Close Menu
  • About Us
  • Services
    • House Plans/Views
    • Books
    • Videos
    • Softwares/Programmes
    • Job/Scholarship Adverts
  • Notes
    • Structural Engineering
    • Surveying
    • Geotechnical Engineering
    • Design Codes
    • Highway/Transportation Engineering
    • Environmental Engineering
    • Concrete Technology
    • Soil Mechanics
    • Mathematics
    • Strength of Materials
    • Fluid Mechanics and Hydraulics
    • Water Resources Engineering
  • Quiz
  • Privacy Policy
  • Terms and Conditions
  • Q&A
  • About Us
  • Services
    • House Plans/Views
    • Books
    • Videos
    • Softwares/Programmes
    • Job/Scholarship Adverts
  • Notes
    • Structural Engineering
    • Surveying
    • Geotechnical Engineering
    • Design Codes
    • Highway/Transportation Engineering
    • Environmental Engineering
    • Concrete Technology
    • Soil Mechanics
    • Mathematics
    • Strength of Materials
    • Fluid Mechanics and Hydraulics
    • Water Resources Engineering
  • Quiz
  • Privacy Policy
  • Terms and Conditions
  • Q&A
  • en
    • ar
    • zh-CN
    • nl
    • en
    • fr
    • de
    • it
    • pt
    • ru
    • es
Facebook X (Twitter) Instagram YouTube LinkedIn WhatsApp
Home»Geotechnics»Slope Stability Analysis using Tekla Tedds | Solved Example
Geotechnics

Slope Stability Analysis using Tekla Tedds | Solved Example

Mezie EthelbertBy Mezie EthelbertUpdated:
Facebook Twitter LinkedIn Telegram WhatsApp Pinterest Email Copy Link
SLOPE STABILITY
Share
Facebook Twitter LinkedIn Pinterest Email Reddit Telegram WhatsApp
Reading Time: 4 minutes

Slope stability analysis can be carried out manually by a number of METHODS. Manual analysis of slope stability is usually a very tedious and time-consuming process. Presently, there are a number of software that can be used to model and analyse a slope. Softwares such as Geoslope, Plaxis, etc. can effectively and efficiently model and analyse a slope.

geoslope
Slope modelling and analysis using Geoslope

The primary essence of slope stability analysis is to determine the factor of safety against failure. It is possible to analyse a slope manually within a shorter period of time using the iterative processes available in Tekla Tedds software. The software has the capacity to analyse slopes to determine and satisfy suitable factors of safety against failure using either of the two most popular methods of slope stability analysis: the Fellenuis (Swedish circle) method and the Bishop’s simplified method. The software determines the suitable method to use based on the input variables.

The software is subject to the following assumptions and limitations:

  1. The slope may feature two layers, each with distinct soil properties. It assumes that the boundary between soil types is horizontal and above the toe of the slope.
  2. The toe of the slope may be submerged as in the case of a water retaining embankment such as an earth dam or canal bank. In this case, it assumes that the soil up to the water surface is saturated.
  3. Where the toe of the slope is submerged only a single soil type may specified.
  4. A hard layer may be specified beneath the toe of the slope, this is assumed to constrain the depth of any slip circle.
  5. In the case of undrained slopes, tension cracks, and hydrostatic force may be applied.
  6. The auto analysis allows a number of trial circles to be analysed in a single process. If a large number of trial circles is specified this calculation can take several minutes to complete, particularly in the case of drained slopes where the method of slices is used.
  7. An option in the calculation includes a check of the factor of safety for an undrained homogenous slope using Taylor’s stability number method.
  8. The radius of any trial circle must encompass the entire slope, the minimum radius stated in the calculation is the shortest radius that achieves this.
  9. Where the minimum radius extends below a hard layer the area of the slip circle is still calculated as it was without the hard layer, ignoring the loss of material below it. This situation will likely occur where the hard layer is located immediately beneath the slope.
  10. An optional factor of safety check ensures that a specified factor of safety is achieved and displays an appropriate message in the output.

Example (Question 9.11, Chapter 9, Pg 351: Geotechnical Engineering by Venkatramaiah):

An earth dam of height 20 m is constructed of soil which the properties are:

Bulk unit weight of soil, γ = 20 kN/m3

Cohesion, c = 45 kN/m2

The angle of internal friction, ϕ = 20o

The side slopes are inclined at 30o to the horizontal. Find the factor of safety immediately after the drawdown.

