Property Owner Information

SR 99 Tunnel Project - Information for Property Owners


December 2015 - Information for residents and businesses in Pioneer Square

Recently, our team detected approximately one inch of ground settlement near the pit Seattle Tunnel Partners is building to access and repair the SR 99 tunneling machine. Settlement was also detected on the Alaskan Way Viaduct and some of the buildings that we are monitoring; the amount of settlement lessens in the surrounding area. Our experts are still analyzing data and conducting daily inspections of the viaduct, but to date, no significant settlement has been observed beyond the initial settlement we reported publically on Dec. 5, 2014. 

We have identified approximately 30 buildings that warrant further investigation. We are working with property owners and managers to complete interior visual inspections of these buildings. These inspections are being completed by a historic architect and include a survey of the building to look for impacts to significant architectural elements or other indications of damage.
 
We’ve received a number of questions from residents and businesses in Pioneer Square regarding recently measured ground settlement in the neighborhood. Below are answers to some of the most common questions. We’ll continue to update this list as we gather additional information. If you live, work or own property in Pioneer Square and have questions or concerns, please call 1-888-AWV-LINE or email viaduct@wsdot.wa.gov.
 

Common Questions for residents and businesses in Pioneer Square
 

What kind of settlement has WSDOT seen near the access pit and in Pioneer Square?
We installed a state-of-the-art settlement monitoring system as part of the SR 99 Tunnel Project. Recently, Seattle Tunnel Partners surveyors detected over an inch of ground settlement near the pit crews are building to access and repair the SR 99 tunneling machine. We have also seen similar settlement on the Alaskan Way Viaduct; the amount of settlement lessens in the surrounding area.
 
Have buildings been damaged in Pioneer Square? 
We have identified approximately 30 buildings that warrant further investigation. We are working with property owners and managers to complete interior visual inspections of these buildings. These inspections are being completed by a historic architect and include a survey of the building to look for impacts to significant architectural elements or other indications of damage. A number of these surveys have already been completed and the project team continues to schedule surveys as needed. So far, our team has seen a small amount of cosmetic cracking in masonry and drywall but no indications of structural damage.
 
How would settlement affect my building?
You may notice new cracks or changes to existing cracks in your building. You may also notice doors or windows that are sticking or do not open properly.  If the building settles more than the ground outside, utility services also could be disrupted. If you notice such changes in your building, please keep a list or take photos, and follow the contact information below. 
 
What should I do if I see new damage in my building?
If you are a resident or tenant, please contact your property manager or building owner. Building owners should contact the Alaskan Way Viaduct Replacement Program (1-888-AWV-LINE or viaduct@wsdot.wa.gov) to report any settlement-related concerns. If you have photos, please share them with our staff. 
 
How do I file a claim if I have building damage?
If you feel your building has been damaged as a result of ground settlement, you can file a claim with WSDOT. Please contact 1-888-AWV-LINE or viaduct@wsdot.wa.gov for instructions on filing a claim and to speak with project staff. 
 
What is WSDOT doing to protect buildings that may be affected by settlement? 
We implemented a comprehensive program to monitor ground movement during SR 99 tunnel construction. Crews are currently analyzing data from this system and conducting extensive surveys near the work zone. If damage occurs to buildings or infrastructure as a result of tunnel construction, we will be responsible for costs associated with repairs. 
 
Based on a thorough analysis of data, it appears that additional settlement is not occurring, though we will continue to closely monitor the situation. 
 
Can WSDOT expand the monitoring program to include more buildings?
Our monitoring system was designed to measure ground movement during tunneling. As part of that system, monitors were installed both in the ground and on structures. The most significant settlement has occurred in areas that include both ground and building monitors. However, some recent settlement has occurred in areas that are not actively monitored. As a result, we do not have specific settlement data for some of these buildings.   
 
Structural engineers and surveyors are inspecting buildings and infrastructure in all areas where settlement was detected. Decisions about the scope of the monitoring program will be made after that analysis is completed.
 
