HomeMy WebLinkAboutSTONEBRIDGE GARDEN APARTMENTS PRELIM PUD - 82 93 - CORRESPONDENCE - (5)s
The base course should be placed on the subgrade at or near optintxa
moisture and compacted to at least ninety-five percent (9Ea) of Standard
Proctor Density ASr':1 D 598-73. (See Appendix C.) It is important that
the base course be shaped to grade so that proper drainage of the
pavement area is obtained.
The asphaltic concrete should r-eet City of Fort Collins specifi-
cations or equivalent and be placed in accordance with those speci-
fications.
GENERAL RECCMENDATIONS
(1). Laboratory tests indicate that water soluble sulfates in the
soil are negligible, and a Tyne I cement may be used in all
concrete exvosed to subsoils. All slabs on crade subjected to
de-icing chemicals should be composed of a more durable con-
crete using a Type II cement with low water -cement ratios and
higher air contents.
(2) Finished grade should be sloped away from the structures on
all sides to give positive drainage. Five percent (5%) for
the first five (5) feet away from the structures is the sug-
gested slope.
..:.(3) 3ackfill around the outside perimeter of the structures
should be mechanically compacted at optimur. moisture to at
least ninety-five percent (95%) of Standard Proctor Tensity
ASTM D 698-73. (See Appendix C.) Puddltng should not be.
permitted as amethod of compaction.
(4) Cutters and downspouts should be designed to carry roof runoff
water well beyond the backfiil area.
(5) Underground sprinkling systems should not be installed within
ten (10) feet of the structures, and this recove-endation
should be taken into account in the landscape planning.
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CONSOLIDATION --SWELL TEST
0.s 1.0
APPLIED PRESSURE—TONS/SQ. FT.
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0.1 0.5 1.0 5 10
APPLIED PRESSURE—TONS/SQ. FT.
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APPENDIX C.
Suggested Specifications for Placement of Compacted Earth Fill
and/or Backfills.
GENERAL
A soils engineer shall be on -site to provide continuous observation
during filling and grading operations and shall be the owner's repre-
sentative to inspect placement of all compacted fill and/or backfill on
the project. The soils engineer shall approve all earth materials prior
to their use, the methods of placing, and the degree of compaction
obtained.
MATERIALS
Soils used for all compacted fill and backfill shall be approved by the
soils engineer prior to their use. The upper two (2) feet of compacted
earth backfill placed adjacent to exterior foundation walls shall be an
impervious, nonexpansive material. No material, including rock, having
a maximum dimension greater than six inches shall be placed in any fill.
Any fill containing rock should be carefully mixed, to avoid nesting and
creation of voids. In no case shall frozen material be used as a fill
and/or backfill material.
PREPARATION OF SUBGRADE
All topsoil, vegetation (including trees and brush), timber, debris,
rubbish, and other unsuitable material shall be removed to a depth
satisfactory to the soils engineer and disposed of by suitable means
before beginning preparation of the subgrade. The subgrade surface of
the area to be filled shall be scarified a minimum depth of six inches,
moistened as necessary, and compacted in a manner specified below for
the subsequent layers of fill. Fill shall .not be placed on frozen or
muddy ground.
c-2
e
pneumatic -tired rollers, three -wheel power rollers, vibratory compactors,
or other approved equipment well -suited to the soil being compacted. If
a sheepfoot roller is used, it shall be provided with cleaner bars
attached in a manner which will prevent the accumulation of material
between the tamper feet. The rollers should be designed so that effective
weight can be increased.
MOISTURE -DENSITY DETERMINATION
Samples of representative fill materials to be placed shall be furnished
by the contractor to the soils engineer for determination of maximum
density and optimum moisture or percent of Relative Density for these
materials. Tests for this determination will be made using methods
conforming to requirements of ASTM D 698, ASTM D 1557, or ASTM D 2049.
Copies of the results of these tests will be furnished to the owner, the
project engineer, and the contractor. These test results shall be the
basis of control for all compaction effort.
DENSITY TESTS
The density and moisture content of each layer of compacted fill will be
determined by the soils engineer in accordance with ASTM D 1556, ASTM D
2167, or ASTM D 2922. Any material found not to comply with the minimum
specified density shall be recompacted until the required density is
obtained. Sufficient density tests shall be made and submitted to
support the soils engineer's recommendations. The results of density.
tests will also be furnished to the owner, the project engineer, and the
contractor by the soils engineer.
C-4
16
PLACING FILL
No sod, brush, frozen or thawing material, or other unsuitable material
shall be placed in the fill, and no fill shall be placed during unfavorable
weather conditions. All clods shall be broken into small pieces, and
distribution of material in the fill shall be such as to preclude the
formation of lenses of.material differing from the surrounding material.
The materials shall be delivered to and spread on the fill surface in a
manner which will result in a uniformly compacted fill. Each layer
shall be thoroughly blade mixed during spreading to insure uniformity of
material and moisture in each layer. Prior to compacting, each layer
shall have a maximum thickness of eight inches, and its upper surface
shall be approximately horizontal. Each successive 6" to 8" lift of
fill being placed on slopes or hillsides should be benched into the
existing slopes, providing good bond between the fill and existing
ground.
MOISTURE CONTROL
While being compacted, the fill material in each layer shall as nearly
as practical contain the amount of moisture required for optimum compaction
or as specified, and the moisture shall be uniform throughout the fill.
