Method and apparatus for building reinforced sea walls and levees

Abstract

A method and apparatus are disclosed for building a reinforced sea wall or levee. The reinforced structure is designed particularly for use in areas of soft sub-soil such as those sub-soils found near the Gulf of Mexico which are capable of bearing loads of less than 5 pounds per square inch of weight. The structure includes first and second rows of soil-cement columns formed on opposite sides of the centerline of the structure. Soil-cement columns are formed by mechanically cutting the soft sub-soil and simultaneously hydraulically mixing the cut soft soil with a cement slurry injected at velocities of 200 feet per second or more. Reinforcing structural elements, preferably H-beams, are embedded in at least some of the soil-cement columns in each of the two rows. Tensile load bearing members, such as cables or beams, are interconnected between some of the reinforcing structural elements in the first row of soil-cement columns with some of the structural elements in the second row of soil-cement columns. Lagging walls are installed between upstanding H-beams. Fill materials, such as sand, silt or sediment, are then deposited between the two rows of soil-cement columns. Optionally, a third row of soil-cement columns is placed between the first and second rows and longitudinal beams are placed at ground level, extending between the outer rows of soil-cement columns and being placed on top of the center row of columns. An optional semi-permeable mat is placed on top of these beams to bear the weight of the sandy fill material and to transfer that weight to the three rows of soil-cement columns.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a first embodiment of the novel sea wall or levee;

FIG. 2 is a section on the line 2-2 of FIG. 1;

FIG. 3 is a plan view of a second embodiment of the sea wall or levee according to the present invention;

FIG. 4 is a section on the line 4-4 of FIG. 3; and

FIG. 5 is a plan view, partially in section, illustrating a portion of a third embodiment of the invention.

Claims

1. A method of building a sea wall or levee, wherein said completed sea wall or levee will have a longitudinal center line, and wherein said sea wall or levee is to be built on soft subsoil, comprising the steps: forming first and second rows of soil-cement columns on opposite sides of said longitudinal centerline, wherein said soil-cement columns are formed by mechanically cutting said soft subsoil and simultaneously hydraulically mixing said mechanically cut soft subsoil with a cement slurry injected through a first nozzle at velocities of 200 feet per second or higher,embedding reinforcing structural elements into at least some of said soil-cement columns in said first and second rows,connecting at least some of said reinforcing structural elements in said first row of soil-cement columns with some of said reinforcing structural elements in said second row of soil-cement columns with tensile load bearing members, anddepositing fill materials between said first and second rows of soil-cement columns, wherein said fill materials include sand, silt and/or sediment.

2. The method of claim 1 wherein said soft subsoil is capable of bearing less than 5 pounds per square inch of weight, and wherein said soil-cement columns include 15-30% by volume of cement and are capable of bearing approximately 100 pounds per square inch or more of weight.

3. The method of claim 1 wherein each of said first and second rows of soil-cement columns forms a curtain wall of interconnected columns.

4. The method of claim 1 comprising the further step of forming an additional row of soil-cement columns, wherein said each column in said additional row is placed in an interstitial space between columns of either said first or second row of columns.

5. The method of claim 1 comprising the further step of forming a third row of soil cement columns extending along, or parallel to, said centerline.

6. The method of claim 5 comprising the further step of placing a semi-permeable mat over said tensile load bearing members.

7. A reinforced sea wall or levee, comprising: a main body having a longitudinal centerline,first and second rows of soil-cement columns formed on opposite sides of said longitudinal centerline,reinforcing structural members embedded in at least some of said first and second rows of soil-cement columns,tensile connecting means connecting at least some of said reinforcing structural members in said first row of soil-cement columns with some of said reinforcing structural members in said second row of soil-cement columns, andfill materials between said first and second rows of soil-cement columns, wherein said fill materials include sand, silt and/or sediment.

8. The sea wall or levee of claim 7, wherein said sea wall or levee is built on subsoil capable of bearing less than 5 pounds per square inch of weight, wherein said soil-cement columns include 15-30% by volume of cement, and are capable of bearing approximately 100 pounds per square inch or more of weight.

9. The sea wall or levee of claim 7 wherein each of said first and second rows of soil-cement columns forms a curtain wall of interconnected columns.

10. The sea wall or levee of claim 7 further comprising an additional row of soil-cement columns wherein each soil-cement column in said additional row is placed in an interstitial space between columns of either first or second row of columns.

11. The sea wall or levee of claim 7 further comprising a third row of soil-cement columns formed along, or parallel to, said longitudinal centerline.

12. The sea wall or levee of claim 11 further comprising a semi-permeable mat placed on top of said tensile connecting means.