Seismic isolation systems designed for extreme events may likely experience low to moderate earthquakes during the design life of the structure rather than the extreme event itself.In new seismic building design codes...Seismic isolation systems designed for extreme events may likely experience low to moderate earthquakes during the design life of the structure rather than the extreme event itself.In new seismic building design codes, low and moderate earthquakes are also mandatory to be investigated in Turkey and some other countries. One of the main reasons is to protect the integrity of non-structural elements or machines during these types of earthquakes. The selection of appropriate seismic isolation is typically decided based on their forcedisplacement characteristics and amount of energy dissipation per cycle. The same energy dissipation per cycle(EDC) can be achieved by high force-low displacement or low force-high displacement response. The focus of this research is given to identify the performance of ball rubber bearing isolation systems compared to different or similar EDC units such as elastomeric bearings and lead rubber bearings through a series of shake table tests performed at low to moderate earthquake levels. Shake table tests were conducted on an almost full scale short span bridge. The tests have revealed that the ball rubber bearings are superior to elastomeric bearings in terms of EDC and can match EDC of LRB. However, although LRB and BRB have the same EDC, BRB is more beneficial to use under low to moderate earthquakes since BRB can transmit less force with larger displacement compared to LRB and LRB can sometimes stay in elastic range with an ineffective EDC as a stiffer elastomeric bearing.展开更多
This study consists of the development and presentation of example of seismic isolation system analysis and design for a continuous, 3-span, cast-in-place concrete box girder bridge. It is expected that example is dev...This study consists of the development and presentation of example of seismic isolation system analysis and design for a continuous, 3-span, cast-in-place concrete box girder bridge. It is expected that example is developed for all Lead-Rubber Bearing (LRB) seismic isolation system on piers and abutments which placed in between super-structure and sub-structure. Design forces, displacements, and drifts are given distinctive consideration in accordance with Caltrans Seismic Design Criteria (2004). Most of all, total displacement on design for all LRBs case is reduced comparing with combined lead-rubber and elastomeric bearing system . Therefore, this represents substantial reduction in cost because of reduction of expansion joint. This presents a summary of analysis and design of seismic isolation system by energy mitigation with LRB on bridges.展开更多
基金supported by TUBITAK through the 110G093 research project and TUBITAK BIDEB 2215 Program
文摘Seismic isolation systems designed for extreme events may likely experience low to moderate earthquakes during the design life of the structure rather than the extreme event itself.In new seismic building design codes, low and moderate earthquakes are also mandatory to be investigated in Turkey and some other countries. One of the main reasons is to protect the integrity of non-structural elements or machines during these types of earthquakes. The selection of appropriate seismic isolation is typically decided based on their forcedisplacement characteristics and amount of energy dissipation per cycle. The same energy dissipation per cycle(EDC) can be achieved by high force-low displacement or low force-high displacement response. The focus of this research is given to identify the performance of ball rubber bearing isolation systems compared to different or similar EDC units such as elastomeric bearings and lead rubber bearings through a series of shake table tests performed at low to moderate earthquake levels. Shake table tests were conducted on an almost full scale short span bridge. The tests have revealed that the ball rubber bearings are superior to elastomeric bearings in terms of EDC and can match EDC of LRB. However, although LRB and BRB have the same EDC, BRB is more beneficial to use under low to moderate earthquakes since BRB can transmit less force with larger displacement compared to LRB and LRB can sometimes stay in elastic range with an ineffective EDC as a stiffer elastomeric bearing.
文摘This study consists of the development and presentation of example of seismic isolation system analysis and design for a continuous, 3-span, cast-in-place concrete box girder bridge. It is expected that example is developed for all Lead-Rubber Bearing (LRB) seismic isolation system on piers and abutments which placed in between super-structure and sub-structure. Design forces, displacements, and drifts are given distinctive consideration in accordance with Caltrans Seismic Design Criteria (2004). Most of all, total displacement on design for all LRBs case is reduced comparing with combined lead-rubber and elastomeric bearing system . Therefore, this represents substantial reduction in cost because of reduction of expansion joint. This presents a summary of analysis and design of seismic isolation system by energy mitigation with LRB on bridges.
