BIM for Site Work and Utilities Analysis
Over the last 8 years, Rafn has integrated Building Information Modeling (BIM) into our constructability review process and we have found the most useful aspect of 3D modeling for us is in site work and utilities analysis. This article will highlight the benefits of BIM that we have realized in several of our recent construction projects.
The Confluence Apartments project had several new utilities designed to be installed on the adjacent arterial street right-of-way between existing utilities. The focus of our BIM analysis was on utility routing and maintaining clearances. The model we created revealed several conflicts with utility clearances and resulted in a revised civil plan that efficiently integrated utility routing and elevations. The model illustrated the utility layouts with clearance requirements at all horizontal intersections. Also, to facilitate placement, utility invert elevations were shown at important locations.
According to the project team, the site model helped avoid potential elevation and utility conflicts by placing each utility at the best elevation and routing possible, while also taking into consideration existing utility mains in the right-of-way.
Eddy at Green Lake Village Apartments
The Eddy at Green Lake Village Apartments project had a challenging shoring design and our focus with BIM was to evaluate the shoring and excavation sequencing. The shoring design at this project called for a significant amount of internal bracing due to tieback restrictions at the neighboring properties. The ability to model each lift of the excavation in coordination with raker and tieback installation helped the project team develop an excavation plan in coordination with our subcontractors.
Taking it a step further, modeling the post-tensioned concrete decks in relation to the internal braces helped to define the concrete slab buck-out locations. Our project team noted that the 3D model combined the multiple design disciplines into one complete model as it exists in the world while exposing complicated details that can be missed in 2D.
Building A at Othello Square
The Othello Square project is located at the corner of two major arterial streets. Due to multiple underground utilities on three sides of the property, our site model was able to identity several conflicts around the perimeter of the site. At the north side of the project, we discovered a conflict with an existing sewer catch basin and tie-backs. On the east side of the property, the model identified a conflict with the proposed bioretention pond in the right-of-way and existing utilities. And on the south side of the property, we uncovered a conflict with two utilities identified with the shoring design.
Within the property itself, we were able to create a model which estimated the volume of contaminated soils which we used as a check against the geotechnical engineer’s quantities, and we were also able to look at the relationship between the contaminated soil and excavation depth.
As Rafn continues to build our modeling practice, it is clear that our BIM modeling takes site work and utility coordination to the next level. We love bringing this enhanced analysis and coordination to our projects for the benefit of the team and project owner.