Method for consolidating soil

Patent metadata

Field	Value
Publication number	US-9328473-B2
Application number	US-201314372663-A
Country	US
Kind code	B2
Filing date	Jan 15, 2013
Priority date	Jan 16, 2012
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

The invention relates to a method for consolidating soil by means of calcifying bacteria, said method comprising washing the consolidated soil and recycling the wash water.

First claim

The invention claimed is:

1. A method for consolidating soil in situ comprising the following steps:
a) injecting a solution of calcifying bacteria, prepared from bacteria in powder form, into the volume of soil to be treated;
b) injecting a calcifying solution;
c) washing the volume of soil treated with water;
d) measuring the ammonium ion concentration in the wash water and in the treated soil;
e) recycling the wash water to the process.

2. The method as claimed in claim 1 , which further comprises monitoring the progress of calcification of the bacteria and, if necessary, repetition of step b) with an identical or different calcifying solution.

3. The method as claimed in claim 2 , wherein step b) is repeated using the same calcifying solution.

4. The method as claimed in claim 1 , wherein the ammonium ion concentration measured in step d) is greater than or equal to 20 g/l, and step e) comprises:
e1) treating the wash water to obtain water whose ammonium ion concentration is below 1 g/l; and
e2) conveying the water thus obtained to a water storage unit.

5. The method as claimed in claim 1 , wherein the ammonium ion concentration measured in step d) is below 20 g/l, and step e) comprises: conveying the wash water to a water storage unit.

6. The method as claimed in claim 1 , wherein step c) is repeated until an ammonium ion concentration in the wash water below 100 mg/l is obtained.

7. A method for in situ consolidation of several plots of soil that comprises carrying out the method defined in claim 1 for each of said plots.

8. The method as claimed in claim 7 , wherein the wash water from one of the plots, whose ammonium ion concentration is in the range from 5 to 50 g/l, is used for preparing the solution of calcifying bacteria required for treating one or more other plots.

9. The method as claimed in claim 8 , wherein the wash water from one of the plots, whose ammonium ion concentration is in the range from 20 g/l to 30 g/l, is used for preparing the solution of calcifying bacteria required for treating one or more other plots.

10. The method as claimed in claim 7 , wherein the wash water from one of the plots, whose ammonium ion concentration is in the range from 1 g/l to <20 g/l, is used for preparing the solution of calcifying bacteria and/or the calcifying solution(s) required for treating one or more other plots.

11. The method as claimed in claim 7 , wherein the wash water from one of the plots, whose ammonium ion concentration is below 1 g/l, is used for washing one or more other plots.

Assignees

• Solentanche Freyssinet
• Soletanche Freyssinet

Inventors

• Esnault Annette
• Mosser Jean-Francois
• Borel Serge

Classifications

• E02D3/12 Primary

  Consolidating by placing solidifying or pore-filling substances in the soil (making piles E02D5/46; soil-conditioning or soil-stabilising materials C09K17/00; consolidation of ground around boreholes or wells E21B43/025) · CPC title

• C09K17/00

  Soil-conditioning materials or soil-stabilising materials (specially adapted for boreholes or wells C09K8/00; fertilisers C05; consolidating by placing solidifying or pore-filling substances in the soil E02D3/12) · CPC title

• C09K17/42

  Inorganic compounds mixed with organic active ingredients, e.g. accelerators · CPC title