SYSTEM OF RAISING EACH SPAN BY CONTROLLING COMPUTER MEASUREMENTS IN THE CONTINUOS BEAM

摘要

A system of lifting each spans according to measurements and controls by a computer is provided to allow lift differences on each points and on each support points to be within allowable errors while independently compensating for the differences in lift by a main control computer analyzing the differences measured by displacement meters and controlling electric valves built in electric control distributors to compensate for the differences, and to prevent overloading hydraulic jacks by installing contact sensing devices to detect malfunctions of the hydraulic jacks. Electric controlled distributors, displacement meters, and contact sensing devices are directly connected to a main control computer. The electric control distributors are controlled by the main control computer, whereas hydraulic pumps are controlled by the electric control distributors. The hydraulic pumps operate hydraulic jacks to lift the upper structures of a bridge. The hydraulic pumps allow difference in lift on each points and on each support points to be within the allowable error. The difference in lift on each points and on each support points are measured by the displacement meters installed on the measurement reference surfaces. The measurements are then analyzed by the main control computer. The main control computer controls electric valves built in the electric control distributors with the new analyzed data to compensate the errors on each points and on each support points. Lift speed controlling valves and error compensating valves are built in the electric control distributors. The displacement meters have lower ends installed on the measurement reference surface, while upper ends are installed to lower parts of the upper structures. The contact sensing devices are installed on upper ends of strokes of the hydraulic jacks and on lower surfaces of the upper structures.