The contractor may be required to add necessary moisture to the fill
material and to uniformly mix the water with the fill material if, in
the opinion of the soils engineer, it is not possible to obtain uniform
moisture content by adding water on the fill surface. 'If, in the opinion
of the soils engineer, the material proposed for use in the compacted
fill is too wet to permit adequate compaction, it shall be dried in an
acceptable manner prior to placement and compaction.
COMPACTION
When an acceptable, uniform moisture content is obtained, each layer
shall be compacted by a method acceptable to the soils engineer and as
specified in the foregoing report as determined by appl i cable' standards.
Compaction shall be performed by rolling with approved tamping rollers,
6
SUMMARY OF TEST RESULTS
Atterbera Summary
Boring No.
11
12
24
25
30
31
32
33
34
Depth (Ft.)
1.0-2.0
1.0-2.0
1.0-2.0
1.0-2.0
1.0-2.0
1.0-2.0
1.0-2.0
1.0-2.0
1.0-2.0
Liquid Limit
35.8
28.7
28.9
31.7
37.2
35.5
37.2
35.9
38.3
Plastic Limit
19.6
15.1
17.5
16..7
18.0
19.0
19.5
20.9
19.5
Plasticity Index
16.2
13.5
11.4
15.0
19.2
16.5
17.7
14.9
18.8
% Passing 200
76.9
63.9
42.8
69.8
78.6
58.9
56.5
41.1
75.4
Group Index
11.3
5.9
1.5
8.3
14.0
7.1
7.2
2.4
13.1
Classification
Unified CL CL SC CL CL CL CL SC CL
AASHTO A-6(1)) A-6(6) A-6(2) A-6(8) A-6(14) A-6(7) A-6(7) A-6(2) A-6(13)
SUMMARY OF TEST RESULTS
Swelling Pressures
Boring
Depth
% Moisture
Dry Density
Swelling
No.
(Ft.)
Before Test
P.C.F.
Pressure PSF
3
3.0-4.0
14.5
104.5
620
4
3.0-4.0
11.8
95.0
240
8
3.0-4.0
13.3
91.5
20
21
3.0-4.0
12.7.
115.7
1345
22
3.0-4.0
11.2
89.9
115
25
1.0-2.0
11.2
105.4
550
26
3.0-4.0
12.7
108.6
515
28
3.0-4.0
11.0
107.4
760
a_ia
BORING
NO.
DEPTH
FT.
32
1.0-2.0
2.0-3.0
6.0-7.0
33
1.0-2.0
2.0- 3.0
6.0- 7.0
0
34
1.0-2.0
2.0-3.0
6.0-7.0
10.5
6.5
9.6
14.0
12.2
15.4
SUMMARY OF TEST RESULTS
DRY DENSITY UNCONFINED COMPRESSIVE
P.C.F. STRENGTH-P.S.F.
107.8 13,530
103.6 1 10,060
WATER SOLUBLE
SULFATES-%
PENETRATION
ILOWS/ INCHES
14/12
15/12
11/12
9/12
12/12
8/ 12
EMPIRE LABORATORIES, INC.
BORING
NO.
DEPTH
FT.
%
MOISTURE
11.6
28
0.5-1.5
3.0-4.0
11.0
4.0-5.0
7.0-8.0
12.5
8.0-9.0
13.5-14.5
17.2
18.5-19.0
12.5
O°
29
1.0-2.0
18.3
�+
2.0-3.0
6.04.0
12.0
30
1.0-2.0
12.8
2.0-3.0
15.6
6.0-7.0
16.2
31
1.0-2.0
11.1
2.0-3.0
6.0-7.0
13.6
SUMMARY OF TEST RESULTS
DRY DENSITY
UNCONFINED COMPRESSIVE
P.C.F.
STRENGTH-P.S.F.
109.7
13,460
109.6
59410
112.1 1 129250
110.3 1 13,810
WATER SOLUBLE
SULFATES-%
PENETRATION
BLOWS/ INCHES
14/12
19/12
6/ 12
9/12
50/ 6
5/12
8/12
14/12
5/12
13/12
3/12
EMPIRE LABORATORIES, INC.
BORING
NO.
DEPTH
FT.
MOISTURE
_
24
1.0-2.0
9.0
2.0- 3, 0
6.0-7.0
18.8
7.0-8.0
13.5-14.5
4.3..
25
1.0-2.0
11.2
2.0- 3.0
6.0-7.0.
8.9
26
0.5-1.5
10.6
3.0-4.0
12.7
4.0- 5.0
7.0-8.0
21.5
8.0-9.0
13.5-14.5
22.8
27
0.5-1.5
11.4
3.0-4.0
10.8
4.0-5.0
7.0-8.0.
15.2
8.0-9.0
13.5-14.5
21.9
SUMMARY OF TEST RESULTS
DRY DENSITY UNCONFINED COMPRESSIVE
P.C.F. STRENGTH-P.S.F.
107.5 49450
109.0 1 11,930
100.8
89.9 1,670
. 98.4 59610
106.6 39330
WATER SOLUBLE
.0150
PENETRATION
BLOWS/INCHES
11/12
11/12
9/12
12/12
21/12
10/12
6/12
2/ 12
4/12
9/12
9/12
4/12
22/12
EMPIRE LABORATORIES, INC.
SUMMARY OF TEST RESULTS
BORING
NO.
DEPTH
FT.
