The development of the construction industry requires comprehensive industry data for strategic and sustained development. The construction sector contributes to a huge percentage of the national GDP due to government and private sector financial involvement in the development of infrastructure, Boh & Šumiga (2008)..
The field work involved the observation and learning to establish qualitative and quantitative information is the industry relating to technologies used, equipment, methodologies and principles of safety involved during the construction process. A blend of these control measures is the best condition in the workplace which also relies on the qualities of the ground soil and material. In developed zones or street lanes, the excavation must be completely or halfway supported or sheeted to prevent landslides because of machinery movement, pressure from adjacent buildings and instability of the soil due to factors such as water content, type of soil and depth and angles of the excavation.
The site selected was a construction site in the outskirts of the city involving major excavation for a large building. The site is an area adjoining many building. Building and construction industry is involved in many aspects of civil engineering.
The basic principles involved during the excavation include the use of steel sheets to form interlocks that stabilize the ground, Peng & Wu (2008). These sheet create a barrier that blocks the flow of soil created due to the instability of the ground during and after exaction. The backfill material is transported away from the construction site because concrete would be used to create the foundation.
In building and construction, different processes are applied during the process. The process of construction begins with a geotechnical engineer analysing the safety and stability of the soil to be excavated. Excavation of the ground soil is the second stage in the construction process to form a strong foundation for the building bridge or roads.
In reference to Russell (2009), development laborers should be legitimately prepared and taught on the undertaking or employment before working, which will help with counteracting wounds and passing. There are numerous techniques for preparing development laborers. One technique is training development site foremen to incorporate wellbeing in their day by day verbal trades with specialists to decrease business related mischances.
Equipment are used during the construction process. During the excavation process, studied in the field, earthmoving machinery such as tracked excavators, back hoes, bulldozers, draglines, trenchers and hand tools such shovels and spades.
Sequence of work in construction site
In this stage of the construction, the whole processes which are related to the collection and assembly of the cores , the interlocking and the diagrids kicks off which putting the setting out procedure into consideration. The assembly of all the materials which are related to the construction of the of the building helps so much to the engineers and the builders during the construction process to get everything in place during the process of excavation and laying foundation of the building, Ali & Kamaruzzaman (2010).
The Hop ups also should be placed on the ground level that is very much stable especially when it is getting to the level which is very high. The whole process of collection of materials for the construction must be done in accordance with the procedure of material collection in the construction industry.
Formwork and reinforcement Prefabrication
The prefabrication and the formwork of ring and the core must be present at this stage. And prefabrication has to be kept in the timber so that the lifting process might be easier.
The utilization of the pre-assembled steel and the concrete segments in structures are the most normally utilized construction type in structural and building designing where a specified shape and part is ordinarily rehashed. It becomes so hard to create the formwork with the needed shape and conveying wet cement to the site before it begins to set the exact time which is needed for the administration, Singh et al (2010). Using solid zones in a plant carries the reimbursements of having the ability to re-use molds and also the solid can be jointed on the spot without being transported to and directed wet on a congested development site. Pre-assembling steel segments diminishes nearby cutting and welding costs and in addition the related perils.
Construction procedures are utilized as a part of the development of loft squares, and lodging improvements with rehashed lodging units. The nature of pre-assembled lodging units had expanded to the point that they may not be recognizable from generally manufactured units to those that live in them. The strategy is likewise utilized as a part of office pieces, distribution centers and processing plant structures. Pre-assembled steel and glass areas are generally utilized for the outside of expansive structures
Setting out always took place in immediately constructors land on the construction site. Despite the many methods of doing the set out, it is sometimes advisable to use the cable avoidance tools in doing the setting out. For the case of the construction under consideration, the interlocking were used for the setting out. This same interlocking are also used by the to prevent the walls from collapsing during excavations process. This is because the area under construction activity is limited and hence the use of interlocking will really help in the above process.
According to Zhang et al (2010). a building is set out keeping in mind the end goal to precisely characterize the layout and width of the exhuming and to decide the middle line of the proposed assembling dividers, with the goal that development as per the building experts drawing plan can be move into the ground, this building procedure is gotten setting out of building. The middle line strategy for setting out is for the most part favored and embraced
Setting out can be an exceptionally complex designing procedure yet with require encounter its very simple. Experienced designer and surveyors are those associated with setting out of structures, in huge ventures, administrations of land surveyors are required for more exact exchange of levels and edges in setting out with the guide of a Theodolite to chose point around the building territory
In order to lay out foundation for the construction, excavation is very much necessary. The region for the construction which is interlocked with interlocking was excavated keeping tract of the region under which the process is taking place. For this case the Banksman are were required in order to flag the excavator agents for the same purpose.
