A structural steel frame, concrete plinth, or fabricated pedestal fixed to the pit floor that positions the car and counterweight buffers at the correct height and transfers buffer impact forces to the building foundation.
Full Definition
Elevator pit buffer supports are load-bearing structures that: (1) raise the buffer to the correct strike height so that when the car rests on a fully compressed buffer, the required refuge space below the sling is achieved (EN 81-20 §5.7.3.2); (2) transmit the buffer reaction force to the pit floor slab without local punching failure — for oil buffers the reaction force equals the rated load plus car weight multiplied by the peak deceleration factor (up to 2.5 g per EN 81-20); (3) provide a stable, level, corrosion-resistant mounting for the buffer base plate. Design: supports are typically fabricated from S235/S355 steel plate or formed from C30/37 reinforced concrete; top surface machined or shimmed to ± 1 mm level; anchor bolts M16–M24 cast-in or chemical-anchored to the pit floor with embedment depth determined by pull-out calculation per ETAG 001. Corrosion protection: hot-dip galvanised for steel supports; epoxy-coated concrete for humid pits. Where the buffer is a spring type, the support is simpler (flat plinth); where it is an oil buffer, the support must also accommodate the oil drain cock and level sight glass access.
