PWA encouraged the successful contractor to setup a fully functional BIM team that would perform the required BIM tasks in coordination with project delivery teams. Autodesk Revit was mainly deployed to create project BIM models at a high level of detail, technically called as LOD 400 that can reflect the finalised design to be constructed. This software helped the BIM team to translate the IFC 2D drawings into a BIM model where an easy and efficient design and constructability review can be performed.
3D Coordination is an important BIM use that was executed to detect geometrical collisions using specialised analysis tool- Navisworks. Clash detection process was carried out with the goal to ensure coordination of the services within a sufficient time span prior to construction.
The clash analysis is performed regularly to ensure that all component models are synchronized with each other and that individual systems do not unintentionally clash. Clashes are qualified and ranked with regards to their impact and are resolved in order from the highest to lowest priority. The results of such an analysis are stored in a database that enables reporting of the identified conflicts. Additionally, the responsibilities and timeframes to resolve the conflicts are defined. The database contains information about clashes such as due date, responsible stakeholder and solution comments.
BIM implementation on the project follows industry best practices recommended by international standards such as British Standards and ISO 19650 to ensure that tested workflows are adopted, and redundant tasks are avoided.
5D Quantification & Cost estimation
Information rich and well-structured BIM played a crucial role in model-based quantity take-off. The bill of quantities items are linked to the BIM model and are exported with necessary estimate data using Autodesk Revit to be further used for cost estimation purposes.
Within this process the model is used to take-off quantities with reference to required rules of measurements and support cost estimation.
As per current process the model-based quantities are being provided from the BIM expert team to the QS Lead, who uses the data for further purposes (e.g. monthly payments, Procurement). The QS Lead distributes quantities exported in XLSX format to other departments (e.g. Planning, Commercial) for further use.
Collaborative Project Delivery
The seamless BIM workflow from design intent model to detailing models and construction documentation has helped the project stakeholders to leverage project information and efficiently collaborate throughout the project delivery phases.
Prior to commencement of physical construction at site the Pre-Construction activities included sharing Issued for Construction information with the General Contractor and preparing necessary documentation such as shop drawings, material approvals etc. General Contractor and subcontractors used the Revit models provided by PWA to develop a more detailed model technically referred as LOD 400 model. In coordination with GC and design team, the MEP sub- contractors converted each Revit system into fabrication services, split them into jobs, optimised the ductwork and added supports. Before the items can be installed at site the GC and MEP Sub- Contractor conducted several coordination reviews on the detailed models
The single model environment made it easier for the project teams including sub- contractors and vendors to coordinate different disciplines, schedules, areas and quantities which were automatically updated.
Reducing the impact of Changes
One of the greatest advantages of BIM in the context of design change management during construction is that it allows to modify the components of the model in real time. Functionalities of BIM such as quantifying, visualizing and analyzing changes made to models helps the project team to understand the impact of change thereby improving decision making. In one such case, the project team has utilised BIM models to develop alternative routing options of rainwater drainpipes as per the required criteria. Speedy incorporation of the change was possible with the use of up-to-date construction BIM models without affecting construction schedule.
Conclusions
Despite many odds and challenges faced in BIM implementation, the project has emerged as one of the best example of how BIM creates value from combined efforts of People, Process and Technology. This was possible through assembling the best teams who are passionate about the technology, implementing right standards, selecting the right digital tools and setting realistic goals. In the current construction industry, which is undergoing a paradigm shift, the project has demonstrated that BIM with collaboration at its core, can provide manifold benefits thereby improving the whole life cycle value of the asset.
The Public Works Authority ‘Ashghal’, with the aim of delivering all public projects in Qatar with fully collaborative Building Information Modeling (BIM) have realised the accomplishments of this project which will provide invaluable insight in shaping the implementation in years to come.
