LANDAU CONSTRUCTION OBSERVATIONS MEMO.pdfr LANDAU
ASSOCIATI
October 20, 2014
PKJB Architectural Group
119 South Main Street, Suite 410
Seattle, Washington 98104
Attn: Mr. Shawn Rafferty
RE: SUMMARY OF CONSTRUCTION OBSERVATIONS
JACOBSEN'S MARINE FACILITY
345 ADMIRAL WAY
EDMONDS, WASHINGTON
Dear Mr. Rafferty:
Landau Associates provided geotechnical observation, testing, and consultation services during
construction of the Jacobsen's Marine Facility in Edmonds, Washington. Our construction observations
and test results are summarized in this letter report. Submission of this letter report completes our scope
of services for this project.
PROJECT BACKGROUND
Jacobsen's Marine constructed a building with maximum dimensions of about 152 feet (ft) by
110 ft for use as a marine sales showroom and office in Edmonds, Washington. The building is supported
on shallow foundations that are founded on 3 ft of crushed recycled concrete. Landau Associates
previously conducted a geotechnical study at the project site and developed conclusions and design -level
recommendations for the project. Results of this study are presented in our December 5, 2007 report
titled Report, Geotechnical Engineering Services, Jacobsen's Marine Facility, Edmonds, Washington.
Supplemental geotechnical information for the project was provided in our February 26, 2014 letter titled
Geotechnical Responses to City of Edmonds' Review Comments, Jacobsen's Marine Facility, 345
Admiral Way, Edmonds, Washington. The recommendations presented in these referenced documents
were incorporated, as appropriate, into the construction documents, which were prepared by PKJB
Architectural Group. The general contractor for the project was SEA CON LLC of Issaquah,
Washington.
SCOPE OF SERVICES
Jacobsen's Marine retained Landau Associates to provide geotechnical observation, testing, and
consultation services during earthwork and foundation -related construction activities for the project. The
focus of our services was to assist the project team in determining that critical earthwork and
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foundation -related construction activities were accomplished in general accordance with the project plans
and specifications. The services we provided included the following tasks:
® Reviewing the project plans and specifications
® Construction observation related to the overexcavation of 3 ft of soil from beneath the
building footprint
® Construction observation related to placement of 3 ft of crushed recycled concrete within the
building footprint
® Construction observation and testing related to fill placement and utility trench backfill
® Construction observation related to the preparation of pavement and sidewalk subgrades
® Performing laboratory testing on structural fill and backfill materials
® Preparing field reports after each site visit
® Preparing this letter report summarizing our conclusions regarding the suitability of the work
completed with regard to the project plans and specifications
® Providing geotechnical consultation related to the tasks outlined above.
OBSERVATION PROCEDURES
Between April 24, 2014 and August 26, 2014, Landau Associates personnel made 9 site visits to
observe critical earthwork and foundation -related construction activities associated with construction of
the Jacobsen's Marine Facility. As of the date of this letter report, all critical earthwork and
foundation -related construction activities have been completed. Construction observations were
performed on a part-time basis. Site visits were typically coordinated through SEA CON LLC.
Qualitative observations were limited to subgrade preparation for building foundations, pavements, and
sidewalks using a steel T -probe. Quantitative measurements were obtained on compacted structural fill
(including utility trench backfill) using a nuclear lensometer.
Summaries of our observations and test results were provided verbally to the contractor during
each site visit. Copies of our written daily field reports, which document our observations, opinions, test
results, and recommendations of the specific areas observed, were previously transmitted to the project
team concurrent with the construction progress. In instances where Landau Associates observed
conditions not in conformance with the project plans and specifications, we recommended corrective
action appropriate to the situation, and subsequently verified that corrective measures were carried out.
SUMMARY OF OBSERVATION RELATED TO FOOTING SUBGRADES
Landau Associates observed the exposed subgrade following the overexcavation of 3 ft of soil
from beneath the building footprint. Landau Associates also observed on a part time basis the placement
and compaction of 3 ft of crushed recycled concrete within the building footprint. In general, the finished
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subgrade for the building was observed to be firm, dense, and unyielding. In our opinion, the prepared
subgrade should provide suitable support for the building.
SUMMARY OF OBSERVATION RELATED TO PAVEMENT AND SIDEWALK SUBGRADES
Landau Associates observed finished subgrades for pavement and sidewalks. Pavement
subgrades were assessed using a steel T -probe and by observing proof -rolling of the exposed subgrade.
Sidewalk subgrades were assessed using a steel T -probe. Proof -rolling equipment generally consisted of
heavy construction equipment. In general, finished pavement and sidewalk subgrades were observed to
be firm, dense, and unyielding. In areas where the exposed subgrade was soft or unstable, unsuitable soils
were either removed to an appropriate depth below subgrade elevations and backfilled with compacted
structural fill or recompacted in place. In our opinion, the pavement and sidewalk subgrade soils
observed should provide suitable support for the onsite pavement and sidewalks.
SUMMARY OF EARTHWORK RELATED TESTING AND MONITORING
Landau Associates observed backfilling operations on a part-time basis throughout the
construction of the project. Coordination of our site visits was generally through the general contractor
(SEA CON LLC). Specific areas observed and tested included fill placed outside the building footprint to
raise site grades and utility trench backfill for onsite utilities.
Backfill was generally observed to be placed in lifts of appropriate thickness and compacted to a
relatively firm, dense, and unyielding surface. Field density tests were performed at locations selected by
our field personnel at a frequency considered to be appropriate to adequately judge whether the earthwork
being performed during our site visits was in substantial conformance with the requirements of the project
specifications. The density tests were performed using a nuclear densometer in general accordance with
ASTM International (ASTM) D2922 test procedures. Our observations and the results of our field
density tests indicate that the structural fill soils were generally compacted to at least 95 percent of their
maximum dry density. Areas of fill that did not initially meet the 95 percent compaction requirement
were subsequently reworked and satisfactorily recompacted.
CONCLUSION
Based on our representative's observations and compaction test results, it is our professional
opinion that critical earthwork and foundation -related portions of the Jacobsen's Marine Facility project
were performed in general accordance with the intent of our geotechnical design report and the project
plans and specifications. This conclusion applies only to work performed under the observation of
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representatives of Landau Associates between April 24, 2014 and August 26, 2014. We cannot provide
advice, opinions, or conclusions relative to site work that we did not observe.
Within the limitations of scope, schedule, and budget, our geotechnical observation and testing
services have been provided in a manner consistent with that level of rare and skill ordinarily exercised
by members of the profession currently practicing in the same locality under similar conditions as this
project. We make no other warranty, either express or implied. Landau Associates' observation of the
contractor's work, does not relieve the contractor of their responsibility to produce a completed project
that conforms to the project plans and specifications.
We appreciate the opportunity to be of service to you on this project. If you have any questions
regarding the content of this letter report, or additional information is required, please contact me.
LANDAU ASSOCIATES, INC.
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Steven R. Wright, P.E.
Principal
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