
US Patent No: 6,604,432
Number of patents in Portfolio can not be more than 2000
Soil compaction measurement
Stats
-
Aug 12, 2003
Issued date -
May 2, 2000
filing date -
09/530,662
serial no -
In Force
status
Importance
Abstract
The in-situ measurement of the shear modulus of a surface layer of soil (12) is performed by apparatus in which a contact foot (11) with a preselected downward bias force engages a defined area of a region of soil. A drive transducer (13) shakes the contact foot (11) vertically and sensing transducers (17, 18) determine the force applied to the foot (11) and the resulting movement of the foot (11) and generate respective first and second output signals. The in-phase movement responsive output signal is analyzed in relation to the force signal to obtain a measurement of a single parameter which is representative of the stiffness provided by the soil (12). The shear modulus as well as the void ratio of the soil can be calculated from the stiffness. The drive transducer (13) is energized by an a.c. signal which progressively varies in frequency over a preselected band with the rate of change also varying with frequency thereby providing a greater force spectrum content at lower frequencies than at higher frequencies in the band, while maintaining a substantially constant force magnitude.
First Claim
Related Publications
International Classification(s)
- [Classification Symbol]
- [Patents Count]
Cited Art
| Patent Info | (Count) | # Cites | Year |
|---|---|---|---|
|
|
|||
| 4,912,979 Method and apparatus for detecting and measuring elastic anisotropy | 11 | 1989 | |
|
|
|||
| 5,105,650 Monitoring compaction of backfill | 8 | 1990 | |
|
|
|||
| 4,467,652 Procedure and device for compaction measurement | 19 | 1982 | |
|
|
|||
| 4,348,901 Apparatus for monitoring the degree of compaction | 19 | 1980 | |
|
|
|||
| 4,655,082 Mining machine having vibration sensor | 15 | 1985 | |
|
|
|||
| 5,398,215 Identification of stress induced anisotropy in formations | 36 | 1994 | |
|
|
|||
| 4,738,138 Measurement of wave propagation power flow in structures | 7 | 1986 | |
|
|
|||
| 4,750,157 Seismic vibrator earth impedance determination and compensation system | 19 | 1987 | |
|
|
|||
| 4,918,988 Method of detecting a defective position in a cement intimate mixture filled portion in a building | 11 | 1989 | |
|
|
|||
| 4,382,384 Acoustic penetrometer for subsoil investigation | 15 | 1981 | |
|
|
|||
| 4,445,378 Acoustic ground impedance meter | 9 | 1982 | |
|
|
|||
| 4,995,008 Method of using a circularly-polarized source to characterize seismic anisotropy | 7 | 1989 | |
|
|
|||
| 4,594,899 Method and apparatus for testing soil | 17 | 1984 | |
Patent Citation Ranking
Maintenance Fees
| Fee | Large entity fee | small entity fee | micro entity fee | due date |
|---|---|---|---|---|
| 11.5 Year Payment | $7400.00 | $3700.00 | $1850.00 | Feb 12, 2015 |
| Fee | Large entity fee | small entity fee | micro entity fee |
|---|---|---|---|
| Surcharge - 11.5 year - Late payment within 6 months | $160.00 | $80.00 | $40.00 |
| Surcharge after expiration - Late payment is unavoidable | $700.00 | $350.00 | $175.00 |
| Surcharge after expiration - Late payment is unintentional | $1,640.00 | $820.00 | $410.00 |