ENGINEERING LTD.287 Tiffin Street, Unit 10, Barrie, Ontario L4N 7R8 TEL: (705) 722-4638 FAX: (705) 722-4958
GEOSPEC ENGINEERING LTD. 11-1655 Slope Rev Mofan 239 Bayview Drive Barrie 1
August 2, 2011
Mofan Holdings Inc.33 Saunders RoadBarrie, OntarioL4N 9A7
Attn: Mr. M. Fanelli
Re: Review of Slope Stability239 Bayview Drive, Barrie 11-1655
Dear Mose,
As requested, Geospec Engineering Ltd. has completed a review of the impact to slopestability of the proposed Bayview Drive Development, at the referenced site. In thisregard, we have completed a site inspection and supporting test pit investigation.
Background
The site servicing plans provided depict the proposed building development as well asshow the existing slopes located to the north and east. Based upon these drawings, it isour understanding that a 2,200 m2 building is proposed within 2 to 20 meters of the top ofslope. A secondary building is proposed away from the slope.
The supporting test pit investigation carried out by Geospec Engineering Ltd., includedsix test pits scattered over the property and slope, as shown on the attached Test Pit &Cross Section Location Plan. The test pits were advanced to a maximum depth of 4.5meters below the original grade levels predominantly terminating within silty sand till.Detailed descriptions of the subsurface conditions encountered are provided in theattached The Test Pit Visual Logs (Enclosure N°s 2 - 4) and Grain Size DistributionsCharts (Enclosure N° 5). Briefly, the subsurface conditions encountered at the test pitscomprised a heterogeneous fill over a compact to very dense silty sand till that extendedto the full depth investigated with occasional pockets of sand. The till exhibited lowpermeability and resistance to erosion. In addition, neither free flowing groundwater norseepage was encountered during the investigation.
We understand that the overlying fill is to be removed and replaced with engineered fill.The geotechnical characteristics of the fill will be dependent upon the material utilized.Nevertheless, an Engineered Fill must be compacted to 100% Standard Proctor DryDensity which would be considered a very dense material. As such an appropriate Angleof Internal Friction for the fill would be in the order of 32° which represents a slopeinclined at 1.6:1.
GEOSPEC ENGINEERING LTD. 11-1655 Slope Rev Mofan 239 Bayview Drive Barrie 2
Slope Condition
A detailed visual review was carried out of the overall slope, on July 4. Based uponvisual observations, the slope was considered to vary in inclination from slight tomoderate. The slope was heavily treed by a variety of species some with trunk diameterin excess of 40 cm. Mature trees with a vertical trunk orientation suggest the slope hasbeen stable through the life of the tree.
A surface run-off erosion gulley was noted on the east slope and a dry creek bed wasnoted approximately 10 to 20 m from the bottom of the east slope.
Slope Geometry
The geodetic elevation of the top of slope was established to be approximately 268meters (ASL) as shown of the AECOM Site Servicing Plan. Furthermore, the bottom ofslope as depicted on the plan is shown as approximately 261 to 262 meters (ASL).
The datum elevations of the Top and Bottom of the Slope, as shown on the documentsprovided were established as follows:
Top of Slope: 268 m Toe of Slope: 261.5 m
Based upon the included topographical data the overall slope appears to be inclined at adegree in the order of 14-23° (~2 to 4 : 1) at representative topographic sections.
The Cross Sections of the existing slope are shown on the enclosed Test Pit & CrossSection Plan (Enclosure N° 1) and resulting Cross Sections (Enclosure N°s 6-9). Basedupon the Cross Sections, that are extended to the proposed driveway, the representativecritical portions of the slope from the Top of Slope to Bottom of Slope and steepestsection are detailed in Table 1.
