UAS Construction Update for 05/06/2016
Water Water Everywhere
On the morning of August 25 2015 UAS experienced an a waterline break, shutting down water to campus just a couple days before freshmen were to enter the John R. Pugh Residence Hall. Fortunately, Admiralty Construction was able to pull their crew off another project and make an emergency repair. We were also fortunate that CBJ had a piece of 16-inch pipe we could use for the repair.
Corrosion (rust) was the cause of the August 2015 waterline break. The following photos shows just how much the pipe had corroded before it finally broke. This pipe is 16-inches in diameter and once had a wall thickness of 0.40-inches. Notice how the pipe joint bolts have corroded so much the heads of the bolts are almost gone.
Corroded Pipe from UAS August 2015 Repair.
Ductile iron pipes are protected from corrosion by a cement lining on the inside and a protective coating on the outside. This protection system typically lasts for 50+ years. Our UAS pipe is 30 years old. Early corrosion of a pipe can be caused by many things, with corrosive soils and electrolysis being the usual culprits. We do not know for sure what caused the corrosion in UAS’s water line and running tests to find out, cost much more than repairing the pipe. However, electrolysis is my best guess based on the number of electrical conduits seen in the below photo. Also, records show that an electrical transformer sat on this site for many years.
Pipe Excavation UAS May 2016 Repair
We are taking additional precautions against corrosion for this waterline repair. First is a high density polyethylene covering around the pipe. This breaks any stray electrical connection between the pipe and the surrounding soil. Second, we are adding some sacrificial zinc anodes attached to the pipe. Zinc is an more excitable element than steel, so the zinc will corrode first, thus protecting the steel pipeline. These function the same way as zincs do on your boat.
The Contractor has been working with Water coming up from the ground, Water falling from the sky and Water leaking out of the pipe. UAS Staff in the Hendrickson Building, Hendrickson Annex, Soboleff Building and Soboleff Annex have been working without any Water. Today makes us appreciate Engineers and Contractors who deliver water where we want it and keeps it from places we don’t.
UAS – Anderson Parking Lot Expansion
UAS Construction Update for 4/22/2016
UAS Campus has several wonderful places to have a picnic, sip morning hot chocolate or just take a short break. The Anderson Building parking expansion project has just added one more that I feel is the Picnic Paradise. The view from Picnic Paradise this morning included bright blue skies, snow caped Admiralty Island, flat calm Auke Bay and some guy in his boat who did not have to go to work today. Later this spring the view will include a blooming lilac bush that the Bedford family planted in their back yard more than 20 years ago. During a mid-day break or during lunch, this will be a great place to take in your vitamin D on sunny days.
Anderson Building Picnic Paradise
The Contractor started this project last fall and was not able to get it completed before the asphalt pavement plant shut down for the winter. This spring the Contractor installed the sidewalks, parking lot lights and has prepared the grade for asphalt pavement. Provide that we do not get heavy rain on Saturday they will pave the parking lot and complete this project. However, the construction by the Anderson Building will just be starting. For the next two summers, the Department of Transportation will be rebuilding Glacier Highway from Fritz Cove to Seaview. Their project will add sidewalks to both sides of the road, streetlights, and wider shoulders for bicyclists. It will also relocate our driveway entrance to the Anderson building and eliminate about half of the parking in the existing lot. This is the reason the Anderson parking lot had to be expanded.
Anderson Building Parking Lot Expansion
UAS Project Update for 02/12/2016
Valentine’s Day – Strengthening Relationships
Valentine’s Day is a good reminder that relationships need to be continuously nourished and reinforced to keep them strong and healthy. Neglecting or taking for granted is a sure way to weaken or completely lose a relationship. In Alaska there is a beautiful view around every corner. So it is easy to forget our relationship with Auke Lake, a wonderful gem right in our back yard.
UAS selected several staff and faculty over this past summer to work with a professional land planner to develop a UAS Shoreline Master Plan. We worked on the Plan for the past 7 months, developing a purpose and need statement and then exploring many different elements that UAS could implement to strengthen our connection with Auke Lake. The Plan went through several revisions, with many elements being added and removed in effort to come up with a plan that meets the needs of the UAS community without defeating the purpose of strong relationship with Auke Lake. The Master Plan has now progressed enough for posting on the UAS website under Facilities Services.
|Auke Lake Shoreline Master Plan
This Valentine’s Day as you read the UAS Auke Lake Shoreline Master Plan, you will see how we identified several ways to strengthen UAS’s connection to Auke Lake. If you have other relationships that need strengthening, I recommend developing your own Master Plan.
Nathan Leigh, UAS Project Manager
UAS Construction Update for 07/27/2015
Alligators in your Pavement
Those of us with lots of experience will remember the Enco gasoline advertising campaign of “Put a Tiger in Your Tank”.
Well we have Alligators in our Pavement…..
Alligator Cracking in Pavement by Egan
I received a great question last week about why are we replacing perfectly good asphalt pavement.