%
MOISTURE
DRY DENSITY
P.C.F.
UNCONFINED COMPRESSIVE
STRENGTH-P.S.F.
10.9
21
0.5-1.5
3.0-4.0
12.7
115.8
209800
4.0-5.0
7.0-8.0
21.9
98.7...
2,880
8.0-9.0
13.5-14.5
23.8
W
22
0.5-1.5
14.6
3.0-4.0
11.2
105.2
779 870
4.0- 5.0
7.0-8.0
19.1
8.0-9.0
17.1
13.5-13.9
13.4
23
0.5-1.5
10.3
3.0-4.0
14.9
4.0-5.0
7.0-8.0
7.0
117.0
8.0-9.0
13.5-13.9
12.5
WATER SOLUBLE
SULFATES-%
PENETRATION
(LOWS/INCHES
20/12
19/12
8/ 12
7/12
13/12
15/12
31/12
50/ 5
13/12
20/12
14/12
50/5
I EMPIRE LABORATORIES, INC.
NO.
BORINGt3.
%
MOISTURE
18
.5
11.1
.0
12.4
4.0-5.0
7.0-8.0
11.5
.8.0-9.0
13.5-14.5
24.2
19
0.5-1.5
13.3
3.0-4.0
12.4
4.0- 5.0
w
7.0-8.0
19.7
8.0-9.0
13.5-14.5
20.6
20
0.5-1.5
11.7
3.024.0
13.9
4.0-5.0
7.0-8.0
26.0
8.0-9.0
13.5-14.5
26.2
18.5-19.5
14.4
23.5-24.4
19.5
SUMMARY OF TEST RESULTS
DRY DENSITY UNCONFINED COMPRESSIVE
P.C.F. STRENGTH-P.S.F.
100.5 69310
113.4 3,370
101.4 39090
104.7 2,910
107.8 159370
98.0 930
WATER SOLUBLE
SULFATES-%
0.0075
PENETRATION
(LOWS/INCHES
9/12
8/ 12
8/12
4/12
12/12
4/12
6/ 12
12/12
14/12
11/12
4/12
12/12
13/12
50/11
EMPIRE LABORATORIES, INC.
i
SUMMARY
OF TEST RESULTS
DRY DENSITY
UNCONFINED COMPRESSIVE
STRENGTH—P.S.F.
WATER SOLUBLE
SULFATES—/o
ENETRATION
BLOWS/INCHES
BORING
DEPTH
%
NO
FT.
MOISTURE
P.C.F.
17/12
15
0.5-1.5
13.0
3.0-4.0
9.8
92.6
7/12
4.0-5.0
7.0-8.0
16.7
105.6
29390
5/12
8.0-9:0
13.5-14.5
22.1
5/12
16
0.5-1.5
10.2
13/12
m
3.0-4.0
9.8
86.8
39660
v
4.0-5.0
11/12
7.0-8.0
11.9
97.8
8.0-9.0
10/12
13.5-14.5
23.7
10112
17
0.5-1.5
10.0
11/12
3.0-4.0
4.0-5.0
12.3
11/12
7.0-8.0
13.8
110.6
3,230
8.0-9.0
5/12
13.5-14.5
20.5
7/12
EMPIRE LABORATORIES, INC.
I
BORING
NO.
DEPTH
FT.
%
MOISTURE
13
0.5-1.5
16.3
3.0-4.0
16.6
4.0-5.0
7.0-8.0
14.5
8.0-9.0
13.5-14.5
18.4
14
0.5-1.5
10.7
W
3.0-4.0
10.3
.4.0-5.0
7.0-8.0
7.3
..
8.0-9.0
13.5-14.5
21.0
18.5-19.5
19.8
23.5-24.5
10.5
28.5-29.5
23.2
33.5-33.9
15.1
SUMMARY OF TEST RESULTS
DRY DENSITY UNCONFINED COMPRESSIVE
P.C.F. STRENGTH-P.S.F.
112.3 1 3,970
186.7 2,600
102.2 2,310
WATER SOLUBLE
SULFATES-%
PENETRATION
(LOWS/INCHES
15/12
5/12
4/12
8/12
15/12
6/ 12
7/12
4/12
11/12
23/12
10/12
50/ 5
EMPIRE LABORATORIES, INC.
I
19
BORING
NO
DEPTH
FT,
%
MOISTURE
10
0.5-1.5
14.6
3.0-4.0
9.8
4.0-5.0
7.0-8.0
14.7
8.0-9.0
13.5-14.5
22.2
11
1.0-2.0
13.6
.'r
2.0-3.0
0
6.0-7.0
14.8
7.0-8.0
13.5-14.5
19.3
12
1.0-2.0
13.5
2.0-3.0
6.0-7.0
18.9
7.0- 8.0
13.5-14.5
24.3
SUMMARY OF TEST RESULTS
DRY DENSITY UNCONFINED COMPRESSIVE
P.C.F. STRENGTH-P.S.F.
96.7 1 2,410
97.8 3,850
110.7 10,470
105.7 11,240
103.8 4,230
WATER
PENETRATION
BLOWS/ INCHES
12/12
10/12
9/12
=i 4/12
8/12
26/ 12
11/12
9/12
8/12
5/ 12
®.
1 EMPIRE LABORATORIES, INC.
BORING
NO.
DEPTH
FT.
