| In order to meet the demand of marine resources exploitation, coastal cities, theislands’ docking and other needs, building cross-sea bridge and other offshoreengineering is becoming more and more urgent, with the increasing emphasis on themarine rights of our country. Including the cross sea bridge, offshore engineering notonly high-cost, construction difficult, but also these projects are usually lifelineengineering. The ensurance of these projects’ function that can often provide veryfavorable conditions for emergency rescue, disaster relief, and national strategic needswhen some areas suffer disasters. As a kind of effective measures to ensure the safetyof structure, applying the seismic isolation technology in these offshore engineeringcan highlight its superiority. In this paper, the rubber material test, isolation bearingtest, finite element analysis, and theory analysis were carried out to research thedeterioration laws of isolation bearings performance, which combined with thespecific circumstances of China’s coastal. Specific contents are as follows:1. Analysis of influence factors of isolation bearings: through access to alarge amount of literature and combine with the material composition and structure ofthe isolation bearings, the factors affecting the the bearings of the marine environmentwere summarized.2. Test program development: with China’s top ten coastal cities’ climatecharacteristics and the seawater composition characteristics to determine temperatureconditions, time conditions of artificial accelerated aging and accelerated marinecorrosion test, artificial seawater composition. According to the artificial acceleratedaging test, artificial accelerated marine corrosion trials program, the rubber bearings,rubber block and the rubber sheets were designed for the study of whole bearings andrubber material properties change after these tests. At the same time, the isolationbearings’ load test program based on a number of countries and regions’ bearing teststandards was developed, considering wind loads, brake load, earthquake and otherfactors.3. Artificial accelerated aging and accelerated marine corrosion test onrubber: rubber sheets’ and rubber blocks’ aging tests，marine corrosion tests andageing tests+marine carrion tests were carried out, and the material performance testof rubber materials were also conducted. The properties of rubber materials thatsubjected to various test conditions were summarized. 4. The deterioration experiment of rubber isolation bearing: No protectivelayer rubber isolators’ and with protective layer rubber isolators’ aging tests，marinecorrosion tests and multiple load tests were carried out. The basic performance testsbefore and after each test conditions were also conducted. Through these, the variationlaws of the stiffness properties of rubber bearings subjected to various conditionswere abstracted. Isolators’ performance assurance measures and antiseptic methodswere proposed, including the reference3D design of the protective shield andinstallation diagram.5. The finite element analysis of rubber isolation bearing and the forecastof rubber isolation bearong: uneven aging model for analysis of rubber bearingsvertical stiffness and horizontal stiffness were established by ABAQUS softfare, andthe results shows that the stiffness of the isolator is mainly related with the size of theaged region, with little to loading direction. Then a simple method for monitoring thelevel of stiffness isolator after aging was presented based on this result.6. The study of rubber isolation bearings performance deterioration lawwith time under the marine corrosion environment: by using rubber sheet hardnessvariation with time and the corrosion rate of steel in marine atmospheric environment,the deterioration laws of no protective layer rubber isolation bearings performance inmarine environment were got after comprehensive analysis. |
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