HomeMy WebLinkAboutItem 01 City Hall Seismic Study and Retrofit Recommendations AGENDA ITEM SUMMARY Meeting Date: 9/21/2015
Meeting Type: Work Session
Staff Contact/Dept.: Jeff Paschall, Ken Vogeney/DPW
Staff Phone No: 541-726-1674/736-1026
Estimated Time: 15 min. S P R I N G F I E L D
C I T Y C O U N C I L
Council Goals: Maintain and Improve
Infrastructure and Facilities
ITEM TITLE: CITY HALL SEISMIC STUDY AND RETROFIT RECOMMENDATIONS
ACTION REQUESTED: Staff seeks Council direction on investments to a seismic retrofit program for Springfield City Hall.
ISSUE
STATEMENT:
Springfield City Hall is at risk of significant structural damage in the event of an
earthquake that produces moderate to severe shaking at City Hall. Staff has prepared recommendations to incrementally retrofit City Hall to reduce this risk
over time.
ATTACHMENTS: 1. Council Briefing Memorandum
DISCUSSION/ FINANCIAL IMPACT:
In December 2014, the City contracted with Hohbach-Lewin Inc., Structural Engineers, of Eugene, to perform a structural seismic evaluation of the existing Springfield City Hall building for the purpose of determining structural sufficiency
and occupant safety in a seismic event. The evaluation concluded that an earthquake that produces moderate to severe shaking at City Hall will likely cause
significant structural damage, thereby rendering the building unusable. In addition,
the existing building could experience structural collapse throughout from an earthquake that produces very strong to severe shaking at City Hall.
Based upon their conclusions, Hohbach-Lewin, Inc. prepared a set of recommended structural seismic retrofit actions that the City could take to improve City Hall’s seismic performance. When these
recommendations are fully implemented, the building should experience minimal structural damage from
an earthquake that produces moderate shaking at City Hall. However, an earthquake that produces very strong to severe shaking at City Hall will still cause significant structural damage, but the building should
not catastrophically collapse.
Staff has developed a proposal for implementing the recommended structural seismic retrofits – see
Attachment 1. Some of the recommended retrofits can be accomplished with little disruption to the normal business functions at City Hall. Others will probably require relocating the staff and equipment from part of the building into other locations to accommodate the construction activity, and then moved back again
when construction is completed. Staff’s proposal includes implementing the recommended retrofits beginning in the current fiscal year and completing them over time as funds become available.
Hohbach-Lewin, Inc. included construction cost estimates for their recommended structural seismic retrofits for a total estimated cost of $1,000,000. However, these costs do not include all of the other work
that would be necessary to implement these recommendations, such as repairing walls or installing a new
roof membrane or relocating staff and equipment during the construction. Staff estimates that these additional costs will probably exceed $1,000,000, although additional study and design are needed to
prepare a complete scope of work and cost estimate.
It is important to note that the structural seismic evaluation included the basic building structure only. The
evaluation did not consider all of the non-structural components such as furnishings; interior non-structural
walls; building utilities such as water, electrical, technology/network equipment, heating and ventilating equipment, etc.; that are necessary to occupy and conduct business from City Hall.
M E M O R A N D U M City of Springfield
Date: 9/8/2015
To: Gino Grimaldi COUNCIL
From: Anette Spickard, Development and Public Work Director
Ken Vogeney, City Engineer
Jeff Paschall, Managing Civil Engineer
BRIEFING
Subject: CITY HALL SEISMIC STUDY AND
RETROFIT RECOMMENDATIONS MEMORANDUM
ISSUE: Springfield City Hall is at risk of significant structural damage in the event of an
earthquake that produces moderate to severe shaking at City Hall. Staff has prepared recommendations to incrementally retrofit City Hall to reduce this risk over time.
COUNCIL GOALS/
MANDATE:
Maintain and Improve Infrastructure and Facilities
BACKGROUND:
In December 2014, City staff contracted with Hohbach-Lewin Inc., Structural Engineers, of Eugene, to perform a seismic evaluation of the existing Springfield City Hall building for the
purpose of determining structural sufficiency and occupant safety in a seismic event. The
completed evaluation was reviewed by the City’s Executive Team on July 14, 2015.