MOISTURE
7
0.5-1.5
9.6
3.0-4.0
7.0
4.0-5.0
7.0-8.0
6.7
8.0-9.'0
13.5-14.5
18.4
8
0.5-1.5
12.6
00
3.0-4.0
13.3
`O
4.0-5.0
7.0-8.0
12.3
8.0-9.0
13.5-14.5
22.6
18.5-19.5
20.3
23.5-24.5
23.2
28.5-29.2
17.5
9
0.5-1.5
10.7
3.0-4.0
10.9
4.0-5.0
7.0-8.0
8.2
8.0-9.0
13.5-14.5
17.1
SUMMARY OF TEST RESULTS
DRY DENSITY
COMPRESSIVE
UNCONFINEDSTRENGTH-P.S.F.
SULFATES-%ATER E
PENETRATION
BLOWS/INCHES
P.C.F.
NGTH
19/12
17/12
16/12
7/12
15/12
91.8
29520
19/12
111.0
139000
14/12
7/12
10/12
19/12
.0200
50/8
10/12
86.1
19030
6/ 12
8/12
10/12
EMPIRE LABORATORIES, INC.
SUMMARY OF TEST RESULTS
BORING
NO.
DEPTH
FT.
% -
MOISTURE
DRY DENSITY
P.C.F.
UNCONFINED COMPRESSIVE
STRENGTH-P.S.F.
4
0.5-1.5
11.7
3.0-4.0
11.8
103.0
13,200
4.0-5.0
7.0-8.0
10.5;
111.0
14,550
8.0-9.0
13.5-14.5
21.5
5
0.5-1.5
10.4
p
3.0-4.0
9.1
107.6
12,980
b
4.0-5.0
700- 8.0
8.5
13.5-14.5
23.6
6
0.5-1.5
13.8
3.0-4.0
8.5
90.8
11190
4.0-5.0 -
7.0-8.0
6.5
112.9
69320
8.0-9.0
13.5-14.5
20.4,
WATER SOLUBLE
SULFATES-%
PENETRATION
BLOWS/INCHES
11/12
13/12
20/12
12/12
16/12
13/12
11/12
8/12
12/12
12/12
4/ 12
6/12
EMPIRE LABORATORIES, INC.
SUMMARY OF TEST RESULTS
DRY DENSITY
UNCONFINED COMPRESSIVE
STRENGTH-P.S.F.
WATER SOLUBLE
SULFATES-%
PENETRATION
INCHES
BLOWS/INCHES
BORING
DEPTH
FT.
MOISTURE
P.C.F.
NO.
10/12
1
1
0.5-1.5
14.0
3.0- 4.0
7.9
107.7
3, 830
12/12
4.0-5.0
7.0-8.0
13.2
.0200
8.0-9.0
2/12
13.5-14.5
24.6
6/12
18.5-19.5
16.8
10/12
23.5-24.5
19.3
28/12
28.5-29.0
17.4
50/6
2
0.5-1.5
11/12
3.0-4.0
16.8
88.0
29070
4.0- 5.0
6/ 12
7.0- 8.0
18.1
104.7
29930
8.0-9.0
3/ 12
13.5-14.5.
14.0
22/12
3
0.5-1.5
16.0
10/12
33.0-4.0
14.5
111.3
189740
4.0-5.0
15/12
7.0-8.0
15.3
108.0
3, 280
8.0-9.0
4/12
13.5-14.5
10.9
19/12
EMPIRE LABORATORIES, INC.
CONSOLIDATION --SWELL TEST
BORING No. 26 DEF
DRY DENSITY 94• 8#/Ft3
% MOISTURE 1 2' 7%
0.1 0.5 1.0 3 10
APPLIED PRESSURE—TONS/SQ. FT.
0.1 0.5 1.0
APPLIED PRESSURE—TONS/SQ. FT.
B- 6
.%0
0.1
CONSOLIDATION --SWELL TEST
0.5 I.o
APPLIED PRESSURE—TONS/SQ. FT.
0.1 0.5 1.0
APPLIED PRESSURE—TONS/SQ. FT.
B-5
FMPIRF 1 AR(-,?ATCIRIFS INC..
BORING NO. 15 DEPTH 3. 0
DRY DENSITY%•!#/Ft3
90 MOISTURE 9. 8%
5 is
5 10
M
.35
A
J
J
W
z 5
0
a
o
z
0
V
CONSOLIDATION --SWELL TEST
0.1 0.5 1.0 5 1c
APPLIED PRESSURE-TONS/SQ. FT.
3
0.1 0.5 1.0
APPLIED PRESSURE—TONS/SQ. FT.
B-3
ru n.nr . •n�n.�.�n.rn ua-
5 10
.70
0
a
n
o .65
.60
.55
o
J
J
5
I
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0
i=
a
n
10
z
0
u
15 L
0.1
CONSOLIDATION --SWELL TEST
APPLIED PRESSURE-TONS/SQ. FT.
t
0.5 1.0
APPLIED PRESSURE-TONS/SQ. FT.
B- 2
5 10
APPEh1DIX B.
LOG OF BORINGS
+•:1
4975
Jbl No. 32. No.33 LkL.14
-
VA
aw
A-12
EMPIRE LABORATORIES, INC.
4975
4970
4965
LOG OF BORINGS
ZWA
•
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A-11
EMPIRE LABORATORIES, INC.
LOG OF BORINGS
4980
4975
4970
4965
4960
4955
1.1 No.25 �lla.Z(o fVo.27 No.28
111 i
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WA
WA WA
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A-10
EMPIRE LABORATORIES, INC.