GEOSPEC ENGINEERING LTD. 11-1655 Slope Rev Mofan 239 Bayview Drive Barrie 3
Table 1: Slope Inclination
Inclination of Slope
Section Length
(m)
Top of SlopeElevation
(m)
Bottomof Slope
Elevation(m)
Height(m) Horiz. Vert. Angle
Cross Section 1 13.6 267.76 262 5.8 2.4 1 23°
Cross Section 2 27 269.5 261.5 8.0 3.4 1 17°
Cross Section 3 20.6 268.35 261.5 6.9 3.0 1 18°
Cross Section 4 28.6 269 262 7.0 4.1 1 14°
Slope Stability
The existing slope was computer modeled with Slide 5.0 using the Analysis MethodsBishop Simplified and Janbu Simplified, which utilize the method of slices forestablishing Factors of Safety for various possible failure circles. The graphical depictionof the computer model is presented as Enclosure N° 10.
The results of the computer modeling, for the current slope represented by the CrossSection, revealed that the minimum Factor of Safety (FS) with respect to global failure is1.881. This value of Factor of Safety would suggest that the slope is stable. Nevertheless,the value is conservative in nature as it does not account for cohesion or vegetativerestraints. More importantly, the Factor of Safety relative to the proposed driveway is4.673. We do advise that this safety factor does not apply to surface sloughing due tosurface erosion.
Natural Hazard Considerations
The subject property proposed for development is situated on a plateau above theseasonally flowing Whiskey Creek. More specifically, the creek flows within a shallowvalley corridor that is confined by the valley walls within 0 to 20 meters of the Toe ofSlope as it passes the subject site. Consequently, the property represents a ConfinedSystem in which the Erosion Hazard Limit must be assessed for toe erosion allowance,stable slope and erosion access allowance.
GEOSPEC ENGINEERING LTD. 11-1655 Slope Rev Mofan 239 Bayview Drive Barrie 4
Geotechnically, our experience in the area has established that the slope is comprised ofshallow surface fill that will be replaced with Engineered Fill overlying dense silty sandtill with no evidence of groundwater seeps. Furthermore, the existing ratio of slopeinclination at the steepest section, as represented by Cross Section 1 is in the order of2.4:1 (horizontal : vertical) and minimal evidence of toe erosion is apparent.
Recommendations
We reiterate that the till in this area has both cohesion and internal friction. As such, anexcavation in the till has the capacity to stand vertically for extended periods.Disregarding cohesion, the till exhibits an Angle of Internal Friction in excess of 35°. Atthis site, the angle would represent a slope inclined at approximately 1.4:1, disregardingthe effects of erosion.
The required allowance for toe erosion in a Confined System where the bank material iscomprised of sand & silt, is one (1) meter where no evidence of active erosion is apparentand the river bank full width is less than 5 meters. The allowance is increased to 5 to 8meters when evidence of active erosion is apparent.
Therefore, accounting for a six (6) meter allowance for Erosion Access and maximum toeerosion for sand & silt of five (5) meters and a conservative allowance for stable slope of2:1, which corresponds to an inclination steeper than the existing slope, a maximumsetback of 27 meters from the creek is required.
Conclusion
Since the proposed driveway is located beyond 35 meters from the creek, it is ourconsidered opinion that the currently proposed position of the buildings within thedevelopment will not compromise the slope stability or negatively impact the slope.
It is assumed that the development will be constructed in accordance with standardbuilding code requirements and founded on soil of appropriate capacity which must beconfirmed by a representative of Geospec. Finally, any vegetation on the slope that isdamaged during the construction operations must be reinstated and exposed soil protectedfrom surface run-off erosion.
GEOSPEC ENGINEERING LTD. 11-1655 Slope Rev Mofan 239 Bayview Drive Barrie 5
We trust this letter meets with your approval. Should you have any questions or requireclarification on any aspect of this letter, please do not hesitate to contact the undersigned.
Respectfully,GEOSPEC ENGINEERING LTD.
