Abstract: A system for protecting a building or piece of equipment against the forces generated by an earthquake is characterized by one or more approximately horizontal interfaces having sliding means associated therewith which permit relative horizontal multi-directional sliding movement between the superstructure and the supporting substructure. Calibrated control means such as low-friction sliding means and/or adjustable friction clamps may be utilized to adjust the threshold horizontal force required to cause such relative movement. Biasing means such as spring members may be utilized to urge the superstructure towards its pre-earthquake alignment relative to the substructure. Other advantages are provided by substrate grid means that permits the ready adjustment of the friction force exerted by the low-friction sliding means, and by the concave configuration of the sliding interfaces. A method of installing such a system is disclosed.

Abstract: A system for protecting a building against the forces generated by an earthquake. The superstructure moves horizontally along a system of movable plates provided at the interface between the superstructure and the foundation. A sandwiched system of three levels of low friction plates lying beneath each column, interconnected by a system of clamps, restricts the movement of the columns and walls solely to a combination of orthogonal, rectilinear motions. A first set of clamps allow linear motion between the top and middle plate in a first direction and a second set of clamps allow linear motion between the middle and bottom plate in a second linear direction that is perpendicular to the first direction without torsional rotation about a vertical axis. By setting a low friction material under the top plate concentric with the column center line, no significant eccentric loads can be introduced into the column.

Abstract: A system for protecting a building against the forces generated by an earthquake. The horizontal movement of the building superstructure relative to the foundation is adjustable to adapt its damping system to prevailing wind conditions. The superstructure moves horizontally along a system of movable plates provided at the interface between the superstructure and the foundation. Wind velocity reading devices placed on the exterior of the building provide signals to a transducer which adjusts a controller to vary a threshold force applied to the superstructure to determine the force required to initiate movement of the superstructure relative to the foundation. A sandwiched system of three levels of low friction plates beneath each column, interconnected by three levels of diaphragm linkages, restricts the movement of the columns and walls solely to a combination of orthogonal, rectilinear motion.

Abstract: A barrier is constructed from a plurality of cell-like elements interconnected to form a rigid barrier under normal circumstances. The linkages between cells provides a friction-brake force which is exceeded upon application of a traumatic force such as a bomb blast. The linkages includes slots in each cell connecting adjacent cells with prestressed nuts and bolts to permit sliding relative movement between adjacent cells after a predetermined threshold force has been exceeded. A transverse reinforcing rod, having a series of plates along its length, passes through adjacent cells. The plates act as a viscous damper as they move through a filler material within the cells while the rod adds strength. The cells may be coated with a dry lubricant to control the static coefficient of friction. The ability of the cells to move protects the barrier from structural failure by dissipating the blast forces through the frictional work required to displace the cells.

Abstract: A system for protecting exterior building walls against damage from pressure waves generated by explosions on the building exterior. Exterior walls are constructed of multiple wall panels mounted in a circumferential framework of building elements formed by columns, a top surface of the floor below the wall and bottom surface of the floor above the wall. A series of guide tracks mounted in the circumferential surfaces extend perpendicular to the wall panel towards the interior of the building. Guide blocks on the perimeter of the wall panel engage the guide tracks so that the wall panel can slidably move along the tracks when a predetermined threshold force is applied to the exterior of the panel. An adjustable brake, on cooperating with the guide blocks and tracks, permits an accurate setting of the threshold force under which inward movement of the panel commences as well as the relatively constant force that acts during sliding.