Does WSDOT have a plan if settlement continues?
Protecting people and infrastructure is our top priority. Protocols are in place to address a range of potential issues that could arise as a result of ground settlement. WSDOT and STP are prepared to shut off the dewatering system if it becomes necessary.   
 

 

General information for property owners

The SR 99 Tunnel Project is one of the largest excavation projects in the history of our state. The project’s five-story-tall tunneling machine will remove approximately one million cubic yards of soil by the time it finishes digging the tunnel. The ground naturally experiences movement over time, but digging underground can cause additional movement.

We have implemented a comprehensive program to monitor and mitigate any effects of tunneling. The following information is intended to be a guide for property owners above and near the SR 99 tunnel route.

 

If you have questions, please email us at viaduct@wsdot.wa.gov or call our hotline at 1-888-AWV-LINE (298-5463).
 

Common Questions related to tunneling
 

How is WSDOT protecting structures along the tunnel route?

Buildings, utilities and streets located above and near the tunnel route will be monitored before, during and after construction. Each building was surveyed prior to construction to document its interior and exterior condition. Monitors installed on the buildings by our crews will be checked against data from before construction, as well as data from monitors installed outside the monitoring area.  As the tunneling machine pushes forward through earth, crews will measure the soil it removes while also tracking any ground movement above its path. If damage does occur to buildings, utilities or streets as a result of tunnel construction, we will be responsible for costs associated with repairs.

What types of monitoring equipment are installed on buildings?

Crews have installed monitoring equipment on buildings along the tunnel route. Automated survey machines on rooftops rotate and take readings of small monitoring points on nearby buildings every few seconds to measure any movement. They also use lasers to take measurements of reference points on the ground. Information from these machines is transmitted and recorded around the clock and reviewed by the project team.      

When taking readings, the survey machines emit a red beam that is similar to a laser pointer. The beam may be briefly visible. Each reading takes less than one second and is not harmful if seen.

What happens if damage occurs to my building during tunnel construction?

If we receive a report of damage to buildings or infrastructure, we will assess the damage and determine the cause. We will be responsible for repairing damage that occurs as a result of tunnel construction. Our staff in the Seattle project office will work with property owners to address claims. 

Crews have conducted pre-construction surveys that document each building’s interior and exterior condition prior to tunneling. This survey will help building owners and our structural experts quickly determine if any damage occurred as a result of tunnel construction.   

To report property damage or discuss any concerns during tunneling, please contact us at 1-888-AWV-LINE (298-5463) or viaduct@wsdot.wa.gov. The hotline is answered 24 hours a day, seven days a week.

When will the tunneling machine be near my building?

The tunneling machine began its journey under downtown Seattle in summer 2013. In December 2013, Seattle Tunnel Partners, our contractor for the tunnel project, stopped excavation approximately 1,000 feet into the dig after measuring increased temperatures in the tunneling machine. While investigating the cause of the high temperatures, STP discovered damage to the machine’s seal system and contamination within the main bearing.

STP is now building a 120-foot-deep pit that will allow crews to access and repair the machine, which is stopped about 60 feet underground between South Jackson and South Main streets. When the pit is complete, the machine will tunnel forward into it. Crews will then partially disassemble the machine, and make repairs and enhancements. After tunneling resumes, we will contact you to let you know when the machine will be close to your property.

Will I be able to hear or feel the tunneling machine?

It is possible that you may hear some noise or feel slight vibrations while the tunneling machine is near your building. If perceptible, noise and vibrations would last less than one week as the machine passes beneath.

Will my building be damaged during tunneling?

It is unlikely that your building will be damaged during tunneling. The machine was designed specifically for the soil and groundwater conditions beneath Seattle. As a result, we do not anticipate significant levels of settlement from tunnel construction. If any damage occurs as a result of tunnel construction, we will be responsible for repairs.