings are found and it plays an integrated roll in mankind life The buildings are classified to many categories like commercial, residential, official, industrial, labour accommodation, hotels etc.,. There are authorities to approve and to control the construction projects, for example: Town Planning Department in Kerala. Buildings have to be very safe and maximum convenient place for the end-users, same time it has to be less expensive and more beautiful to look. So it is crystal clear that high qualified and specially trained people have to involve in this subject Sky scraper towers with very special features and small villas are not covered in this report, but design and construction of normal buildings like ground + 1 to G+35 stories in U.A.E are covered. The data has been collected through my working experience, visiting construction sites and my colleagues 2. The crew 2.1 Parties involved: 2.1.1 Investor or Client: Building construction is a business and money is the main capital of this business like all others. Client is the owner of the building. The client should invest a big amount of money to develop the building. 2.1.2 The Consultant or Engineer: Consultants are the brain of the project and same time they are representatives of the client. They make a basic concept design of the building at the beginning as per the owner requirement and detailed design for construction within the limit of Authorities rules and regulation and obtain a design NOC from all relevant authorities. Authorities have written rules and regulation specifically for each type of buildings and the consultant also looks after the development and controls the contractor and finance flow as the construction in progress. Consultant should have qualified Architectural, Structural and Electro Mechanical engineers who can design the building. Architects concentrate aesthetics and ergonomics while structural engineers more concerned about the strength of the building. Electro Mechanical engineers take care of electrical supply, lighting facility, fire protection, cooling system and drainage services. It is in the scope of Consultant s work to inspect and certify the work which has been completed by the Main contractor on a monthly basis in order to the owner can release the payment to the Main Contractor. 4
2.1.3 Contractor: Contractor is a company who executes or constructs the project. Contractor has to have different skilled and unskilled labours, engineers and managers in various departments, construction equipments, etc., 2.2 Authorities All the authorities are mostly government representatives and look after the quality and safety of the developments and control the construction within the regulations set by the government. A No Objection certificate has to be obtained by the Consultant by submitting the preliminary details. Then again a set of detailed drawings should be provided to Municipality to obtain the final building permit including floor layout, longitude sections, stair details, electro mechanical services details, structural details are considered. Once the final building permit is issued the contractor can commence the site and a completion certificate has to be obtained by submitting as built drawings and specification when it is completed the project The main authorities are involved in the above topic are Dubai Municipality, Dubai Water and Electricity Department, Etisalat, Civil Defence, Dubai Roads and Transport Authority and Civil Aviation. As mentioned above the No Objection Certificate issued by the concern departments shows the details of existing services running around the subjected plot. So the designer can design the development at maximum convenient and avoid making damages by digging on existing services. 2.3 Construction Team Construction team consists of the following engineers and technicians in different filed headed by project manager. Site Engineer: to supervise and lead whole or part of a project Quantity Surveyor: works on quantities, specification, cash flow and approvals Planning Engineer: Planning and Monitoring Draughtsman: drawings Surveyor: Land surveying, GPS positioning, etc., Foreman: to lead a construction crew of specific task Skilled labour: experienced labour in a specific task, eg: carpenter, mason 3. Project process 3.1 Construction procedure: Once the preliminary design and approval has been finalized consultant prepare a tender document contains detail drawings, Tender and contract conditions, specification and Bill of Quantities, tender out on behalf of the investor to the well known contractors in town. The participated contractors have to submit their price within the specific date and time and job will be awarded to the most reasonable contractor by the owner. Then the consultant prepare three sets of drawings and specification which have to be stamped and signed by all parties and keep one copy each as a contract document for reference as an when the construction is on. No changes can be applied to the design without written approval by the owner and the consultant. The contractor should obtain approval for each and every part of the construction on a shop drawing which details how it will be applied on the building from the 5
