STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND
The present disclosure relates generally to assemblies and methods for foundation underpinning. More particularly, the present disclosure relates to pier or piling assemblies and methods for installing same to support and/or level pre-existing building foundations or new construction building foundations.
Several systems and methods have been developed and used for lifting, leveling and stabilizing above-ground structures such as buildings, slabs, walls, columns, etc. One conventional technique employs a stack or pile of pre-cast concrete, cylindrical pile segments that are positioned underneath and support the structure to be stabilized and leveled. Typically, a hole is dug underneath the structure to a depth slightly greater than the height of a pile segment, then multiple pile segments are driven into the ground one on top of the other with a hydraulic ram positioned between the pile segments and the structure. The driven pile segments form a vertical stack or pile of the pre-cast pile segments, which may also be referred to as a pier. The pile segments are usually driven into the ground until a subsurface structure (e.g., rock strata) prevents further downward advancement of the pile and/or the resulting pile is believed to be sufficiently deep to support the structure. For instance, in situations where a subsurface structure preventing further downward advancement of the pile cannot be reached, the pile segments are typically driven to a depth great enough to cause sufficient friction between the earth and the outer surfaces of the pile segments to prevent substantial vertical movement of the pile. Next, a jack is positioned on the upper end of the pile, between the uppermost pile segment and the structure, and the structure is raised to the desired height with the jack.
BRIEF SUMMARY
Embodiments of pier assemblies for supporting structures are disclosed herein. In an embodiment, a pier assembly for supporting a structure has a vertically oriented central axis and comprises a plurality of horizontally spaced apart elongate members disposed in the ground and arranged about the central axis of the pier assembly. Each elongate member directly contacts the ground. Each elongate member has a length-to-width ratio greater than 10.0.
Embodiments of pier assemblies for resisting lateral movements of structures are disclosed herein. In an embodiment, a pier assembly for resisting lateral movement of a structure comprises a plurality of horizontally spaced elongate members positioned laterally adjacent to the structure. Each elongate member extends downward from the structure into the ground and each elongate member directly contacts the ground. An upper end of each elongate member is fixably coupled to an outer periphery of the structure. Each elongate member has a length-to-width ratio greater than 10.0.
Embodiments of methods for installing piers coupled to structures are disclosed herein. In an embodiment, a method for installing a pier coupled to a structure comprises (a) bending a first elongate member having a lower end inserted into the ground and an upper end coupled to a driver. In addition, the method comprises (b) actuating the driver to advance the lower end into and through the ground during (a). Further, the method comprises (c) bending a second elongate member having a lower end inserted into the ground and an upper end coupled to the driver after (b). Still further, the method comprises (d) actuating the driver to advance the lower end of the second elongate member into and through the ground during (c). Each elongate member has a length-to-width ratio greater than 10.0.
Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
For a detailed description of various exemplary embodiments, reference will now be made to the accompanying drawings in which:
FIG. 1 is a schematic side view of embodiments of pier assemblies for supporting and/or stabilizing a structure in accordance with principles described herein;
FIG. 2 is an enlarged, partial cross-sectional side view of one of the pier assemblies of FIG. 1;
FIG. 3 is a flowchart illustrating an embodiment of a method for installing the pier assembly of FIG. 2 in accordance with principles described herein;
FIG. 4 is a schematic side view illustrating a process for driving the elongate members of FIG. 1;
FIG. 5 is an enlarged, partial cross-sectional side view of another pier assembly of FIG. 1;
FIG. 6 is a flowchart illustrating an embodiment of a method for installing the pier assembly of FIG. 5 in accordance with principles described herein;
FIG. 7 is an enlarged, partial cross-sectional side view of another pier assembly of FIG. 1;
FIG. 8 is a flowchart illustrating an embodiment of a method for installing the pier assembly of FIG. 7 in accordance with principles described herein; and
FIG. 9 is a schematic side view of an embodiment of a pier assembly in accordance with the principles described herein.
DETAILED DESCRIPTION
The following discussion is directed to various exemplary embodiments. However, one of ordinary skill in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.
The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the given axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. As used herein, the terms “approximately,” “about,” “substantially,” and the like mean within 10% (i.e., plus or minus 10%) of the recited value. Thus, for example, a recited angle of “about 80 degrees” refers to an angle ranging from 72 degrees to 88 degrees.
