SHOCK-ABSORBING DEVICE FOR SEISMIC PROTECTION OF STRUCTURES Russian patent published in 1997 - IPC

FIELD: antiseismic equipment. SUBSTANCE: reduced or complete elimination of dry friction between foundation and supporting slabs is achieved by shaping of adjacent surfaces at which some parts of slabs are in contact with each other, and other parts have spaces filled with water or other liquid and are subjected to surplus hydrostatic pressure which is maintained by compensator which connects slabs and permits their relative horizontal displacement. Protection of structure in vertical direction is ensured by increasing natural oscillation period of caisson located on slabs of supporting component of structure being protected. Caisson is partly floating in liquid and partly resting on layer of compressed air and it is made up of at least two concentric sleeves. Circular clearance between external sleeve and adjacent internal sleeve is enclosed by water-tight bottom connected over its outer perimeter with supporting slab through compensator which permits their relative vertical displacement and maintains preset air pressure in caisson cavity. Space between slabs and lower part of caisson cavity filled with liquid are connected by pipelines with reserve vessels located above corresponding spaces. EFFECT: reliable antiseismic protection. 9 cl, 2 dwg