HomeMy WebLinkAbout2906_DavidsonCoCDLF_Resp_to_comment_ClosurePlan_DIN26841_20161013
October 13, 2016
Mr. Ming-Tai Chao, P.E.
Environmental Engineer
NC DEQ Division of Waste Management
217 W. Jones Street
Raleigh, NC 27603
RE: Davidson County C&D Landfill (Permit No. 29-06)
Alternative Final Cover System
Response to Review Comments
Dear Ming:
On behalf of Davidson County, Smith Gardner, Inc. (S+G) would like to respond to the
comments in your emails dated and received by S+G via email on October 3rd and October 6th,
2016 (see attached). These comments are repeated below in italics followed by our response
in bold.
October 6th Email:
Address Comments Nos. 1, 2, and 4 from October 3rd email. Comment No. 3 was addressed
by provided CQA Manual (dated October 2016).
See the responses below.
If the leachate generation from the closed CDLF is expected to last for a long period time,
rather than a temporary removal action; the activities and costs associated inspection, O&M,
and leachate removal and leachate pipe final closure/cap should be added to the Post-
Closure Plan & post-closure estimates.
See the response to Comment 4 below.
October 3rd Email:
1. What is the size (acreage) of the closed area? The permitted disposed area of the
CDLF is 7.6 acres but the drawings show the “Contract Limits” is 9.1 acres. Please
clarify. The acreage will be used as the basis for calculating post-closure care costs.
The waste footprint (area to be closed) of the C&D landfill is 7.6 acres. The area
shown for the contract limits is the area anticipated to be impacted by contractor
activities during the closure work.
Mr. Ming-Tai Chao, P.E.
October 13, 2016
Page 2 of 3
The approved maximum side slope of the final cap of the CDLF is 4 (horizontal) to 1 (vertical)
as shown on the Section 3.1 of the Facility and Engineering Plan dated March 2009 and
revised April 2011 (DIN 13912). The proposed closure side slope is 3 to 1 or 4 to 1 as stated
in the September 29, 2016 letter (DIN 26790). The section(s) of the closed cap has 3 to 1 side
slope requires to be illustrated/noted on the closure plan drawing(s), and the slope stability
analysis of the 3 to 1 side slope must be submitted for a review and approval.
The closure drawings do indicate the steeper side slope on the details. In general,
however, the slope of the closure from bottom to top of slope is generally flatter than
3H:1V. S+G performed a slope stability evaluation of one selected cross section than
had overall a longer/steeper slope than other areas. The results of this evaluation
(attached) show that the steeper slopes are anticipated to be adequately stable.
2. Comment addressed in CQA Manual.
3. A side riser pipe located in the Phase 1 area as shown on Sheet No. 3/Drawing No. S2
will be used for leachate removal. Is there any special requirement(s) for protecting
the pipe? How is the pipe incorporating to the final closure cover? Please clarify.
The side riser pipe was part of a leachate monitoring/removal system installed
during Cell 1 construction to address the potential for leachate buildup in Cell 1. In
addition to the side riser, a nearby 18-inch diameter CPE (Type S) (monitoring) pipe
and a precast concrete vault were installed as a monitoring system. Any liquid in the
monitoring pipe drains to the concrete vault. Since filling Cell 1, no leachate flow has
been observed in the vault and, thus, no leachate has been removed using the side
riser.
For the closure, the soil cover will be placed around the side riser, allowing future
access if needed. The monitoring vault will also remain accessible.
The County will continue to periodically monitor for leachate in the vault. However,
given the lack of flow to date, it is not anticipated that there will be future buildup of
leachate within Cell 1 to cause flow into the vault.
Please contact us at your earliest convenience should you have any questions or comments
or if you require additional information related to this submittal.
Mr. Ming-Tai Chao, P.E.
October 13, 2016
Page 3 of 3
Sincerely,
SMITH GARDNER, INC.
Gregory G. Mills, P.E. Pieter K. Scheer, P.E.
