CROSS-REFERENCE TO RELATED APPLICATIONThis application is a continuation-in-part of U.S. Nonprovisional Patent Application No. 11/966,413, filed Dec. 28, 2007, and incorporates the disclosure of such application by reference.
BACKGROUND OF INVENTIONPortions of the ground exhibit fluid characteristics. As a consequence, it is generally necessary to provide a solid surface, such as a slab, before construction of a building. While a slab may provide a more stable substructure than bare ground, the fluid properties of the ground may reduce the utility of the foundation and/or slab. Fluctuations in soil conditions, such as heaving and settling, may move the foundation, slab, and/or superstructure. Fluctuations may also cause structural stresses within and damage to the foundation, slab, and/or superstructure.
Prior art attempts to reduce or eliminate the adverse consequences of ground fluctuations beneath a foundation and/or slab have seen limited success. Many prior art attempts have been limited to removing or adding soil and/or structural supports only proximate the edges of a foundation. Where structural stress has been present in areas not proximate the edges of a foundation, prior art solutions have involved removing and rebuilding large portions of a building or foundation. Other prior art attempts have focused on pumping chemicals into the ground to modify the expansion properties of the ground, or placing heavy weights on the foundation and/or slab. These prior art solutions have had limited success and have been costly, and have sometimes resulted in further foundational cracks or damage.
SUMMARY OF THE INVENTIONMethod and apparatus for supporting a foundation and/or slab on a surface material according to various aspects of the present invention operate in conjunction with coupling a vertical support to the foundation and removing a portion of the surface material from below the foundation to form a void. A supplemental support is placed in the void between the surface material and the foundation. The vertical support is removed from the foundation.
BRIEF DESCRIPTION OF THE DRAWING FIGURESA more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the following illustrative figures. In the following figures, like reference numbers refer to similar elements and steps throughout the figures.
FIG. 1 is a cross-sectional view of a foundation on soil.
FIG. 2 is a top view of one embodiment for realigning a foundation on soil having heterogeneous soil pressures.
FIG. 3 is a flow diagram representing a process for adjusting an existing foundation.
FIG. 4 is a cross-sectional view of a foundation on soil with a vertical support.
FIG. 5 is a cross-sectional view of a foundation on soil with a hole formed in the foundation.
FIG. 6 a top view of one embodiment for finishing a realigned foundation.
FIG. 7 is a cross-sectional view of a foundation on soil with supplemental supports.
FIG. 8 is a cross-sectional view of a foundation on soil with a patched hole over the supplemental supports.
Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be performed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTSThe present invention may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of hardware or software components configured to perform the specified functions and achieve the various results. For example, the present invention may employ various tools, apparatus, and systems for formation and repair of foundations, e.g., machinery, jacks, supports, measurement devices, manometers, helical piers, bar joists, slabs, blocks, grout, drilling and/or sawing equipment, filler materials, cement, reinforcing materials, patching materials, weights, and the like, which may carry out a variety of functions. The present invention may also employ various processing steps and design considerations. In addition, the present invention may be practiced in conjunction with any number of construction applications and with any other foundation formation or repair method or apparatus, and the system described is merely one exemplary application for the invention. Further, the present invention may employ any number of conventional techniques for construction technologies, such as raising a foundation, removing a portion of the foundation, excavating soil, putting supports in place, backfilling soil and/or other filler materials, patching removed portions of the foundation, reinforcing the foundation, lowering the foundation, applying temporary or permanent weight to the foundation, and the like.
Various representative implementations of the present invention may be applied to any system for installation, repair, and/or adjustment of foundations. Certain representative implementations may include, for example, preparing and installing a foundation before or during new home or building construction, adjusting a foundation before or during new home or building construction, repairing or adjusting an existing or old foundation after home or building construction, etc.
Referring now toFIG. 1, afoundation100 may comprise aslab102 positioned abovesoil103. Thesoil103 may exhibit heterogeneous conditions, such asdifferent soil103 pressures. For example, referring toFIG. 2, manometer readings representing different soil pressures may be mapped using isometric lines for an area under theslab102. Different soil pressures may tend to move or deform theslab102 due tosoil103 movement below theslab102. Such movement can cause external and internal cracks in a building.
To reduce the effects ofsoil103 movement on theslab102, theslab102 may be installed or adjusted by excavatingsoil103 below theslab102 and adjusting theslab102 to a desired position. Supplemental supports may then be installed below the raisedslab102. To facilitate the removal ofsoil103 and/or insertion of the supplemental supports, theslab102 may be coupled to one or more vertical supports to support and/or adjust the position of theslab102. The adjustedslab102 may be positioned onto the supplemental supports to achieve a substantiallyflat foundation100. The vertical supports may be removed and theslab102 may rest upon the supplemental supports. Any void below the adjustedslab102 may be at least partially filled with an insulating material, such as a waterproofing agent and/or foam, to reduce the likelihood of damage to thefoundation100 as a consequence of the void. Additionally, aprotective wall108 may be installed around the perimeter of theslab102 to prevent material from accumulating below theslab102.
Theslab102 may comprise a base for a building or other structure formed of any appropriate materials, such as post-tension concrete, poured concrete, cellulose, and/or rebar. Theslab102 may be configured according to various design considerations, including the properties of the intended superstructure, the properties of thesoil103, and/or the like. In the present embodiment, theslab102 comprises a slab for a building. Reduced utility in theslab102 due to changingsoil103 conditions may take the form of cracks in theslab102, cracks in the superstructure connected to theslab102, misalignment of theslab102 and/or superstructure, or other structural issues.
Theslab102 may be adjusted according to various aspects of the present invention, such as by identifyingsoil103 to be excavated, excavating therelevant soil103, installing one or more vertical supports, coupling theslab102 to one or more vertical supports, adjusting the elevation and/or the tilt of theslab102, and/or the like. Referring toFIG. 3, in one embodiment, the vertical supports are installed (302) andsoil103 to be excavated is accessed (304). A selected portion ofsoil103 is excavated (306) and theslab102 is adjusted to a desired position (308). At least one supplemental support may be installed between theslab102 and the ground below theslab102. Theslab102 is secured to or rested upon the supplemental support206 (310) and any finishing operations are performed (312).
Thesoil103 below and/or around theslab102 may be evaluated for stability according to various methods and techniques. For example, thesoil103 may be analyzed prior to construction. Analysis that was done prior to construction may apply to thepresent soil103 conditions, as in the case of substantially stable soils. Analysis done prior to construction, however, may no longer apply topresent soil103 conditions, as in the case of substantially unstable soils. Accordingly, equipment such as soil borings, manometers, ultrasound equipment, subterranean imaging systems, and/or the tike may be employed to determinepresent soil103 conditions. For example, in the case of a manometer, thesoil103 may be tested to determine areas of high and low pressure below thesoil103. Based on the test results, the source of damage or potential damage to thefoundation100 may be determined and excavation may proceed accordingly.
Theslab102 may be stabilized to permit the excavation. Theslab102 may be stabilized in any appropriate manner to inhibit unwanted movement. For example, referring toFIGS. 1 and 4,vertical supports106 may be installed around portions or all of the perimeter of theslab102. Thevertical supports106 may be selected and installed using any appropriate criteria and/or techniques. In the present embodiment, thevertical supports106 may at least partially support theslab102 above thesoil103. Thevertical supports106 may comprise various materials, embodiments, and geometries, such as helical piers or hydraulic piers. Thevertical supports106 may be driven into the ground to a depth at which thesoil103 fluctuations are limited. For example, ahelical pier510 may be installed via rotation of thehelical pier510 according to an inclined plane portion of thehelical pier510. As another example, a post may be installed with an axial force as by a hammer. As yet another example, avertical support106 may be formed within the ground as in the case of a concrete and rebar pillar.
Thevertical supports106 may be coupled to theslab102 to accommodate adjustment of theslab102 relative to the substantially fixed portion of the vertical supports106. Referring again toFIG. 2, in situations where theslab102 is disposed proximate toother slabs102,114,116, thevertical supports106 may be installed through and/or around theother portions102,114,116 of theslab102. In addition, theslab102 may be removably or permanently fixed to the vertical supports106. In one embodiment a hole, is drilled in theslab102 and a stem is doweled to theslab102 through the hole such that the stem facilitates support and movement of theslab102 by thevertical support106. In one such embodiment, the dowel comprises steel rebar from ⅛ inch to 3 inches in diameter, such as ½ inch to 1 inch in diameter.
Thevertical supports106 may be installed at any appropriate time, such as before or after excavation. For example, thevertical supports106 may be installed and attached to theslab102 before excavation to support theslab102 assoil103 is removed from below theslab102. Alternatively, thevertical supports106 may be installed and attached to theslab102 during or after excavation to adjust and/or maintain the position of theslab102.
