METHOD OF LIFTING A STRUCTURE ON THE EARTH

Abstract

A method of lifting a structure includes extending a pipe so as to have one end opening to a lens in the earth, connecting a pump to the pipe, and pumping a grout material through the pipe and into the lens so as to cause a strata of the earth above the lens to heave upwardly and to cause the structure to move upwardly. The grout is solidified in the lens. The pipe is removed after the step of pumping. The grout is a low mobility cement grout. A location of the lens nearest to the structure is determined prior to the step of extending the pipe.

Claims

1. A method of lifting a structure, the method comprising: extending the pipe so as to have one end opening to a lens in the earth; connecting a pump to said pipe; and pumping a grout material through said pipe and into said lens so as to cause a strata of the earth above the lens to heave upwardly and to cause the structure to move upwardly.

2. The method of claim 1, further comprising: solidifying the grout material in the lens.

3. The method of claim 1, further comprising: removing said pipe after the step of pumping.

4. The method of claim 1, said grout material being a particulate grout or a solution grout.

5. The method of claim 1, said grout material being a low mobility cement grout.

6. The method of claim 1, further comprising: disconnecting a utility from the structure prior to the step of pumping.

7. The method of claim 1, further comprising: determining a location of the lens in the earth nearest to the structure.

8. The method of claim 7, the lens being a sand/silt lens having a clay formation overlying the lens and a clay or rock formation underlying the lens.

9. The method of claim 1, the step of pumping comprising: pumping the grout material at a pressure of between 50 and 150 p.s.i.

10. The method of claim 1, said pipe being a casing pipe or a drill stem.

11. The method of claim 1, the step of extending comprising: extending said pipe generally vertically through the earth to the lens.

12. The method of claim 1, the step of extending comprising: extending a plurality of pipes through the earth in spaced relation to each other, the step of pumping comprising pumping the grout material through said plurality of pipes to the lens.

13. A method of lifting a structure that resides on the surface of the earth, the method comprising: determining a location of a lens in the earth; extending a pipe through the earth so as to have a lower end opening to the lens; and pumping a grout material through said pipe and into the lens so as to cause a strata of the earth above the lens to heave upwardly so as to cause the structure to move upwardly.

14. The method of claim 13, further comprising: connecting a pump to the pipe so as to pump the grout material under pressure into the pipe.

15. The method of claim 13, further comprising: solidifying the grout material in the lens.

16. The method of claim 13, further comprising: removing said pipe after the step of pumping.

17. The method of claim 13, said grout material being a low mobility cement grout.

18. The method of claim 13, the lens being a sand/silt lens having a clay formation overlying the lens in a clay or rock formation underlying the lens.

19. The method of claim 13, the step of pumping comprising: pumping the grout material at a pressure of between 50 and 150 p.s.i.

20. The method of claim 13, the step of extending comprising: extending a plurality of pipes through the earth in spaced relation to each other, the step of pumping comprising pumping the grout material through said plurality of pipes to the lens.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0039] FIG. 1 is an illustration showing the process of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0040] Referring to FIG. 1, there is an illustration associated showing the method 10 of the present invention for lifting a structure 12 located on the surface 14 of the earth 16. In particular, the structure 12 can be a commercial building, a home, a facility, or other construction. Typically, the structure 12 will have a foundation 18 that is supported by the surface 14 of the earth 16. In particular, the surface 14 of the earth is likely to undergo subsidence or has encountered some subsidence.

[0041] The earth 16 includes a first strata 20, a lens or seam 22 and a second strata 24. In particular, the first strata 20 is a clay formation. This clay formation extends from the lens 22 to the surface 14. The clay formation formed in the first strata 20 overlies the lens 22. The second strata 24 is a clay or rock formation which underlies the lens 22. The strata formations shown in FIG. 1 would be typical of coastal regions.

[0042] Typically, the lens 22 is a seam in the earth located between the first strata 20 and the second strata 24. In particular, this lens 22 is a sand/silt lens which can contain groundwater therein. In normal use, as the groundwater is depleted by the communities located adjacent to this lens 22, the thickness of the lens 22 will be reduced so as to cause the first strata 22 subside. When this subsidence occurs, the foundation 18 and the structure 22 can be damaged, as was described hereinbefore. As such, in order to avoid this subsidence, it is important to enhance the integrity of the lens 22 and to maintain the thickness of such a lens.

[0043] In the method of the present invention, a pipe 26 is extended through the first strata 20 so as to have an end 28 opening to the lens 22. A suitable pump 30 can be connected to the pipe 26. The pump 30 will pump a grout material through the pipe 26 and into the lens 22 so as to cause the first strata 20 of the earth above the lens 22 to heave upwardly so as to cause the structure 12 to move upwardly.

[0044] The grout is a fluid form of concrete that is used to fill gaps. It is used in construction to embed rebars in masonry walls, connect sections of pre-cast concrete, fill voids, and sealed joints, such as though be those between tiles. Grout is generally a mixture of water, cement, sand and sometimes fine gravel. Unlike other structural pastes, such as plaster or joint compound, correctly-mixed and applied grout forms a waterproof seal. Grout is distinguishable from its close relative mortar by its viscosity. Grout is thin so that it flows readily into gaps, while mortar is thick enough to support not only its own way, but also that of the masonry placed on top of it.