Senior Project Engineer Vice President, Senior Engineer
gregm@smithgardnerinc.com pieter@smithgardnerinc.com
Attachments: DEQ Email with Comments (October 3rd and 6th, 2016)
Supplementary Slope Stability Evaluation
cc: Rex Buck, Davidson County
Steven Sink, Davidson County
John Murray, P.E., NC DEQ - DWM
Susan Heim, NC DEQ - DWM
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1
Pieter Scheer
From:Chao, Ming-tai
Sent:Monday, October 3, 2016 11:33 AM
To:Pieter Scheer
Cc:Murray, John E
Subject:RE: Davidson County C&D Landfill (Permit No. 29-06)
Follow Up Flag:Follow up
Flag Status:Flagged
Hi Pieter:
Please send me the electronic file of the approved Closure and Post-closure plan and CQA plan of the Davidson
County CDLF; it is evident that the requested plans are not available in the file or document tracking system. I
conducted a review of the documents that attached to the September 29, 2016 e-mail, few comments state
below:
1. What is the size (acreage) of the closed area? The permitted disposed area of the CDLF is 7.6 acres but the
drawings show the “Contract Limits” is 9.1 acres. Please clarify. The acreage will be used as the basis for
calculating post-closure care costs.
2. The approved maximum side slope of the final cap of the CDLF is 4 (horizontal) to 1 (vertical) as shown on
the Section 3.1 of the Facility and Engineering Plan dated March 2009 and revised April 2011 (DIN
13912). The proposed closure side slope is 3 to 1 or 4 to 1 as stated in the September 29, 2016 letter (DIN
26790). The section(s) of the closed cap has 3 to 1 side slope requires to be illustrated/noted on the closure
plan drawing(s), and the slope stability analysis of the 3 to 1 side slope must be submitted for a review and
approval.
3. The LLDPE is directly placed over the intermediate soil cover; therefore, the top 6-inch (at a minimum) of
this soil cover must be specified for the maximum soil grain size (including testing method and frequency)
and the final preparation (including the subgrade acceptance & the base-line survey) for receiving the
overlying LLDPE. The Specification Section 02223 – Embankment Table 1 Note 5 may be amended to
incorporate the revision or cross-referenced of Part D. 3 of Section 02778 - LLDPE.
4. A side riser pipe located in the Phase 1 area as shown on Sheet No. 3/Drawing No. S2 will be used for
leachate removal. Is there any special requirement(s) for protecting the pipe? How is the pipe incorporating
to the final closure cover? Please clarify.
Please contact me if you have any questions of the comments.
Ming Chao
Ming-Tai Chao, P.E.
Environmental Engineer
Permitting Branch, Solid Waste Section
NCDEQ, Division of Waste Management
(Mailing Address)
1646 Mail Service Center
Raleigh, NC 27699-1646
(Street Address)
Green Square, 217 West Jones Street
1
Pieter Scheer
From:Chao, Ming-tai
Sent:Thursday, October 6, 2016 10:19 AM
To:Pieter Scheer (pieter@smithgardnerinc.com)
Cc:Murray, John E
Subject:Comments on the Closure Plan, Davidson County C&D Landfill (Permit No. 29-06)
Follow Up Flag:Follow up
Flag Status:Flagged
Hi Pieter:
I completed a review of the revised CQA Plan dated October 2016 and have no comment on it. The Comment
No. 3 in the 10/03/2016 e-mail is properly addressed.
The Closure Plan and Post-Closure Plan dated May 2012 (portion of the application [DIN 16964]) indicated the
side slope is 4 to 1 (Section 1.3 of the Closure Plan, page 1.0-2) but the Closure Plan Drawing NO. D3 - 1/D3
& 2/D3 show the side slope either varies or 3 to 1. So you still have to address the Comment No. 2 in the
10/03/2016 e-mail.
Also clarifications/responses to Comment Nos 1 & 4 are also required. Additionally, if the leachate generation
from the closed CDLF is expected to last for a long period time, rather than a temporary removal action; the
activities and costs associated inspection, O&M, and leachate removal and leachate pipe final closure/cap
should be added to the Post-Closure Plan & post-closure estimates.
Please contact me if you have any questions of the comments. Thanks and have a wonderful day.
