BRIDGE FOOTING

FIELD: bridge building; protection of bridge footing built over rivers at drift ice and varying level of water, mainly in regions under severe climatic conditions. SUBSTANCE: bridge footing includes cluster of piles in river of varying level of flow and drift ice with high pilework and embracing ice protective envelope which copies external shape of pilework plate whose interior is divided into sections by means of diaphragms-strainers fitted at horizontal air gap relative to bottom of pilework plate; their lower end is immersed in water at all times. Novelty of invention consists in availability of flat member in underwater portion; these members are inclined towards side opposite to direction of river stream; they are secured to diaphragms-retainers and to piles in one or several tiers at angle of inclination of alpha = 30°-60°; total horizontal projection of flat inclined members ranges from 0.3 to 1.5 of area of inner cavity of ice protective envelope; diaphragms-strainers are perforated; area of perforations is no less than 0.3 of part of area of each diaphragm submerged in water; height of diaphragm walls with horizontal air gap taken into account is lesser than height of walls of ice protective envelope by (0.2-0.7)h, where h is vertical projection of inclined members, m. EFFECT: enhanced reliability and durability of bridge due to reduction of internal ice forming and pressure of ice on envelope walls. 2 dwg