Solution (as obtained from Tekla Tedds software)

Slope Geometry

Angle of slope;                                                                 b = 30 deg

Height of slope;                                                                H = 20000 mm

Horizontal length of slope;                                             L = H / Tan(b) = 34641 m

slope Fellenuis circle

Soil Properties

Bulk unit weight;                                                               g = 20 kN/m3

Drained shear strength;                                                  c’ = 45 kN/m2

Shear resistance;                                                             f’ = 20 deg

Pore pressure ratio;                                                         ru = 0.3

Slope stability analysis

Origin co-ordinates;                                                         x = 5000 mm; y = 20000 mm

Radius of circle;                                                                R = 29825 mm

Sector angle;                                                                    θ = 137.888o

Number of slices;                                                             N = 20

Width of each slice;                                                         b = (AB + L + EF) / N = 2598 mm

For each slice, angle;                                                      αN = asin(xN / R)

Weight of slice;                                                                 WN = b x hN x g

Effective normal reaction force at the base of slice; N’N = max(WN x (cos(aN) – ru ´ sec(aN)), 0 kN/m)

Shearing force induced along base;                            TN = WN x sin(aN)

Sum of effective normal reaction forces;                    SN’ = 5999.011 kN/m

Sum of shearing forces induced along the base;            ST = 3263.375 kN/m

Factor of safety using Fellenius’ method;                   F = (R x c’ x θ x π / 180o + tan(f’) x ΣN’) / ΣT = 1.659

Required factor of safety;                                               Freq = 1.5

PASS – Actual factor of safety exceeds required factor of safety

From the Results of the analysis, it can be seen that the required factor of safety is 1.5. This value corresponds with the value obtained from the Text from which this question was extracted. The software went ahead to determine the actual factor of safety and was able to show that the slope would be stable at the specified parameters after drawdown because the required factor of safety is less than the actual factor of safety.

Share this:

  • Click to share on Facebook (Opens in new window) Facebook
  • Click to share on X (Opens in new window) X

Related

Bishop method Fellenuis (Swedish circle) slope stability Tekla Tedds
Share. Facebook Twitter Pinterest LinkedIn Email Telegram WhatsApp Copy Link
Previous ArticleHow to Design and Operate Signal-Controlled Junctions
Next Article Groundwater Prospecting | Methods & Techniques
Mezie Ethelbert

An inquisitive engineer with considerable skills in analysis, design and research in the field of civil engineering.

Related Posts

Common Rules of Thumb in Geotechnical Engineering

Concise Notes on Bearing Capacity and Settlement of Soils (PDF)

How to Check Shear for Pad Footings according to EC 7

Add A Comment

Leave a ReplyCancel reply

May 2025
M T W T F S S
 1234
567891011
12131415161718
19202122232425
262728293031  
« Dec    
INTRO VIDEO OF OUR SERVICES
https://mycivillinks.com/wp-content/uploads/2022/01/Lemarg-Consulting-Services-Intro-Video.mp4
CLICK ON THE BOOK COVER TO SEE CONTENT
theory of structures
CLICK ON THE BOOK COVER TO SEE CONTENT
BLOG SUBSCRIPTION

Get the latest posts on this blog

MOST RECENT POSTS

Common Rules of Thumb in Geotechnical Engineering

Important Tests Required in Tunnel Construction

Concise Notes on Bearing Capacity and Settlement of Soils (PDF)

MOST VIEWED POSTS
  1. Differences between University and Polytechnic Education System in Nigeria (Example of Civil Engineering Syllabus) (9,964)
  2. COREN Past Interview Questions for different Engineering Divisions in Nigeria (8,035)
  3. Standard Rules for Setbacks in Nigeria for Structures (8,031)
  4. COREN professional interview (COREN P.I.) (7,553)
  5. Structural Analysis and Design of Sawtooth or Slabless Staircase (7,238)
  6. Analysis and Design of Sheet Piles (PDF) (6,821)
POSTS CATEGORIES
© {2025} Mycivillinks. All rights reserved
  • About Us
  • Services
    • House Plans/Views
    • Books
    • Videos
    • Softwares/Programmes
    • Job/Scholarship Adverts
  • Notes
    • Structural Engineering
    • Surveying
    • Geotechnical Engineering
    • Design Codes
    • Highway/Transportation Engineering
    • Environmental Engineering
    • Concrete Technology
    • Soil Mechanics
    • Mathematics
    • Strength of Materials
    • Fluid Mechanics and Hydraulics
    • Water Resources Engineering
  • Quiz
  • Privacy Policy
  • Terms and Conditions
  • Q&A

Type above and press Enter to search. Press Esc to cancel.