Ming Chao
Ming-Tai Chao, P.E.
Environmental Engineer
Permitting Branch, Solid Waste Section
NCDEQ, Division of Waste Management
(Mailing Address)
1646 Mail Service Center
Raleigh, NC 27699-1646
(Street Address)
Green Square, 217 West Jones Street
Raleigh, NC 27603
Tel. 919-707-8251
ming.chao@ncdenr.gov
http://portal.ncdenr.org/web/wm/sw
E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third parties.
ADDRESS TEL WEB
PROJECT SHEET 1 OF 18 DATECOMPUTED BY
SUBJECT JOB #CHECKED BY
OBJECTIVE:
REFERENCE:
ANALYSIS:
RESULTS:
14 N. Boylan Avenue, Raleigh, NC 27603 919.828.0577 www.smithgardnerinc.com
Davidson County C&D Landfill
Circular Failure (Static): 2.49
Circular Failure (Seismic): 2.07
Richardson, G.N., Kavazanjian, E., and N. Matasovic (1995), RCRA Subtitle D (258) Seismic Design Guidance
for Municipal Solid Waste Landfill Facilities, EPA/600/R-95/051, U.S. Environmental Protection Agency,
Washington, D.C.
Based on the results of the evaluation (see attached), the minimum factor of safety satisfies EPA
guidelines.
This slope stability evaluation was performed using the computer program STABL5M, a computer program
developed by Purdue University.
The slope stability evaluation was performed on the cross section shown on the attached figures (base and
final grades shown) which has a longer/steeper side slope than other portions of the landfill. The shear
strength envelope assumed for the waste in this evaluation was cohesion = 500 psf and phi = 25 degrees;
which is believed to be conservative for C&D wastes. Also, the shear strength envelope assumed for the
subgrade/berms in this evaluation was cohesion = 100 psf and phi = 25 degrees; which is believed to be
conservative as well. The results are as follows:
10/11/2016PKS
Supplemental Slope Stability Eval.DAVDCO-16-12 GGM
To perform a slope stability evaluation for the C&D landfill. Note that although the landfill is not in a
seismic impact zone (apeak = 0.08), both static and seismic conditions were evaluated. For the evaluation
of seismic conditions, the pseudo-static seismic coefficient used was taken as at least half of the ground
surface acceleration value to account for the average acceleration predicted within the waste mass
(EPA/600/R-95/051). Based on EPA guidance for MSW landfills (EPA/600/R-95/051), landfills are required
to have minimum factors of safety of 1.5 and 1.0 for static and seismic conditions, respectively.
SMITH GARDNER, INC.DC Supplemental Slope Stability Eval.xls
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5 of 18
** PCSTABL5M **
by
Purdue University
--Slope Stability Analysis--
Simplified Janbu, Simplified Bishop
or Spencer`s Method of Slices
Run Date: 10/11/2016
Time of Run: 11:10AM
Run By: Pieter K. Scheer, PE
Input Data Filename: H:dcacgs.in
Output Filename: H:dcacgs.OUT
Unit: ENGLISH
Plotted Output Filename: H:dcacgs.PLT
PROBLEM DESCRIPTION Davidson Co. C&DLF Closure - X. Sect. A
Circular Static
BOUNDARY COORDINATES
9 Top Boundaries
18 Total Boundaries
Boundary X-Left Y-Left X-Right Y-Right Soil Type
No. (ft) (ft) (ft) (ft) Below Bnd
1 0.00 690.00 20.00 686.00 1
2 20.00 686.00 40.00 686.00 1
3 40.00 686.00 60.00 688.00 1
4 60.00 688.00 80.00 697.00 1
5 80.00 697.00 110.00 698.00 1
6 110.00 698.00 115.00 698.00 2
6 of 18
H:dcacgs.OUT Page 2
7 115.00 698.00 325.00 760.00 2
8 325.00 760.00 385.00 765.00 2
9 385.00 765.00 570.00 762.00 2
10 115.00 698.00 140.00 690.00 1
11 140.00 690.00 220.00 698.00 1
12 220.00 698.00 250.00 700.00 1
13 250.00 700.00 280.00 708.00 1
14 280.00 708.00 320.00 710.00 1
15 320.00 710.00 335.00 712.00 1
16 335.00 712.00 390.00 714.00 1
17 390.00 714.00 455.00 722.00 1
18 455.00 722.00 570.00 722.00 1
ISOTROPIC SOIL PARAMETERS
2 Type(s) of Soil
Soil Total Saturated Cohesion Friction Pore Pressure Piez.
Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface
No. (pcf) (pcf) (psf) (deg) Param. (psf) No.
1 110.0 110.0 100.0 25.0 0.00 0.0 1
2 75.0 75.0 500.0 25.0 0.00 0.0 1
2 PIEZOMETRIC SURFACE(S) HAVE BEEN SPECIFIED
Unit Weight of Water = 62.40
Piezometric Surface No. 1 Specified by 3 Coordinate Points
Point X-Water Y-Water
No. (ft) (ft)
1 0.00 676.00
2 275.00 680.00
3 570.00 680.00
Piezometric Surface No. 2 Specified by 2 Coordinate Points
Point X-Water Y-Water
No. (ft) (ft)
1 132.00 688.00
2 205.00 688.00
A Critical Failure Surface Searching Method, Using A Random
Technique For Generating Circular Surfaces, Has Been Specified.
2500 Trial Surfaces Have Been Generated.
50 Surfaces Initiate From Each Of 50 Points Equally Spaced
Along The Ground Surface Between X = 50.00 ft.
and X = 200.00 ft.
Each Surface Terminates Between X = 300.00 ft.
and X = 550.00 ft.
Unless Further Limitations Were Imposed, The Minimum Elevation
At Which A Surface Extends Is Y =675.00 ft.
20.00 ft. Line Segments Define Each Trial Failure Surface.
**** ERROR - RC11 ****
>>200 attempts to generate failure surface have failed. Revise limitations
Following Are Displayed The Ten Most Critical Of The Trial
Failure Surfaces Examined. They Are Ordered - Most Critical
First.
* * Safety Factors Are Calculated By The Modified Bishop Method * *
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 95.92 697.53
2 115.21 692.26
3 134.85 688.46
4 154.71 686.15
5 174.70 685.34
6 194.69 686.03
7 214.56 688.22
8 234.22 691.91
9 253.55 697.06
10 272.43 703.66
11 290.76 711.65
12 308.44 721.00
13 325.37 731.66
14 341.44 743.55
15 356.58 756.63
16 363.09 763.17
Circle Center At X = 175.5 ; Y = 950.3 and Radius, 265.0
*** 2.486 ***
7 of 18
H:dcacgs.OUT Page 3
Individual data on the 25 slices
Water Water Tie Tie Earthquake
Force Force Force Force Force Surcharge
Slice Width Weight Top Bot Norm Tan Hor Ver Load
No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs)
1 14.1 3341.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0
2 5.0 1873.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0
3 0.2 133.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0
4 19.6 18652.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0
5 4.0 5200.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0
6 1.2 1639.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0
7 14.7 24597.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0
8 20.0 45073.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0
9 20.0 55457.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0
10 10.3 31586.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0
11 9.6 30571.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0
12 5.4 17799.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0
13 14.2 47155.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0
14 15.8 52142.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0
15 3.5 11598.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0
16 18.9 60585.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0
17 7.6 23324.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0
18 2.7 8066.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0
19 8.1 23459.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0
20 17.7 47967.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
21 16.6 38925.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0
22 0.4 782.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
