Work Breakdown Structure for the Construction of the Bridge Abutment - Report Example

Name of the student Name of the institution Date of admission Report background Project management is the discipline of carefully projecting or planning, organizing, motivating and controlling resources to achieve specific goals and meet specific success criteria. In order to achieve aims and objectives of project management, work breakdown is used and in most cases, other tools like gant charts are used to explain and give direction in project management (Richardson & Lee 2011). The present Project Managers are frequently finding it very valuable in the creation of Work Breakdown Structures (WBS) as they begin the process of project management. Project success may be attributed specifically to use of a WBS. This report gives the work breakdown in the construction of abutment (Hunt & Lyons 2010) Building of abutment An abutment is a retaining structure normally designed and put up at the edge of a bride to act as support. Abutments in most cases are necessary to act as resistant as well as transfer excess weight that may be caused by the lateral earth pressure. An abutment is composed of a stem wall, an end diaphragm, and wingwalls. A stem wall or diaphragm functions as a wall providing lateral support for fill material on which the roadway rests immediately adjacent to the bridge. Abutments shall generally be of the cast-in-place, reinforced concrete type and shall be founded on spread footings, drilled shafts or driven pile footings (Landva et al., 2008). With the proposal of having an underpass linking A45 Stonebridge Highway to the A46 Coventry Eastern Bypass at Toll bar End junction a retaining wall with abutments at both sides should be constructed in such a way that highway is able to withstand the pressure of the motorist plying the route especially next to the underpass structure. Abutments are used at the ends of bridges to retain the embankment and to carry the vertical and horizontal loads from the superstructure to the foundation. The design requirements for abutments are similar to those for retaining walls and for piers; each must be stable against overturning and sliding. Abutment foundations must also be designed to prevent differential settlement and excessive lateral movements. The figure below shows a sample of abutment constructed (Hunt & Lyons 2010). Recommended abutment structure Abutment structures are structural elements that are connected to the ground and are designed to withstand the material pressure of the earth or other loads that may be above it at a given time. They are in most cases a combination of steel, concrete, masonry stone, soil, blocks or even pieces of wood firmly fixed together. Following the surveillance findings as well as the public opinion, a number of issues as raised by the relevant bodies must be adequately taken into consideration prior to deciding on the most appropriate retaining structures to be put up built (Seed & Whitman 2010). Among the issues that need to be scrutinized is the type of soil, that is, whether the soil is sandy, clay or loamy. However, the constructing a standard abutment structure is very costly and thus adequate measures needs to be in place to manage the entire construction phase. It’s therefore advisable that adequate resources are of financial or labour must be sought in advance so as to manage the construction phase to the end. The loads especially the backfill load which will be as a result of the pressure exerted by the external materials such as trucks will be calculated at –rest lateral earth pressure before the construction commences. Stability in determination of the critical reaction from the beam seat; It involves the calculation of the nominal loading on each 1m length of the abutment beam. Estimating the length of the back wall; this will depends on the recommended maximum height of the trucks and motor vehicles to use the underpass. Estimation of the footing; the footing heel and toe depends on the width of the highway to be constructed. Work Breakdown Structure for the Construction of the Bridge Abutment The WBD below gives the stages of the construction of abutment bridge:- Estimation of the footing Expected activity schedules The estimation of required resources, three areas must be taken into consideration, these includes the inputs, tools and techniques as well as the anticipated output. Input Methods & Tools Output Enterprise Environmental requirements Judgment of the Experts Duration of each activity estimate Firm process assets Analogous estimation Activity based updates Alignment of the project scope Parametric estimation List of construction activities Three-point estimates Activity based updates Reserve analysis Activity resource requirements Resource calendar Project management plan The duration estimates are often carried based on the idea that there are adequate resources to enable completion of the project in queue. The casual labors will be working 5 days in a week Determination of the limit States of the Bridge abutment Activity 2/11/2015 16/11/2015 25/11/2015 9/12/2015 4/1/2016 11/1/2016 Labour Required Determination of the critical reaction from the beam seat                             100                 Estimating the length of the back wall             70                                 Estimation of the footing                             100                 Back fill load calculation at “at-rest” lateral earth pressure                             70                 Determination of the limit States of the Bridge abutment                             50 Setting up of the Abutment Structure             50                 Precedence Diagram This is a diagram showing nodes representing activities connected by arrows which indicates the dependencies. It normally works in such a way that an activity begins only after completion of the previous activity. For instance activity (1.1) has to be completed before the commencement of activity (1.2) 1.1 1.2 1.3 Path 1 R 2.1 2.2 2.3 Path 2 ES-Earliest Start time of an activity EF-Earliest Finish time of an activity LS-Latest Start time of an activity LF-Latest Finish time of an activity Therefore, Float will be as follows:- Path 1 (Longest critical path duration-Shortest critical path duration) (10 + 7 + 10)- (7+4+7) =9 days Path 2 (Longest critical path duration-Shortest critical path duration) (7+5+5)- (4+3+3) =7 day PART 2 a) Gantt Chart (Attached-Gantt Chart-PM) Activity 2/11/2015 16/11/2015 25/11/2015 9/12/2015 4/1/2016 11/1/2016 Labour Required Determination of the critical reaction from the beam seat                             100                 Estimating the length of the back wall             70                                 Estimation of the footing                             100                 Back fill load calculation at “at-rest” lateral earth pressure                             70                 Determination of the limit States of the Bridge abutment                             50 Setting up of the Abutment Structure             50                 b) Precedence Diagram 1.1 1.2 1.3 Path 1 2.1 2.2 2.3 Path 2 c) New Completion Date (Attached-Gantt Chart-PM 2) d) Five ways to Amend the Project (Attached-Gantt Chart-PM 2) In the usage of the shortest time period to complete a given activity: The time taken in every activity will have to be reduced so as to have enough time for the succeeding activities. The available work force can be combined so as to have a maximum output in one activity before proceeding to the next activity, that is, Project Manager A and B both pool their teams together to have one activity acted upon at once. The project managers can outsource some activities such as transportation of materials to the construction site in order to enable them get ample time to work on the necessary activities. The team managers should hire or buy effective and enough working tools to enable the casual labors work with speed in order to complete the job within the shortest time possible The project management should consider increasing the workforce based on the ground that the project owner is aware of the delay that the contractor was subjected to, prior to the project commencement. Reference Hunt, J. G., & Lyons, G. D. 2010. Modelling dual carriageway lane changing using neural networks. Transportation Research Part C: Emerging Technologies, 2(4), 231-245. Landva, A. O., Valsangkar, A. J., & Pelkey, S. G. (2008). Lateral earth pressure at rest and compressibility of municipal solid waste. Canadian Geotechnical Journal, 37(6), 1157-1165. Richardson, G. N., & Lee, K. L. 2011. Seismic design of reinforced earth walls. Journal of the geotechnical engineering division, 101(2), 167-188. Seed, H. B., & Whitman, R. V. 2010. Design of earth retaining structures for dynamic loads. In Lateral Stresses in the Ground and Design of Earth-Retaining Structures (pp. 103-147). ASCE. Read More