•'1
4975
4970
4965
4960
LOG OF BORINGS
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KEY TO BORING LOGS
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TOPSOIL
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SILTY SAND & GRAVEL
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SANDY SILTY CLAY
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SHELBY TUBE SAMPLE
-
STANDARD PENETRATION
DRIVE SAMPLER
rJ
WATER TABLE 24 HOURS
AFTER DRILLING
T
HOLE CAVED
5/12 Indicates
that 5 blows of a 140 pound
hammer falling
30 inches was required to penetrate 12 inches.
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EMPIRE LABORATORIES, INC.
TEST BORING LOCATION PLAN
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APPENDIX A.
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I
(o) It is recommended that all cor^paction requirements specified
herein be verified in the field with density tests performed
under the direction of the geotechnical engineer.
(1) It is recor:a^ended that a registered profassicnal engineer
design the foundations using the reccrr-zendations presented in
this report.
GE! UAL CC im-ENTS
This report has been prepared to aid in the evaluation of the
property and to assist the architect and/or engineer in the design of
this project. In the event that any changes is the design of the
structures or their locations are planned, the conclusions and recorrxaen-
dations contained in this report will not be considered valid unless
said changes are revieti:ed and conclusions of this report modified or
approved in writing by Empire Laboratories. Inc., the soils engineer of
record.
Every effort was made to provide comprehensive site coverage
through careful locations of the test borings, while keeping the site
investigation economically feasible. Variations in soil and groundwater
conditions between test borings may be encountered during construction.
In order to permit correlation between the reported subsurface conditions
and the actual. conditions encountered during construction and to aid in
carrying out the plans and specifications as originally contemplated, it
is recori"mended that Empire Laboratories, Inc. be retained to perform
continuous construction review during the excavation and foundation
phases of the work. Empire Laboratories. Inc, assumes no responsibility
for corapliance with the recorr.,endations included in this report unless
they have been retained to perform adequate on -site construction review
during -the course of construction.
Select Subbase
Select Base Course
Asphaltic Concrete
Total Payment Thickness
Collector
Arterial
•"
7■
6"
6"
2"
2"
12"
15"
'We understand that Monte Carlo and Wheaton Drives are both collector
streets. Harmony Road to the south of the property is an arterial
street.
Within the proposed Neighborhood Center, the following pavement
thicknesses are recommended using the group index design procedure:
Automobile Parking
Select Subbase ---
Select Base Course
Asphaltic Concrete
Total Pavement Thickness
1'
2"
9"
Service Drives
4"
6"
2"
12"
Hveem stabilometer tests are presently being performed on representative
samples of the subgrade materials. When these tests are completed,
pavement thicknesses using the new City of Fort Collins design procedure
will be submitted. At that tire: we will also include concrete pavement
alternatives.
The base course overlying the subgrade should consist of a hard,
durable, crushed rock or stone and filler and should have a mininum. "R'
value of 80. The composite base course material should be free from
vegetable matter and lumps or balls of clay and should meet the Colorado
Department of Highways Specification Class 6 Aggregate Base Course which
follows:
Sieve Size
% Passing
3/4"
100
04
30-65
gg
25-55
1200
3-12
Liquid Limit - 30 Maximum
Plasticity Index - G Maxim -arm
u
vation should be accomplished as discussed in the "Site Grading" section
of this report. As previously discussed, the near -surface soils encoun-
tered at the site are plastic and may be susceptible to swelling if they
are allowed to dry below their in situ -moisture contents and then are
rewetted. To prevent drying of the clay soils, foundation and building
excavations should not be allowed to rar•.ain open for extended periods of
time.
Slabs on grade supporting heavy floor loads should be underlain by
at least six (6) inches of crushed gravel base course, placed at optimum
moisture content and compacted to a minicum of ninety-five percent (95%)
of Standard Proctor Density ASTM D 698-73. (See Appendix C.) Office
and other areas transmitting li;ht floor loads should be underlain by a
minimum of four (4) inches of clean gravel or crushed rock free of
fines. The gravel base course and/or graval will help to distribute
floor loads and will act as a capillary break. All slabs on grade
should be designed for the imposed loading, and it is suggested that
they be designed and constructed structurally independent of all bearing
ambers. To mininize and control shrinkage cracks which will develop in
slabs on grade, we suggest that control joints be placed every twenty
(20) to twenty-five (25) feet and that the total area contained within
these joints be no greater than six hundred Vwenty-five (625) square
feet.
Pavements
Preparation to pavement subgrade elevation should be accomplished
as previously discussed in the "Site Grading" section of this report.
AASHTO classification of the on -site near -surface materials forming
pavement subgrade is A-6 with group indices 2 to 14. Using the group
index design procedure and a group index of 13, the follcwing pavement
thicknesses are recormended:
Ed
trousand (30,000) pounds per square foot. An estimated skin friction of !
three thousand (3000) pounds per square foot will be developed for that
portion of the pier embedded into the firm bedrock stratum. To counter- i
act swelling pressures which will develop if the subsoils become wetted, j
all piers should he designed For a ninirvr.) dead load of ten thousand
(10,COC) pounds per square foot. There this minimur, dead load require-
ment cannot be satisfied, skin friction from additional embedment into
the firm bedrock should be used to resist uplift. All piers should be j
reinforced their full length to resist tensile stresses created by
swelling pressures acting on the pier. It is essential that all grade
beads have a minimum four (4) inch void between the bottom of the beam
and the soil below. The anticipated settlement of pigs under the above
maximum loading should be negligible.