23 16.1 27845.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0
24 15.1 13519.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0
25 6.5 1466.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Failure Surface Specified By 17 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 92.86 697.43
2 112.13 692.08
3 131.73 688.12
4 151.57 685.58
5 171.54 684.47
6 191.54 684.78
7 211.46 686.53
8 231.21 689.70
9 250.68 694.28
10 269.77 700.23
11 288.39 707.54
12 306.43 716.16
13 323.82 726.06
14 340.44 737.17
15 356.24 749.44
16 371.11 762.81
17 372.18 763.93
Circle Center At X = 177.1 ; Y = 963.6 and Radius, 279.2
*** 2.509 ***
Failure Surface Specified By 17 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 92.86 697.43
2 112.17 692.24
3 131.80 688.39
4 151.64 685.91
5 171.61 684.80
6 191.61 685.08
7 211.54 686.73
8 231.31 689.76
9 250.83 694.14
10 269.99 699.86
11 288.71 706.89
12 306.91 715.20
13 324.48 724.74
14 341.36 735.48
15 357.45 747.35
8 of 18
H:dcacgs.OUT Page 4
16 372.69 760.30
17 376.80 764.32
Circle Center At X = 177.6 ; Y = 974.3 and Radius, 289.5
*** 2.517 ***
Failure Surface Specified By 17 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 86.74 697.22
2 105.95 691.66
3 125.51 687.52
4 145.33 684.83
5 165.29 683.59
6 185.29 683.82
7 205.22 685.51
8 224.97 688.66
9 244.44 693.24
10 263.52 699.24
11 282.11 706.62
12 300.10 715.34
13 317.42 725.36
14 333.95 736.62
15 349.61 749.05
16 364.32 762.60
17 365.00 763.33
Circle Center At X = 172.2 ; Y = 956.4 and Radius, 272.9
*** 2.520 ***
Failure Surface Specified By 15 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 98.98 697.63
2 117.73 690.68
3 137.08 685.62
4 156.83 682.48
5 176.80 681.29
6 196.78 682.08
7 216.59 684.84
8 236.04 689.52
9 254.92 696.10
10 273.07 704.51
11 290.30 714.65
12 306.46 726.45
13 321.37 739.78
14 334.90 754.51
15 339.96 761.25
Circle Center At X = 178.8 ; Y = 884.3 and Radius, 203.0
*** 2.521 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 95.92 697.53
2 115.42 693.07
3 135.17 689.97
4 155.10 688.24
5 175.10 687.88
6 195.07 688.91
7 214.92 691.32
8 234.57 695.08
9 253.90 700.20
10 272.84 706.64
11 291.28 714.36
12 309.15 723.35
13 326.36 733.54
14 342.82 744.90
15 358.46 757.37
16 364.96 763.33
Circle Center At X = 170.2 ; Y = 976.8 and Radius, 289.0
*** 2.521 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
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H:dcacgs.OUT Page 5
1 89.80 697.33
2 108.78 691.02
3 128.20 686.27
4 147.95 683.09
5 167.89 681.51
6 187.89 681.55
7 207.82 683.19
8 227.55 686.44
9 246.96 691.26
10 265.92 697.63
11 284.31 705.51
12 302.00 714.84
13 318.88 725.56
14 334.84 737.61
15 349.78 750.90
16 361.38 763.03
Circle Center At X = 177.4 ; Y = 929.2 and Radius, 247.9
*** 2.524 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 83.67 697.12
2 102.95 691.80
3 122.57 687.88
4 142.41 685.39
5 162.38 684.32
6 182.38 684.70
7 202.29 686.51
8 222.03 689.76
9 241.48 694.41
10 260.55 700.45
11 279.13 707.85
12 297.13 716.57
13 314.45 726.56
14 331.02 737.77
15 346.73 750.14
16 360.83 762.99
Circle Center At X = 167.1 ; Y = 961.9 and Radius, 277.7
*** 2.527 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 83.67 697.12
2 102.84 691.42
3 122.39 687.17
4 142.20 684.41
5 162.16 683.14
6 182.15 683.38
7 202.08 685.12
8 221.82 688.35
9 241.25 693.05
10 260.28 699.21
11 278.80 706.78
