Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
  • E02D3/12—Consolidating by placing solidifying or pore-filling substances in the soil

Definitions

• This imention relates tojet gioutingand to chemical compositions for use in j el grouting
• Jet giouting is a soil consolidating teclinique, widely used for many civil engineering applications For example, it can be used to provide foundations for ultimatelyctuics to be erected, to underpin existing sliucluies, to create low pe ⁇ ncdbihtv ba ⁇ ieis, to create ietaining or supporting stnictuies to rcmfoice a soil mass and to complement othci geotechnical structures
• the jet grouting piocess consists of the disaggregation of the soil or weak rock and its mixing with, and 10 partial replacement by, a cementing agent, normally a cement based giout, the disaggregation is achieved by means of a high energy jet of a fluid which can be watei or the grout itself depending on the system employed
• This invention pio ⁇ ides a method of de-wate ⁇ ng a slurry mixture produced fiom a jet grouting operation, compi ising the addition to the mixture of an anionic polyacrylamide in such mannei that it is uniformly distributed therein, the anionic polyacryl amide having a high molecular weight and a low-medium charge density
• An anionic polyacrylamide for use in this inv ention has a high molecular weight, that is, a weight-average molecular w eight of at least 4,000,000 The molecular weight is prefeiably between 5,000,000 and 20,000,000
• the polyacrylamide has a low -medium chaige density Chai ge density, which is an indication of the number of charged species for a given molecular weight, is a parameter well known to the art and to which theie are frequent references in the commercial hteratui e It is quoted as the percentage of the sodium acrylate content of the polymer
• a low-medium charge density is one w hich lies within the i ange of from 5-70%
• Those high MW anionic polyacrylamides having a charge density of from 10%-50% are the most effectiv e and are the prefe ⁇ ed matenals for the purposes of this in ⁇ ention Among the commercially-axailable mate ⁇ als which
• the dosage used is fiom 150-500, preferably fiom 200-350, ppm of the sluiry
• the polyacrylamide is First dissolved in water, to gi ⁇ e a topical! 05-1% weight solution, and this solution is added to the slurry with stirring This has the effect of separating water out of the soil-cement sluiry, and changing the consistency of
• the slurry from fluid to mortai-like The sepaiation normally takes less than 5 minutes when some agitation is employed, and the sepaiated water can be simply drained out, or some pressure may be employed to press it out
• the water which comes out is normally clear, and aftet appropriate neutiahzation can be simply discharged into the sewage system, or where allowed, the open enviionment
• the disposal cost such as in a landfill for the abovementioned ; slurry would be diasticalh ieduced, because of the lowei ⁇ olume of slurry due to de-wate ⁇ ng and the lower pi ice for disposing of dry material as opposed to fluid mate ⁇ al
• the solids content by weight of a slurry to be treated should generally be 50% maximum, prefciably 45% maximum, as ⁇ measuied b ⁇ dning a sample in an o ⁇ en at 105 0 C
• contents figuies are based on a relatively uniform distribution of particle sizes of clay, silt, cement, etc in the slurry
• the measuied solids content of a given sample can be considerably higher hi such a case, the performance of the piocess of the imention is 5 unaffected, and, for the purposes of this invention, such a slurry is consideied to fall within the solids content limits given hereinabo ⁇ e
• a se ⁇ es of anionic polyacrylamides are tested for dewate ⁇ ng activity
• the mateiials tested are as follows Example No, Polvacrylamide Avera ⁇ e MW Charge densitv 1 SED ⁇ PUR APl oo 10,000,000 10% 2 SEDIPUR AF203 5,000,000 20% SEDDPUR AP204 12,000,000 20%
• the mateials are tested as follows. A slurry containing 25% fine soil (silt and clay), 15% cement and 60% water is prepared. Each of the polyacrylamides hereinabove mentioned is added with gentle stirring to a sample of this slurry at a rate of 280ppm. The effectiveness of each polyacrylaimide is assessed by how quickly water is removed, how much Water is removed and how quickly the remaining solid forms a stiff mass as a result of this dewatering.

Landscapes

• Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Paleontology (AREA)
• General Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Agronomy & Crop Science (AREA)
• Civil Engineering (AREA)
• Soil Sciences (AREA)
• Soil Conditioners And Soil-Stabilizing Materials (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Treatment Of Sludge (AREA)
• Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
• Glass Compositions (AREA)
• Iron Core Of Rotating Electric Machines (AREA)
• Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
• Separation Of Suspended Particles By Flocculating Agents (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=33427906

Family Applications (1)

Country Status (10)

Cited By (1)

Citations (2)

Family Cites Families (3)

• 2004
  • 2004-10-01 GB GBGB0421841.8A patent/GB0421841D0/en not_active Ceased
• 2005
  • 2005-08-24 CN CN2005800335061A patent/CN101035951B/zh not_active Expired - Fee Related
  • 2005-08-24 WO PCT/EP2005/009112 patent/WO2006037403A1/en active Application Filing
  • 2005-08-24 DE DE602005021386T patent/DE602005021386D1/de active Active
  • 2005-08-24 AU AU2005291642A patent/AU2005291642B2/en not_active Ceased
  • 2005-08-24 AT AT05776352T patent/ATE468439T1/de active
  • 2005-08-24 ES ES05776352T patent/ES2345990T3/es active Active
  • 2005-08-24 EP EP05776352A patent/EP1805374B1/en not_active Not-in-force
  • 2005-08-24 JP JP2007533888A patent/JP2008514411A/ja active Pending
• 2007
  • 2007-04-27 NO NO20072228A patent/NO20072228L/no not_active Application Discontinuation

Patent Citations (2)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events