The following table provides the results of the consultant’s evaluation for each of the Basic
Performance Objectives used. It also includes the estimated cost – for structural construction work only – to retrofit City Hall to meet each Basic Performance Objective. It is important to
note that even moderate seismic shaking at City Hall would likely result in significant structural
damage that may render the building unusable.
Hazard Level/ Performance Level Desired Performance Description Evaluation Results Estimated
Retrofit Cost*
BSE-1E/Damage Control Minimal structural damage from a moderate shaking (V) event at City Hall
Existing City Hall does not meet this Performance Level – significant structural damage likely, with potential for failure of some structural elements
$160,000
75% BSE-1N/Damage Control (evaluation uses 75% of Building Code design for a new building)
Minimal structural damage from a moderate to strong shaking (V to IV) event at City Hall
Existing City Hall does not meet this Performance Level – substantial structural damage likely, with potential for partial collapse
$700,000
BSE-2E/Limited Safety Major structural damage but no collapse from a strong to very strong shaking (VI to VII) event at City Hall
Existing City Hall does not meet this Performance Level – structural collapse likely throughout
$1,000,000
*Note: Estimated cost is for the structural retrofit only and does not include costs for removing and restoring other elements, for example the cost of removing the existing roof membrane and installing a new roof membrane after the retrofit work is completed is not included in these estimates.
RECOMMENDATIONS:
Attachment 1, Page 1 of 3
MEMORANDUM 9/8/2015 Page 2
The Executive Team directed the Development and Public Works Director with a team of staff members to review the seismic evaluation report, and develop a list of proposed
recommendations for moving forward. The following is the list of recommendations from the
review team: 1. The City should reprioritize projects in the Building Preservation Fund to make this a
top priority and invest in retrofits to the building that will eventually bring it up to the
BSE-2E standard.
2. Design and construction of the recommended retrofits should be phased such that those
items that can be done independent of a major roof overhaul or HVAC replacement are
done first. The first phase of recommended retrofit projects is estimated to cost
$200,000. These are:
a) Glue-lam beam connections in multiple locations
b) Concrete girder splices in multiple locations
c) Construction plans for new concrete walls and grade beams on the street level
3. The City should hire Hohbach-Lewin Inc. now to prepare the detailed construction plans
for the items listed in #2 with the goal of hiring contractors for construction to start in
spring 2016 on items 2a and 2b. The reasons we recommend having the construction
plans for item 2c drawn up now are:
a) The City will be able to analyze whether the work will trigger the application of
new building codes. We are currently grandfathered under the old building
codes until such time as we do substantial remodeling of the building.
b) Getting a better understanding of construction interdependencies and impacts
c) Creation of a logical and sound approach to phasing the construction
d) Refining and expanding construction estimates to include all of the costs
necessary to access the structural elements, make the currently recommended
improvements and return the building to an architecturally appropriate
condition.
4. The City should incorporate the remaining items into a HVAC replacement/roofing
project. When the roof and walls are opened up for these projects it makes sense to also
do the seismic retrofit. A financing strategy will need to be designed for these items.
5. The City should develop a temporary relocation plan for workers depending on the type
of construction activity that will occur for the different retrofits.
6. The City should conduct communication outreach to staff through an Inforum prior to
Supplemental Budget #1 and then follow up with information when the construction
activities are close to beginning.
7. Engage the City Hall safety committee in promoting low cost educational opportunities
and nonstructural improvements such as rearranging shelves with heavy items stored
lower, lighter items higher and securing bookshelves to walls and rolling item in place.
8. The City should prepare public information about the project for the media and others.
The Executive Team agreed with the approach presented, and staff is currently working on the details to hire Hohbach-Lewin to prepare the construction plans and then bid out the work, in
addition a Supplemental Budget request is being prepared to appropriate $200,000 toward the project this fiscal year. Additionally, staff will begin work on a larger financing strategy to address the roof, HVAC and remaining seismic retrofits over the course of the next year.
Attachment 1, Page 2 of 3
MEMORANDUM 9/8/2015 Page 3
FINANCIAL IMPACT:
The strategy provided does not necessarily increase the current budget at this time, but
rather reprioritizes several building preservation projects and utilizes realized savings from
completed projects to dedicate approximately $200,000 toward seismic retrofits.
RECOMMENDED ACTION: The Council is requested to review and provide direction and
consensus on the outlined strategy.
Attachment 1, Page 3 of 3