12 296.69 715.71
13 313.86 725.97
14 330.21 737.49
15 345.65 750.20
16 358.81 762.82
Circle Center At X = 169.0 ; Y = 948.7 and Radius, 265.7
*** 2.529 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 92.86 697.43
2 111.66 690.61
3 130.97 685.42
4 150.66 681.90
5 170.58 680.06
6 190.58 679.93
7 210.51 681.51
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H:dcacgs.OUT Page 6
8 230.24 684.79
9 249.62 689.73
10 268.51 696.31
11 286.77 704.47
12 304.26 714.16
13 320.87 725.31
14 336.46 737.84
15 350.93 751.64
16 360.96 763.00
Circle Center At X = 182.0 ; Y = 913.7 and Radius, 233.9
*** 2.534 ***
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13 of 18
H:dcacgd.OUT Page 1
** PCSTABL5M **
by
Purdue University
--Slope Stability Analysis--
Simplified Janbu, Simplified Bishop
or Spencer`s Method of Slices
Run Date: 10/11/2016
Time of Run: 11:12AM
Run By: Pieter K. Scheer, PE
Input Data Filename: H:dcacgd.in
Output Filename: H:dcacgd.OUT
Unit: ENGLISH
Plotted Output Filename: H:dcacgd.PLT
PROBLEM DESCRIPTION Davidson Co. C&DLF Closure - X. Sect. A
Circular Static
BOUNDARY COORDINATES
9 Top Boundaries
18 Total Boundaries
Boundary X-Left Y-Left X-Right Y-Right Soil Type
No. (ft) (ft) (ft) (ft) Below Bnd
1 0.00 690.00 20.00 686.00 1
2 20.00 686.00 40.00 686.00 1
3 40.00 686.00 60.00 688.00 1
4 60.00 688.00 80.00 697.00 1
5 80.00 697.00 110.00 698.00 1
6 110.00 698.00 115.00 698.00 2
7 115.00 698.00 325.00 760.00 2
8 325.00 760.00 385.00 765.00 2
9 385.00 765.00 570.00 762.00 2
10 115.00 698.00 140.00 690.00 1
11 140.00 690.00 220.00 698.00 1
12 220.00 698.00 250.00 700.00 1
13 250.00 700.00 280.00 708.00 1
14 280.00 708.00 320.00 710.00 1
15 320.00 710.00 335.00 712.00 1
16 335.00 712.00 390.00 714.00 1
17 390.00 714.00 455.00 722.00 1
18 455.00 722.00 570.00 722.00 1
ISOTROPIC SOIL PARAMETERS
2 Type(s) of Soil
Soil Total Saturated Cohesion Friction Pore Pressure Piez.
Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface
No. (pcf) (pcf) (psf) (deg) Param. (psf) No.
1 110.0 110.0 100.0 25.0 0.00 0.0 1
2 75.0 75.0 500.0 25.0 0.00 0.0 1
2 PIEZOMETRIC SURFACE(S) HAVE BEEN SPECIFIED
Unit Weight of Water = 62.40
Piezometric Surface No. 1 Specified by 3 Coordinate Points
Point X-Water Y-Water
No. (ft) (ft)
1 0.00 676.00
2 275.00 680.00
3 570.00 680.00
Piezometric Surface No. 2 Specified by 2 Coordinate Points
Point X-Water Y-Water
No. (ft) (ft)
1 132.00 688.00
2 205.00 688.00
A Horizontal Earthquake Loading Coefficient
Of0.050 Has Been Assigned
A Vertical Earthquake Loading Coefficient
Of0.050 Has Been Assigned
Cavitation Pressure = 0.0 (psf)
A Critical Failure Surface Searching Method, Using A Random
Technique For Generating Circular Surfaces, Has Been Specified.
2500 Trial Surfaces Have Been Generated.
50 Surfaces Initiate From Each Of 50 Points Equally Spaced
Along The Ground Surface Between X = 50.00 ft.
and X = 200.00 ft.
Each Surface Terminates Between X = 300.00 ft.
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H:dcacgd.OUT Page 2
and X = 550.00 ft.
Unless Further Limitations Were Imposed, The Minimum Elevation
At Which A Surface Extends Is Y =675.00 ft.
20.00 ft. Line Segments Define Each Trial Failure Surface.
**** ERROR - RC11 ****
>>200 attempts to generate failure surface have failed. Revise limitations
Following Are Displayed The Ten Most Critical Of The Trial
Failure Surfaces Examined. They Are Ordered - Most Critical
First.
