9921 Water compaction test.pdfGeological Vii:
-Y A IT'lowers, PLLC (,e.oLechY_6cal Services
11`11'i'11'11_�'] 111"') MEMI() #2 Pag, 12.
'11b: Ron,loliu.nsou, Architect NAC.' Mal'(1121, 2013
1"I'r- (','hary Flowersj'.E.Grl, GAF [11%.-,jed No: 11039
S lit Re: Mcf)onald Residei..icc 9921 SL
Water , Ed R'nonds ll Pe-#BLD20Ii.8o8
Oj,.i site on multiple times -for evaluation of bacIdIll around, two new catch basins (CBs) an(I
the storm water pipe trench between the 41-l'Bs. C13-1 is located near the sotittimest corrier of
the McDonald property. (--'B--2 is located abo"It 50 west of CB i along the north edge of
Water Street. Immedia-16ty adv-jacent to CB2- is another CB that was previously installed for
the new home construction downslope of the McDonald residence. Ourevaluatioudid.-not
inc,lude this acjjacent CB.
On arrival on 3/11/13 the bacIffill was visually evaltiated. and p�robedwith as T. -handle soils
probe. The backfill around the CBs consisted Of 5/8" minus crushed rock while the treneb
bacicfill was asphalt grindings. The crushed rock did nod appear to be well compacted
around either CB andcouldbe easily probed. 'The asphalt grindings appeared to bay ani
'tight and were difficult to probe. Proctor samples were collected during this site visit and a
follow up site visit and subi.nitted to as soft testing laboratory for proctor testing as per ASTM
D:1557 modified proctor. Recommended to general contractor (ROD Johnson) that the
ert-tshed rock would lik6ly fail compactiontests and should be 1'edo-ne. Also noted to
contractor that -testing asphalt grindings canbe difficult with a unclear densometer and.
passing results wei.e unlikely even though the mater�ial was tight and unyielding. Also,
aspbalt grindings were not included in the project specifications as an approved backfill,
material for the pipe trench.
On 3/13/13 Andrew Glandon arrived on site to take a series of IPDs (in place density -tests)
with a nuclear densorneter. Contractor was completing i.,,e-corapactiou of the CB bacicfill —
however the compaction equipment was not working properly and suitable densification did
not appear likely. Density test results taken on this date showed less than go% compaction
in both the crushed rock andi asphalt grindings, Advised contractor not to proceed. with
roadway asphalt placement at this time and that additional corrective measures were
required in order to ineet city requirements for suit able"bac1cfill placement and compaction.
On site On 3/19/13 (2 site -visits) for further evaluation of CB and pipe trench backfill. Due to
issues with previously installed backfill earthwork contractor (TME) has decided to remove
,existing backfill and replace entirely with 5/8" minus crushed rock. Excavation and removal
from site of asphalt grindings was observed. Excavation proceeded to about i" above top of
pipe resulting in only a tiny amount of asphalt grindings remaining.. Backfill around pipe up
to the spring line or above is pea gravel. Remainder of backfill is F)/8" minus crushed rock.
Crushed rock was placed in lifts and each lift. was compacted with as on as double drum
riding vibratory compactor urail it was dense and unyielding, Trench was filled to
approxiinately 6" below planned paveynent sti.rface,, Asphalt contrador is responsible fear
remainjug crushed rock and HMA placeineii-L
195r 32 u.111 Ave NE Stwreline, WA 98155
PIIOFIC.�� 2o6zp7-76/,jo FRX: 2o6 -W36--3,831
Field Memo # 2_.W
McDonald Residence
9921 Water ,Street, Edmonds, WA
Page 2 of'2
Earthwork contractor (TT&E) also excavated the existing crushed rock around CBs 1 and 2
for a depth of about 18 inches. The remaining material Was then thoroughly compacted to a
dense and unyielding condition With a "jumping jack" type compactor. Probing With a T-
handle soils probe indicated sufficient compaction Was attained. The area around the CBs
Was then backfilled in lifts and each lift compacted to a dense and unyielding condition with
the compactor prior to placing the succeeding lift.
On 3/20/13 Andrew Glandon returned to the jobsite to take additional 1PDs on the crushed
rock around the CBs and along the trench line. A total of 6 tests Were taken. Results of the
tests are presented below. All tests showed compaction of 95% or greater which meets or
exceeds city standards.
Test#
Location
Depth
Dry
Density
%
Moisture
Proctor
Comp
%
Pass/Fail
1
Just E of CB#1
SG
119.4
6.9
124.5
95.9
P
2
15ft W of CB#1
SG
122.5
7.1
124.5
98.4
P
3
35ft W of CB#1
SG
120.9
6.0
124.5
97.1
P
4
55ft W of CB41
SG
123.1
5.4
124.5
98.9
P
5
75ft W ofCB#1
SG
121.8
6.4
124.5
97.8
P
6
5ft E of CB#2
SG
1 118.6
6.2
124.5
95.3
P
1953212th Ave NE Shoreline, WA 98155
Phone: 206--417-7640 Fax: 206-686-3834