SCREW ANCHOR AND ITS INSTALLATION PROCESS Russian patent published in 2001 - IPC

FIELD: construction engineering. SUBSTANCE: screw anchor used in arrangement of foundations for fastening various mechanisms and devices to ground, in particular for anchoring pile-indentation tools and other building structures or pile testing by indenting dead load has body and screw blades; it is also provided with member moving along longitudinal axis of bore and installed for ground compression by means of load-bearing members due to moving member arranged in operating position at certain distance from underlying screw blade. Screw anchor is installed by driving its body through desired depth by means of drilling assembly and applying opposing forces to body with blades and to moving member while displacing the body carrying rigidly fixed blades upward relative to moving member; screw anchor body and moving member are relatively displaced until distance between moving member and lower blade is not lower than diameter of the latter. When screw anchor is installed in soft or watered grounds, moving member is to be lifted as soon as it approaches lower blade as close as possible and hole formed in the process is filled with stiff building material; after that operation is repeated until desired force of pulling thrust is attained; the latter is checked by pressure in hydraulic cylinders. EFFECT: improved bearing capacity on pulling thrust, strength and strain characteristics of ground around screw anchor; enlarged application area; reduced cost and labor consumption. 8 cl, 7 dwg