IDeX Team- I thought the presentation was good. It took me a little bit to get caught up with things. In the future maybe some "big picture" info would be good for folks that are not up on things, such as a site plan with the approximate location of the boardwalk and surround features, areas where you will need the sound barrier, etc. Here are a few more specific suggestions and considerations as you move forward.
Foundations: I am a little concerned about the bearing capacity of the diamond piers with the expected soils that I assume are out there. I would be surprised if you are able to get 6 ksf bearing, but I may be wrong. Once you've had a chance to review the logs can you upload them to the site and let me know? I also think settlement, especially long term, is going to have a major factor in design. I am expecting some soft materials in the upper 10 to 20 feet that will consolidate over time. I do like the idea of pin piles. They may need to extend down to a bearing stratum to provide resistance. Is there going to be any uplift in design of the boardwalk foundations? As for the sound barrier foundations, I agree with you, I dont think a shallow foundation is feasible due to lateral loads. A pile foundation maybe feasible but you may not see much lateral support if the deposits are soft. A glance at the bore logs will help.
Boardwalk Concept: Good ideas. The one issue I see is what Department of Ecology is going to allow in a wetland area. They are pretty protective of these areas and will likely want to see as little impact/disturbance as possible. You maybe able to do some online research or call the DOE and get some direction. I am sure either way there is going to be a lot of permitting, which is a whole other animal that may be worth looking into as well and presenting to the client/owner so they know what they are up against. After doing this you may find out what concepts are worth pursuing and others that can be put on the shelf.
Stream Restoration: There are some huge issues that come along with stream restoration. Including permitting, fish studies, channel migration, modeling, flood mapping, etc. Things that you do upstream may have huge effects downstream amd to adjacent property owners. I like the idea of bringing it back to its more natural meandering path but its going to take some thought. The weirs maybe a tough one to sell to the fisheries folk due the potential blockage of fish migration. Those areas maybe a source for material to cause dams in a flood.
Anyways, those are my thoughts so far. If you have any specific questions feel free to contact me.
Here is the website for the online geodatabase. Go to the menu and click on Online Geodatabase. Zoom into the project area and click on the explorations that you want to look at. Good place to get some nearby info for your site. http://geomapnw.ess.washington.edu/index.php
It is neat to see the tecnological/creativity and sharing (web conferencing) of information since I was in college over 25 years ago. I agree with the first comment posted in that contextual orientation is one element that could have strengthened the presentation. Also, it would be good to include your process and show what challenges or ideas helped to shape the design and/or changes. Please find the following comments for some of the items presented.
Boardwalk Concept:
Some interesting and practical ideas and one that would be very difficult and expensive to construct ( ie. flexing walled boardwalk). Remember to always consider safety and visibility of the user. Consider creating boardwalk transition nodes at entrances and viewing platforms for educational purposes. Also, include cost effective design for handrails/guardrails with integrated interpretive panels and curbs where the guardrails are not needed.
Decking Material:
Two ideas are presented for decking material (i.e., plywood sheathing and precast concrete planks). Both materials have some draw-backs in this application. Plywood sheathing typically does not stand up well to the weather and foot traffic. Marine plywood would handle the weather better; but, is very expensive. Plywood also tends to be a slick surface when wet and could lead to falls. The plywood could be coated with a non-sliip coating, however this would warrant considerable maintenance over time. The concrete planks are a nice idea; but, would be cost prohibitive in this case. In addition to the increase cost of the concrete plank, they would also add considerable additional weight to the supporting members (I like the idea of being able to personalize for fund raising or contributions). Consider other elements that could be incorporated into the boardwalk for donations etc. More conventional materials, such as timber decking or Trex decking would be more appropriate for the boardwalk surface application.
Modular Construction:
To minimize impact to the wetland (and often because there is standing water and extremely soft soils), the boardwalks are often constructed a section at a time. Materials are brought in on the completed sections of boardwalk, in order to build the next section. To bring in a completed boardwalk “module”, the forklift would need to drive along the completed sections of boardwalk. This would require considerable upsizing of the boardwalk members to support the loaded forklift. This has been done for heavier boardwalks designed to carry light vehicular traffic; however, would probably not be appropriate for our rather light pedestrian-only boardwalk. Consider devising a method to transport construction materials in an efficient manner as project construction progresses.
Diamond Pier Foundations:
To minimize impact to the wetland, diamond pier foundations are appropriate and have been adopted for the AEP boardwalk project based on the existing soils. The geotech report has been provided to you. Structural engineering has determined that in using a 6-ft wide boardwalk design, we will utilize a 10-ft span between piers, with a 15-psf dead load allowance (accommodates deck framing + guardrails) – with this, they estimate reactions to be: 3.5kips/pier (if 100-psf live load is used) 2.25kips/pier (if 60-psf live load is used – most likely) If we use FOS = 3 for the 60psf live load it would seem the DP-100E Diamond Pier would be appropriate for the intended use.
Noise Barrier:
Verify location in which the noise barrier can be constructed. Consider multiple noise baffling effects using plant material in conjunction with vegetation. Determine appropriate screen height based on vehicular/tire sound projection and analyze effectiveness based on distance. Consider arrangement and/or artistic visual improvements.
Storm Channelization:
I like the reuse of materials for creating an environment that would change depending on the season. Consider expanding the sculptural art character to make the whole experience more engaging with a stronger sense of public art.
