This document presents a study on improving the performance of conventional retaining walls through the use of geogrid reinforcement. It begins with an introduction to reinforced earth retaining walls and their typical components. A literature review is then presented summarizing previous studies on geosynthetic reinforced soil walls. Key research gaps are identified regarding the influence of geogrid properties and placement on wall stability. The objectives and methodology of the current study are outlined, involving the use of PLAXIS 3D finite element software to model retaining walls with and without geogrid. Results indicate that geogrid reinforcement significantly reduces wall deformation under surcharge and lateral loading and increases stability factors of safety. The study concludes that geogrid reinforcement improves load capacity and deformation

1. GOVERNMENT COLLEGE OF ENGINEERING, KEONJHAR
SUPERVISED BY
Mr. AJIT BARIK
(ASSISTANT PROFESSOR)
SUBMITTED BY
ASUTOSH JENA – 1901104006
BADAL KUMAR PRADHAN– 1901104007
JANMAJAY MAHANTA – 1901104014
NIRLIPTA SAMAL – 1901104022
SATABDI DAS – 1901104033
(GROUP- 09)
IMPROVEMENT OF CONVENTIONAL RETAINING WALL BY
PROVIDING GEOGRID AS REINFORCEMENT

2. CONTENT
• INTRODUCTION
• LITERATURE REVIEWS
• RESEARCH GAPS
• OBJECTIVES
• METHODOLOGY
• RESULTS AND DISCUSSIONS
• CONCLUSIONS
• REFERENCES

3. INTRODUCTION
• Reinforced earth is a composite construction material which generally comprises of soil and
reinforcement.
• RRE(Reinforced Retaining Earth) wall is designed to hold back soil or other materials and
prevent them from sliding or collapsing.
• RRE wall also known as Mechanically stabilized earth(MSE) wall which is mainly consists of
4 components;
I. Retained soil
II. Backfill material
III. Reinforcement elements
IV. Facing element or panel
Fig-1 Reinforced earth retaining wall
Source: https://www.mdpi.com/2076-3417/12/19/9930

4. • Generally, there are various types of soil reinforcement like steel, Geosynthetics, glass fibre,
wood, rubber, aluminium and thermoplastics
• In this study we are minimizing the deformation in the retaining wall by providing geogrid
layers inside the soil backfill with particular spacing manner using finite element method
software PLAXIS 3D
• Geogrid is a type of geosynthetic reinforcement and are applied
under some favorable spacing criteria in the retaining wall which
stabilizes the soil mass in the backfill
• The deformation analysis is done in PLAXIS 3D by creating a
geometry model of retaining wall with geogrid
• PLAXIS 3D is a user-friendly geotechnical program intended for
three-dimensional analysis of deformation and stability.
Fig-2 Geogrid
Source: https://www.geobera.com/geogrid-manufacturers/

5. LITERATURE REVIEW :
Sl. No. Author’s Name/
Year
Key findings or remarks
1 Kong et. Al.
(2021)
After taking different length of reinforcements 1m, 3m, 5m and 7m keeping height of the
retaining wall constant it was found that curved section demanded more reinforcement
than straight section.
2 Linhares et al.
(2021)
They used experimental studies and numerical simulations to explore the effectiveness of
Geosynthetic Reinforced Soil (GRS) walls based on the effect of surcharge width under
working stress conditions
3 Wang et. Al
(2019)
They studied horizontal displacement of the wall face, vertical and horizontal soil
stresses, and geogrid strains in the geogrid reinforced soil retaining wall.The lateral
displacement of geogrid reinforced soil retaining walls with deformation buffer zone
decreased.

6. Sl. No. Author’s
name/ year
key findings or remarks
4 Sadat et al.
(2018)
They looked into the performance of an MSE wall and the impact of different parameters
on its efficiency when the wall face stabilized with respect to the reinforcement zone.
5 Song et al.
(2018)
They used the FEM software plaxis to study the failure process of a GRS wall
numerically. The mode of failure of the high-strength geocell-built wall in the bottom half
was essentially equal to the complete high-strength geocell-built wall.
6 Holtz et.al.
(2017)
They reviewed evolution of a geosynthetic reinforced soil slopes and wall. The resulting
reinforcement tension must be assessed directly for soil–geosynthetic interaction
behavior; else, the interaction parameters are only a suggestion.
7 Yu et. Al.
(2016)
They introduced thorough numerical modelling of a geogrid reinforced incremental
concrete panel earth retaining wall in this study, which uses the finite difference method
(FDM) to predict the behaviour of the wall.

7. RESEARCH GAPS:
After going through all the literature reviews, we concluded the following research gaps;
• There is no proper observation of vertical spacing of reinforcement, stiffness of geogrid on the stability
of reinforced earth retaining wall under combined loading conditions which includes surcharge loading
and lateral earth pressure.
• The most appropriate behaviour of geogrid materials used in reinforced retaining wall construction to
provide maximum stability is still not defined properly.

8. OBJECTIVES:
These are the primary objectives or goal of our study;
• To observe the impact of vertical spacing of reinforcement, stiffness of geogrid on the stability of
reinforced earth retaining wall under combined loading conditions which includes surcharge loading
and lateral earth pressure.
• To compare the deformation, factor of safety between conventional retaining wall and reinforced
retaining wall with geogrid reinforcement.

