Connectivity

My thesis statement is as follows. “Are parks built over highways successful in connecting severed neighborhoods, reducing noise and increasing urban open space?”  A large part of this project concerns connectivity. What is connectivity? I have read about, “connecting the urban grid”. Precedence studies like the recently named Klyde Warren Park in Dallas literally provide pedestrian access along all borders. It is not hindered by interstate ramps. These ramps prevent both street and pedestrian connections. As discussed before, pedestrian entrance to each section is limited to the corners along the cross streets. Section IV is the only exception to this.

So if this park does not “reconnect the urban fabric” then what is it reconnecting? Is it simply making the narrow sidewalks flanking the cross streets over the interstate safer and more pleasurable? I do believe that wider sidewalks and separation from vehicular traffic will be a positive improvement, but I think there is more here. I think connectivity goes further than reconnecting roads and providing pedestrian access over the interstate.

The area between midtown and downtown, the area around the interstate, is void. Midtown is active. Downtown is active. The Gulch is becoming more active. In between there is nothing. Perhaps connectivity is about taking a part of town that will continue to be void due to the presence of the interstate and making it usable. I think it’s more about filling a void in Nashville than it is about a physical connection like a bridge. This park, by covering the interstate and providing the open space that is necessary to make urban living truly attractive, will fill the void and activate an entire part of town.

People focused master plan

I made this master plan with people in mind. People are the primary focus. With people in mind, some of the ideas are difficult to represent. A good example of this is the skate park pedestrian bridge over the interstate ramp. For the next master plan, I will do further exploration in section. Another example is the BRT station on Broadway.

Section I

This section is programmed for a nature play area, a skate park, a splash pad, and active recreation. One of the big changes was moving the skate park to the plan East end of the section near Broadway. The purpose of doing this was to utilize the vertical façade of the skate park, which will be as tall as ten feet. By moving it next to Broadway, there is an opportunity to have some kind of artist display on the wall facing Downtown. It would be 60’ wide by about 6-8’ tall. There is also a café at this plaza with outdoor seating. The façade on the plan north side can be used as a climbing wall. The West end of this section is utilized as an open lawn for active recreation. Both plazas have raised planters over the interstate lanes which will provide visual identity and shaded seating.

Section II

I think I am most excited about this section. It is programmed as a cultural center for the park given its proximity to Broadway. Broadway is the main transportation corridor and also has the new BRT transit line. As of now, there is not a bus stop at the site. This is because there is not much worth stopping for there right now. It is also likely due to the fact that there are Interstate exchanges on either side of the park. I am exploring the idea of widening Broadway to make room for a BRT stop at the park. The stop needs a bus lane on either side of the 15’ wide stop. There is room to do this with the presence of the highway deck. A closer evaluation at a larger scale will prove or disprove. I look forward to having a conversation with my committee members concerning traffic. Moving to the plan West plaza of this section includes another restaurant/café & a visitor center with bike rentals similar to that on the riverfront. Raised planters over the interstate lanes provide shaded seating. These planters will be bordered on the West side with spaces for food trucks.

The amphitheatre is oriented the same way as the previous plans. This is due to the natural slope of the deck dictated by the surrounding topography. Like the planting master plan, there is a promenade on either side of the amphitheatre that converge on a sculpture garden on the plan East side of the section. There are two shallow pools that will look to use vibration from the traffic below in some type of interacting fashion. This idea will be explored further when I zoom in on one section.

Section III

This section is programmed for passive recreation and meditation. Previous drawings for this section featured walking paths, gathering spaces planted with meadow grasses and cedar trees. This design keeps the densely planted trees on the park edges but leaves the center as an open lawn. The open space has enough room for a disc golf course. The dense plantings would help keep discs on the deck. Cedar planting at either entrance would keep the make a nice entrance to this section of the park and are show in the sketch below.

Section IV

Section IV focuses on active recreation. This section is level enough to offer a 150’x300’ open field. Previous plans have extended 14^th and 13^th avenue across 12^th South to Division street. This plan does not. It makes this space into pedestrian allee’s, providing more space for the open field. There are not plazas at this section. There are, however, much wider sidewalks separating pedestrian from automobiles.