Temporary casing of all pier holes !ray he required to prevent
sloughing of the overburden materials and to permit dewatering prior to
concreting. To facilitate, cleaning, de►latering, and inspection of
piers, minimum twenty-four (24) inch diameter piers are recoarsended.
It is recorrended that qualified geotechnical personnel be present
during drilling operations to identify and verify penetration into the
firm bedrock, make certain that all piers are of proper diameter and
plumbness and that they are thoroughly cleaned and dewatered, and ensure
that reinforcing steel and concrete are properly placed.
Basements and Slabs on Grade
i
The subsurface conditions encountered at the site will permit exca-
vations of basements if desired. He do recommend that the basement
finished floor be placed at least three (3) feet above groundwater i
levels encountered in this investigation and a rainiman of three (3) feet
above the bedrock surface. Cue to the shallow bedrock encountered in +
Borings 22 and 23, basersent construction may not be feasible in the
extreme southeast corner of the property.
The subsurface conditions at the site will also permit conventional
slab -on -grade construction. Preparation to slab -on -grade subgrade ele. +
tests should be taken daily to detemine the degree of compaction being
attained and compliance with project specifications.
Foundations
Based upon the subsurface conditions encountered at the site and
the loads transmitted by the proposed construction, we recommend that
all structures be supported by conventional continuous or isolated
spread footings bearing in undisturbed natural soil or fill placed as
recosrended above. As on -site materials will be used for fill. struc-
tural fill placed and compacted as reconriended above will have com-
parable shear strength and bearing qualities to those of the in situ
materials. Exterior footin;s should bear a minimum of thirty (30)
inches below exterior finished grades for frost protection. The nature
of the bearing soil should be verified by qualified ceotechnical per-
sonnel prior to placement of foundation concrete.
Footings bearing at the above-recocnended depths tray be designed
for a maximum allowable soil pressure of one thousand five hundred
(1500) pounds per square foot under dead plus maximun live loads. To
resist swelling pressures which will develop if the subsoils become
wetted, footings should be designed for a ainimum dead load pressure of five'
hundred (500) pounds per square foot.
The anticipated settlemnt under the above-reconrended maximum
pressures should not exceed three -fourths (3/4) inch.
The overburden materials encountered at the site are plastic and'
tray be susceptible to swelling if they are allowed to dry below their in
situ moisture levels and then are rewetted. Therefore, to prevent
drying of the clay soils below their in -place moisture levels, foundation
and building excavations should not be allowed to remain open for ex-
tended periods of time.
As an alternativef, the proposed structures can be supported on !
straight -shaft drilled piers end bearing in the bedrock formation.
Piers drilled a minimum of three (3) feet into the fires bedrock stratum
may be designed for a maxinun allowable end bearing pressure of thirty
I
recorr.end that all fill in building and pavement areas be placed in
horizontal six (6) to eight (2) inch lifts at two ;percent (2N) wet of j
optimum moisture content and ccmpacted to a minimur, of ninety-five
percent 195%) of Standard Proctor Tensity AS I C. 6920-78, rill placed in
proposed greenbelt areas should be compacted to a minimum of ninety
percent (901) of Standard °rector Density AMI C 692-78.
There fill is placed on slopes greater than 4:1, horizontal benches
should be cut in the slopes to insure integrity of the new fill on the
existing slopes. For stability, we recommend that all cut and t111
slopes be no steeper than 2:1; however, flatter slopes are suggested for
ease of maintenance. Finished slopes should be seeded with native
grasses to minimize erosion.
All utility trenches extending four (4) feet or care into the upper
soils should be excavated on slopes no steeper than 1:1. The bedrock
may be excavated on vertical slopes. Excavation of the bedrock may
require the use of heavy-duty construction equipment. Where utilities
are excavated below groundwaterg, dewatering will be required during
placement of pipe and backfilling to insure proper construction. All
piping should be bedded to insure proper load distribution and to elim-
inate breakage during the backfilling operations.
backfill placed in utility trenches ir, open and planted areas
should be compacted in uniform lifts at optimum moisture to at least
ninety percent (901%) of Standard Proctor Density AST-4 D 698-78 the full
depth of the trench. The upper four (4) feet of backfill placed in
utility trenches under roadways and paved areas should be compacted at
or near optimum moisture to at least ninety-five percent (95%) of Stand-
ard Proctor Density ASTM D 698-78, and the lower portion of these trenches
should be compacted to at least ninety percent (90:) of Standard Proctor
Density ASV D 693-73. Addition of moisture to and/or drying of the
subsoils may be required to assure proper compaction. Proper placement
of the bedrock as backfill my be difficult, as is discussed above.
Qualified geotechnical personnel should be present during all
phases of earthwork to observe stripping of the topsoil, scarification
of the subgrade, and placement and compaction of fill. In -place density
-5-
16
one-half (10-1/2) to sixteen (lE) feet below present grades.
No water was encountered in the remaining test borings at the j
tirre of this investigation. Groundwater levels at the site
will fluctuate with seasonal variations and conditions.