9. METHODOLOGY:
Input
• Soil parameters
• Boundary conditions
Calculation
• Mesh generation
• Staged construction
Result
• Result
• Deformed
mesh
• Graphs

10. Material Retained backfill Foundation Soil Geogrid reinforced soil
ߛ‫ݐܽݏ݊ݑ‬ (kg/m3) 19 16 19
ߛ‫ݐܽݏ‬ (kg/m3) 20 16 20
E (kN/m2) 12500 5500 30000
C (kN/m2) 1 8.45 1
𝜑 (°) 34 27 34
𝜓(°) 0 0 0
Material Flexural Rigidity EI
(kN m2 /m)
Normal Rigidity EA
(kN/m)
Weight W (kN/m/m)
Foundation block 370000 18000000 0.15
Concrete facing panel 11000 5000000 38
Input data for PLAXIS 3D
TABLE1-Finite Element Material Properties
TABLE-2 Finite Element Plate Properties

11. Fig-3 Rough model of Retaining wall structure with reinforcement

12. There are 4 stages in the geometry modelling of Retaining wall using PLAXIS 3d
• Soil: In this stage the soil section is created by using borehole.
• Structures: In this stage the structural components and the boundary conditions are defined.
• Mesh: Here the mesh is generated and the geometry model is transformed into finite element model.
• Staged construction: The calculation settings are defined and the calculation is done for the model.
Fig-4 Interface of PLAXIS 3D
After that the deformation value is noted for both the conditions( with geogrid and without geogrid)

13. • Soil strata is created using borehole for backfill and
foundation.
• In structure phase boundary conditions are defined
and the other components including geogrid
reinforcement, facing plate, foundation block are
created and surcharge load and lateral earth
pressure is applied.
Fig-5 Soil strata created using borehole
Fig-6 Applied surcharge load on the top of the backfill i.e. 20 kN/m2

14. • In this mesh generation mode structure is modified
into finite element called mesh.
Fig-7 Generated mesh

15. In stage construction section 5 phases are created including initial phases.
• Initial phase: In this phase only structure is present
Fig-8

16. • Phase 1:only the surcharge load is applied which is 20 kN/m2 on the surface of retained backfill & reinforced soil.
Fig-9

17. • Phase 2: Here only the lateral earth pressure is applied horizontally on the reinforced soil which is 20kN/m2
Fig-10

18. • Phase 3: Both the surcharge load and lateral earth pressure is applied in this phase.
• Then the calculation is done to compare the deformation before adding geogrid and after adding geogrid to the
backfill soil.
Fig-11

19. RESULT AND DISSCUSION:
• After calculating final phase, the results obtained include horizontal and vertical displacements,
stress, and factor of safety.
• In this analysis there is a surcharge load of 20 kN/m2 act on retaining wall.
• In this analysis results are obtained for Retaining wall using geogrid as well as with out geogrid.

20. CASE 1: RETAINING WALL WITHOUT GEOGRID
Fig 12: Vertical deflection of 4m high retaining wall
without geogrid
Fig 13: Horizontal deflection of 4m high retaining wall
without geogrid
• The total displacements for surcharge load 20kN/m2
is 1.311m.
• The total displacements for lateral load 20kN/m2 is
1.309m.

21. • The total displacements for both surcharge load and
lateral load is 1.285m.
• Maximum value for deformed mesh is 2.999m.
Fig 14: Both vertical and horizontal deflection of 4m high
retaining wall without geogrid
Fig 15: Deformed mesh for 4m high retaining wall without geogrid

22. CASE 2: RETAINING WALL WITH GEOGRID
• The total displacements for surcharge load 20kN/m2
is 0.2117m.
• The total displacements for lateral load 20kN/m2 is
0.2116m.
Fig 16: Vertical deflection of 4m high retaining wall with geogrid
Fig 17: Horizontal deflection of 4m high retaining wall with
geogrid

23. • The total displacements for both surcharge load and
lateral load is 0.233m.
• Maximum value for deformed mesh is 2.888m.
Fig 18: Both vertical and horizontal deflection of 4m high
retaining wall with geogrid
Fig 19: Deformed mesh for 4m high retaining wall with geogrid

24. Effective principal stress:
Fig-20 Effective principal stress of Retaining
wall without geogrid
Fig-21 Effective principal stress of Retaining wall
with geogrid

25. Factor of safety:
Graph-1 For Surcharge Load Graph-2 For Lateral Load
Graph-3 For Both surcharge load And lateral load
CASE-1 factor of safety of MSE wall without geogrid:
Load type Factor of safety
Graph-1 for surcharge load 1.56
Graph for lateral load 1.79
Graph-3 for both
surcharge load And lateral
load
1.571

26. Graph-4 For Surcharge Load Graph-5 For Lateral Load
Graph-6 For Both surcharge load And lateral load
CASE-2 factor of safety of MSE wall with geogrid:
Load type Factor of safety
Graph-4 for surcharge load 1.782
Graph-5 for lateral load 1.917
Graph-6 for both surcharge
load And lateral load
1.727

27. CONCLUSIONS:
 The retaining wall is able to withstand the applied loads with minimal deformation.
 The use of geogrid as reinforcement significantly improves the load capacity and deformation
behaviour of the reatining wall.
 When geogrid is added to the retaining wall, the deformation value decreases up to 84.43% after
applying surcharge load and after applying lateral load to the retaining wall the deformation value
decreases up to 84.41% .
 Similarly after applying combined load to the retaining wall the deformation value decreases up to
82.80%.
 The geogrids-reinforced exhibited the highest load capacity with the least vertical displacements.
 It is important to carefully select the materials and design the wall to meet the specific
requirements of the project.

28. FUTURE SCOPES:
 The study could be extended to include a wider range of soil types and reinforcement types.
 The work may be expanded to examine how seismic loading affects Retaining wall walls.

29. REFERENCES: