Large Pull Out Test Apparatus For Geo Synthetics
Large Pull Out Test Apparatus for Geo Synthetics
EKE 255:
Pull out Test Apparatus is being especially designed to measure the interface friction between GI Strips I Geosynthetics and Soil.
The use of reinforcements provides additional shear stress in the soil mass through the tensile force in the reinforcement. The considerable increase in the use of geosynthetics in the reinforced soil structures led to the development of testing procedures to evaluate their interaction properties.
Pullout apparatus is mainly used for finding the interfacial friction between GI Strips I Geosynthetics with soil. The interfacial friction coefficient is most important parameter for design of reinforced earth walls, reinforced earth slopes and other reinforcement applications.
This test is carried out to find pullout interface properties of geogrids used as reinforcement in the Soil structures. In this method, a geosynthetic is embedded between two layers of soil. For conducting the pullout test Normal compressive stress is applied to the top soil layer & horizontal force is applied to the geosynthetic & the force required to pull the geosynthetic out of the soil is recorded.
Pullout resistance is obtained by dividing the maximum load by the test specimen width. A plot of maximum pullout resistance versus applied normal stress is obtained by conducting a series of such tests. The test method is applicable to all geosynthetics and all soils.
Features:
• Suitable for testing Pull Out Interface properties of Geogrids in
Soil structures.
• Normal Load upto 250 kN.
• Pull Out force upto 300 kN.
• Sample size from 600 mm x 450 mm to 2m x 1.5m.
• Rugged & study Construction to ensure Accuracy of results.
• Variable Pull Speed available.
• Used in the design of Geosynthetic reinforced retaining walls slopes & embankments.
• Robust & accurate data acquisition system.
• 25 Channels Data Acquisition System (Feasible for expansion).
The Major Components of Pullout Test Apparatus are :
• Steel Box – where sample is embedded between two layers of Soil.
• Hydraulic Jack mounted on Vertical Frame for application of Normal Load.
• Pulling Arrangement mounted on Horizontal Frame along with the Steel Box.
• Loading Pad/Plate.
• Chain pulley Arrangement for lifting Loading Pad.
• LVDT’s to measure Sample Displacement.
• Load cells for vertical load & Pull out.
• Strain Gauges.
• Stand alone data acquisition system.
Detailed Specifications:
• Steel Box:
Steel – 1.5 m x 1.0 m x 1.0 m.
Material- Steel plates. Reinforcements are provided in all the plates to strengthen them.
• Load Frame:
a) Vertical Frame
Steel Frame 1.5 m long x 2.5 m high fabricated out to heavy duty Channels, Plates & other sections.
b) Horizontal Frame.
Steel Frame 3.5 m long x 1.5 m wide fabricated out to heavy duty Channels, Plates & other sections.
• Loading Pad:
1.50 m long x 0.91m wide Loading pad with sufficient plate thickness & ribs etc. for reinforcement to prevent bucking at the time of application of Load.
• Hydraulic Jack for Vertical /Normal Load:
Hydraulic Jack to be operated with the help of suitable Power Pack.
Capacity 250 kN Double Acting with 20 cm ram dia. & 20 cm Travel.
• Spherical Seat:
Spherical Seat for placing above the Loading Pad.
• Power Pack for Operating Jack:
Power Pack with Direction Control Valve for operating Double Acting Jack.
• Measurement of Normal Load:
Load Cell (250 kN capacity).
• Measurement of Geosynthetic or GI Strips Displacements (Pull): 4 Nos
Linear Variable Differential Transformer (LVDT) – 150 mm travel with ± 1% accuracy.
• Measurement of Pullout Force:
Load Cell (100 kN capacity).
• Application of Pull Out Force on Front Face:
Strain Controlled through Geared system.
• Arrangement for pulling out the GI Strips/ Geosynthetic:
Motorised arrangement with 3 displacement rates – (1 mm/min. 3mm/min & 5mm/min).
• Data Logger:
Electronic Data Acquisition System (All readings – Pullout Load, displacement & strain to be recorded automatically & stored at six second intervals by an electronic data acquisition system & the data can be downloaded in Excel format).
• Foundation Work:
The equipment rates on pillars of size 10 inch & height 20 inch above the ground level.
Note : Foundation Work to be arranged by the customer
• General requirement:
- Chain pulley Block – 2 Ton Capacity – 2 Nos
• Optional Requirement :
- Strain Gauges
Note: Pullout arrangement is as per ASTM Code D 6706-01
Note: The Instrument can be customized as per customer requirement