consultant, prior to comments at the site. And the contractor also should obtain approval from the consultant on each and every material by specifying details of the manufactures, quality and origin. The Main Contractor appoints so many subcontractors by seeking the owner s and consultant s no objection to do the various works like Joinery, Sanitary Ware, Tiling, Water Proofing, Sauna, Aluminium works, Refuse Chute, Marble works etc. Planning Engineer has to prepare detailed schedule of activities and should be approved by all the parties involved. BOQ: is the Bills Of Quantities explains all the material specifications with the quantities 3.2 Flow diagram: General flow diagram of a construction process is presented below. Start Client requirement Preliminary design by consultant Tender documents: drawings and BOQ Selection of contractor Approval of materials, sub contractor, etc.. Begin construction Partial payment to contractor Review and monitoring Handing over End 3.3 Software used Some of the engineering softwares used are: AutoCAD for drawing by draughtsmen Primavera for planning and monitoring by planning engineers STAAD structural analysis and design by structural engineers 4. Construction 4.1 Drawings: As described above for each and every single part of the building has been explained in the drawings and specification. Drawings can be classified to four categories 6
commonly. They are Plan, Section, Elevation and Details. A plan indicates the top view and section indicates the cut view. Elevation represents the front view. Details detail the dimension, location and materials- how and where to be fixed Seminar 4.2 Site preparation: Once it is obtained a Building permit from concerned Authority the Contractor can comments work on site. Part of checking the water contents and strength of the plot, collecting some soil by digging in various part of the site and sent it to the laboratory. The contractor places some motor pumps in various part of the plot for some days and make sure the site is ready for excavation. This process is called dewatering. Also a Topographical survey plan is prepared by the specialized parties in that field. This plan has the geographical coordinates of the plot and it is referred to locate the existing site conditions and levels A fence has to be provide around the site and a sign board has to be placed showing the details including the Building Permit Number, owner and consultants details at the entrance gate of the site. 7
4.3 Shoring and excavation: After completion of all these pre arrangement, now it can be started to excavate the site. Most of the buildings have one or more basement floors those are used for Car Parking and stores. Basement floors are below ground level, so the plot has to be excavated to obtain enough clear head room below. To prevent the soil falling to the plot from the surrounding areas, a barrier has to be placed. This procedure is called Shoring. Makes holes like a bore well on plot boundary continuously and adjacently by machine till achieve the sufficient depth and fill it with iron and concrete. There are many kinds of shoring depends how deep the plot has to be excavated. A special approval has to be obtained to start the shoring work from Dubai municipality and RTA in order to avoid damaging the existing service pipe lines running surround the plot when it is excavated.. When the excavation is reached to the calculated level, very deep holes are made according the structural engineers instruction at specific distance and size inside the plot, and circle shape mesh, made of strong steel bars are dropped in to it and fills with concrete. This process is called piling, and those act like strong legs of the building, the whole building wait is distributed to the earth through the piles. Quantity 8
On the footings a huge quantity of iron bars are laid vertically and horizontally at specific distance and shape as designed by the structural engineers and fill with concrete it is called foundation slab. 9
4.4 Super Structure: Part of the building above ground level is called super structure. The following facts are considered for the design of super structure. Shear stress, compressive stress, tensile stress and wind load. Concept of this is to provide enough strength for the building to defend against to the pressure from various sides. Concrete columns and core walls around the lifts and stair cases and other important part of the building to prevent the natural calamities like, Earthquake and Storm. Columns and beams are designed in a particular size and location to distribute the building load to the earth Normally the height of each floor is 3.1 meter. With 200mm slab thickness. Some cases, instead of concrete structure, steal structures and pre-casted slabs are applied When the columns reached to a floor height level, the floor slab is casted. Columns and beams are act like bone in human body. Gap in between columns and beams is filled with block work which is called walls. The building strength is depends the structural engineer brain while the quality depends the architect s. Lifts are used to access floor to floor up and down in multi story Buildings. Even though there are lifts, stair cases should be provided. Because lifts work with electricity only, emergency situation the staircases are more considered, especially for fire exit. All the doors and openings in the slabs are to be provided with fire proofing system in order to prevent the fire spreading from place to place in a short time. The department of Civil Defence regulation instructs to provide necessary precautions prior to issue a building permit. 4.5 Equipments and Meterials: Tower crains and Fork Lifts are very important in construction, they handle heavy equipments and meterials to move all over the building and it is operated by an operator. Scaffolding helps the people to stand on and reach the higher level places and do the necessary works. Hoist acts like a lift at constructin stage. All the consultants and the contractors have to have temporoarly offices at the site and full time site engineers to look after the project. Window Craddle helps the technision to move around the building for the necessary actions. Mexer is used to make the concrete. There are many other equpiments also used. Refer the construction magzins. Water Proofing Membrain applies on the floor and roof slabs and all other wet areas to prevent the water leakage. Expansion Joints are fixed in between two slabs to reduce the span. Angle beeds, Raw Cool insulation, Sealant, Iron Mongery, Ducts, Thermalited blocks, Cable trays, Flexcel sheets, Gypsum boards, Aluminium Cladding Sheets, Tuffen Glasses, are a few meterials among the hundreds applies on the building for various purposes 10
Lifts, Automatic sliding doors, Car Park Barriors, Door access cards, Fire Alarm systems and Fire proofed doors are some of the technologies used in the building. 4.6 Electrical and Mechanical works: Electrical and Mechanical services make alive the building. Providing hot and cold water, air cooling system, lighting, ventilation, waste water discharge and fire protection system, are the major services. As mentioned above the owner has to provide enough number of transformers to generate sufficient power as suggested by DEWA and DEWA connects the power to substation. Ancient people used to use manual fan to get relieved from the hot climate, and then the Electrical fans are founded. Soon the Air Condition system became very common for this purpose. There are various kinds of Air condition units, such window A/C, Split Unit and Central A/C. Basic functioning for all of these are same. It has four main units. Evaporator, compressor, condenser and fan coil unit. Air inside the room is exhausted through the evaporator unit and passed through the fan coils. The compressor sprays the form type gas and makes cool the air and push back to the room with help of a fan located inside. Window air condition unit has all the units attached together while split A/c s evaporator unit is inside the room and rest parts are somewhere outside. The Central A/C has main central unit for all this mechanism and can be fixed anywhere in the building. The produced cooled air is distributed through ducts to all over the building. Another system is chilled water system. It has huge cooling tower unit. The chilled water is sprayed to fan coil so the produced air becomes cold. And it is distributed through the pipe lines to various places. Hot and cold water distribution is another major service. Cold water is produced with help of compressor and hot water with help of heater. Drainage system is how the used and waste water is discharged, and usually it does not require the power supply. It is an arrangement of pipelines in 11
a particular an accurate manner. Any how some case it may be needed a support of pressure pump to push or pull then, the power should be required. Fire Alarm and Fire Protection system work with help of many sensors which detect the smoke and Fire and give signal to make alarms then the people realize that something wrong in the building, get the necessary precautions. With the help of modern technology most of the buildings have been connected to the Department of Civil Defense, so the department can realize themselves the danger spot and rush to there without any information. 4.7 Finishes : finishes means, dressing and apply enough make-up for good look and protection for the building. Externally it decorate with plastering, Curtain walls, Cladding and painting while internally with tiles, marbles, ceilings, attractive lightings and furniture. Interior designer s ideas can make the building lovelier by internally for the end-users. 4.8 Completion stage The project has to be completed as programmed and agreed schedule. In case of any delay due to some parties failure to complete their scope of work without any reason, the owner can penalize those parties as it is mentioned in the contract document and the owner has also right to penalize the contractor in case he realize that any cheating or violation has been carried out in the construction. That is why the owner insists on the contractors to keep a security bond before they involve in the project. Failing to complete their scope of work the owner has right to encash the bond. At the stage of completion the contractor should prepare an as built set of the drawings and obtain all the authorities approval stamp on it. The contractor is also instructed to submit a warranty letter for the work and material applied on the building as well. These documents are the owner property, can be presented in case of any discrepancies raised in future. Anyhow there will be a one year maintenance period. If any self damages happen, that is contractor s liability to rectify the defects. The owner retains a 5% of money till this maintenance period is over. 12
References 1. My Colleagues 2. www.dm.gov.ae 3. Mr. Paul D Souza. Project Manager for Pull Man Hotel in Jumeirah Lakes 4. The Construction Week 5. Jumeirah Lake Towers. Dubai Contact Info: Shamsudheen Kottayil abunaseel71@googlemail.com Mobile: +971-50-4522069 13