I haven’t brought this up much yet, but the grading plan reveals that there is room for a deck on the other side of Division St. This plan uses this space for community gardens. The pedestrian walks continue to the end of the deck, where there are viewing platforms. The interstate can be interesting to watch as a pedestrian when viewed from an overhead, sage place. This would also provide an opportunity to design a visually interesting entrance into the tunnel from the interstate.

Tree Focused Master Plan

This master plan version focuses on tree plantings. This means that the design was primarily driven by where large trees can go. Trees cannot go everywhere in the park due to shallow soils. I know this from previous analysis. It was shown in a diagram posted on this blog under site analysis.

One of my favorite ideas with this master plan came from trying to figure out how to get some plantings into the plazas adjacent to the cross streets. Soil would certainly be shallow in these areas. The obvious answer is in using raised planters. These may also provide seating. I have also been thinking of ways to link the four sections so that they may “feel” like a linear park despite fragmentation by cross streets. One of these linking elements could be in the plantings at the entrances to each section.

What if each of these plantings was somehow planted in a manner that abstractly related to the interstate lanes below? Each row of trees could represent a lane. These spaces could serve as shaded sitting areas as shown here.

Or they could serve as a vertical visual element. The sketch here shows rows of cedar trees under planted with broomsedge, a common site in Middle Tennessee. This idea would work in section III which is programmed for passive recreation.

The same form could be given to the splash pad in section 1.

 Master Plan

I scanned each section so they might be a little more legible on screen.

Section I

As with the previous plan, the areas near the cross streets are treated as plazas, as they are the primary pedestrian entrances to the park. As I was looking back at my tree planting diagram, I was thinking hard about the site vertically. The skate park will be elevated at least ten feet from the deck, as this is a good depth for skating pools and bowls. Since the skate park is elevated, there is opportunity to provide shade with trees on the skate park. Thinking about the skate park in section led me to think about the idea of a pedestrian bridge over the I-40 on ramp at the plan Southeast corner of the park. The corners of the park are planted with trees as possible. These tree plantings will not be thick enough to block vision into and out of the park. They are canopy trees, which could also help users recognize the presence of the park.

Section II

The underlying structure of Section II provides the opportunity to have an allee’ on both sides of the Broadway entrance. Again, the amphitheater stays largely in the same spot as before. I believe this is an obvious place for an amphitheatre given its proximity to Broadway and that it is the steepest part of the entire park. The lateral allee’s converge on the plan East side of this section in a sculpture garden. The East plaza is planted with shade trees at the corners and is largely open to the street. Both plazas feature raised planters located over the interstate lanes below, as described above.

Section III

Section III was treated in a similar fashion as it was in the last master plan. East and West ends are planted as meadows with a cedar glade in the center. There are two pavilion/gathering spaces and a central council ring. The North and South flanks are planted as a meadow edge. The entrances to each end are planted with a grid of cedar trees. There is no need for a raised bed this time due to the shallow soil depth tolerated by these trees. They will have a nice parallax effect and are appropriate for a section that is programmed for passive recreation and meditation.

Section IV

Section IV is programmed for active recreation, a dog park, and community gardens. This plan uses pedestrian promenades to level the open spaces. Community gardens are located at the corners of the park. They are located over the interstate lanes and will be raised to achieve proper soil depth.

All in all, I think the tree helped to reach some good design ideas.   

schematic design

The time has finally come to start getting into some schematic designs. I have decided to do several of these over the next week, each exploring a different goal. For example, the first one focused on hydrology. I am still keeping the programming goals which I established earlier in the semester in mind, but the first diagram I refer to is hydrology and topography. This was done pretty quickly, so I hope it is legible enough on screen.  