Thesoil103 to be excavated may be accessed to facilitate removal or adjustment of thesoil103. Access may be gained using various methods and/or techniques, including removing asection104 of theslab102 and/or excavating around the perimeter of theslab102 to access thesoil103 below theslab102. Removal of asection104 may be desirable in scenarios in which the perimeter of theslab102 is not available for excavation, as in the case of row houses. Alternatively, excavation around the perimeter of theslab102 may be desirable in scenarios in which theslab102 is not available for removal of asection104, as in the case of an exceedingly brittle and/or exceedinglythick slab102, or other situations in which removing a section may be impractical.
Asection104 may be removed using various methods and/or techniques. For example, referring toFIG. 5, asection104 of theslab102 may be removed using equipment to drill and/or cut concrete orother slab102 material. Alternatively, for aslab102 comprised of a different material, such as wood, a corresponding set of equipment may be employed. In one embodiment, theslab102 comprises concrete and a saw is employed to cut and remove thesection104.
The removedsection104 may be configured according to any appropriate criteria, such as the area available in which to work without removing interior walls, proximity to other structures such as plumbing and electrical systems, and the thickness of theslab102. For example, if the section ofsoil103 to be removed112 has been determined prior to removal of thesection104, thesection104 may have dimensions according to the section ofsoil103 to be removed112. As another example, if materials to patch the section have specified dimensions, thesection104 may have dimensions according to the specified dimensions. In one embodiment, the removedsection104 has dimensions of 5 feet by 5 feet, while in another embodiment the removed section has dimensions of 3 feet by 3 feet. The removedsection104 could be any other size or shape, however, according to the particular situation.
Thesoil103 may be excavated to remove and/or adjust thesoil103. Thesoil103 may be excavated in any appropriate manner, such as using high power compressor nozzles, potholing, and/or vacuum excavation.Soil103 may be removed from any suitable area, such as via the perimeter of theslab102 and/or through the removedsection104. The area ofexcavation112 may extend directly below the removedsection104 and/or laterally110 around the removedsection104 below theslab102.Multiple sections104 may be removed andsoil103 may also be excavated from multiple areas.
In the present embodiment, thesoil103 may be excavated through the removedsections104 using a nondestructive removal process, such as water or air vacuum excavation. For example, high pressure air or water may be directed to thesoil103 to break up thesoil103. A powerful vacuum removes the loosenedsoil103 and transports through the removedsection103 to a remote area, such as a holding tank, where the removedsoil103 may be stored for backfill or hauled away for disposal. The excavation system may also create small holes dig “slot trenches” to identify obstructions, such as existing utilities, and work around the obstructions without removing or damaging them.
Theslab102 may be adjusted to a desired position. For example, ifexpansive soil103 has moved theslab102, theslab102 may be returned to its original position following excavation of theexpansive soil103. Any appropriate techniques may be applied to move theslab102 into the desired position. In one embodiment, thevertical supports106 attached to theslab102 may be adjusted to raise or lower various portions of theslab102. In addition, mass may be placed on theslab102 to force theslab102 downward, such as sandbags or concrete blocks.
In the present embodiment, one or more of thevertical supports106 comprises anadjustable support204 disposed between theslab102 and thesoil103, such as a temporary adjustment jack to be removed at some point after thesupplemental support206 is put in place. Theadjustable support204 may support theslab102 above thesoil103 and to facilitate movement of theslab102 relative to thesoil103. Theadjustable support204 may be used to locally adjust the position of theslab102, such as to raise or lower theslab102 or to facilitate placement of asupplemental support206. For example, theadjustable supports206 may be adjusted to raise theslab102 to facilitate placement of supplemental supports under theslab102 or to move theslab102 to a particular position. Theadjustable supports206 may also be adjusted to lower theslab102 to a desired position and/or to rest theslab102 on supplemental supports placed beneath theslab102.
At least onesupplemental support206 may be disposed between thestab102 and thesoil103, such as to support theslab102 above thesoil103. Thesupplemental support206 may comprise a structure, such as a preformed cement block, disposed between thesoil103 and theslab102. Thesupplemental support206 may be adapted and positioned to support, theslab102 in position and/or reduce stresses within thestab102 due to the weight of theslab102. Thesupplemental support206 may be driven into place through thesoil103 below theslab102, placed directly below theslab102 through a removedsection104 or via the perimeter of thestab102, formed from a malleable material within the void, and/or the like.
In the present embodiment, thesupplemental support206 comprises a standard 8×8×16 concrete masonry unit (CMU). Referring toFIGS. 6 and 7, thesupplemental support206 may be placed in the void formed by the excavation of thesoil103, for example via the removedsection104. Thesupplemental support206 rests on thesoil103 remaining below theslab102, and is positioned below theslab102 so that when theslab102 is lowered, theslab102 rests upon thesupplemental support206. Thus, thesupplemental support206 is adapted to support theslab102 when theunstable soil103 has been removed and adjustment of theslab102 position is complete. Upon placement of thesupplemental supports206, thevertical supports106 may be removed to allow theslab102 to rest on the supplemental supports206.