As previously described, some conventional methods for installing piles and piers use pre-cast concrete cylindrical pile segments that are pressed into the soil using a hydraulic ram positioned between the pre-existing structure to be supported and the upper most pile segment. The ram bears against the pre-existing structure to push the pile segments into the ground. After each pile segment is pressed into the soil, the hydraulic ram is released, another pile segment is placed on top of the previous pile segment, and the hydraulic ram is again pressurized to further drive the vertical stack of pile segments into the soil. Ideally, this procedure is repeated to form a pier or pile that extends to a depth sufficient to support the structure, however this is not always possible and a shorter and less supportive pier may result. For example, localized dense rock or soil strata may resist further driving via the hydraulic ram, yet the pier may still not be adequately supportive if it does not extend to a static zone where minimal soil movement occurs. In addition, such conventional methods require a pre-existing structure for the hydraulic ram to push against, and thus, typically cannot be used with new construction (i.e., cannot be installed prior to the construction of the structure itself). Still further, such conventional methods are limited by the weight of the pre-existing structure, as the maximum pushing force of the hydraulic ram is limited to the weight of the pre-existing structure as a force in excess of the weight of the pre-existing structure will simply raise the structure upward without advancing the depth of the stack of pile segments. Stated differently, the driving depth of the stack of pile segments is directly related to the weight of the pre-existing structure. Therefore, in some applications, relatively light weight structures may not allow for the installation of piers to sufficient depths. It should also be appreciated that pushing with a sufficient force against the pre-existing structure may damage the pre-existing structure. For example, if the force applied by a hydraulic ram is sufficiently large to lift a portion of the pre-existing structure while other portions remain substantially stationary, undesirable flexing of the pre-existing structure may occur. Accordingly, embodiments of pier assemblies and methods disclosed herein enable pier depths that are independent of the structure to be supported or leveled (e.g., independent of the weight of a pre-existing structure), and further, can be used with pre-existing structures or in new construction applications (i.e., prior to the structure being built). In addition, embodiments of pier assemblies and methods disclosed herein can be employed without exerting substantial loads on pre-exiting structures as compared to conventional methods, and thus, may be used to preserve the mechanical integrity of pre-existing structures.
Referring now to FIG. 1, embodiments of support or pier assemblies 100, 200, 300 for underpinning and supporting a pre-existing structure 2 are shown. In FIG. 1, pre-existing structure 2 is a building (e.g., a house) having a foundation that generally supports structure 2 above the ground 4. In this embodiment, the foundation comprises a plurality of laterally spaced supports 6, however, in other embodiments, the foundation may be a poured, concrete slab.
In FIG. 1, the subsurface below ground 4 is shown as including a dynamic zone 8 including a dense strata 12, and a static zone 14 below dynamic zone 8. Dynamic zone 8 represents soil and rock layers that translate or move over time, for example, heave, expand, settle, contract, or combinations thereof. Such movement may occur in response to moisture changes, freeze-thaw cycles, or other geological subsurface activity. The soil composition within dynamic zone 8 may contribute to the magnitude of movement within dynamic zone 8. For example, clay soils are particularly susceptible to volumetric swelling and contraction in response to excessive moisture or a sufficient reduction in moisture, respectively, while sandy soils are particularly susceptible to settling. Independent of the specific cause of the soil motion, dynamic zone 8 generally provides insufficient support for structure 2 as supports 6 may translate together with dynamic zone 6. Dense strata 12 represents a localized region within dynamic zone 8 that has a higher density and/or hardness than the soil in the remainder of dynamic zone 8. In FIG. 1, dense strata 12 is depicted as a discrete single horizontal layer (e.g., such as a hardpan layer), however, dense strata 12 may comprise a plurality of layers that are distributed throughout dynamic zone 8 (e.g., discrete rocks, aggregate, a plurality of dense layers, etc.). As will be described in more detail below, dense strata 12 may provide increased resistance to installation of pier assemblies 100, 200, 300 due to the increased localized density, but may still experience movement within dynamic zone 8 or in response to the movement of dynamic zone 8. Consequently, dense strata 12 may also provide insufficient support for pier assemblies 100, 200, 300 and structure 2. Static zone 14 represents soil and rock layers that exhibit little to no movement over time, and thus, provide a more stable base to support pier assemblies 100, 200, 300 and structure 2.
