Site Management and Engineering - Essay Example

Formwork for Modern Constructions Q1. The above figure shows the site plan, along with the space allocation for different components of the site. Where the exit and entrance has been kept at the maximum distance apart, this will avoid any accidents due to traffic flow in opposite direction. In addition as shown in the site plan the flow of the traffic is unidirectional and movement corridors are shown. Then, the location of the site office/ Admin area is kept in such a place, from where the whole site is visible, which include the construction site, plant area and entrance, so that the administration can monitor both the incoming resources and directly view the progress of construction. For further safety of the site, an additional gate is placed just in front of the construction area, this is for occasional use. For instance movement of formwork when it is no longer required, this will not disrupt the movement at the entrance and in movement corridors, further making the site safe. The plant area is kept just in front of the construction area, as it will avoid to and fro movement of materials to construction site and save money, manpower and time. The junk area and storage area is kept at the corner end, this place will have minimum disturbance to corridor movement, will be safe from any theft and access to general public could be monitored as it is far from the working area. Lastly the rest area and cafeteria is kept opposite and away from the construction area, this will have a psychological effect on the workers as they will feel easy and this area will have least construction activities, hence least safety supervision will be required in this crowded area. Q 2 a) The most appropriate formwork system for insitu concreting of lift walls would be Jump formwork system. This system consists of two components one being the formwork itself and the other the working platform from which the steel is fixed, concrete is poured. This type of formwork is self supporting and is most suitable for vertical elements such as lift walls. As the formwork is designed for staged processing hence it enables the speedy and efficient construction. The material of choice for our construction site would be Steel, this enables a perfect surface finish. But these steel frames must be properly designed before concrete is poured. The individual panels are attached to the frames which have different supporting conditions such roller support, once the concrete is poured and set, the panel is rolled back and a perfect finish is acquired. In the next process the jacks and lifting mechanism lifts the whole frame up one stage. The process is repeated again where panels are attached and then concreteing is done. This shift of formwork and its components can take as less as 2 hours. This gives speedy and time effective solutions. Some of the views of the system made by Transkon FormworkSystem, are given in the figures below. Transkon are specialist of the field and renowned for new innovative formwork solutions. Q2 b) Although, the jump formwork provides several benefits such as increase in construction speed and low resource requirement interms of manpower. But at the same time it possesses considerable hazards against safety of workers and failure of formwork structural system. As mentioned earlier the formwork is self supporting and self climbing, hence there are chance of structural failures of formwork, incase any joint or member fails and damages will be collateral. The first step towards safety is properly checked safe design of formwork and false work. As these formworks work at a height hence an efficient free-fall breaking devices must be incorporated in the design. Then the platform in use must always be clear from any unnecessary material and waste should be removed as soon as possible. In addition a well maintained false work must be used for erection of the formwork and the platform. Each component must be oiled and painted properly. If excessive damages are seen on these parts they must be replaced. As our material of choice for false work and formwork is steel and metals hence corrosion of these components is to be monitored by the safety supervision team. Braces must be fastened properly, edge protections should be erected on the corners. With the increase of height the lateral support must be increased as well. Incase the height for working increase by two meters or more then continuous ‘false deck’ should be provided. This deck consists of form ply, scaffolding and modular section platform. These decks should not have large gaps; this is very detrimental to safety of the workers. Lastly these false decks must be properly designed for self weight, live load and dead load of materials. Similarly using the deck system the bearers and joists are installed. The figure below shows the mechanism of the decks and erection of formwork and keeping the height restriction in consideration. Figure showing workers working using decks if the height increases more than 2 meters Then fall protection is to be provided along with edge protection, these two protections are very important on vertical shafts such as lift shaft walls. Then one of the most important components for the safety is a safe working area, this is firstly guarded my guard rails and temporary walkways. Lastly, once the concreting is done then the next process is the stripping of the formwork which requires a lot of care and safety. The sequence of removal activities must be appropriate and frame’s structural stability must be maintained at all times. Then proper lighting must be provided while any process, then good housekeeping, appropriate stacking and removal of formwork. Lastly every activity must be properly monitored and movement of the resources should be planned for best practices and any non compliance should be dealt strongly. All issues and incidences must be reported and appropriate remedial measures should be taken. Q3. The basic Gantt chart could only show the starting dates and the ending of a certain activity under the work break down structure. There are advantages and disadvantages of this project progress presentation. The most important advantage is organizes the thoughts in relation to time and activities, consequently the critical activities can be seen. But at the same time the disadvantage is that resource allocation and resource leveling cannot be done through the Gantt chart. Whereas this aspect can be partially accommodated in the new forms of gantt chart where the percentage of shaded/colored bar shows the percentage of completed activity and the no of resources allocated could be written at end of the bar. Hence if the activity is lagging the more resources can be assigned and vice versa, but this is a very crude form of resource allocation and utilization. Then Gantt chart displays the connectivity between activities and find the critical path. In our case the modified version of Gantt chart could be used where all activities of first frame are connected to the second frames on the basis of end to start. As the dimension and shapes of both frames are similar hence same time is allocated to each activity under the work breakdown structure. Inaddition it could be safely said that all resources used on activity one of first frame are shifted to activity one of second frame once the activity of first frame is completed. It is to be noted that the advantage of presentation of connectivity in gantt chart could turn into a disadvantage if number of activities are numerous which would result into very complex chart which could not be read easily and increase the chances of error. Secondly the time allocation on each activity should be estimated with extreme care and accuracy. If there is change in time duration of one activity the entire critical path could change. As the two frames are intensively connected, therefore the time management of construction of each frame is important. Concluding the facts that gantt chart can show connectivity, increase the understanding of the viewer, lag lead of an activity, help in organization and increase the forecasting ability but it cannot help in resource allocation, resource leveling, cannot provide early start early finish, cannot display risks associated and lastly the success of Gantt chart depends greatly on the expertise of its maker in time allocation and later in monitoring of time. References TRANSKON,UK Wall Formwork System. (2005). WALL FORMWORK SYSTEM. Available: http://www.transkonunispan.com/twallform4.html. Last accessed 28-07-2012. Rohan Rupasinghe and Éanna Nolan, BRE (2010). FORMWORK FOR MODERN, EFFICIENT CONCRETE CONSTRUCTION. BRE, Garston, Watford WD25 9XX, UK: IHS BRE Press Willoughby Road. 1-25. Workplace and Health Safety, Queensland. (2011). Risks associated with lifting formwork. Available: http://www.deir.qld.gov.au/workplace/publications/alerts/risks-lifting-formwork/index.htm. Last ccessed 27-07-2012. KHK Scaffolding & Formwork LLC (2005). Special Formwork. Ajman, United Arab Emirates: KHK Scaffolding & Formwork LLC. 1-14. The Concrete Centre. (2009). Jump form. Available:http://www.concretecentre.com/technical_information/building_solutions/formwork/jump_form.aspx. Last accessed 27-07-2012. Read More