Geophone handheld drop light weight falling weight deflectometer FWD
Working principle
Impact load simulation:
By
using a hydraulic system, a hammer of a certain mass (usually 50-300kg)
is lifted to a predetermined height (such as 10-30cm) and then freely
falls to impact the bearing plate (usually 30cm in diameter), generating
a transient pulse load (lasting about 25-30 milliseconds), simulating
the dynamic wheel load during vehicle operation (equivalent to standard
axle load, such as 50kN or higher).
Bending measurement:
Under
the action of impact load, the road surface undergoes elastic
deformation (deflection). By arranging high-precision sensors (such as
velocity or acceleration displacement sensors) at the center of the
bearing plate and different radial distances (such as 0, 30, 60, 90cm,
etc.), the dynamic deflection time history curves of each measuring
point are recorded, and the maximum deflection value (μ m level
accuracy) is extracted.
Data collection and analysis:
The
system automatically collects deflection Basin data and combines
inversion algorithms (such as elastic layered system theory) to
calculate the elastic modulus of each structural layer (asphalt layer,
base layer, soil foundation) and evaluate the structural integrity.
Advantages:
-Fast, non-destructive, and high-precision;
-Dynamic loads are closer to actual traffic conditions;
-Multi sensor synchronous measurement provides spatial deformation information.
PRoduct Feature
1.Imported sensors and parts of components are used to achieve high test accuracy.
2.LCD display in English, with corresponding hints in Chinese and English under different interfaces, and with backlight, has better visibility in various environments;
3.Easy to operate and fast to test. It only takes 35 seconds to detect a point.
4.Automatically calculate Evd value and display curve, accurate and intuitive;
5.Hand-held mainframe with Bluetooth micro printer can print directly on the spot to ensure the accuracy and objectivity of the test results. 6.USB transmission interface, easy to connect with the computer;
7.The Falling Weight Deflectometer simulates the impact effect of high-speed train on subgrade. Compared with static load test, it can better reflect the actual stress of subgrade soil.
Application scenarios
Road surface structure evaluation: detecting hidden diseases such as loose base, void, and weak soil foundation.
Maintenance decision: Based on the shape of the deflection basin, determine the damaged layer and guide milling or reinforcement.
Construction quality control: Verify the compaction and uniformity of the newly constructed road surface.
Inverse modulus calculation: Use software such as MODULUS and EverCalc to invert the material parameters of each layer.
Parameter
|
Product Name |
Evd Dynamic Deformation Modulus Tester |
|
Maximum impact force |
7.07kN |
|
Impact duration |
17.0 ± 1.5ms |
|
Power supply |
4 R6 batteries |
|
Measurement range of settlement value |
0.1-2.0mm ± 0.02mm |
|
Applicable types of garbage |
Various types of soil and soil rock mixed fillers with particle size not exceeding 1/4 of the diameter of the load plate |
|
Scope of testing |
10mpaEEvdE225_ pa |
|
Test the depth of impact |
0~500-m |
|
Working environment temperature |
-10~40 ℃ |
|
Material: |
Aluminum alloy |
|
Whole machine volume |
1220 × 395 × 380mm |
|
weight |
56kg |
FREQUENTLY ASKED QUESTIONS (FAQ)
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