I have divided the park into four sections. I have also done calculations to know the amount of stormwater runoff produced by each section in a one inch rain event.  This tells me approximately how large a storage reservoir might need to be.  Calculations were made using pervious and impervious CN values and % coverage. I do not know the surface types of the park because it is yet to be designed so I used 40% impervious surface with a CN value of 98. The remaining 60% was considered greenroof with a CN value of 84. The diagram outlining the beam walls and available areas for substantial tree roots can also serve as suitable areas for under deck water storage. Later in the design process, I can determine how much runoff is available from runoff. I can also determine possible use quantities for that water according to irrigation needs for lawns or gardens.

 Section I

Using this method, the first section (between Church and Broadway) is 3.56 acres and produces 3,950 cubic feet of runoff in a one inch rain event.  Water is collected on the plan north end of the park in a natural streambed surrounded by grasses. The water runs to an underwater storage reservoir for possible use in irrigation. A splash pad is located nearby and could possibly use this water with the addition of a UV filter. Runoff from the skate park is also channeled into a streambed.

Section II

Section II is 2.95 acres in size and produces 3,273 cubic feet of runoff. Section II features a similar streambed planted with grasses to channel water through the site to a storage reservoir below the deck. Water is also channeled in the east plaza, and could make for a nice design element. One issue with a ephemeral stream running the length of the site is pedestrian crossing. Since it will be dry a majority of the time, crossings could be a step over a rock. Bridges would provide crossing when the stream is wet.

Section III

Section III is the largest section at 4.47 acres and creates 4960 cubic feet of runoff. Section III was designed in this version as a park for passive recreation and reflection. The structure below allows for substantial tree planting on the North and South ends, blocking the city traffic. The East end is planted as a cedar glade, which is perfect for shallow soils. Cedar glades are common in the Central Basin of Tennessee. The West end is planted as a meadow. A streambed provides natural division of the meadow and the glade. Both feature a central gathering space at the conversion of the pedestrian paths. The stream culminates with a below grade storage reservoir. Since the plantings in this section will require little water, the topography could allow for the irrigation of the lawns with Section II to the East. There are obvious issues with this design. Blocking out the city also screens the view into the park, but I wanted to put it down on paper anyways as I think it would be a special space in the city. It could be closed at night at each plaza to prevent any funny business after hours.

Section IV

Section IV is 3.36 acres in size and produces 3,728 cubic feet of runoff. Streets on the North and South sides of the park dictate the park edges (thanks again Erin). This design keeps the roads. Unlike the other decks, this deck is 75% on grade with its surrounding topography. This means that pedestrians have more entrance points into the park. Water is collected in a similar method as the other decks. The streambed is on the North end of the deck. This section is programmed for active recreation. The field of the West end of the deck has the opportunity to be leveled, making it a suitable surface for ball fields. The West section will be sloped and is suitable for a dog park.

Site Analysis

I drew this series of site analysis diagrams earlier in the week. Each one reveals specific characteristics of the site. My hope is that these will drive my decisions when designing the park.

Hydrology

As discussed in an earlier post, I did a grading plan for the proposed park, yielding the necessary clearance for the interstate below and graded as flat as possible. The park can not go any lower than that grading, but it can build up from there if needed. Using that plan I drew a hydrology diagram showing where the water would naturally flow and collect on the deck. Again, this will likely change as the park is designed, but this is a good starting point. Not the lowest points on each deck. These may be logical places for water collection.

Pedestrian Circulation

This diagram shows the pedestrian circulation through and around the site. I used thicker lineweights to show the routes most traveled, particularly the East/West corridors. The surrounding buildings are either existing or proposed. The proposed buildings are from Erin Gray's design on the site last semester. The dashed lines represent the deck where it will not be on grade with the topography due to interstate ramps or lower terrain. The solid lines representing the deck are where it will be on grade with the existing topography. The key point to this diagram are that the entrances to the park mostly fall along the streets and at the corners of each deck.

Vehicular Circulation

This diagram shows the vehicuar circulation around the site. It includes the city streets, the interstate and the ramps leading to the interstate. Since I have been staring at these maps for most of the semester, I have a good understanding of how the ramps work. This diagram was drawn so that people who have not spent as much time with the project can gain a quick understanding of the flow of traffic arround the site. It also includes the additional roads proposed by Erin Gray last semester. Key points from this are that this park is surrounded by ramps. The streets running parallel to the decks are one way streets, which is easir for pedestrain crossing. The streets running perpindicular to the decks and running through the park are much busier. Like the pedestrain circulation, there is heavier East/West flow. Broadway is the busiest of these crossing streets and will also host the new BRT line. This will certainly be considered in the design. Division and 12th South are less traveled and have only 4 lanes.

