07-18-2019-mock-residence-retaining-wall-reconstruction-18b291-01-ipd-soil-compaction-report-d209458 (1)MTC
Materials Testing & Consulting, Inc. s
Geotechnical Engineering & Consulting o Special Inspection o Materials Testing o Environmental Consultingacw�"`"`'"
Mock Residence Retaining Wall Reconstruction - 18I3291-01 - IPD-Soil Compaction:
Report #D209458
CLIENT
Darrin Mock
DATE 07/18/2019
PROJECT LOCATION 21100 88th Place West Edmonds WA PERMIT #
Inspection Information:
Inspection Date: Time Onsite: 7:30 - Weather Overcast, 60's, light intermittent rain
07/18/2019 8:45 AM Conditions:
Inspection Performed: IPD-Soil Compaction
Field Data:
Work / Location: IPD-S / Behind retaining wall Gauge Standard MS: 602
Equipment ID & Serial #: Troxler 3430D, Ser. #19286 Gauge Standard DS: 1595
Test Samples:
Sample #: Description: Proctor Value(pcf): Optimum Moisture and Oversize Rock
Correction:
1. B19 0611 SP-SM, Poorly graded Sand with Silt and Gravel 124.2 JOMC = 6.8%, ORC = 24%
2. B19 0611 SP-SM, Poorly graded Sand with Silt and Gravel 117.9 OMC = 8.7%, No ORC
N(uncorrected)
TEST METHOD
0 ASTM D-1557 /AASHTO T-180
In Place Density Test Results (ASTM D-6938):
Test Mode /
# Depth
Location of Test Elev. Wet
Dens.
Dry Moist % Sample
Dens. #
% Comp. % Regd.
1 ®10'
E of W end SG + 3' 117.6
98.4 19.5 0
83.5 95
2 ®10'
W of E end SG + 3' 118
100.7 17.2 0
85.4 95
3 ®10'
W of E end SG + 2' 119.6
103.4 15.7 0
87.7 95
4 ®10'
W of E end SG + 1.5' 124.7
112.4 10.9 0
95.3 95
® Native Soils
Soils consistent with Proctor
O Yes O No
❑ Imported Fills
Soils found to be firm and stable; and to the best of our knowledge, meet
O Yes O No
compaction
Contractor notified of results
O Yes O No
Remarks:
MTC arrived on site as requested by client to perform compaction tests on native material placed as fill for the backside
of the retaining wall. Material had been previously approved for use based on visual inspection pending lab testing, and
was placed and compacted prior to MTC's arrival. Approximately 2.0 to 2.5 feet of material had been placed over the
base cut level behind the wall, and MTC was informed that it had been compacted every 4 to 6 inches with a vibratory
plate compactor. Geotextile was pending placement at 3' above base of wall, and MTC was informed there was another
level of mesh located at 1' above wall base per MTC's wall design plans. The geogrid extended the length of the wall and
spanned from the backside of the wall to undisturbed native soil surpassing the minimum width required.
Upon arrival, we noted conditions were wet from rain the prior night and early morning. No proctor was available at the
time, however when tests were performed the density readings were much lower than typical soils of similar content.
Moisture readings were also observed to be highly elevated nearing 20%. Soils at the test level probed 6 to 8 inches with
little effort due to saturated conditions. MTC requested the contractor to excavate a pot hole to investigate the fill at
lower levels. This was repeated, and it was found that moisture decreased and density increased with depth to a more
reasonable level.
Corporate • 777 Chrysler Drive o Burlington, WA 98233 • Phone 360.755.1990 • Fax 360.755.1980
Regional Offices: Olympia Bellingham Silverdale Tukwila
360.534.9777 360.647.6111 360.698.6787 206.241.1974
Visit our website: www.mtc-inc.net
Mock Residence Retaining Wall Reconstruction - 18B291-01, 0711812019, #D209458, Page 1 of 2
MTC
Materials Testing & Consulting, Inc. s
Geotechnical Engineering & Consulting • Special Inspection • Materials Testing • Environmental Consulting'�AsC�"°`' n`
MTC deemed the soil at about 18" above wall base grade as suitable based on probing and test results, and that material
below this elevation was usable. Further excavation was not done to avoid damaging the lower geogrid. It was decided
that the material above this elevation would need to be removed and replaced with new material. The contractor was
informed on site of the results and agreed to replace the upper approximately 1.5 feet of fill.
Final report includes laboratory data. The lowermost test passes 95% compaction using proctor value without rock
correction, accounting for some observed variability. The other tests above within the material to be replaced are
confirmed to be failing compaction. MTC agreed to return to test new fills once prepared.
Work in progress. Additional inspection needed.
Images:
UPLOADED: 07/18/2019 19:35:22 Digging UPLOADED: 07/18/2019 19:37:02 Behind
through wet fill to test below retaining wall looking East
REPORTED BY: Leigh Robinette REVIEWED BY: John Gillaspy, Project Manager
Corporate • 777 Chrysler Drive • Burlington, WA 98233 • Phone 360.755.1990 • Fax 360.755.1980
Regional Offices: Olympia Bellingham Silverdale Tukwila
360.534.9777 360.647.6111 360.698.6787 206.241.1974
Visit our website: www.mtc-inc.net
Mock Residence Retaining Wall Reconstruction - 18B291-01, 0711812019, #D209458, Page 2 of 2