* * Safety Factors Are Calculated By The Modified Bishop Method * *
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 95.92 697.53
2 115.21 692.26
3 134.85 688.46
4 154.71 686.15
5 174.70 685.34
6 194.69 686.03
7 214.56 688.22
8 234.22 691.91
9 253.55 697.06
10 272.43 703.66
11 290.76 711.65
12 308.44 721.00
13 325.37 731.66
14 341.44 743.55
15 356.58 756.63
16 363.09 763.17
Circle Center At X = 175.5 ; Y = 950.3 and Radius, 265.0
*** 2.073 ***
Individual data on the 25 slices
Water Water Tie Tie Earthquake
Force Force Force Force Force Surcharge
Slice Width Weight Top Bot Norm Tan Hor Ver Load
No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs)
1 14.1 3341.2 0.0 0.0 0.0 0.0 167.1 167.1 0.0
2 5.0 1873.8 0.0 0.0 0.0 0.0 93.7 93.7 0.0
3 0.2 133.7 0.0 0.0 0.0 0.0 6.7 6.7 0.0
4 19.6 18652.8 0.0 0.0 0.0 0.0 932.6 932.6 0.0
5 4.0 5200.3 0.0 0.0 0.0 0.0 260.0 260.0 0.0
6 1.2 1639.9 0.0 0.0 0.0 0.0 82.0 82.0 0.0
7 14.7 24597.7 0.0 0.0 0.0 0.0 1229.9 1229.9 0.0
8 20.0 45073.5 0.0 0.0 0.0 0.0 2253.7 2253.7 0.0
9 20.0 55457.6 0.0 0.0 0.0 0.0 2772.9 2772.9 0.0
10 10.3 31586.7 0.0 0.0 0.0 0.0 1579.3 1579.3 0.0
11 9.6 30571.6 0.0 0.0 0.0 0.0 1528.6 1528.6 0.0
12 5.4 17799.5 0.0 0.0 0.0 0.0 890.0 890.0 0.0
13 14.2 47155.4 0.0 0.0 0.0 0.0 2357.8 2357.8 0.0
14 15.8 52142.7 0.0 0.0 0.0 0.0 2607.1 2607.1 0.0
15 3.5 11598.4 0.0 0.0 0.0 0.0 579.9 579.9 0.0
16 18.9 60585.7 0.0 0.0 0.0 0.0 3029.3 3029.3 0.0
17 7.6 23324.9 0.0 0.0 0.0 0.0 1166.2 1166.2 0.0
18 2.7 8066.8 0.0 0.0 0.0 0.0 403.3 403.3 0.0
19 8.1 23459.5 0.0 0.0 0.0 0.0 1173.0 1173.0 0.0
20 17.7 47967.0 0.0 0.0 0.0 0.0 2398.3 2398.3 0.0
21 16.6 38925.5 0.0 0.0 0.0 0.0 1946.3 1946.3 0.0
22 0.4 782.0 0.0 0.0 0.0 0.0 39.1 39.1 0.0
23 16.1 27845.8 0.0 0.0 0.0 0.0 1392.3 1392.3 0.0
24 15.1 13519.2 0.0 0.0 0.0 0.0 676.0 676.0 0.0
25 6.5 1466.8 0.0 0.0 0.0 0.0 73.3 73.3 0.0
Failure Surface Specified By 17 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 92.86 697.43
2 112.13 692.08
3 131.73 688.12
4 151.57 685.58
5 171.54 684.47
6 191.54 684.78
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H:dcacgd.OUT Page 3
7 211.46 686.53
8 231.21 689.70
9 250.68 694.28
10 269.77 700.23
11 288.39 707.54
12 306.43 716.16
13 323.82 726.06
14 340.44 737.17
15 356.24 749.44
16 371.11 762.81
17 372.18 763.93
Circle Center At X = 177.1 ; Y = 963.6 and Radius, 279.2
*** 2.083 ***
Failure Surface Specified By 17 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 92.86 697.43
2 112.17 692.24
3 131.80 688.39
4 151.64 685.91
5 171.61 684.80
6 191.61 685.08
7 211.54 686.73
8 231.31 689.76
9 250.83 694.14
10 269.99 699.86
11 288.71 706.89
12 306.91 715.20
13 324.48 724.74
14 341.36 735.48
15 357.45 747.35
16 372.69 760.30
17 376.80 764.32
Circle Center At X = 177.6 ; Y = 974.3 and Radius, 289.5
*** 2.087 ***
Failure Surface Specified By 17 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 86.74 697.22
2 105.95 691.66
3 125.51 687.52
