MEASURING BEARING CAPACITY WITH A FALLING WEIGHT DEFLECTOMETER: EVALUATION OF EQUIPMENT AND MEASURING PROCEDURE
BAERIGHETSBESTAEMNING MED FJAEDRAD FALLVIKT PROVNING AV UTRUSTNING OCH MAETFOERFARANDE
The work described investigates the peak value, shape and duration of the force and deformation pulses when a road surface is loaded with a falling weight deflectometer (fwd). The theory of the fwd method, and its application on several different types of surfacings are described. Compared with the static-plate bearing tests, fwd loading gives the deformation of the road surface. This pulse simulates a fast moving wheel load and can be adjusted to correspond to loads of 5 tons or less. The 150 kg falling weight falls onto a spring system resulting in a half-size wave-force curve. A seismometer and peak voltmeter are used to measure deformation through a small hole in the middle of the loading plate. Detailed results of the work are given and it was found that sand should be used to even-out uneven bases. Measurements on a lime-stabilised clay terrace show a significant increase in the modulus of elasticity after stabilisation. Results did not show a good correlation between compaction and dynamic elastic modulus; but although there was a large spread between readings, the method is so simple that further experiments would be of interest. This article was originally published in Swedish as: Examensarbete 1974, by Kungliga Tekniska Hoegskolan, Institutionen foer Vaegbyggnad, Stockholm. (TRRL)
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Corporate Authors:
Transport and Road Research Laboratory (TRRL)
Wokingham, Berkshire United Kingdom -
Authors:
- Lindstroem, M
- Naesman, L
- Publication Date: 0
Media Info
- Features: Figures; Tables;
- Pagination: 87 p.
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Serial:
- TRRL TRANSLATION
- Issue Number: 3086
- Publisher: Transport and Road Research Laboratory (TRRL)
Subject/Index Terms
- TRT Terms: Base course (Pavements); Bearing capacity; Calcium oxide; Clay; Compaction; Deflectometers; Deformation; Falling weight deflectometers; Hammers; Liming of soils; Loads; Measurement; Measuring instruments; Modulus of elasticity; Sand; Simulation; Soil stabilization; Surfacing; Translations; Wheel loads
- Old TRIS Terms: Sand stabilization
- ITRD Terms: 3085: Bearing capacity; 4177: Clay; 5904: Compaction (state of); 6187: Deflectograph; 5595: Deformation; 3681: Hammer; 4574: Lime; 5567: Load; 6136: Measurement; 5919: Modulus of elasticity; 2961: Roadbase; 4105: Sand; 9103: Simulation; 3689: Soil stabilization; 2972: Surfacing; 8538: Translation
- Subject Areas: Design; Geotechnology; Highways; Pavements; I22: Design of Pavements, Railways and Guideways;
Filing Info
- Accession Number: 00382155
- Record Type: Publication
- Source Agency: Transport Research Laboratory
- Report/Paper Numbers: Monograph
- Files: ITRD, TRIS
- Created Date: Apr 30 1984 12:00AM