In general, pier assemblies 100, 200, 300 may be used individually or in combination to support structure 2. For explanatory purposes, three different pier assemblies 100, 200, 300 are shown in FIG. 1, however, the same or different types of pier assemblies 100, 200, 300 can be used to support a given structure (e.g., structure 2). Although each pier assembly 100, 200, 300 will be described in more detail below, it should be appreciated that in embodiments described herein, each pier assembly 100, 200, 300 includes a plurality of laterally and horizontally spaced elongate members or rods 130 that extend from a hole 20 excavated beside or below a corresponding support 6 to static zone 14. Each elongate member 130 has a central or longitudinal axis 119, a first or lower end 130a disposed in static zone 14, and a second or upper end 130b at hole 20. It should be appreciated that elongate members 130 of embodiments of pier assemblies 100, 200, 300 described herein are not encased in concrete or used to reinforce concrete. Indeed, no portion of any of the elongate members 130 disposed in the ground is encased or surrounded by concrete. Rather, as will be descried in more detail below, each elongate member 130 is independently and separately driven into the ground and directly contacts and is surrounded by the natural subsurface materials (e.g., soil, gravel, rocks, clay, etc.) in the ground 4. In other words, in embodiments described herein, no intermediate device or structure is disposed between each elongate member 130 and the surrounding ground 4.
As used herein, the term “elongate” is used to refer to an object that has a length that is substantially greater than its width. In general, the ratio of the length of an object measured parallel to its longitudinal axis to its maximum width or diameter (for objects having a circular cross-section) measured perpendicular to its longitudinal axis, also referred to herein as a “length-to-width ratio,” can be used to quantify and characterize the degree to which the object is “elongate.” For most applications, embodiments of elongate members 130 described herein have a length of at least 10 feet, alternatively at least 20 feet, alternatively at least 40 feet, or alternatively at least 60 feet; and a maximum width or diameter less than or equal to 2.0 inches, alternatively less than or equal to 1.25 inches, alternatively less than or equal to 1.0 inches, alternatively less than or equal to 0.75 inches, alternatively less than or equal to 0.625 inches, alternatively less than or equal to 0.5 inches, alternatively less than or equal to 0.375 inches, or alternatively less than or equal to 0.25 inches. Accordingly, for most applications, embodiments of elongate members 130 described herein have a length-to-width ratio of at least 10.0, at least 20.0, at least 100.0, at least 160.0, at least 190.0, or at least 240.0. In general, the smaller the maximum width or diameter of an elongate member 130, the easier it is to advance the elongate member 130 to a greater depth D. It should be appreciated that the maximum width or diameter of each elongate member 130 and the length-to-width ratio of each elongate member 130 may be varied and adjusted depending on a variety of factors including, without limitation, the particular application, the condition of the soil, the weight of the structure to be supported, the type of structure to be supported, the desired depth to be advanced into the soil, or combinations thereof. As will be described in more detail below, elongate members 130 are made of relatively rigid metal such as steel, however, due to the relatively large length-to-width ratios, elongate members 130 can elastically flex during installation. In this embodiment, each elongate member 130 is an elongate, solid metal rod having a solid, continuous cross-sectional taken in any plane oriented perpendicular to its longitudinal axis, and in particular, each elongate member 130 is steel rebar. It should be appreciated that rebar has a textured, ribbed outer surface that provides an increased outer surface area for frictionally engaging the ground 4, which offers the potential to enhance stability in the ground 4. In general, each hole 20 is excavated to provide sufficient clearance beside or below structure 2 and supports 6 for the installation of the corresponding pier assembly 100, 200, 300.