ANALYSIS AUD RECYNENDATIMS
We understand that the Neighborhood Center will be developed for
cor.ercial use. The proposed buildings will be one- or two -stories with
conventional slab -on -grade construction. A basement is proposed for the
building to be constructed at the southwest corner of the site.
i
The following are our recommendations for development of the site
as influenced by the subsurface conditions encountered in the test
borings.
Site Grading
We anticipate that some cutting and filling will be required on the
site to achieve desired finished grades. As building foundations and/or
slabs on grade may be supported on fill, we reccmnend that fill place-
ment be in accordance with FkA "Data Sheet 19G." The following are our
recoranendations for site grading and placement of coepacted fill.
The upper six (6) inches of all topsoil should be stripped in
proposed cut and fill areas and in building and pavement areas which
will regain at present grades. The topsoil can be stockpiled on the
site and usedfor final grading outside of building .and pavement areas.
At cut subgrade elevation and in areas to receive fill. the upper six
(6) inches of the subgrade should be scarified and recompacted at two
percent (20A) wet of optimums moisture content to a ninimum of ninety
percent (90%) of Standard Proctor Density ASTM D 699-78. (See Appendix
C.)
The on -site overburden materials are suitable for use as fill in
proposed building and pavement areas. Any additional off -site fill
required should be a material approved by the geotechnical engineer. We
i
(1) Topsoil and Fill: Thickness of topsoil at test boring lo-
cations varies frog:, approxirately six (S) to twelve (12)
inches. The upper six (5) inches of the topsoil have been
penetrated by not growth and organic :natter and are not
suitable for foundation bearing or as backfill material. Fill
was encountered in 21orings 23, 24, 29, 301, and 33 extending to
depths one (1) to vvro (2) feet below present grades. The fill
is primarily sandy silty clay with some fine gravel. The fill
is not suitable for support of foundations.
.(2) Sandy Silty Clay: The topsoil and fill are underlain by
brown, tan and red sandy silty clay extending to the bedrock
surface or the depths explored. Some fine gravel and seams
and layers of silty sand and gravel were encountered within
the sandy silty clay. The primary layers of silty sand and
gravel are identified on the Log of Borings. The near -surface
portions of the sandy silty clay are rfedium stiff to stiff and
have moderate shear strength and bearing characteristics.
With increased penetration into the sandy silty clay, the
material becomes more moist and softer. The near -surface
portions of the sandy silty clay also exhibit moderate swell
potential upon wetting.
:.(3) Siltstone-Sandstone Bedrock: The surface of interbedded silt -
stone and sandstone bedrock was encountered in Borings 1, 8,
14, 209 220 23, and 23 at depths seven and one-half (7-1/2) to
twenty-nine and one-half (29-1/2) feet below present grades.
The upper one-half (1/2) to two (2) feet of the bedrock for-
mation is weathered. The underlying interbedded siltstone and
sandstone is firm and has good shear strength and bearing
characteristics.
(4) Groundwater: Water was encountered in Borings 1 through 4, 8,
1 % 12, 149 15, 139 20 through 22, and 28 at depths ten and
SITE LOCATION ANC DESCRIPTION
The project site is located on the north side of Harmony Road we
of ic.4urra; Avenue, southeast of Fort Collins, Colorado. More specs-.
cally, the site is situate in the southwest 1/4 of Section 31, Towns;
7 North, Range 68 Uest of the Sixth Prime Meridian. Larimer County,
Colorado.
The project site is presently an open, grass- and weed -covered
field. Slope and drainage are positive to the south. An earth berm.
been constructed along the south property line adjacent to Harmony Pc
Fill has been end dumped on portions of the site and small irrigation
ditches across the property have been filled in. McMurray Avenue, t-
the east of the site, has been paved. Property to the north is pre-
sently being developed for residential use. Open fields exist to tzi
west of the site.
LABORATORY TESTS AND EXAMINATIO3
Representative samples recovered in the test borings were seiec'
for tests in the laboratory to dete"fl ne their physical characterist-
and engineering properties. Included in the test program were natur:
moisture content, water soluble sulfates. Atterberg limits, dry dens-
unconfined compressive strength, consolidation characteristics, swe V
potential, and swell -consolidation characteristics. Laboratory test
results are susunarized in Appendix B. .
Hveem stabilometer tests are also being performed for desi;n of
paverrent sections. The results.of the Hveem tests will be submitted!
upon completion.
SOIL AND GROLMOWATER CONDITIONS
The following are the characteristics of the primary soil strata
encountered at the site.
REPORT
OF A
GEOTECHNICAL INVESTIGATION
SCOPE
This report presents the results of a geotechnical investigation
prepared for the proposed Golden Meadows Neighborhood Center, Larimer
County, Colorado. The investigation included test borings, laborator•=
testing, engineering evaluation, and preparation of this report.
The purposes of the investigation were to determine subsurface
conditions at the site and to provide recomendations for developntent
the site as influenced by the subsurface conditions.
SITE INVESTIGATION
Thirty-four (34) test borings were drilled at the site on October
1, 2, and 3, 1980. Locations of the test borings are shown on the T
Boring Location Plan included in Appendix A.
The borings were advanced with continuous -flight augers to depths
seven (7) to thirty-four (34) feet below present grades. Samples were
recovered with two and .one-half. (2-1/2) inch Shelby tubes and the star.
and penetration sample technique. During drilling, a field engineer o
Empire Laboratories, Inc. was present and made a continuous visual
In spection of soils encountered. Logs prepared from the'field notes a
included in Appendix A of this report. Indicated on the logs.are the
primary strata encounteredg locations of samples, and groundwater con-
ditions.