There are many things in life that are hard to tell when it will fail or break. Some good examples include; the transmission in your car, the roof over your house, a freezer full of fish or your favorite high school sweater. These things always seem to break down at the worst possible time and cost much more than expected. However, a good steward will ask an expert how much longer the item will last and what it will cost to repair or replace. By the way, my mechanic says my car transmission has less than a year left and my wife has thrown out my high school sweater.
UAS hired an Engineering Consultant to inventory and analyze all of the Asphalt Pavement here on the Juneau Campus. The Engineer categorized the asphalt pavement by how long it was expected to last; Less than three years, three to Ten years, and more than Ten years remaining useful life. UAS then followed the expert’s recommendations in planning for and carrying out the current asphalt pavement replacement project.
Engineers use the type and severity of cracking in the asphalt as one variable to determine it's remaining useful life. The asphalt in front of Eagan and up at Housing was experiencing Alligator Cracking. This cracking was caused by a sandy sub-base with weak shear strength, thin layer of asphalt and an asphalt mix that was dry and brittle.
The asphalt repair by the UAS Recreation center was to fix some Joint Cracking/Raveling. This is where the joint between two sections of pavement did not adhere together very well and the asphalt had begun to break apart at the joint.
New Asphalt Pavement at Egan
Asphalt Pavement Engineers use several other classifications of pavement failure including; Longitudinal Cracking, Transvers Cracking, Block Cracking, Edge Cracking, Reflection Cracking, Slippage Cracking, Shoving, rutting, raveling and wearing. Sort of makes you want to sign up for an Engineering Class :)
UAS Facilities is tasked with being a good steward for the entire infrastructure here on campus. This includes knowing when something is reaching its expected life and preparing for it to be repaired or replaced, before it fails. When something fails, it costs more to repair and can interfere with our mission to Learn, Engage, Exchange.
UAS Construction Update for 05/01/2015
Lighting the Pathway
UAS will replace the old High Pressure Sodium (HPS) pathway lights with new Light Emitting Diode (LED) lights this summer. We will be using the same small scale lights that were installed along the Auke Lake Way sidewalk last summer. Many UAS students, faculty and staff have commented on the inviting atmosphere these lights give the walkways. These LED light fixtures have a mounting bracket below the LED light which deflects enough light that you can see it from the end of the pathway. With this type of light fixture, we will see a trail of lights stretched before us and our minds will perceive that the pathway is lighter, and more inviting to walk.
UAS Pathway Lights installed in 2014
The Contractor will start next week marking the locations of the new lights and then remove the existing lights beginning later in May. The new lights will extend from Housing down to Eagan Library as shown on the figure below. Please note that there will be periods this summer when the pathway will be closed to pedestrian traffic. Signs and markers will lead the way for detours around the construction zone. The work will be completed before school starts this coming fall.
Please feel free to contact me with any questions about this project.
Nathan Leigh, UAS Project Manager, 796-6487
UAS Construction Update for 12/05/2014
Answer to Last Month’s Puzzler
Last month we asked the question on why bubbles formed in the silicone window joint. (See Post on Oct 31) This question turned out to be more of a puzzler than I had expected. We received several good theories and some not so good. Here are some of the answers we received.
- Something left on edges of glass that reacted with the silicone causing gas bubbles.
- Calking gun not uniform and backing off a little and allowing an air bubble to form.
- Edges of glass not cleaned and the silicone lost “grip” of the glass when it cured. Thus creating small suction cup bubbles. (See Oct 17 Entry for suction cup physics)
- Silicone emits gas as it cures. When the Silicone is too thick the gas gets trapped inside the silicone joint causing bubbles.
- Silicone not stored properly causing it to go bad.
- The bubble ferry…… and it gets feathers caught when the silicone dries too fast.
- The glass has a film sandwiched in the center so it will not shatter if it breaks. This film is emitting a gas or is reacting with the Silicone creating gas bubbles.
- There is movement in the joint as it cures causing the bubbles to stretch or tear. Movement can as little as someone leaning up against a pane of glass.
These answers came from Contractors, Architects, Engineers and the Silicone manufacture’s Product Manager. All of these answers have a sense of plausibility. However, none of them address all of the questions in our puzzler, particularly why bubbles only formed on one side of the joint, why some sections had large bubbles and some small bubbles, why some sections had no bubbles.
Feather Bubble Suspended in Silicone
My theory is that it is a combination of answers 4, 7 and 8. It may not be the cut and dry answer you were hoping for, but it’s my answer and I’m sticking to it.
Good Luck on finals next week and lets all hope your exams have easier questions than “Why did bubbles form in the Silicone joint of the UAS Freshman Residential Housing conference room glass wall”.
UAS Construction Update for 11/21/2014
Inspection with a View
The Architectural Team performed an inspection of the exterior metal siding and window flashing. The weather was excellent for an outside inspection, considering it is the third week in November. The inspection team found the Contractors work to be good with just a couple of items that need to address. Providing the weather holds, the Contractor has another couple of weeks completing the siding and window flashing on Hall #2. We greatly appreciate patience our UAS freshmen have had the past couple of months while the finishing touches are being made to the UAS Freshman Hall.