K. Malcolm,Consulting Engineer
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ENGINEERING LTD.287 Tiffin Street, Unit 10, Barrie, Ontario L4N 7R8 TEL: (705) 722-4638 FAX: (705) 722-4958
GEOSPEC ENGINEERING LTD. 11-1655 239 Bayview Drive ENCLOSURE N° 2
TEST PIT VISUAL LOGSGEOSPEC ENGINEERING LTD. PROJECT NO: 11-1655
TEST HOLE N: 1 North east of proposed Building B Elev. 270.0 m (estimated)
DEPTH (cm) COLOUR DENSITY MOISTURE SOIL DESCRIPTION
0-200 Brown Loose MoistSilty SAND with trace gravel (FILL)Bulk Sample at 100cm, Moisture Content 6.9%Sand 67%, Silt 25% gravel 8%
200-440 BrownVery
DenseMoist
Silty SAND with trace gravel (Till)Bulk Sample at 320cm, Moisture Content 6.5%%
NB: No water observed in test pit.
TEST HOLE N: 2 East of Proposed Building B Elev. 270.0 m (estimated)
DEPTH (cm) COLOUR DENSITY MOISTURE SOIL DESCRIPTION
0-150 Brown Loose MoistSilty SAND with trace gravel (FILL)Bulk Sample at 50cm, Moisture Content 5.7%
150-290 Brown Dense MoistSilty SAND with trace gravel (Till)Bulk Sample at 240cm, Moisture Content 10.4%
290-440 Brown Compact MoistSAND with some siltBulk sample at 410cm, Moisture Content 5.4%Sand 87%, Silt 13%
NB: No groundwater observed in test pit.
ENGINEERING LTD.287 Tiffin Street, Unit 10, Barrie, Ontario L4N 7R8 TEL: (705) 722-4638 FAX: (705) 722-4958
GEOSPEC ENGINEERING LTD. 11-1655 239 Bayview Drive ENCLOSURE N° 3
TEST HOLE N: 3 North west of proposed Building B Elev. 270.2 m (estimated)
DEPTH (cm) COLOUR DENSITY MOISTURE SOIL DESCRIPTION
0-150 Brown Loose MoistSilty SAND with trace gravel (FILL)Bulk Sample at 70cm, Moisture Content 3.3%
150-450 BrownVery
DenseMoist
Silty SAND with trace gravel (Till)Bulk Sample at 300cm, Moisture Content 9.6%
NB: No water observed in test pit.
TEST HOLE N: 4 West of proposed Building B Elev. 271.0 m (estimated)
DEPTH (cm) COLOUR DENSITY MOISTURE SOIL DESCRIPTION
0-120 Brown Loose MoistSilty SAND with trace gravel & cobbles (FILL)Bulk Sample at 100cm, Moisture Content 5.1%
120-400 BrownVery
DenseMoist
Silty SAND with trace gravel (Till)Bulk Sample at 350cm, Moisture Content 11.6%Sand 61%, Silt 30%, Gravel 9%
NB: No water observed in test pit.
ENGINEERING LTD.287 Tiffin Street, Unit 10, Barrie, Ontario L4N 7R8 TEL: (705) 722-4638 FAX: (705) 722-4958
GEOSPEC ENGINEERING LTD. 11-1655 239 Bayview Drive ENCLOSURE N° 4
TEST HOLE N: 5 South west of proposed Building B Elev. 267.3 m (estimated)
DEPTH (cm) COLOUR DENSITY MOISTURE SOIL DESCRIPTION
0-100 Brown Loose MoistSilty SAND with trace gravel (FILL)Bulk Sample at 70cm, Moisture Content 6.8%
100-300 BrownVery
DenseMoist
Silty SAND with trace gravel (Till)Bulk Sample at 300cm, Moisture Content 8.7%
NB: No water observed in test pit.
TEST HOLE N: 6 South east of proposed Building B Elev. 267.2 m (estimated)
DEPTH (cm) COLOUR DENSITY MOISTURE SOIL DESCRIPTION
0-20 Black Loose Moist Topsoil
20-60 Brown Compact Moist Silty SAND
60-400 BrownVery
DenseMoist
Silty SAND with trace gravel (Till)Bulk Sample at 300cm, Moisture Content 8.1%
NB: No water observed in test pit.
ENGINEERING LTD.287 Tiffin Street, Unit 10, Barrie, Ontario L4N 7R8 TEL: (705) 722-4638 FAX: (705) 722-4958
DATE:
ENCLOSURE N°: 5
PROJECT N°:
/ DATE SAMPLED:
DATE RECEIVED:
DATE TESTED:
TP / m TP 2 / 4.1 m
Sand 87%, Silt 13%TP / m
TP = Test Pit Sand 61%, Silt 30%, Gravel 9%
GRAIN SIZE IN MILLIMETERS
PE
RC
EN
TP
AS
SIN
GP
ER
CE
NT
RE
TA
INE
D
Silty SAND with trace gravel
Sand 67%, Silt 25%, Gravel 8%
SAND with some silt
UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D 2487)
Silty Sand with trace Gravel
4 3.5
SAMPLED FROM: 1 1.0
LAB N° / TYPE: 73 Original Undisturbed July 13, 2011
SAMPLED BY: W.J.
SAMPLED TYPE: Bulk July 15, 2011
ou ss July 13, 2011
PROJECT: 239 Bayview Drive, Barrie 11-1655
GRAIN SIZE DISTRIBUTION CHART
CLIENT: Mofan Holdings Inc. July 18, 2011
Clay & SiltSand
Fine Medium Coarse
Gravel
Fine Coarse Co
bb
les
50
1"3/4
"
3/8
"
41650200
0
10
20
30
40
60
70
80
90
100
100 30 80
.53
"5
/8"
2" 3"
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10 100
262.5
263
263.5
264
264.5
265
265.5
266
266.5
267
267.5
267.76
268.4 268.3
CL W
hiskey C
reek
Top of Slope
269.55
Pro
ject
Bo
un
da
ry
263
264
265
266
267
268
269
270
PROPOSED
DRIVEWAYSLOPE DETAILS:
: 1
%
°
2.4
42.4
23
2.4 : 1 42.4 23.°
CLIENT:
PROJECT:
Mofan Holdings Inc.
239 Bayview Drive, Barrie
CROSS SECTION 1287 Tiffin Street, Unit 10
Barrie, Ontario, L4N 7R8
TEL: (705) 722 - 1638
FAX: (705) 722 - 4958ENGINEERING LTD
DATE: July 11 / 2011
PROJECT Nº: 11 - 1655
ENCLOSURE Nº: 6
SCALE: NOT TO SCALE
261 261
261.4261.5
262
262.5
-8.6
-3.5
0.0
6.0
18.4
19.8
21.1
23.3
23.5
24.8
26.0
27.4
28.5
29.5
30.6
31.6
32.0
38.0
48.6
CL W
hiskey C
reek
Bottom of Slope
260
261
262
-10.0 0.0 10.0 20.0 30.0 40.0 50.0
263
263.5
264
264.5
265
265.5
266
266.5
267
268
268.5
269
269.5
270
CL W
hiskey C
reek
Top of Slope
269.6
Pro
ject
Bo
un
da
ry
264
266
268
270
272
PROPOSED
DRIVEWAY
SLOPE DETAILS:
: 1
%
°
3.4
29.6
16.5
3.4 : 1 29.6 16.5°
CLIENT:
PROJECT:
Mofan Holdings Inc.
239 Bayview Drive, Barrie
CROSS SECTION 2287 Tiffin Street, Unit 10
Barrie, Ontario, L4N 7R8
TEL: (705) 722 - 1638
FAX: (705) 722 - 4958ENGINEERING LTD
DATE: July 11 / 2011
PROJECT Nº: 11 - 1655
ENCLOSURE Nº: 7
SCALE: NOT TO SCALE
260.5
260.91
260.5
261
261.5
262
262.5
263
0.0
2.0
4.0
6.0
11.0
14.0
15.2
16.5
17.8
19.4
21.0
22.8
24.6
26.5
28.4
30.2
31.8
33.6
35.5
37.4
39.1
41.0
46.5
CL W
hiskey C
reek
Bottom of Slope
260
262
-5.0 5.0 15.0 25.0 35.0 45.0
262.5
263
263.5
264
264.5
265
265.5
266
266.5
267
267.5
268
268.35
268.5269
CL W
hiskey C
reek
Top of Slope
269.51
Pro
ject
Bo
un
da
ry
263
264
265
266
267
268
269
270
PROPOSED
DRIVEWAYSLOPE DETAILS:
: 1
%
°
3.0
33.3
18.4
3.0 33.3 18.4°
CLIENT:
PROJECT:
Mofan Holdings Inc.
