The extent of changes to the site’s topography depends on a number of factors that include the current lay of the land (flat, rolling or steep) the size of the property, the need or the desire to minimize the disruption to the natural lay of the land, if the land is undisturbed soil or if it has been previously changed, whether the land can be made usable through changes and the nature of the development of the site. If the site is relatively flat, then not much is needed to introduce the development, but some shaping is typically required as few pieces of land come with ready-made building pads and pathways for roads and walks.
At any rate, it is important to have the building and site be one with each other and in order nestle the building onto the site, some of the existing contours of the land have to be changed. Golf courses, even those build on already rolling terrain, may be a prime example of sculpting the ground creating rolling fairways, elevated greens that sometimes resemble tacos and those magnetic sand traps that draw everyone’s approach shot into them (well, that’s what happens to mine).
I once saw an architect sculpting the contours of a site and diligently calculating the spot elevations down to 3 decimal points of a foot. He was driving the civil engineer bonkers. She asked for my intervention and brought things back to earth when she commented that even extending the grade elevation by 2 decimal points is asking the operator of a road grader to be accurate to within 1/8 inch. Have you ever stood next to one of those pieces of earth moving equipment? What do you think the level of accuracy is with one of those things?
The design team of architects and engineers works with the client in exploring the possibilities for developing the site and how to best sculpt the ground. These possibilities were investigated in the programming/design charrette phase that was shared in the blog post titled “En Charrette-exploring the site.” Once the early design effort winds down, it became the civil engineer’s challenge to convert all the desired sculpting ideas into reality and make technical sense out of it all. While we could change the contours within our property, each contour eventually had to tie back to the existing contours at the surrounding streets and adjacent property. This was no easy task.
Our site is more than challenging with the drop in grades along the west property being 12 feet in 184 feet; a grade of 6.5%. The existing contours of the site can be seen in the graphics that are a part of the blog post “The Site.” The west property line is also adjacent to state highway 177 and therefore under the jurisdiction of the Oklahoma Department of Transportation. One of the requirements when providing pedestrian access along the street is that you must also provide an accessible route from intersection to intersection. Maximum accessible grade is 1 foot in 20 feet or 5%. Where grades are not less than 5% handrails must be provided. However, the accessible route does not need to run along the property line adjacent to the street.
After many variations and as many in-house brainstorming sessions, we are successful with a solution. We are able to provide a route through the site via our internal sidewalk system that allows access from the northwest corner to the southwest corner. We also provide a sidewalk that runs along the street, but due to the grades it is a combination of sloped walks and stairs. While working through these challenges can sometimes leave frayed nerves, once again teamwork prevails and we move on to solve other design challenges of which there is no shortage. That’s the nature of a day in the life of those working out the design in the construction drawings phase.