RU2000119667A - METHOD FOR ESTABLISHING A PILED FOUNDATION ON LAYING SOILS - Google Patents

Claims (6)

1. A method of erecting pile foundations on subsiding soils, including the formation of water-absorbing cavities to the entire depth of the subsiding soil with deepening into non-subsiding soil, filling water-absorbing cavities with drainage material, bunding the site around the perimeter of the structure, supplying water to the site and water-absorbing cavities connected with it and immersion piles into water-absorbing cavities to their incomplete depth, characterized in that each pile is made having a longitudinal cavity with side holes and closed with studied, themselves piles placed in the cavities of the water-absorbent leaving gaps between the pile and the walls of the water-absorbent barrel cavities cased to a depth h _1, as determined from the relationship

where p ₀ is the pressure of the soil rupture, MPa;
c, γ and s _{sl, g} are, respectively, specific adhesion (MPa), specific gravity (KN / m ³ ) and drawdown from the own weight (m) of soil;
K is a parameter taken depending on the angle of internal friction and the coefficient of transverse expansion of the soil;
and the gaps are filled with draining material to the bottom mark of the casing element, the platform is equipped with marks - piezometers, after which, pouring water into the water-absorbing cavities and maintaining the position of the depression surface fixed by piezometers in the lower part of the subsiding soil thickness, pile piles with cavities communicating with water-absorbing cavities are immersed , to the design mark, then the water supply to the water-absorbing cavities is stopped, casing elements and gaps in the water-absorbing cavities are removed above the drainage material to a depth of h ₂ = h ₁ - s _{sl, g is} filled with a low-permeability reinforced hardening material, and the piles are divided into two groups with the location of one group of piles between the piles of the other group and the cavity of the piles of one group are equipped with devices to remove water from them, after which they go to the platform and through the cavity piles in the water-absorbing cavity supply water with maintaining its constant level until the depression reaches the level of the site, then stop the flow of water to the site and in the water-absorbing cavity, and one group of the latter, through devices to remove water, they are freed from the water contained in them and periodically, using the same devices, they remove water that is filtered from the surrounding water-saturated subsidence massif into water-absorbing cavities until the depression surface drops to the bottom of the subsidence thickness of the soil, after which the soaking cycles are repeated until achieving daily conditional stabilization of subsidence determined by grades at the moments of the depression surface in the lower part of the subsidence of the soil, and with the onset of stabilization of subsidence from the cavities to extract piles device for removing water and water-absorbing cavity through the cavity filled with a hardening material piles pressurized sealingly ground surrounding the pile.  2. The method according to p. 1, characterized in that the water-absorbing cavity below the casing element is formed in the form of a truncated cone, oriented upward with a large base.  3. The method according to p. 1 or 2, characterized in that when the subsidence soil is saturated, water is supplied under excess pressure to the water-absorbing cavities, and during periods of lowering of the depression surface, water-absorbing cavities with devices for removing water create less pressure than atmospheric.  4. The method according to any one of paragraphs. 1-3, characterized in that during periods of saturation of subsidence soil in water-absorbing cavities create excessive pressure with hot water, superheated steam.  5. The method according to any one of paragraphs. 1-4, characterized in that along the perimeter of the bunded area in subsidence soil, a slot is made that is filled with material with low acoustic rigidity, which, after saturation with water, has low permeability and low shear resistance.  6. The method according to any one of paragraphs. 1-5, characterized in that on the site and in communicating with the water-absorbing cavities maintain a constant water level.