Matakuliah
Tahun
Versi
: S0522/ Aplikasi Geosintetik Dalam Teknik Sipil
: Juli 2005
: 01/01
Pertemuan 05
PEMILIHAN MATERIAL
GEOTEKSTIL,
GEOGRIDS/GEONETS
Learning Outcomes
Pada akhir pertemuan ini, diharapkan
mahasiswa akan mampu :
 Mahasiswa mampu mengkategorikan
pemakaian geonets, geogrid dan geotekstil
sesuai kebutuhan desain di lapangan  C5
Outline Materi
•
•
•
•
Pertimbangan desain
Kondisi tanah
Analisa pemilihan material
Perbandingan penggunaan geotekstil dan
geogrid , serta geonets sesuai kebutuhan
dan kondisi lapangan
Sebagian materi ini diambil dari IGS Lecturer notes
No. 9 of 19
Reinforced Soil - Steep Faced Embankments
By Jerry Love
Geotechnical Consulting Group, UK
Lecture Outline
1 Application areas and general
introduction
2 Types of geosynthetics and fill material
used
3 Review of design methods
4 Examples of installation of geosynthetics
5 Examples of completed structures
Application Areas
Highway Widening
Temporary Structures
Slip Repairs
Noise Barriers
Use of Poor Quality Fills
Summary
• Reinforcement allows soil structures to be built at
angles steeper than the natural angle of repose of the
soil
Advantages include :
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Simple construction methods
Manual handling
Lightweight plant
Cheaper fill material
More rapid construction
Tolerance to differential movement
Visually pleasing structures
Types of Geosynthetic Used
Geogrid/soil Interlock
Woven Geotextiles
Non Woven Geotextiles
Fill Materials
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•
•
•
Granular fill
Cohesive fill
Chalk fill
PFA
Design Methods
X
Slip circle centre
R
Y
W
Le
Step 1
Establish the geometric, loading, and
performance requirements for design:
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•
•
Geometry
Loads
Performance requirements
Step 2
Determine the stratigraphy and
engineering properties of the insitu soils
in and below the slope:
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Soil profiles
•
Soil strength parameters, unit weight,
and consolidation parameters
Groundwater regime
Cause of previous instability if
applicable
•
•
Step 3
Determine the engineering properties of
the fill material
• Gradings and plasticity
• Compaction characteristics and
placement requirements
• Shear strength parameters
• Chemical composition of soil
Step 4
Determine design parameters for the
reinforcement.
• Long-term rupture strength
• Pull-out strength
• Direct sliding coefficient
Step 5
Determine the factor of safety of the unreinforced slope:
Standard stability analysis computer
programs
• Is reinforcement required?
• Establish the size of the critical zone to
be reinforced
Step 6
Establish reinforcement layout
•
•
Method 1: Direct method using
prescriptive design rules or charts
Method 2 : Iterative method using
trial-and-error technique
Two Part Wedge Method
(UK Highways)
Trial Surfaces
T (available) = t1+t2+t3+t4
T (available) > t
(required)
t1
t2
t3
t4
Typical Reinforcement
Layout
Main reinforcement
wrapped round face
Secondary
reinforcement
Primary reinforcement
Check External Stability
Step 8
Evaluate requirements for subsurface
and surface water control
• drains placed at the rear and/or beneath
the reinforced zone.
• Surface water collector drains above
the reinforced slope.
• Front face erosion protection
This completes the design process.
Typical Installation – by
Pushing Fill Forward
Placing Fill by Excavator
Bucket
Steep Faced Slope With Mesh Facing
Steep Faced Slope, Soft
Face With Berms
Green Faced Steep Slope
Bridge Abutment
Geotextile Wrap Round
Face
Green Faced Steep Slope