-1-
N
Empire Laboratories, Inc.
MATERIALS AND FOUNDATION ENGINEERS
214 No. Howes Fort Collins, Colorado 80522
P.O. Box 429 (303) 48"359
ectaber 17, 1980
ZVFK, Architects/Planners
I13 Nest Mountain Avenue
Fort Collins, Colorado a0521
Attention: Ar. Ed Zdenek
Gentleven:
Branch Offices
1242 Bramw000 Ptace
Longmont, Colorado 80501
P.O. Box 1135
(303) 776.3921
3151 Nation Way
Cheyenne, Wyoming 82001
P.O. Box 10076
(307) 632-9224
We are pleased to submit our Report of a Geotechnical Investigation
prepared for the proposed Colden Meadows Neighborhood Center, Larim.er
County, Colorado.
The subsurface conditions revealed by this investigation are suitable
for the intended construction, provided construction is in accordance
with the reco=endations contained in this report. Tne attached report
presents the subsurface conditions at the site and our reconu*endations
for development of the site.
We appreciate this opportunity of consulting with you on this project.
If you have any questions or if we can be of further assistance, please
contact us. ---
Very truly yours,
DIP ' c" LABORATORRIIES�s I 'C.
James E. Veith, P.E.
Geotechnical Engineer
Rev i ewed�byf:
Chester C. Smith, P.E.
President
clC
cc: Collindale South II - Bill Tiley
MEMBER OF CONSULTING ENGINEERS COUNCIL
TABLE OF CONTENTS
Table of Contents .................. 0.0.................. 0......
Letter of Transmittal...................................0......
Report.........................................................
Appendix A .....................................................
Test Boring Location Plan ....................................
Key to Borings ...............................................
Log of Borings ..................:............................
Appendix B.....................................................
Consolidation Test Data ......................................
Appendix
of Test Results ..........
A............................
ppendix C.....................................................
REPORT
OF A
GEOTECHNICAL INVESTIGATION
FOR
ZVFK* ARCHITECTS/PLANNERS
FORT COLLINS, COLORADO
PROJECT NO. 4213-80
RE: GOLDEN MEADOWS NEIGHBORHOOD CENTER
LARIMER COUINTY, COLORADO
BY
EMPIRE LABORATORIES, INC.
214 NORTH HO'WES STREET
FORT COLLIHS, COLORADO
80521
m
C n P t G \
PHA -4
.. % N C` \ f I --I- 16 ARTA{ENT UNITS Ir '
(BUIL � 64_ MEf)
Av
1A Li
_. C�
COMML—OPEN ON-, 001,. pEOi G A` _ _ L O sp W
-1
.\ 4 SPACES £H � eL � � � Z I v t
} r Q
�HA / y'
T 1 }
I"
LUTHERAN
CHURCH
I
7
2 A ART E
( 811 ILL
\ \'\ PHASE 2 PHASE 4
STONEBRIDGE KING SOOPERS
119 APARTMENT UNITS NEIGHBORHOOD CENTER
(166. UNITS PROPOSED)
�4L"oJ6:CT P(ipRiRTY t
'(]C]OQDO=PEDESTRIAN/SIKEWAY lCONNECTION [] Q= C:j Q' -- -- -
NOTE DENSITYALLOWED: PHASE 1.2 A 3 TOTAL-525 UNITS. PROPOSED 469 D.U. (A 12% REDUCTION)
I -I A. R IY o Y R o A. D
PACE WAREHOUSE
DEVELOPER:
SQUARE FOOT DEVELOPMENT
JIM LOFTUS
4700 WALNUT STREET
BOULDER,COLORADO
303-449-1449
STEEL'S SUPERMARKET
FIRST
BANK
—04RIDO[ --- -- -- --� �..
' MAIN KEY REAL
IENTRYI BANK ESTATE FUTURE COMMERCIAL
OFFICE
OAKRIDOE
STONEBRIDGE GARDEN APARTMENTS
PHASE 2: GOLDEN MEADOWS P.U.D.
EAST HARMONY ROAD AT WHEATON DRIVE
cOPT CCLL !NS CO ORADO
PLANNER: JUNGE / REICH / ASSOCIATES
4141 ARAPAHOE AVENUE
BOULDER, COLORADO 80307 (303-444.2887)
RIPLEY ASSOCIATES
DSO. S, loss 117 EAST MOUNTAIN AVENUE (SUITE 201)
FORT COLLSIS. COLOAADO SOS&4 (303-SS4-S w)
JUNGE / REICH / RSSOCIATES
ARCHITECTURE & PLANNING PROFESSIONAL CORPORATION
December 22, 1993
Steve Olt, Case Planner
Planning Department
City of Ft. Collins
P.O. Box 580
Ft. Collins, CO 80522
RE: STONEBRIDGE APARTMENTS/GOLDEN MEADOWS P.U.D.
Enclosed please find the P.U.D. site plan reduction and a copy of the original
subsurface soils investigation for your files. Let's meet the week of January
3rd to review our project and to address current issues.
Happy Holidays!
pectfully Submitted,
Jamey S. Junge, AIA
Linda Ripley
Jim Loftus
444212ARRPAHOE AVENUE, SUITE 100
BOULDER, COLORADO 80303
303 444•2987
FAX 303 444.5085