Wilson Tunnel improvements Frequently Asked Questions as of 10-2-15

Posted on Oct 2, 2015 in Highways News, Main, News

HONOLULU – Upon routine inspection, the Hawaii Department of Transportation (HDOT) found deficiencies in the steel rods that help support the ceiling of the Honolulu-bound Wilson Tunnel on the Likelike Highway. HDOT has since closed the left lane and is working diligently to make the necessary repairs. Motorists are advised to drive cautiously through the work zone and allow extra travel time to their commutes. Below is a list of frequently asked questions pertaining to the Wilson Tunnel improvements.

When and how was the damage discovered?

Damage to eight stainless steel rods which support the tunnel ceiling was discovered during a routine inspection on Sept. 25, 2015. To protect the health and safety of our highway users, the tunnel was closed to traffic over the weekend. During the closure, HDOT crews and a structural engineering consultant identified 22 other rods that were damaged.

What is the tunnel ceiling made of and what work is going to be done?
The tunnel ceiling is made of five inch thick reinforced concrete slabs that rest on ledges along both side walls of each tunnel and are supported in the center by a stainless steel rod. Eight of the rods have disconnected from the ceiling and need to be repaired. Upon further inspection, crews found an additional 22 rods that have some damage. There is also spalling in some of the concrete areas near the vents. We are investigating the cause of the deterioration.

How many rods are in the tunnel?
There are more than 350 rods in each tunnel.

Are these the original rods?
Yes. The stainless steel rods are the original ones that were installed when the tunnel opened in 1960.

What did crews complete over the weekend?
Crews performed initial assessments, installed wooden support beams from floor to ceiling for temporary support, placed concrete barriers in the tunnel for safety and have begun making necessary repairs to the spalling concrete.

Why were the wooden beams installed?
The beams are used to temporarily stabilize and support the ceiling until the permanent repair can be completed.

How long do you expect one lane to be closed?

Parts and materials are expected to arrive in 3-4 weeks. It is estimated to take construction crews an additional 2-4 weeks to complete the repairs. In all the project may last 6-8 weeks.

When will the construction take place?
The construction schedule is being finalized. Crews may work in the overnight hours. In an effort to finish faster they may work seven days a week.

Is it still safe?
Yes. The Wilson Tunnel continues to be safe. Public health and safety is the top priority for HDOT. Crews have inspected the tunnel and determined it is structurally sound and safe for travel.

Has the speed limit on the Likelike Highway changed?

Yes. The speed limit in the Wilson Tunnel Honolulu bound has been reduced from 35 mph to 25 mph.

Will both lanes need to be closed again at any point?
The left lane will continue to be closed 24/7. The right lane will remain open until further notice. The construction schedule is still being finalized, however one option is to close both lanes of the Highway in the Honolulu-bound direction during the overnight hours. If a right lane closure is necessary the public will be notified of such closures via message boards, social media and media advisories.

Will HDOT contraflow traffic during the morning commute hours?
HDOT has not made any operational changes to replace the inbound lane at this time. Engineers are looking at options such as potentially reversing the flow of the two outbound (Kaneohe-bound) lanes during the AM peak traffic. The options will be evaluated for safety, cost, and operational impacts with respect to the repair work schedule. HDOT crews are currently assessing the delays from the one lane closure during the morning hours. More details will be released if this option is implemented.

Will tow trucks be on standby to move a stalled vehicle off the highway?
Yes. A tow truck is stationed on the Likelike Highway during the morning commute to move a stalled vehicle off the roadway to quickly reduce the traffic congestion and open up the lane for travel.

How much will the project cost?
The cost is currently being negotiated with the contractor.

How often are inspections done?
Full inspections are done every two years with visual inspections done more frequently. The last full inspection was performed in 2013. The rods were not damaged during that inspection.

What caused the damage to the rods?
Now that the tunnel is shored, we will continue our assessments to determine the cause of the damage.

Are the Pali Highway and H-3 Freeway Harano Tunnels built the same?

No. The Pali Highway Tunnel is an arch and does not have the stainless steel rods or a plenum above the structure. The Harano Tunnels do have a plenum above the structure, similar to the Wilson Tunnel, however the Harano Tunnels also have a median wall down the middle to support the tunnel. HDOT examines all tunnels on State jurisdiction as part of its routine inspection program.

Are there alternatives for people to use instead of the Likelike Highway?
Yes. The Pali Highway and H-3 Freeway remain open and viable alternatives. Please drive safely and with caution at all times.

Is there additional information on the Wilson Tunnels?
The Wilson Tunnel opened to traffic in 1960. The Honolulu-bound tunnel is 2,775 feet in length. The Kaneohe-bound side is 2,813 feet long. The tunnel was built by the City & County of Honolulu for $12 million. At the time HDOT had not been established. The facility was later turned over to the State.

Who is doing the work?
The State is working on the project with assistance from contractors.

What is the contractor’s name?
The structural engineering consultant is Nagamine Okawa Engineers. The contractor helping repair the rods and patching of the ceiling is Abhe & Svoboda, Inc.