Referring now to FIGS. 1 and 2, pier assembly 100 has a central axis 115 and includes a plurality of elongate members 130 extending from or through hole 20 to static zone 14, a cap or cover plate 120 seated directly on top of upper ends 130b of the plurality of elongate members 130, and a pair of supports or columns 150 seated on top of cover plate 120. Pier assembly 100 is generally symmetric about central axis 115, which is vertically oriented in the embodiment shown in FIGS. 1 and 2. In addition, central axis 115 is geometrically centered relative to the plurality to elongate members 130, which are arranged in a symmetrical pattern about axis 115 as each elongate member 130 extends downward from cover plate 120. In top view (not shown) of a plane oriented perpendicular to axis 115, the plurality of elongate members 130 may be uniformly spaced and arranged in a rectangular matrix, polygonal matrix, or circular matrix. In addition, as best shown in FIG. 2, one or more of the plurality of elongate members 130 may be oriented parallel to axis 115 (e.g., axes 115, 119 are parallel), while one or more of the plurality of elongate members 130 may be oriented at an acute angle α relative to axis 115 in side view (e.g., axes 115, 119 are not parallel). For example, in this embodiment, a first plurality of elongate members 130 are oriented parallel to axis 115, while a second plurality of elongate members 130 are oriented at acute angles α measured between axes 115, 119 in front and/or side view. Angle α may lie in a plane parallel to axis 115 or may lie in a plane that is not parallel to axis 115. In this embodiment, the radially outermost elongate members 130 are flared outward such that each extends outward and away from axis 115 moving downward from cover plate 120 and hole 20 into the ground 4. In some embodiments described herein, angle α is an acute angle less than or equal to 45°, alternatively an acute angle greater than or equal to 5° and less than or equal to 30°, and alternatively an acute angle greater than or equal to 10° and less than or equal to 15°.
Referring still to FIG. 2, cover plate 120 is a rigid plate having a central axis 125, a first or upper planar surface 120a, a second or lower planar surface 120b oriented parallel to surface 120a, and an outer edge 122 extending axially between surfaces 120a, 120b. Surfaces 120a, 120b are oriented perpendicular to axis 125. In addition, axis 125 is vertically oriented when pier assembly 100 is installed as shown in FIG. 2.
Plate 120 is sized such that it extends radially and horizontally beyond the upper ends 130b of the radially outermost elongate members 130, and thus, plate 120 covers and sits directly on top of the upper ends 130b of the plurality of elongate members 130. In other words, the upper end 130b of each elongate member 130 abuts lower planer surface 120b of plate 120. As shown in FIG. 2, elongate members 130 do not extend through plate 120 or any other guide or structure placed in the ground 4. In addition, because elongate members 130 may be installed and arranged in various patterns as previously described, plate 120 may have a variety of possible shapes (e.g., rectangular, polygonal, or circular) in top view in a plane oriented perpendicular to axis 125.
Referring now to FIG. 3, an embodiment of a method 400 for installing pier assembly 100 is shown. FIG. 3 will be described in connection with FIG. 2 and FIG. 4, which illustrates select blocks of method 400. In addition, method 400 will be described in the context of lifting and/or leveling pre-existing structure 2, however, in general, embodiments of pier assembly 100 and method 400 can be used to support new construction with pier assembly 100 being installed prior to construction of the structure that pier assembly 100 ultimately supports.
In FIG. 3, method 400 begins at block 420, where a hole 20 is excavated below structure 2 at the desired installation location for pier assembly 100. In embodiments where pier assembly 100 is installed below existing structure 2 (as opposed to use in new construction), hole 20 may provide vertical clearance for personnel to work beneath structure 2, to accomodate equipment used to install pier assembly 100, and to accommodate components used in connection with pier assembly 100 as described in more detail below. The depth of hole 20 may be varied as needed and may be omitted in some embodiments. For example, hole 20 may not be required for new construction, wherein the structure to be supported is not yet constructed.
Moving now to block 430, a plurality of elongate members 130 are driven downward into the bottom of hole 20 and into the ground 4 therebelow as shown in FIG. 4. More specifically, a first or lower end 130a of each elongate member 130 is inserted into the ground 4 at the bottom of hole 20, while a second end or upper end 130b of the elongate member 130 is coupled to a gun or driver 170 operated by a user 180. In this embodiment, each elongate member 130 is rigid steel rebar that may elastically flex (e.g., little to no plastic deformation) due to its length-to-width ratio. Such flexing allows the elongate member 130 to curve between user 180 when standing on ground 4 and the bottom of hole 20. The degree of curvature imparted to elongate member 130 establishes angle α (as best shown in FIG. 2), and thus more or less curvature may be imparted to each elongate member 130 by user 180 depending on the desired angle α for each installation position. Driver 170 applies continuous, repeated, cyclical axial impacts to end 130b and/or vibrations to elongate member 130 during the driving of block 430 to advance elongate member 130 into the ground 4 below the bottom of hole 20. In general, driver 170 may be any device known in the art for applying repeated, cyclical axial impacts and/or vibrations to elongate member 130 including, without limitation, a jack hammer, demolition hammer, rotary hammer, hammer drill, chisel, or the like. In some embodiments, driver 170 may also apply torsional forces to rotate elongate member 130 about its longitudinal axis during installation in block 430. As best shown in FIG. 1, elongate members 130 are preferably driven into ground 4 to a depth D that extends to static zone 14. In many applications, depth D ranges from about 2.0 ft. to about 100 ft., alternatively from about 10 ft. to about 40 ft., or alternatively from about 10 ft. to about 30 ft. Each elongate member 130 has a length sufficient to enable lower end 130a to be disposed in static zone 14 while upper end 130b is disposed at or in the bottom of hole 20. It should be appreciated that each elongate member 130 is separately and independently driven into the ground 4. In general, elongate members 130 may be driven one at a time, or multiple elongate members 130 may be driven simultaneously by multiple users 180.