Monday, February 14, 2011 at 2:05PM
Reader Comments (2)
IDeX Team-
I thought the presentation was good. It took me a little bit to get caught up with things. In the future maybe some "big picture" info would be good for folks that are not up on things, such as a site plan with the approximate location of the boardwalk and surround features, areas where you will need the sound barrier, etc. Here are a few more specific suggestions and considerations as you move forward.
Foundations:
I am a little concerned about the bearing capacity of the diamond piers with the expected soils that I assume are out there. I would be surprised if you are able to get 6 ksf bearing, but I may be wrong. Once you've had a chance to review the logs can you upload them to the site and let me know? I also think settlement, especially long term, is going to have a major factor in design. I am expecting some soft materials in the upper 10 to 20 feet that will consolidate over time. I do like the idea of pin piles. They may need to extend down to a bearing stratum to provide resistance. Is there going to be any uplift in design of the boardwalk foundations? As for the sound barrier foundations, I agree with you, I dont think a shallow foundation is feasible due to lateral loads. A pile foundation maybe feasible but you may not see much lateral support if the deposits are soft. A glance at the bore logs will help.
Boardwalk Concept:
Good ideas. The one issue I see is what Department of Ecology is going to allow in a wetland area. They are pretty protective of these areas and will likely want to see as little impact/disturbance as possible. You maybe able to do some online research or call the DOE and get some direction. I am sure either way there is going to be a lot of permitting, which is a whole other animal that may be worth looking into as well and presenting to the client/owner so they know what they are up against. After doing this you may find out what concepts are worth pursuing and others that can be put on the shelf.
Stream Restoration:
There are some huge issues that come along with stream restoration. Including permitting, fish studies, channel migration, modeling, flood mapping, etc. Things that you do upstream may have huge effects downstream amd to adjacent property owners. I like the idea of bringing it back to its more natural meandering path but its going to take some thought. The weirs maybe a tough one to sell to the fisheries folk due the potential blockage of fish migration. Those areas maybe a source for material to cause dams in a flood.
Anyways, those are my thoughts so far. If you have any specific questions feel free to contact me.
Here is the website for the online geodatabase. Go to the menu and click on Online Geodatabase. Zoom into the project area and click on the explorations that you want to look at. Good place to get some nearby info for your site.
http://geomapnw.ess.washington.edu/index.php
IDeX Team:
It is neat to see the tecnological/creativity and sharing (web conferencing) of information since I was in college over 25 years ago. I agree with the first comment posted in that contextual orientation is one element that could have strengthened the presentation. Also, it would be good to include your process and show what challenges or ideas helped to shape the design and/or changes. Please find the following comments for some of the items presented.
Boardwalk Concept:
Some interesting and practical ideas and one that would be very difficult and expensive to construct ( ie. flexing walled boardwalk). Remember to always consider safety and visibility of the user. Consider creating boardwalk transition nodes at entrances and viewing platforms for educational purposes. Also, include cost effective design for handrails/guardrails with integrated interpretive panels and curbs where the guardrails are not needed.
Decking Material:
Two ideas are presented for decking material (i.e., plywood sheathing and precast concrete planks). Both materials have some draw-backs in this application. Plywood sheathing typically does not stand up well to the weather and foot traffic. Marine plywood would handle the weather better; but, is very expensive. Plywood also tends to be a slick surface when wet and could lead to falls. The plywood could be coated with a non-sliip coating, however this would warrant considerable maintenance over time. The concrete planks are a nice idea; but, would be cost prohibitive in this case. In addition to the increase cost of the concrete plank, they would also add considerable additional weight to the supporting members (I like the idea of being able to personalize for fund raising or contributions). Consider other elements that could be incorporated into the boardwalk for donations etc. More conventional materials, such as timber decking or Trex decking would be more appropriate for the boardwalk surface application.
Modular Construction:
To minimize impact to the wetland (and often because there is standing water and extremely soft soils), the boardwalks are often constructed a section at a time. Materials are brought in on the completed sections of boardwalk, in order to build the next section. To bring in a completed boardwalk “module”, the forklift would need to drive along the completed sections of boardwalk. This would require considerable upsizing of the boardwalk members to support the loaded forklift. This has been done for heavier boardwalks designed to carry light vehicular traffic; however, would probably not be appropriate for our rather light pedestrian-only boardwalk. Consider devising a method to transport construction materials in an efficient manner as project construction progresses.
Diamond Pier Foundations:
To minimize impact to the wetland, diamond pier foundations are appropriate and have been adopted for the AEP boardwalk project based on the existing soils. The geotech report has been provided to you. Structural engineering has determined that in using a 6-ft wide boardwalk design, we will utilize a 10-ft span between piers, with a 15-psf dead load allowance (accommodates deck framing + guardrails) – with this, they estimate reactions to be:
3.5kips/pier (if 100-psf live load is used)
2.25kips/pier (if 60-psf live load is used – most likely)
If we use FOS = 3 for the 60psf live load it would seem the DP-100E Diamond Pier would be appropriate for the intended use.
Noise Barrier:
Verify location in which the noise barrier can be constructed. Consider multiple noise baffling effects using plant material in conjunction with vegetation. Determine appropriate screen height based on vehicular/tire sound projection and analyze effectiveness based on distance. Consider arrangement and/or artistic visual improvements.
Storm Channelization:
I like the reuse of materials for creating an environment that would change depending on the season. Consider expanding the sculptural art character to make the whole experience more engaging with a stronger sense of public art.