Primary Structure

Here we go again. I think I touched on this as I was making the initial deck grading. This project would require a team of structural engineers. I am not a structural engineer, nor am I an architect. I do want to have enough understanding of the structure to draw up the basics. I know there will be verticle walls running parrallel to the interstate to serve as beams. Upon these walls will be the joists, which will run perpendicular to the interstate. This diagram shows the primary walls running parallel to the interstate, one on each side and one down the center between the lanes. This configuration does allow for on and off ramps.

Tree Planting Zones and Secondary Structure

The diagram above shows not only the primary walls, but also some secondary walls that would allow for areas between the outermost interstate lanes or ramps and the city above to be backfilled with soil or perhaps used for water storage. The primary purpose of this would be to allow for the planting of larger trees. This may be difficult on much of the deck due to shallow soils. The green hatching represents areas that would be suitable for larger tree plantings with the additional structure and backfill. The section drawing helps illustrate the idea. The solid green represents areas suitable for large trees simply by backfilling the primary structure.

The joists would look something like the option on the left. The option on the right allows for more soil depth and tree plantings between the joists, but it will cause problems with freezing. The option on the left also allows for free movement of water along the deck. Loads have yet to be calculated and are dependent on the design.

 

Site Model Finally Finished

I finally got the buildings put onto the site model. I also made pieces that place over the interstate to represent the deck. I wanted to get some pictures up of the completed version. The site model gives a instant visual understanding of the current lay of the land. It also gives anyone who is unfarmiliar with the project an instant understanding of what is happening. 

Although it is at 8 ft. contours, it still gives a good picture of how the ramps come to and from the interstate below. Perhaps the aerial image helps show some detail where the large contours are lacking. Hopefully I will have time at the end of the semester to make some final models of the actual designed park to place into the site model instead of the blank, white deck that is there now.

moving forward

I think my next steps are to layout the structural supports for the park and to start master planning. I am not how the structural elements will fit together, but the Woodall-Rogers Park in Dallas shows 13’ box beams spaced 7’ apart. This aerial image shows the beams being laid across the interstate. Simple enough, but what about the curve in the interstate between 12^thSouth and Division?

 I will also start sizing some of my programming elements and seeing how things fit. Where does pedestrian circulation go? These will help form the basis for the master plan, which I would like to present to my committee on trace paper by early next week.

grading

I know from my site model and from visiting the site that the engineering of the park will be a little trickier than the Woodall-Rogers Freeway park in Dallas. The park in Dallas is flat and straight. The terrain in Nashville, typical to Middle Tennessee, contains rolling hills. There is also the issue of surrounding ramps, which I have expressed concern with before discussing the possibility of these ramps limiting accessibility to and from the park. There must be proper clearance below not only for interstate traffic, but also for vehicles exiting and entering the highway. I am by no means a structural engineer, but do need to have a good understanding of how this would work. I will likely learn more during my next committee meeting (3 architects, 1 landscape architect) but for now, I am using the thickness of a parking garage floor I measured (38”) with the required bridge clearance for an urban interstate (14’…I used 14.5’ for a little extra room). This comes to 17’8”. I rounded up and decided the deck needs 18’ from the surface to the interstate below work.

 My site map only has 4’ contours, so it is not exact. I feel that I now have a good idea of where how the ramps will affect the deck above. Bottom line is that there is less room for these ramps than I had originally thought. The drawing below shows where the deck can occupy space without regarding the ramps. As I begin to conceptualize the master plan, I will decide if the ramps should be regraded or not.