As shown in FIG. 4, elongate members 130 may locally straighten (e.g., reducing the curvature imparted by user 180) when passed into the ground 4, and thus, may extend into ground 4 along a straight and linear path. As shown in FIGS. 1 and 2, in some embodiments angle α may result in the plurality of elongate members 130 forming a bell arrangement 113 that generally expands radially outward relative to axes 115, 125 moving downward from hole 20 such that the spacing between the lower ends 130a of elongate members 130 is greater than the spacing between upper ends 130b of elongate members 130. Although each elongate member 130 is shown as a single continuous member, in other embodiments each elongate member 130 may by formed as a series of coupled or connected segments. Each segment may be coupled end to end with any method (e.g., by welding, bolting, coupling with a separate connector, etc.). The coupling of each elongate member 130 segment may occur before the driving of elongate members 130 in block 430, or may occur concurrently with the driving of block 430. In particular, in some embodiments, a first elongate member 130 may be at least partially driven into the bottom of hole 20, the driving may be postponed while another elongate member 130 is coupled to the current elongate member 130, and the driving of the extended elongate member 130 may continue.
As described above, elongate members 130 are driven directly into the ground 4. In this embodiment, elongate members 130 are not driven through or guided by a guide or other structure. For example, in this embodiment, a rigid guide is not placed in hole 20 or above the ground 4 for guiding elongate members 130 in a particular direction or orientation as they are driven into the ground 4 in block 430. This offers the potential to simplify installation, reduce installation time, and reduce installation costs.
Moving now to block 440 of FIG. 3, after the desired number of elongate members 130 are installed, cover plate 120 is placed into the bottom of hole 20 and onto the upper ends 130b of the plurality of elongate members 130. In particular, abutting contact is established between lower surface 120b of cover plate 120 and upper ends 130b of elongate members 130. As previously described, cover plate 120 is sized such that each of the plurality of elongate members 130 is contacted therewith and is generally restricted from moving upwards. In some embodiments, concrete is poured into hole 20 after block 430 and before block 440 to completely surround and encapsulate the portions of elongate members 130 extending from the ground 4 into hole 20 (e.g., upper ends 130b). In such embodiments, the concrete is poured into hole 20 and allowed to fully cure, thereby rigidly locking upper ends 130b together and forming a rigid, solid base on which cover plate 120 can be seated in block 440. Accordingly, in such embodiments, plate 120 may be seated on top of the concrete that contains the upper ends 130b of elongate members 130, and thus, plate 120 may not directly contact upper ends 130b.
Referring still to FIG. 3, in block 450 jack 140 is placed on top of cover plate 120, and then in block 460, jack 140 is used to lift structure 2. It should be appreciated that the lifting according to block 460 may be performed on one pier assembly 100 at a time or be performed with a plurality of jacks 140 installed on a plurality of pier assemblies 100 concurrently. After the desired lifting or loading of structure 2 is achieved, a pair of supports or columns 150 are positioned between cover plate 120 and structure 2 on opposite sides of jack 140 in block 470 and as shown in FIG. 2. Columns 150 may be placed equidistant from axis 115 so that vertical loads applied to pier assembly 100 are substantially balanced and no moment is applied to pier assembly 100. In some embodiments, an additional distribution block 160 may be used as to provide load reaction points in positions coinciding with columns 150. In addition, shims 152 may also be used along one or more columns 150 to adjust for inaccuracies in supports 6 or distribution block 160. Moving now to block 480, jack 140 is lowered to transfer the load of structure 2 onto columns 150 and pier assembly 100, and then jack 140 is removed.
