Bridges and BIM: An Overview
BIM aka Building Information Modeling is a process that is used for planning and implementation of Building construction. Readers can wonder how we can categorize BIM as a tool used for planning and implementation of a project whereas it is actually used in a pre-construction phase. Actually, BIM Modeling or any Virtual Design Construction process for that matter is not limited to one phase, it has a seamless approach and can be used across multiple phases of construction.
Construction Companies, Architectural firms, General Contractors etc. use BIM Modeling extensively. Its utilization in the civil domain is still not massive. Structures like Bridges, Roads, Tunnels etc. still use less of the technology. However civil structures like bridges are more complex and require quite a bit of analysis along with good design validation. The construction can be new and can be renovation or rebuilding of the older bridges. In both the cases, BIM Services can help the project stakeholders to plan, collaborate and implementation of the overall construction.
While constructing bridges it is important to focus on the overall geological conditions, location references, water proximity and the utilization of bridges. Calculating the loads, pressure, checking it’s connectivity with the cities, rainfall, footfalls on the bridge, transport movement etc. needs to be validated and checked prior to designing. Post the design stage we can definitely rely on Virtual Construction modeling to ensure that the designs and calculation are good for construction.
How many vehicles cross the bridge has to be the key determinant of the load bearing calculations. The intensity of the traffic and peak traffic time should be taken into consideration. If the bridge is connecting two ends of a river, it needs to be stronger keeping in mind the river flow and current as the flow becomes dangerous during cyclones and monsoon seasons.
Let us talk about using BIM Services in two scenarios
- Using BIM Modeling for New Bridge construction
- Using BIM Modeling for the renovation of an existing bridge
BIM for New Bridge Construction
Virtual Construction Design for Bridge is different than other building structures. The purpose and the utilization both are different. Hence the utilization of Building Information Modeling also is different. In this type of construction, there is a need to construct detailed 3D Model with detailing and construction standards applicable for bridges. It is very important to keep the process robust with continuity through design, development, and construction. Hence apart from 3D BIM Modeling, we need to focus on the other advanced systems like construction sequencing, topography development, detailed coordination of multiple disciplines and systems like Architectural, Structural and MEP systems. These intelligent models and BIM processes make the construction more productive, budget-oriented and planned. We can create a detailed and discipline-specific model with all the elements and later coordinate. Generally, the civil structures can be modeled using software that supports BIM. Just like Revit is more popular in residential and commercial buildings, Civil 3D is more popular for civil structures. Once the modeling is completed, the disciplines can be coordinated and then clashes can be removed. The coordinated model can be later used for extracting model, presentation and construction sequencing. Construction sequencing helps in understanding the construction timeline and the schedule from start to finish.
BIM for Renovating Bridge
There are many bridge constructions that need repairs and renovation. Old tunnels, bridges above rivers etc. needs to be redesigned and renovated based on changing climatic conditions, the age factor of the bridge and so on. Also, the age of the bridge also leads to declining strength which poses as a large safety threat during hurricanes and cyclones. Hence it becomes mandatory to renovate these bridges. Laser scanning is a great solution for the renovation process of any building or civil structure. The bridge can be scanned using laser scans and later perform a scan to BIM conversion for the bridge. This exercise reduces the manual survey time and helps in accurate capturing of the existing design with all the repairs, interior elements, and its design. This exercise helps in developing the proposed design minus the errors and issues in the existing ones. Once we complete the laser scanning exercise, this model can be converted into BIM Model, Construction Drawings, Topography, and construction sequence to present the renovation process. The models can also be developed and phase-wise additions can be made to the model by different teams or parties based on different disciplines.
Since the bridge structure is a part of Civil discipline, processes like photogrammetric surveys help in monitoring the live construction. BIM Modeling basically follows a parametric work process hence it can be viewed and handled by a group of people simultaneously. The live construction check and other features help in having updated information thus helping in decision making.
Benefits of BIM Modeling and Scan to BIM Conversion are as under
- Quick and efficient project implementation
- Collaborative approach results in effective problem solving
- More accuracy in terms of output
- Controlled cost