239 Bayview Drive, Barrie
CROSS SECTION 3287 Tiffin Street, Unit 10
Barrie, Ontario, L4N 7R8
TEL: (705) 722 - 1638
FAX: (705) 722 - 4958ENGINEERING LTD
DATE: July 11 / 2011
PROJECT Nº: 11 - 1655
ENCLOSURE Nº: 8
SCALE: NOT TO SCALE
260.18
260.5
261
261.5
262
262.5
0.0
2.5
7.7
10.6
12.1
13.5
15.0
16.4
17.8
19.4
20.8
22.4
23.9
25.4
26.9
28.5
30.0
31.2
34.3
40.0
46.3
CL W
hiskey C
reek
Bottom of Slope
260
261
262
-5.0 5.0 15.0 25.0 35.0 45.0 55.0
267
266.5
265.5
265
264
263.5
263 263
263.5
264
264.5
265
265.5
266
266.5
267
268
268.5
269269.5
Top of Slope
269.6
En
d o
f D
raw
ing
Pro
ject
Bo
un
da
ry
264
266
268
270
272
PROPOSED
DRIVEWAY
SLOPE DETAILS:
: 1
%
°
4.1
24.5
13.8
4.1 : 1 24.5 13.8°
CLIENT:
PROJECT:
Mofan Holdings Inc.
239 Bayview Drive, Barrie
CROSS SECTION 4287 Tiffin Street, Unit 10
Barrie, Ontario, L4N 7R8
TEL: (705) 722 - 1638
FAX: (705) 722 - 4958ENGINEERING LTD
DATE: July 11 / 2011
PROJECT Nº: 11 - 1655
ENCLOSURE Nº: 9
SCALE: NOT TO SCALE
263
262.5
262
262.5
263
-16.0
-12.6
-11.2
-8.4
-7.0
-5.6
-4.3
-2.9
-1.5
0.0
1.8
3.5
5.2
6.7
8.3
9.6
11.5
14.5
17.0
19.4
21.5
23.6
26.0
28.6
34.0
Bottom of Slope
To
p o
f S
lop
e
21.0
260
262
-18.0 -8.0 2.0 12.0 22.0 32.0
1.881
4.673
1.8811.881
4.673
1.881
Slope Analysis - Slide 5.011-1655 Mofan 239 Bayview Drive
Global MinimumsMethod: janbu simplifiedFS: 1.881170Center: 19.724, 280.155Radius: 18.303Left Slip Surface Endpoint: 17.610, 261.974Right Slip Surface Endpoint: 33.319, 267.901Resisting Horizontal Force=333.106 kNDriving Horizontal Force=177.074 kN
Material PropertiesMaterial: Silty Sand TillStrength Type: Mohr-CoulombUnit Weight: 22 kN/m3Cohesion: 1 kPaFriction Angle: 35 degreesWater Surface: None
Geospec Engineering Ltd.Enclosure N° 10
Safety Factor
0.000
0.250
0.500
0.750
1.000
1.250
1.500
1.750
2.000
2.250
2.500
2.750
3.000
3.250
3.500
3.750
4.000
4.250
4.500
4.750
5.000
5.250
5.500
5.750
6.000+
31
03
00
29
02
80
27
02
60
25
0
-30 -20 -10 0 10 20 30 40 50 60
(48.600, 255.000)
(48.600, 268.300)(38.000, 268.400)(32.000, 267.760)
(18.400, 262.000)(0.000, 261.400)
(-10.000, 261.000)
(-10.000, 255.000)