PILED RAFTS OF RESERVOIR FOUNDATION Russian patent published in 2014 - IPC E02D27/12 

FIELD: construction.

SUBSTANCE: invention relates to construction, in particular, to foundations of large steel reservoirs. The piled rafts of the reservoir includes a round foundation slab, combining vertical drilled reinforced concrete piles and a soil cushion, of alternate thickness. Piles have alternating diameter along their length that reduces with depth in steps, proportionately to the value of additional vertical deformations with the pitch 10%-40% D, where D - diameter of piles, and alternating length that varies in the plan at the following ratios of pile lengths L₁=0.8÷0.9L₂; L₂=0.8÷0.9L₃; L₃=0.8÷0.9L₄; where L₁; L₂; L₃; L₄ - length of piles determined by calculation proportionately to the depth of development of rated vertical deformations. The distance between piles in plan is directly proportionate to the value of the vertical normal stresses.

EFFECT: increased bearing capacity of a foundation, reduced material intensity.

2 dwg