METHOD AND DEVICE FOR CHECKING BRIDGE FOOTING DEFORMATION AT LONGITUDINAL THRUST OF BRIDGE SPAN Russian patent published in 2001 - IPC

FIELD: construction of bridge spans. SUBSTANCE: bridge span displacements relative to bank and controlled footing are measured by means of displacement transducers; one of the latter is placed on controlled footing, other one is arranged on bank and interacts with bridge span. Pulses whose number equals linear displacement distance of span arrive at outputs of comparator unit made in the form of reversible counter and pre- loaded with pulses whose number corresponds to maximum permissible distance of footing linear displacement. Up-counting input is connected to footing-mounted transducer and down-counting one, to transducer installed on bank. If footing is not deformed, equal number of pulses will come to counter inputs and number of pulses pre-loaded in counter does not change. If footing starts moving together with span (is deformed), smaller number of pulses arrive from footing-installed transducer and number of pulses loaded in counter decreases. If their number drops to zero, which indicates critical deformation of footing, signal is supplied to circuit breaker which disconnects driving gear of pusher. EFFECT: facilitated procedure; improved precision and reliability of footing deformation check-up, timely disconnection of pusher. 2 cl, 4 dwg