[0045] Portland cement is the most common cementing agent in the grout, but urethane-and epoxy-based formulas are also popular. Portland cement-based grout come in different varieties depending on the particle size of the ground clinker used to make the compound, with a standard size of around 15, microfine at about 6-10, and ultrafine below 5. Finer particle sizes with the grout penetrate more deeply into a fissure.

[0046] In the present case, the grout material can be a particulate grout or a solution grout, such as polyurethane. In particular, the grout is a low mobility cement grout. As such, it will be generally contained within the area in which it is pumped.

[0047] The pipe 22 can be driven through the strata 20 of the earth so that the end 28 opens to the lens 22. In particular, the pipe 26 can be a casing pipe or a drill stem. If necessary, a hole can be first driven and the pipe inserted therethrough. In FIG. 1, the upper end 32 of the pipe 26 will be adjacent to the surface 14 of the earth. However, this is not critical to the function of the present invention. The upper end 32 can be below the surface 14 or can be above the surface 14. It is only important that the pump 30 be connected to the pipe 26 so that the grout can be delivered to the lens 22.

[0048] A supply of grout will be positioned on the surface 14. The pump 30 serves to transfer the grout from the supply into the pipe 26 and ultimately into the lens 22. The pump will deliver the grout at a pressure of between 50 and 150 p.s.i. However, the amount of pressure that is delivered will be dependent upon the weight of the structure 12. As such, if a very heavy structure 12 rests on the surface 14 of the earth, then it may be desirable deliver the grout with higher pressures. If the structure 12 is relatively small, such as a house, then a smaller amount of pressure will satisfy the requirements for the purposes of causing the strata 20 to heave. Also, the weight of the strata can also be important in determining the amount of pressure at which the grout is delivered into the lens 22.

[0049] Ultimately, when a desired amount of grout is delivered by the pipe 26 into the lens 22, the grout will solidify and cause the strata 12 to heave upwardly so as to cause the structure 12 to also move upwardly. The solidification of the grout will also create a permanent thickness of the lens 22 in the area of the structure 12. As such, this will to prevent any further subsidence caused by the depletion of groundwater from the lens 22. As such, this avoids the problem associated with piers, and other supporting structures, which do not maintain the structural integrity of the lens 22.

[0050] In order to properly lift the structure 12, it is first necessary to disconnect the various utilities from the structure 12. In particular, gas lines, water lines, and electrical lines are properly disconnected from the structure 12 prior to the step of pumping grout. As a result, any heaving of the strata 12 and the lifting of the structure 12 will not adversely affect the connections. After the structure 12 has been lifted by the process of the present invention, the utility lines can then be reconnected.

[0051] The location of the lens 22 should be that lens which is closest to the surface 14. Although it is possible to achieve the effect of the present invention by the delivery of grout to a lower lens, it is believed that the substantial benefits of the present invention are better achieved by introducing the grout into the lens closest to the surface 14 and closest to the structure 12. The location of the lens 22 can easily be determined by the drilling of a hole. As such, it is possible to establish the depth at which the end 28 should be moved through the strata 20 in order to allow the grout to be introduced into the lens 22. Seismic equipment can also be used so as to determine the location of the lens 22. Typically, in coastal areas, the sand/silt lens 22 will be approximately ten to twelve feet below the surface 14. However, in other circumstances, this lens may appear that a deeper location or a closer location.

[0052] To further cause the grout to maintain the structural integrity of the lens 22, a plurality of pipes 34, 36, 38 and 40 can also be used in spaced location so as to introduce the grout into the lens 22. Typically, the pipes 34, 36, 38 and 40 will be spaced by approximately twenty feet apart. As such, this creates injection points at various locations below the structure 12. The plurality of pipes 26, 34, 36, 38 and 40 further assures that the low mobility grout will only extend for a limited area. Also, the use of several pipes will further enhance the ability to cause heave in the first strata 20. The pumping of the grout will continue until the desired amount of heave is achieved. Each of the pipes 26, 34, 36, 38 and 40 extends generally vertically. However, it is possible within the concept of the present invention to actually use directional drilling in order to cause the grout to enter the lens 22.

[0053] After the desired amount of heave has been achieved in the first strata 20, the various pipes 26, 34, 36, 38 and 40 can then be removed and used in a different location. The grout will solidify so as to create a solid barrier between the strata 20 and strata 24 in order to maintain or enhance the thickness of the lens 22. The pump 30 can be sequentially used with the pipes 26, 34, 36, 38 and 40 in order to cause the grout material to flow through these pipes.

[0054] Since the present invention maintains the thickness of the lens 22, the amount of groundwater depletion will no longer adversely affect the structure 12. In other words, the grout will solidify so as to create a concrete barrier between the strata 20 and 24. If groundwater in locations away from the grouted-in the area occurs, it will not adversely affect the strata 20 nor result in further subsidence of the surface 14. Additionally, if there any piers or supports that underlie the structure 12, these piers or supports will heave with the heaving of the first strata 20 so as to continue to support the structure 12. As result, the present invention provides an effective technique for lifting the structure 12 to a desired elevation and to avoid the adverse effects of subsidence caused by the depletion of groundwater the reduction of the thickness of the lens 22.

[0055] It is contemplated that the method of the present invention can be utilized with seams other than the sand/silt lens. In certain circumstances, there are scenes are zones located between different strata of the earth. Even if the seam or zone does not contain the sand/silt lens, it can be utilized to receive the grout material for further avoiding subsidence.

[0056] The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.