For the disposal of the excavated material which is majorly soil, this must was put more than a meter away from the excavated region. Though since the region was so much limited, the excavated materials were carried away far away from the region where the construction was being done. All precautionary measures which are supposed to be taken while excavating were all observed, some of the measures included cautioning signs were put all over with reflective signs showing that excavation is taking place in that place. partition hindrances, and cautioning signs. The interlocking was also used to block people from entering the area where the process of excavation is taking place, Abd El-Razek et al()2008.
In order to prevent and avoid over excavation, the level under which excavation was taking place was being checked upon time to time. This was also helpful so the process does not go further past the measured level. Just after the level of excavation was reached, the ground was leveled in order to be equal from all corners of the region.
According to Fugar & Agyakwah-Baah (2010). Excavation s the process that involves, uncovering, removal and unearthing of the ground soils and materials using the explosives, and other gadgets. This includes the following, the trenching , the earthworks, the divider shafts and burrowing process. The process of excavation contains the following critical areas, this are; investigations, mining , ecological reconstruction, and development. Among the above areas, the development is the most critical area of excavation. The excavation is taken as the part of development process of both buildings and also the streets. As part of excavation, the processes involved in this includes trenching, digging, burrowing and also site advancements. Each and every process in excavation demands plans, hardware equipment and manpower too
Earlier to the uncovering procedure can begin, the construction site has to be analyzed precisely to make sure that the common natural surroundings and curios encircling it are driven forward all through the removal. Then, the strategies for the extent and perspicacity of the location are the created and the unearthing organization influences illustrations from them to unmistakably stamp the removal to site's limits. After these two important advances have been taken, the exhuming work can start.
Developing excavation requires ability, involvement and close meticulousness since it controls extensive edifices and creates the formation for the complete undertaking. Considerable mechanical short-term employees makes us of the propelled methods, devices and overwhelming hardware to ensure that the activity is done well. Enlisting an overwhelming modern temporary worker to finish vast unearthing ventures will yield the best outcomes. Kick your undertaking off by investigating the substantial modern temporary workers that administration your territory. You will need to observe their notorieties and qualities on security to limit your rundown to the best in the business. You can discover this data by directing a speedy Google seek, making an inquiry or two in the development business and additionally inspecting their sites. Choosing an overwhelming mechanical temporary worker who esteems wellbeing, is known for quality effort and has engrossment in the excavation growth will produce the greatest results for your considerable amputation undertaking, Seppänen (2009)..
Hard-core and Blinding
The hard core was used for the ring beam in the construction site, the foundation too was filled with the thick materials which was about 400mm after which it is compacted. The top part of the hard core is then filled with thin layer of the concrete approximately 50mm high. This thin layer of concrete is then what is referred to as blinding.
Before the oversite concrete is laid it is common to daze the best surface of the bad-to-the-bone. The reason for this is to keep the wet solid running down between the chunks of broken block or stone, as this would make it less demanding for water to leak up through the bad-to-the-bone and would be inefficient of cement. To visually impaired, or seal, the best surface of the bad-to-the-bone a thin layer of exceptionally dry coarse cement can be spread over it, or a thin layer of coarse clinker or cinder can be utilized, This blinding layer, or coat, will be around 50 mm thick, and on it the site concrete is spread and completed with a genuine level best surface. Indeed, even with a decent in-your-face bed underneath the site concrete a thick hard floor complete, for example, tiles, might be somewhat clammy in winter and will be frosty underneath. To decrease the coldness experienced with some strong ground floor completes it is great practice to shape a constant soggy verification layer in the site concrete.
Placing formwork & Pouring concrete.
Under this stage of the construction on the site, the foundation ring and the core was further marked just after the binding has been cured. The support of the ring beam and the core was also placed of the layout which had been marked before. The formwork which is supported was then arranged around the central core temporarily. It was necessary for the ring beam inner shuttering to be arranged according to the early drawings. This was further followed by keeping the outer shuttering.
The jet washer was also used to clear the area where construction has to take place, then after this, the concrete was then poured inside the layers of the ring and the core too. For the purposes of compaction, the layers were compacted together using the vibrating pokers which is a machine used in compacting two layers together in construction sites.
After the formwork was ready for removal, this was carefully done and the de-nailing of the concrete too pace after the curing of the formwork in order to keep off the accidents that might cause the same. The expulsion of cement formwork can also be referred as stripping or rather striking process of the formwork which is ought to be performed immediately after the adequate increase in quality of the concrete, when the formwork is removed, no less than twice the apprehension that the solid will be passed through. It is also very much important to make sure that the soundness of the rest of the formwork after the expulsion of the formwork.
