US 5,614,670 AGranted

Movable seismic pavement analyzer

AssigneeBoard of Regents, The University of Texas System

InventorsSoheil Nazarian, Mark R. Baker, Kevin Crain

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Abstract

A device and method for monitoring conditions associated with pavement deterioration are disclosed. Conditions such as voids or loss of support under a rigid pavement, moisture infiltration in asphalt concrete pavement, fine cracking in pavements, delamination of overlays, and aging of asphalt may be measured according to the present invention. These pavement conditions are detected by estimating Young's and shear moduli in the pavement, base, and subgrade from the following wave propagation measurements: Impact Echo; Impulse Response; Spectral Analysis of Surface Waves; Ultrasonic Surface Wave; and Ultrasonic Body Wave Velocity. The pavement response produced by high- and low-frequency pneumatic hammers on five accelerometers and three geophones is recorded. A computer controls data acquisition, instrument control, and interpretation; measurements and interpretations are reported in both screen and database formats.

Claims13

Dependent claims

A device for seismically testing a multi-layer roadway surfacing, said surfacing comprising a paving layer, the device comprising:

a mobile support adapted to be moved across the surface of the paving layer;
a high-frequency seismic source mounted on said mobile support and adapted to be impacted on the paving layer so as to transmit a high-frequency seismic wave into said roadway surfacing;
a low-frequency seismic source mounted on said mobile support and adapted to be impacted on the paving layer so as to transmit a low-frequency seismic wave into said roadway surfacing;
a plurality of seismic transducers mounted on said mobile support and adapted to be coupled to the paving layer so as to detect said seismic waves following transmission through said roadway surfacing, wherein each said transducer is coupled to said mobile support through a separate pneumatic cylinder;
and
a computer electrically coupled to said transducers and seismic sources, said computer comprising:
means for initializing acquisition options to define measurement values for N seismic measurements to be made on said roadway surfacing to obtain selected surfacing parameters;
means for defining a bank of seismic transducers for each of N seismic measurements;
means for selecting a transducer bank based on said acquisition options;
means for receiving seismic data from said bank of seismic transducers;
means for processing said seismic data to obtain processed seismic data;
means for computing said selected surfacing parameters based on said processed seismic data;
means for evaluating said selected surfacing parameters to detect defects in said roadway surfacing;
and
means for diagnosing paving-layer-specific pavement distress precursors based on evaluated surfacing parameters.

12 more elements

A seismic pavement analyzer, comprising:

a mobile support adapted to be moved across the surface of a pavement;
a high-frequency seismic source mounted on said support and adapted to repeatedly impact said pavement to generate a high-frequency seismic wave in said pavement, said high-frequency source comprising a load cell for measuring an impact force of said source;
a low-frequency seismic source mounted on said support and adapted to repeatedly impact said pavement to generate a low-frequency seismic wave in said pavement, said low-frequency source comprising a load cell for measuring an impact force of said source;
an actuator coupled to each of said seismic sources;
a plurality of transducers for receiving said seismic waves through said pavement, wherein each said transducer is coupled to said mobile support through a separate pneumatic cylinder, each of said cylinders being configured to actuate its corresponding transducer upon said pavement;
and
a computer electrically coupled to said transducers and seismic sources, comprising:
means for selecting a surfacing parameter to be measured;
means, responsive to said selection of a surfacing parameter, for selectively activating at least one of said actuators coupled to a seismic source associated with said selected surfacing parameter;
means for receiving seismic data from said transducers based on detected seismic waves;
means for processing said seismic data to obtain processed seismic data;
means for computing said selected surfacing parameter based on said processed seismic data;
means for evaluating said selected surfacing parameter to detect defects in said pavement;
and
means for diagnosing paving-layer-specific pavement distress precursors based on evaluated surfacing parameters.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/674,460Filed 2 Jul 1996 · continuation
Priority: 29 Oct 1993
Granted: 25 Mar 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

E01C 23/00
Auxiliary devices or arrangements for constructing, repairing, reconditioning, or taking-up road or
G01M 7/08
Vibration-testing of structures; Shock-testing of structures: shock-testing
G01N 29/045
Analysing solids: by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks
G01N 33/42
Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00: road-making materials