As stated before, the rolling terrain will have to be dealt with. My next step was to draw out how the park would be graded to make the existing grade transitions at the edges of each deck as smooth as possible. The deck grading could be thought of as a base map for the deck. It can be modified of course, but this shows the smoothest transitions possible without changing the elevations at each corner or each of the sections. Certainly, regarding at the edges will probably be desired in some areas. The green represents the deck. Solid lines are at existing grade while dashed lines represent edges that are not at grade. Again, this is partly due to the existing topography and partly due to the ramps at the edges. Pedestrian access can only be gained where the deck is at grade with the existing topography, mostly at the corners for three of the sections.

Development Moments

In learning about the history of the city and the site, I have discovered some old maps from various sources. I have assembled some of these maps into a diagram series that shows development moments through time in Nashville. The series focuses on transportation and building density and development as perceived. Together the maps and the diagrams show a shift in transportation from the river, to street trolleys and railroad, to the pikes, to the interstates. The development shows a very dense city in the 1860’s becoming increasingly decentralized through the 20^th century until the height of sprawl we see today. But we are seeing people moving back into the city with a downtown resurgence. But where will this development take place? Historically, development has most heavily followed the East West Corridors from East Nashville, through town and into midtown. Future development predicts an increase in centralized living and a need for increased growth of the city across the interstate loop along the same corridors growth has followed historically. This deck park would help to facilitate this growth and make downtown living more appealing to people considering moving from the suburbs to the city. This park would serve its growing community.

Sketches

I attended a design sketching workshop last weekend. The leader of the workshop went over some techniques for the first hour, and then asked us to sketch whatever came to mind. Of course, I sketched a deck park. I didn’t have a scale or specific dimensions, so proportions are not accurate, but it shows the general idea. I also came up with an interesting idea that I might use in the design of the park. What if I could use the vibration, sound, and movement below to create a reaction above the park? The sailboat looking object I sketched could be a way of channeling the vibration below into through the large metal shape. This vibration could cause ripples in the surrounding water on calm days.

The Foundry Event

The event at the foundry was an opportunity for graduating students to share their semesters work to this point with local professionals. This proved to be a valuable experience. I was able to have a nice conversation about my project with a talented landscape architect early in the evening, before things got too busy. My design decisions to this point are simply programmatic, based on context and demographic information. I think I am on the right track with my programming ideas, but it was suggested that perhaps I don’t be so dry about how I word these ideas. Perhaps I’ve spent too much time in the architecture building lately. It was also suggested that I produce a master plan for the entire park, and focus a detailed design on one section of my choice. This would prevent me from just doing a mediocre design by taking on too much.

I also got some good information on the Rose Kennedy Greenway from someone who has lived in Boston. This person suggested that perhaps I am being too critical with my assessment, and I think this is probably true. I guess that is to be expected from a former Bostonian. We did agree that some sections of this park serve the community better than others.

As far as the rest of the evening went, it was great to get some work pinned up. I also got to show off the site model I built (which I’m quite proud of, in case you couldn’t tell). I finished the buildings and made some inserts to place over the interstate, representing the park. The model served as a useful tool in gaining a quick understanding of the concept and the site.

The event at the foundry was an opportunity for graduating students to share their semesters work to this point with local professionals. This proved to be a valuable experience. I was able to have a nice conversation about my project with a talented landscape architect early in the evening, before things got too busy. My design decisions to this point are simply programmatic, based on context and demographic information. I think I am on the right track with my programming ideas, but it was suggested that perhaps I don’t be so dry about how I word these ideas. Perhaps I’ve spent too much time in the architecture building lately. It was also suggested that I produce a master plan for the entire park, and focus a detailed design on one section of my choice. This would prevent me from just doing a mediocre design by taking on too much.

I also got some good information on the Rose Kennedy Greenway from someone who has lived in Boston. This person suggested that perhaps I am being too critical with my assessment, and I think this is probably true. I guess that is to be expected from a former Bostonian. We did agree that some sections of this park serve the community better than others.

As far as the rest of the evening went, it was great to get some work pinned up. I also got to show off the site model I built (which I’m quite proud of, in case you couldn’t tell). I finished the buildings and made some inserts to place over the interstate, representing the park. The model served as a useful tool in gaining a quick understanding of the concept and the site.