Method of upgrading seismic performance of existing spillway piers on dams and coupled earthquake-resistant structure

Abstract

A method of improving earthquake resistance of existing spillway piers provided in a dam. The method includes a following step. End portions of a main beam and top portions of existing spillway piers are connected to each other with a high damping device having a history damping property with high primary rigidity. The high damping device has a yield displacement amount in seismic velocity smaller than a tolerance of a displacement amount of the existing spillway piers. The high damping device has a yield load value in seismic velocity greater than a maximum seismic force generated therein in a bridge-axis direction due to a large-scale earthquake.

1 . A method of improving earthquake resistance of existing spillway piers on a dam, the existing spillway piers being arranged on two sides of a gate provided in the dam, the existing spillway piers supporting an existing bridge including a main beam made of steel, a gate lifting device provided on the existing bridge, and the gate, and the main beam including a fixed bearing structure on one side and a movable bearing structure on another side, the method comprising a step of:
 connecting an end portion of the main beam close to the movable bearing and a top portion of one of the existing spillway piers with a high damping device including Bingham fluid as working fluid and having a history damping property with high primary rigidity,   the high damping device having a yield displacement amount in seismic velocity smaller than a tolerance of a displacement amount of the existing spillway pier, and   the high damping device having a yield load value in seismic velocity greater than a maximum seismic force generated in the high damping device in a bridge-axis direction due to a large-scale earthquake.   
     
     
         2 . The method of improving earthquake resistance of existing spillway piers on a dam according to  claim 1 , further comprising connecting an end portion of the main beam close to the fixed bearing structure and a top portion of the existing spillway pier with a connecting member of a pin structure in each span of the existing bridge. 
     
     
         3 . A method of improving earthquake resistance of existing spillway piers on a dam, the existing spillway piers being arranged on two sides of a gate provided in the dam, the existing spillway piers supporting an existing bridge and a gate lifting device provided on the existing bridge, the method comprising:
 providing a beam member made of steel between the existing spillway piers that are adjacent to each other in each span of the existing bridge so as to be parallel to a bridge-axis direction;   connecting one end portion of the beam member and one of the spillway piers with a connecting member of a pin structure in each span of the existing bridge; and   connecting another end portion of the beam member and one of the existing spillway piers in each span of the existing bridge with a high damping device including Bingham fluid as working fluid and having a history damping property with high primary rigidity,   the high damping device having a yield displacement amount in seismic velocity smaller than a tolerance of a displacement amount of the existing spillway pier,   the high damping device having a yield load value in seismic velocity greater than a maximum seismic force generated in the high damping device in a bridge-axis direction due to a large-scale earthquake, and   the high damping device receiving the maximum seismic force generated therein in the bridge-axis direction due to the large-scale earthquake within an area of the high primary rigidity before the history damping property is exerted.   
     
     
         4 . An earthquake-resistant bridge in a dam comprising:
 a bridge;   a number of spillway piers provided on two ends of a gate in the dam, the spillway piers supporting the bridge, a gate lifting device provided on the bridge, and the gate;   a main beam made of steel and forming a beam of the bridge, the main beam provided between the spillway piers that are adjacent to each other in each span of the bridge and having a fixed bearing structure between one end thereof and one of the spillway piers and having a movable bearing structure between another end thereof and one of the spillway piers; and   a high damping device configured to connect an end portion of the main beam close to the movable bearing structure and a top portion of the spillway pier in each span of the bridge, the high damping device including Bingham fluid as working fluid and having a history damping property with high primary rigidity, wherein:   the high damping device has a yield displacement amount in seismic velocity smaller than a tolerance of a displacement amount of the spillway pier, and the high damping device has a yield load value in seismic velocity greater than a maximum seismic force generated in the high damping device in a bridge-axis direction due to a large-scale earthquake; and   the high damping device receives the maximum seismic force generated therein in the bridge-axis direction due to the large- scale earthquake within an area of the high primary rigidity before the history damping property is exerted.   
     
     
         5 . The earthquake-resistant bridge in a dam according to  claim 4 , further comprising a connecting member of a pin structure configured to connect an end portion of the main beam close to the fixed bearing structure and a top portion of the spillway pier. 
     
     
         6 . An earthquake-resistant bridge in a dam comprising:
 a bridge;   a number of spillway piers provided on two ends of a gate in the dam, the spillway piers supporting the bridge, a gate lifting device provided on the bridge, and the gate;   a beam member made of steel and provided between the spillway piers that are adjacent to each other in each span of the bridge so as to be parallel to a bridge-axis direction;   a connecting member of a pin structure configured to connect one end portion of the beam member and one of the spillway piers in each span of the bridge; and   a high damping device configured to connect another end portion of the beam member and one of the spillway piers in each span of the bridge, the high damping device including Bingham fluid as working fluid and having a history damping property with high primary rigidity,   the high damping device having a yield displacement in seismic velocity smaller than a tolerance of a displacement amount of the spillway pier, and the high damping device having a yield load value in seismic velocity greater than a maximum seismic force generated in the high damping device in a bridge-axis direction due to a large-scale earthquake, and   the high damping device receiving the maximum seismic force generated therein in the bridge-axis direction due to the large-scale earthquake within an area of the high primary rigidity before the history damping property is exerted.