Concrete Formwork Removal Time
The actual rate at which the cement can solidify and its quality is reliable to the temperatures and also the influence under which removal time of the formwork is influenced. Taking the example, the time which is required for the removal of the cement in the season of winter will actually be more than the time of the summer.
A special consideration should be preferred at the removal time. Some of the examples includes the chunks and the pillars. As these individuals are endangered to self-stack and in addition animate capacity notwithstanding amid development, they might divert if at all the quality picked up isn't sufficient to deal with to weights.
In order to do the evaluation of the cement just before he removal exercise, the 3D solid shapes tests and the barrels are supposed to be done. The barrels and the 3D solid squares are supposed to be set out just from the blends which cannot be distinguished from the barrels of the basic persons which are cured under the conditions which are the same in both dampness and the temperature too as that of basic part, Sweis et al (2014).
After an assurance that the basic tested solid has increased in the quality hence can withstand the pressure for the stack, the formworks therefore are supposed to be removed. On the off chance that conceivable, the formworks therefore must be left for quite sometimes since it helps in the curing process.
Splits development because of warm compression of cement just after the process of striking the formwork. On the off chance that their exists is a serious risk of the harms as above , it is smarter for deferment of the expulsion moment of the formwork. Again, on the off chance the formwork need to be evacuated for streamlining the solid development exercises, at that point these structures must be protected well to anticipate such harms.
The trench that was around the ring beam was to be backfilled which the excavated materials. The pebbles and the vegetation which are around were removed, this is in order to give out space for backfilling process to take place. The materials which are backfilled were then compacted together in to the stage that is standardized.
Backfilling is the process that involved returning the excavated material into the trench just after the excavation process is done. The overall process of backfilling needs expertise and training of the whole process, which involves the contracting and also getting to understand how the soil or material conditions are. The process of backfilling is considered as the pasrt of construction process which includes, establishment, securing, filling and arranging of potholes on the structures which are underground. Muhwezi, Acai & Otim (2014)..
Effects of stacking of the shafts ,pipeline, appurtenances and structures has to be avoided from amid the position of inlay. Refilling should be possible utilizing the accompanying methods.
Refilling with stream enables the temporary worker to leave the trench and return later constraining pressurized water into the trench utilizing a long metal gadget. Water flying ought to be maintained a strategic distance from on plastic soils or overwhelming earth soils, in any case, it is prescribed in sand or in exceedingly fissured bedrock. In flying, you direct the water under strain and utilize the power of the streamed water to move the bedding or inlay material around.
Similarly as with any inlaying, material ought to be put gradually and in lifts. Flooding or 'streaming' inlay by and large delivers poor to exceptionally poor compaction. It is important to take preventive measures to contain water containing dregs, and specifically, counteract it entering channels and water courses, all as per EPA Guidelines. In the event that the water can't deplete from the refill soils, the material will be setup for future fall. This particular material is then compacted making use of some mechanical means, for example, a compactor on an excavator or a "bouncing jack" which is a type of a compactor. Smaller soils to at least the rates of greatest dry thickness. The dirt lift will rely on the idea of the inlay, and the compaction gear to be utilized. Water might be included amid the compaction procedure, to help with compaction.
Risks in construction and their mitigation.
Accidents occur during the process of construction. Many of the accidents occurring in the construction industry are during excavation process. There risks include:
Construction industry requires human efforts and labour for a smooth success. However, the people working at the construction sites are exposed to risks of falling off high places or building material falling on them and therefore the workers end-up sustaining injuries and death. The mitigations involved in the construction industry to avoid falls as safety hazards to the individuals working in the site or by-standers are;
- Substantial barriers are installed around edges of trenches, holes and cavities to prevent people from falling into them.
- Support and use of controlled safety belts for workers at great heights who are at increased risk of falls.
- Use of temporary work platforms.
- Collapse of the excavated sides and landslides.
Excavation causes the surrounding soils to become unstable. This instability causes the shifting of ground matter such as soil and their collapse into the excavation. Ground collapse occurs suddenly and thus allow no time for escape manoeuvres for the workers.
This risk is mitigated through;
Adherence to the safety principles of excavation that are recommended from the geoengineers report on soil stability of the area such as water content, type of the soil and slopping of the area.
The excavation slopes are benched and battered at safe angles. Benching ensures stability through reduction of the excavation wall heights and therefore offering more stability. The steps constructed during the excavation process allow soil strength to be retained. Battering involves the excavation of the wall to a predetermined angle to maintain stability. Both these techniques are employed for more stability.
Steel sheet pilling are also installed prior to the excavation process to maintain the stability of the ground. This technique employs the use of light and heavy duty interlocking sheets of steel to reinforce the walls of the excavation.
