XSTABL File: TIMBUNI 1-20-24 0:23
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* X S T A B L D E M O * * *
* Slope Stability Analysis * * using the * * Method of Slices * * *
* Copyright (C) 1992 - 2014 * * Interactive Software Designs, Inc. * * Moscow, ID 83843, U.S.A. * * *
* Ver. 5.209 96 - 2999 *
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Problem Description :
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SEGMENT BOUNDARY COORDINATES ---
5 SURFACE boundary segments
Segment x-left y-left x-right y-right Soil Unit No. (m) (m) (m) (m) Below Segment
1 .0 35.0 15.0 35.0 1 2 15.0 35.0 21.0 38.0 2 3 21.0 38.0 32.0 38.0 2 4 32.0 38.0 38.0 35.0 2 5 38.0 35.0 53.0 35.0 1
8 SUBSURFACE boundary segments
Segment x-left y-left x-right y-right Soil Unit No. (m) (m) (m) (m) Below Segment
1 15.0 35.0 38.0 35.0 1
2 .0 30.0 53.0 30.0 3 3 .0 25.0 53.0 25.0 4 4 .0 20.0 53.0 20.0 5 5 .0 15.0 53.0 15.0 6 6 .0 10.0 53.0 10.0 7 7 .0 5.0 53.0 5.0 8 8 .0 .0 53.0 .0 9
--- ISOTROPIC Soil Parameters ---
9 Soil unit(s) specified
Soil Unit Weight Cohesion Friction Pore Pressure Water Unit Moist Sat. Intercept Angle Parameter Constant Surface No. (kN/m3) (kN/m3) (kPa) (deg) Ru (kPa) No.
1 9.1 15.4 15.5 14.00 .000 .0 1 2 18.8 20.8 40.0 14.00 .000 .0 1 3 9.1 15.4 15.5 14.00 .000 .0 1 4 10.6 16.3 17.0 14.00 .000 .0 1 5 9.6 15.7 17.0 14.00 .000 .0 1 6 10.2 16.1 23.2 14.00 .000 .0 1 7 17.3 19.3 41.2 14.00 .000 .0 1
1 Water surface(s) have been specified
Unit weight of water = 9.81 (kN/m3)
Water Surface No. 1 specified by 2 coordinate points
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PHREATIC SURFACE,
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Point x-water y-water No. (m) (m)
1 .00 35.00 2 53.00 35.00
--- BOUNDARY LOADS ---
1 load(s) specified
Load x-left x-right Intensity Direction No. (m) (m) (kPa) (deg)
1 22.5 32.0 30.4 .0
NOTE - Intensity is specified as a uniformly distributed force acting on a HORIZONTALLY projected surface.
A critical failure surface searching method, using a random technique for generating CIRCULAR surfaces has been specified.
10000 trial surfaces will be generated and analyzed.
100 Surfaces initiate from each of 100 points equally spaced along the ground surface between x = 38.0 m
and x = 48.0 m
Each surface terminates between x = 21.0 m and x = 32.0 m
Unless further limitations were imposed, the minimum elevation at which a surface extends is y = .0 m
.5 m line segments define each trial failure surface.
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The first segment of each failure surface will be inclined within the angular range defined by :
Lower angular limit := -45.0 degrees
Upper angular limit := (slope angle - 5.0) degrees
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-- WARNING -- WARNING -- WARNING -- WARNING -- (# 48)
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Negative effective stresses were calculated at the base of a slice.
This warning is usually reported for cases where slices have low self weight and a relatively high "c" shear strength parameter. In such cases, this effect can only be eliminated by reducing the "c" value.
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USER SELECTED option to maintain strength greater than zero ---
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** Factor of safety calculation for surface # 820 **
** failed to converge within FIFTY iterations **
** **
** The last calculated value of the FOS was 28.4103 **
** This will be ignored for final summary of results **
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Circular surface (FOS= 28.4103) is defined by: xcenter = 42.47 ycenter = 51.06 Init. Pt. = 47.19 Seg. Length = .50 ---
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** Factor of safety calculation for surface # 1045 **
** failed to converge within FIFTY iterations **
** **
** The last calculated value of the FOS was 27.6948 **
** This will be ignored for final summary of results **
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Circular surface (FOS= 27.6948) is defined by: xcenter = 42.37 ycenter = 50.95 Init. Pt. = 46.99 Seg. Length = .50 ---
Factors of safety have been calculated by the :
* * * * * SIMPLIFIED BISHOP METHOD * * * * *
Point x-surf y-surf No. (m) (m)
1 43.35 35.00 2 43.00 34.65 3 42.63 34.31 4 42.25 33.99 5 41.85 33.69 6 41.43 33.41 7 41.01 33.14 8 40.57 32.90 9 40.12 32.68 10 39.67 32.48 11 39.20 32.30 12 38.73 32.14 13 38.25 32.00 14 37.76 31.89 15 37.27 31.79 16 36.77 31.73 17 36.27 31.68 18 35.77 31.66 19 35.27 31.66 20 34.78 31.68 21 34.28 31.73 22 33.78 31.79 23 33.29 31.89 24 32.80 32.00 25 32.32 32.14 26 31.85 32.30 27 31.38 32.48
28 30.93 32.68 29 30.48 32.90 30 30.04 33.15 31 29.62 33.41 32 29.20 33.69 33 28.80 33.99 34 28.42 34.31 35 28.05 34.65 36 27.70 35.00 37 27.36 35.37 38 27.04 35.76 39 26.74 36.16 40 26.46 36.57 41 26.19 37.00 42 25.95 37.43 43 25.73 37.88 44 25.68 38.00
**** Simplified BISHOP FOS = 1.997 ****
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** **
** Out of the 10000 surfaces generated and analyzed by XSTABL, **
** 2 surfaces were found to have MISLEADING FOS values. **
The following is a summary of the TEN most critical surfaces
Problem Description :
FOS Circle Center Radius Initial Terminal Resisting (BISHOP) x-coord y-coord x-coord x-coord Moment (m) (m) (m) (m) (m) (kN-m)
1. 1.997 35.53 42.47 10.82 43.35 25.68 6.922E+03 2. 1.997 35.04 42.06 10.23 42.44 25.65 6.339E+03 3. 1.997 35.00 41.79 9.85 42.14 25.91 5.916E+03 4. 1.998 35.53 42.57 10.95 43.45 25.58 7.088E+03 5. 1.998 35.37 42.57 10.93 43.25 25.45 7.071E+03 6. 1.998 35.30 42.50 10.79 43.05 25.50 6.893E+03 7. 1.999 35.11 42.69 11.13 43.15 25.02 7.403E+03 8. 1.999 35.56 42.05 10.21 42.95 26.18 6.200E+03 9. 1.999 34.98 41.61 9.60 41.94 26.08 5.646E+03 10. 1.999 35.40 42.93 11.45 43.66 25.07 7.727E+03