Voids between thesoil103 and theslab102 may be filled, for example to inhibit moisture, provide insulation, or deter animals. For example, referring toFIG. 8, filler material810, such as polyurethane foam, may be placed below theslab102 in the void around thesupplemental support206. The filler material810 may be adapted to distribute the mass of theslab102 and superstructure as well. In various embodiments, the tiller material810 may be compressible, such as a low density polyurethane foam, which allows the filler material810 to at least partially absorbfuture soil103 movement without transferring the movement to theslab102. Any appropriate filler material810 may be selected for example according to the particular environment or application. In one embodiment, the tiller material Bit) comprises a higher modulus compressible foam. In another embodiment, the filler material810 comprises polyurethane foam balls, in yet another embodiment, the filler material810 comprises a balloon or bladder containing a compressible foam, such as a polyurethane foam.
In addition, thefoundation100 may also include other protection against potentially damaging agents, such as water, frost, flora, and/or fauna. For example, aprotective wall108 may be installed at least partially along the perimeter of the adjustedslab102, such as by digging a trench along and/or around the perimeter of theslab102, at least partially lining the trench with a waterproofing material such as plastic, and at least partially filling the trench as with fluid cement,soil103, and/or concrete blocks. In one embodiment, theprotective wall108 comprises a 5-foot deep trench lined with 30 mil plastic and backfilled with cement. The dimensions, geometry, and materials comprising aprotective wall108 may relate to the likely properties of the potentially damaging agents.
Any removedsection104 may he patched (312) to return the integrity of theslab102, such as for structural and/or aesthetic purposes. Theslab102 may be patched in any appropriate manner, such as usingconventional slab102 repair materials and techniques. For example, within the removedsection104, acoupling material208 may be employed to couple theslab102 to at least one piece of patchingmaterial212. Thecoupling material208 may comprise a fibrous material, such as carbon fiber laminate. The patchingmaterial212 may comprise pre-formed cement tile like that sold under the trade name WonderBoard. The patchingmaterial212 may be reinforced using various reinforcingmembers210, such as rebar. Above the patchingmaterial212, a smoothing layer of material, such as grout and/or cement, may be poured to provide a substantially smooth horizontal surface to thefinished slab102.
For example, referring again toFIG. 6, theslab removal area200 may comprise aperimeter202 defining the removedsection104. Theperimeter202 may be modified to accommodate a preformed material, such as concrete sheet material. Alternatively, a preformed material may be modified to fit within theperimeter202 of the removedsection104. A preformed material may be doweled to theslab102 and/or otherwise attached. In addition to patching the removedsection104, finishing operations for the adjusted and/or patchedslab102 may include patching cracks in theslab102 and/or the superstructure. Any appropriate techniques and materials may be used during finishing, such as for stitching, laminating, grouting, and/or the like. In one embodiment the patchingmaterial212 comprises carbon fiber laminate stitch (which is sanded rough on one end) engaging theslab102, ½-inch WonderBoard, and #4 rebar.
To the extent that thesoil103 conditions impair the utility of thefoundation100, the present methods and apparatus may be employed to improve the utility of thefoundation100. Potential and/or actual structural problems due to heaving of thefoundation100 may be mitigated without the need to remove the superstructure. Additionally, afoundation100 may be adjusted to a desired elevation.
The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of the present invention in any way. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and/or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in a practical system.
In the foregoing description, the invention has been described with reference to specific exemplary embodiments; however, it will be appreciated that various modifications and changes may be made without departing from the scope of the present invention as set forth herein. The description and figures are to be regarded in an illustrative manner, rather than a restrictive one and all such modifications are intended to be included within the scope of the present invention. Accordingly, the scope of the invention should be determined by the generic embodiments described herein and their legal equivalents rather than by merely the specific examples described above, for example, the steps recited in any method or process embodiment may be executed in any order and are not limited to the explicit order presented in the specific examples. Additionally, the components and/or elements recited in any apparatus embodiment may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same result as the present invention and are accordingly not limited to the specific configuration recited in the specific examples.
Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problems or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components.
As used herein, the terms “comprises”, “comprising”, or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present invention, in addition to those not specifically recited, may be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same.
The present invention has been described above with reference to a preferred embodiment. However, changes and modifications may be made to the preferred embodiment without departing from the scope of the present invention. These and other changes or modifications are intended to be included within the scope of the present invention, as expressed in the following claims.