VIBRATION TESTING METHOD TO CONTROL TECHNICAL BRIDGE SPAN STATE Russian patent published in 2006 - IPC G01M7/02 

FIELD: measuring equipment, particularly vibration-testing of structures.

SUBSTANCE: method involves installing measuring vibration pickups in several control points; determining parameters of vertical self- and stimulated span structure oscillations caused by ordinary traffic through time period; determining horizontal displacement of load-bearing beam end with the use of computer program, which determines horizontal displacement of lower or upper beam end points from vertical beam displacement in span structure center in dependence of vibration pickup locations; determining scale factor of vertical load-bearing beam displacement in span structure center from above horizontal displacement value in lower of upper beam end points obtained from formula. To control technical state of bridge span structure horizontal load-bearing beam oscillation values are used, wherein the horizontal load-bearing beam oscillation values are obtained by means of vibration pickups horizontally installed in load-bearing beam ends. Vertical span structure oscillation frequency may be determined from horizontal load-bearing beam oscillation frequency. Amplitudes of vertical oscillation frequency in span structure center are defined from horizontal load-bearing beam end displacement with the use of previously calculated scale factor.

EFFECT: simplified measurements along with increased measurement reliability.

3 cl, 1 dwg