Metal Siding Inspection
Inspection with a View
I have received several Theories’ on the puzzler asked last month on why bubbles appeared in the clear silicone glass joints in the seminar room. All of these Theories start out with a good basis. However, they do not stand up to all of the facts we have in this scenario. The design team has a call into the silicone manufacturer to see if they have a better Theory. Until then, let’s just hold tight.
Puzzler for the Week
Many of life’s great discoveries have been made with someone asked Why? and then spent the time and energy to figure it out. We also learn more and retain that knowledge when we ask Why. I am not going to try and discuss the great questions asked by Mr. Cosby like “Why is there Air”. But, we did run across an interesting puzzler this week at the UAS Freshman Residential Housing project.
The fourth floor seminar room looks out over the UAS campus, Auke Lake and Mendenhall Glacier through several large panes of 1/2-inch thick glass. The contractor filled used a special clear silicone to fill the space in-between adjoining panes of glass. They used the electric calking gun so the placement of the silicone is very continuous and uniform. The first day that the silicone was installed, it looked good. However, over the next couple of days air bubbles formed in the silicone.
View from UAS Freshman Residential Hall seminar room.
The Puzzler for the week is:
- Why did air bubbles form in the Silicone?
- Why there were no air bubbles the first day when it was installed?
- Why did air bubbles form only on one side of the joint in some locations?
- Why did lots of small air bubbles form in some sections while large bubbles form in other sections?
- Why do some air bubbles have what looks like a small feather coming out of them?
e-mail your answers to email@example.com by noon November 6, 2014.
The top 3 answers will be included in next week’s UAS Construction Update.
UAS Construction Update for 10/17/2014
497 lbs of Glass
How do you lift a 497 pound piece of glass 50 feet in the air?
Very Carefully (Banda Bing).
No, with four suction cups and a fork lift.
But how can a suction cup lift 500 pounds? The physics behind the suction cup is a little counter intuitive, but actually very simple.
Suction Cup Physics (not)
This is how I thought a suction cup worked, before I took engineering classes. You place the suction cup up against the window and then with a small pump suck the air out of the inside of the suction cup. The more air you suck out of the cup, the greater the negative pressure created inside the cup force holding the cup onto the window. I thought that the only limitation on the negative force you could create inside the cup was the power of the pump creating the suction force.
Suction Cup Physics
This is how I understand a suction cup works, after I took engineering classes. You place the suction cup up against the window and then with a small pump suck the air out of the inside of the suction cup. However, once you suck out all of the air, there is nothing left inside the cup, it’s a vacuum. It does not matter how powerful the pump is you can’t suck out something that is not there. Since there is nothing inside the suction cup there is any negative pressure, in fact there is no force at all. So what is holding the suction cup on the window? It is the air outside the suction cup that is pushing the cup onto the window. That force is usually one earth atmosphere.
Calculating how much one suction cup can lift is just the force (one atmosphere) times the surface area (area of the suction cup) which can be expressed in the formula F=PA
L = Load that a suction cup can hold
P = Pressure = Atmospheric pressure in Juneau at 9:00 am today is 995 mb = 0.98 Standard Atmosphere = 29.38 in-Mercury = 14.43 pounds/square inch
A = (Pi)(Radius Squared) = (3.14)(11)(11) = 95 square inches
L = (14.43 pounds/square inch)(95 square inches) = 1,370 pounds!
Suction Cup Window Lifter
The Contractor is using a suction cup window lifter by www.powrgrip.com This window lifter has four suction cups attached to adjustable arms connected to a center pivot bearing. This allows workers to attach the lifter to the window lying on its side and then lift it and rotate it into position.
You may think that with four suction cups we could lift (4)(1370) = 5,480 pounds. However, the safety rating on this window lifter is only 700 pounds. Just like most things in life, there are deductions. Suction Cup Window Lifters are no different. There are deductions for; changes in shape of the suction cup, non-perpendicular lifting forces, strength of suction cup materials, changes in atmospheric pressure and safety of workers and by standards.
Lifting a 497 pound window
Placing 497 pound window
Another Wonderful View from the UAS Freshman Housing
Lighting Outage Tonight
There will be no lights in the parking lot and along Auke Lake way tonight October 15, 2014. The Contractor that has installed the new LED lights on campus has removed the old control cabinet and is installing the new control cabinet. This is a two day job and there is no practical way to make a temporary power connection.
New Lighting Control Panel.
All of the UAS parking lots will be dark tonight in addition to the road and sidewalk coming into campus. The Noyse Pavilion and the parking lot lights in front of the new Freshman Housing and the new pathway lights between the parking lot and the Soboleff building are all fed from this control panel and will be off tonight. The courtyard, corridor and chapel by the lake shared parking lot are not affected by this project and will have lights. Lights will be back on tomorrow night. We apologize for the involving this will cause everyone here at UAS. If we are very lucky the clouds will dissipate and we will be able to see the Aurora display that has been very active the past 36 hours.
The UAS Site lighting project will be constructed under two separate phases as shown on the figure below. Phase II is scheduled for construction during the summer of 2015.