4 145.33 684.83
5 165.29 683.59
6 185.29 683.82
7 205.22 685.51
8 224.97 688.66
9 244.44 693.24
10 263.52 699.24
11 282.11 706.62
12 300.10 715.34
13 317.42 725.36
14 333.95 736.62
15 349.61 749.05
16 364.32 762.60
17 365.00 763.33
Circle Center At X = 172.2 ; Y = 956.4 and Radius, 272.9
*** 2.092 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 89.80 697.33
2 108.78 691.02
3 128.20 686.27
4 147.95 683.09
5 167.89 681.51
6 187.89 681.55
7 207.82 683.19
8 227.55 686.44
9 246.96 691.26
10 265.92 697.63
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H:dcacgd.OUT Page 4
11 284.31 705.51
12 302.00 714.84
13 318.88 725.56
14 334.84 737.61
15 349.78 750.90
16 361.38 763.03
Circle Center At X = 177.4 ; Y = 929.2 and Radius, 247.9
*** 2.093 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 92.86 697.43
2 111.66 690.61
3 130.97 685.42
4 150.66 681.90
5 170.58 680.06
6 190.58 679.93
7 210.51 681.51
8 230.24 684.79
9 249.62 689.73
10 268.51 696.31
11 286.77 704.47
12 304.26 714.16
13 320.87 725.31
14 336.46 737.84
15 350.93 751.64
16 360.96 763.00
Circle Center At X = 182.0 ; Y = 913.7 and Radius, 233.9
*** 2.099 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 83.67 697.12
2 102.84 691.42
3 122.39 687.17
4 142.20 684.41
5 162.16 683.14
6 182.15 683.38
7 202.08 685.12
8 221.82 688.35
9 241.25 693.05
10 260.28 699.21
11 278.80 706.78
12 296.69 715.71
13 313.86 725.97
14 330.21 737.49
15 345.65 750.20
16 358.81 762.82
Circle Center At X = 169.0 ; Y = 948.7 and Radius, 265.7
*** 2.099 ***
Failure Surface Specified By 16 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 83.67 697.12
2 102.95 691.80
3 122.57 687.88
4 142.41 685.39
5 162.38 684.32
6 182.38 684.70
7 202.29 686.51
8 222.03 689.76
9 241.48 694.41
10 260.55 700.45
11 279.13 707.85
12 297.13 716.57
13 314.45 726.56
14 331.02 737.77
15 346.73 750.14
16 360.83 762.99
Circle Center At X = 167.1 ; Y = 961.9 and Radius, 277.7
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H:dcacgd.OUT Page 5
*** 2.101 ***
Failure Surface Specified By 17 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 86.74 697.22
2 105.68 690.82
3 125.08 685.94
4 144.80 682.63
5 164.73 680.90
6 184.73 680.77
7 204.67 682.23
8 224.44 685.28
9 243.90 689.90
10 262.93 696.05
11 281.41 703.70
12 299.22 712.81
13 316.24 723.30
14 332.38 735.12
15 347.52 748.19
16 361.57 762.42
17 362.13 763.09
Circle Center At X = 176.4 ; Y = 931.1 and Radius, 250.5
*** 2.101 ***
Failure Surface Specified By 17 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 95.92 697.53
2 115.36 692.82
3 135.05 689.33
4 154.92 687.09
5 174.90 686.10
6 194.90 686.37
7 214.84 687.89
8 234.65 690.66
9 254.24 694.67
10 273.55 699.90
11 292.48 706.33
12 310.98 713.94
13 328.96 722.69
14 346.36 732.56
15 363.10 743.50
16 379.13 755.46
17 390.25 764.91
Circle Center At X = 180.6 ; Y = 1004.5 and Radius, 318.5
*** 2.101 ***
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