Infrastructure Equipment

Falling Weight Deflectometer

At Almondz we rely on the latest technology from around the world to build our Infrastructure projects. Falling Weight Deflectometer (FWD) is used around the world by Engineers to evaluate the physical properties of pavement in highways, local roads, airport, harbour areas and railway tracks. Falling Weight Deflectometer is a smart and fully automatic equipment built around intelligent microcontroller based system which, acquires and processed data at high speeds with high accuracy and reliability. FWD test for road is fully automated control system which is controlled by a processor to ensure consistent results. During testing, a FWD subjects the pavement surface to a load pulse which simulates the load produced by a rolling vehicle wheel. During the deflection test, the load pulse is produced by dropping a large weight onto a "buffer" which shapes the pulse, and then transmitted to the pavement through a circular load plate. Data are acquired from various sensors for use in post-test analysis of pavement properties.

Sequence of Analysis

  1. The recorded data is normalised to a standard load as per IRC Standards.
  2. The normalised deflections are then processed and back calculated using software such as KGPBACK, MichBack , PVD etc. to obtain Elastic Modulus values of Bituminous, Granular layer and Sub-grade.
  3. The corrections factors for temperature corrections and seasonal variations are applied to all layers as suggested in IRC Code.
  4. At this stage we begin the Preparation of Homogenous sections and selecting 15th percentile Moduli values for the purpose of design.
  5. Checking the in-serviceability of the Pavement layers through Performance criteria - analysing the Remaining life and Overlay thickness required with reference to the Traffic MSA.

FWD Analysis Using KGPBACK Software

  • FWD Testing Method Designed With Client
  • FWD Testing Undertaken By IRSM
  • IRSM Data Quality Check Procedures (e.g Data Inconsistency Check)
  • Raw Deflection Data Is Normalised To 40KN
  • Adopting Proper Correction For Arrieved Moduli
  • Identify Homogenous Section - Throught Cumulative Difference Approach Method
  • Section Of 15th Percentile Modulus
  • Analysis Of The In-Service Of Critical Strains (IITPAVE)
  • Estimation Of Remaining Life-Fatigue & Rutting Performance Checks
  • Design Overlay Thinkness

Technical Specification

Make and Model Model No: GTFWD V
Make : Geotran , Roorkee
Mounted on TATA Yodha 1700
Operation Fully Automatic. All operation through Laptop/Tab
Impact Load 75 kN (Max.)
Load Resolution: 0.01 kN
Load Sensor 100 kN
Loading Impact Plate 300mm diameter and 31 mm thick with reinforced checkered rubber (solid/segmented)
Impact Height 4 to 40 Cm (Software adjustable)
Impact Weight Min 100 kg (as Standard), max 400 kg (add weight 25 kg to each side) plate along with a universal hinge at the upper part of plate to ensure that the loading plate align itself as per the camber of the road
GPS and Distance Measuring Unit Integrated GPS (Latitude, Longitude and Altitude) and distance measuring unit
Geophone 7nos. (for deflection measurement)
Deflection Resolution: 0.001mm (1 micron)
Temperature Sensor 2 nos. One each for air & road surface temperature
Data Acquisition Laptop with High speed Data Acquisition System, acquire data of geophones, load, temperature and GPS etc
Software ▪ GEOTRAN FWD Analysis software
▪ Easy operation.
▪ Graphical presentation of captured data of geophones, load cell.
Operating System Window XP/7/8/10
Back Calculation KGP back 4-layer and 3-layer/ BAFAA
Supply 48 Volt Battery, chargeable from AC mains (external source)
Power backup 6 to 7 hours continues operation with one full charge of battery

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Meet our Experts -
Gaurav Sharma
: 011-43500700
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