- Vehicle and machine accidents;
The processes of building and construction involves the use of a lot of heavy equipment to drill, excavate and transfer loads. The utilization of such equipment exposes the workers to safety threats that require precautions. Engine vehicle crashes are another significant wellbeing danger on development destinations. It is imperative to be careful while working engine vehicles or hardware on the site. An engine vehicle ought to have an administration stopping mechanism, crisis slowing mechanism, and a stopping slowing mechanism. All vehicles must be outfitted with a capable of being heard cautioning framework if the administrator utilizes it. Vehicles must have windows and entryways, control windshield wipers, and an unmistakable perspective of site from the back window. All workers ought to be appropriately prepared before utilizing engine vehicles and hardware. The accidents include crashes and collisions.
These risks are reduced through:
- Strict supervision and good communication among the workers in the construction site.
- Safe access for use of the construction equipment in form of temporary roads and pathways.
- Operation of excavation equipment away from the edges of the excavation and ensuring a safety distance away from other workers and machinery.
- Damage to pre-existing services such cables, gas pipes and water and sewerage systems.
In construction operations involving penetrating the ground level, buried services are assumed to be present unless proven otherwise. The damage to these services causes widespread environmental and community destruction in cases of explosions and fires, floods and power losses.
Precautions taken to reduce such accidents include;
- Strict observation of the elements of construction, that is planning of the work, cable and pipe locations and safe digging processes.
- Proper training of the workers before the commencement of the building process and supplement the training with onsite supervision.
- Use of cable and pipes detectors and locating devices that employ different techniques to detect and report underground services such as cables and pipes.
- Use of safe digging processes such as use of digging tools and high velocity water and air jets to remove excavated material.
- Noise pollution;
The construction industry produces a lot of noise from the machines and equipment used in the different processes. Continuous exposure may result in hearing problems and losses.
- The employees are advised to use ear plugs to control the amount of noise.
- The project management are encouraged to utilize new technology systems that minimize noise emission.
The construction of any building by using the construction industries must take the above procedure for the whole process of construction to be successful. Those process and the procedure might vary in accordance with the location of the site where construction has to take place. Though this process was only up to the backfilling process, it is really good for the whole process to be followed in accordance with the set out conditions. The process of excavation is so much risky since some situations where the walls of the excavated region might fall hence causing injuries to the engineers who are responsible for the process, Lai et al (2008).
It is recommended that the site precautionary measures must be taken to avoid future injuries and deaths. The use of the interlocking must be applied in order to prevent the walls to fall in any case it happens.
Boh, B., & Šumiga, B. (2008). Microencapsulation technology and its applications in building construction materials Tehnologija mikrokapsuliranja in njena uporaba v gradbenih materialih. RMZ–Materials and Geoenvironment, 55(3), 329-344.
Peng, C., & Wu, Z. (2008). In situ measuring and evaluating the thermal resistance of building construction. Energy and Buildings, 40(11), 2076-2082.
Russell, A., Staub-French, S., Tran, N., & Wong, W. (2009). Visualizing high-rise building construction strategies using linear scheduling and 4D CAD. Automation in Construction, 18(2), 219-236.
Lai, Y. T., Wang, W. C., & Wang, H. H. (2008). AHP-and simulation-based budget determination procedure for public building construction projects. Automation in Construction, 17(5), 623-632.
Ali, A. S., & Kamaruzzaman, S. N. (2010). Cost performance for building construction projects in Klang valley. Journal of Building Performance, 1(1).
Singh, A., Berghorn, G., Joshi, S., & Syal, M. (2010). Review of life-cycle assessment applications in building construction. Journal of Architectural Engineering, 17(1), 15-23.
Zhang, X., Shen, L., & Zhang, L. (2010). Life cycle assessment of the air emissions during building construction process: A case study in Hong Kong. Renewable and Sustainable Energy Reviews, 17, 160-169.
Abd El-Razek, M. E., Bassioni, H. A., & Mobarak, A. M. (2008). Causes of delay in building construction projects in Egypt. Journal of construction engineering and management, 134(11), 831-841.
Fugar, F. D., & Agyakwah-Baah, A. B. (2010). Delays in building construction projects in Ghana. Construction Economics and Building, 10(1-2), 103-116.
Muhwezi, L., Acai, J., & Otim, G. (2014). An assessment of the factors causing delays on building construction projects in Uganda. International Journal of Construction Engineering and Management, 3(1), 13-23.
Sweis, G., Sweis, R., Hammad, A. A., & Shboul, A. (2008). Delays in construction projects: The case of Jordan. International Journal of Project Management, 26(6), 665-674.
Seppänen, O. (2009). Empirical research on the success of production control in building construction projects. A PhD thesis, Department of Structural Engineering and Building Technology, Helsinki University of Technology, Finland.