CONTROLLED SEMIACTIVE HYDRAULIC VIBRATION ABSORBER FOR BRIDGES

Heavy truck traffic on highway bridges is known to produce impact load s that cause large vibrations. This phenomenon can reduce the expected service life of many highway bridges. A means to mitigating those del eterious vibrations using an automatic control system that requires no pumps or line power is proposed. A semiactive hydraulic bridge vibrat ion absorber that can be retrofitted to an existing bridge is describe d. The bridge/vehicle system is modeled, and a practical feedback cont rol that uses either strain-gauge or accelerometer readings to sense t he state of the system is synthesized. The results of an experimental test of the new system indicates reductions of peak amplitudes of 65-7 0%.