Ductile Anchor Bolts for Tall Chimneys

This paper describes the design and testing of holding down bolts of the type used at the base of large industrial chimney stacks. The bolts provide a ductile mechanism whereby large earthquake induced vibrations, displacements and forces can be absorbed and so isolate the rest of the structure from the bulk of the input energy. Results from static tensile tests on 50 mm diameter holding down bolts show that satisfactory behavior can be achieved from bolts made from structural grade mild steel bars with coarse pitch ISO metric screw threads. The 800‐mm long bolts stretched 50 mm‐100 mm before fracture. The performance of holding down bolts is found to be in good agreement with that predicted by conventional bolt theory. Yield and ultimate loads can be determined by multiplying yield or ultimate stresses by the tensile stress area as given in standards or codes.