Without being limited by this or any particular theory, the bell arrangement 113 (as shown in FIGS. 1 and 2) of elongate members 130 offers the potential to enhance soil stabilization within dynamic zone 8 and reduce the magnitude of movement and shifting of pier assembly 100 within dynamic zone 8 over time. In addition, bell arrangement 113 may transfer the compressive loading of pier assembly 100 over a large volume of soil within ground 4, and thus, thus may result in lower soil pressures for a given structure 2 weight, as compared to conventional cylindrical concrete piers. In addition (as best shown in FIG. 1), because elongate members 130 are installed sequentially, with each presenting a smaller frontal cross-sectional area than traditional concrete cylinder systems, elongate members may be able to achieve increased depths D as compared to prior art systems. More particularly, elongate members 130 may be driven through dense strata 12, past dynamic zone 8, and into static zone 14.
Referring to FIG. 5, pier assembly 200 is shown. In general, pier assembly 200 can be used in place of any one or more pier assemblies 100 previously described. Pier assembly 200 is substantially the same as pier assembly 100 previously described, and thus, components of pier assembly 200 that are shared with pier assembly 100 are identified with like reference numerals, and the description below will focus of features of pier assembly 200 which are different from pier assembly 100.
In this embodiment, pier assembly 200 has central axis 215, and includes a plurality of elongate members 130 extending to static zone 14 and a plurality of rigid cylinders 260 seated directly on top of the plurality of elongate members 130. As shown in FIGS. 1 and 5, central axis 215 is vertically oriented. Elongate members 130 are as previously described. Each elongate member 130 may be oriented parallel to axis 215 or at an acute angle α relative to central axis 215. In addition, elongate members 130 may be arranged in any pattern around central axis 215. In particular, in some embodiments, in top view in a plane oriented perpendicular to axis 215, the plurality of elongate members 130 may be uniformly spaced and arranged in a rectangular matrix, polygonal matrix, or circular matrix with axis 215 positioned at the geometric center. In the embodiment shown in FIG. 5, the plurality of elongate members 130 are arranged in a circular matrix and each extends in a direction generally parallel to axis 215, thereby forming a column arrangement 213 that has a substantially uniform and constant width moving axially from upper ends 130b to lower ends 130a of elongate members 130.
Cylinders 260 are stacked one atop the other on to form a vertical stack on top of upper ends 130b of elongate members 130. Each cylinder 260 and the stack of cylinders 260 are coaxially aligned with axis 215. Cylinders 260 may be pre-cast concrete segments or may include additional layers (e.g., such as a separate or cast-in steel layer) to reduce damage to the end of cylinder 260 directly abutting upper ends 130b of elongate members 130. Cylinders 260 may be stacked to directly abut and support structure 2; or additional supports 6, 150, distribution blocks 160, shims 152, or combinations thereof may be used as needed, in the manner previously described with respect to pier assembly 100.
Referring now to FIG. 6, an embodiment of a method 500 for installing pier assembly 200 is shown. FIG. 6 will be described in connection with FIGS. 4 and 5, which illustrate select blocks of method 500. In addition, method 500 will be described in the context of lifting and/or leveling pre-existing structure 2, however, in general, embodiments of pier assembly 200 and method 500 can be used to support new construction with pier assembly 200 being installed prior to construction of the structure that pier assembly 200 ultimately supports.
In FIG. 6, method 500 begins at block 520, where a hole 20 is excavated below structure 2 at the desired installation location for pier assembly 200. As previously described for pier assembly 100 and method 400, hole 20 may provide vertical clearance for personnel to work beneath structure 2, to accommodate equipment used to install pier assembly 200, and to accomodate components used in connection with pier assembly 200, as described in more detail below. The depth of hole 20 may be varied as needed and may be omitted in some embodiments. For example, hole 20 may not be required for new construction, wherein the structure to be supported is not yet constructed.
Moving next to block 530, a plurality of elongate members 130 are driven downward into the bottom of hole 20 and into the ground 4 therebelow as shown in FIG. 4. The driving of the plurality of elongate members 130 is performed in the manner as previously described for pier assembly 100. While driving elongate members 130, the user 180 may manipulate and elastically flex elongate members 130 to enable each elongate member 130 to be oriented parallel to axis 215 and form the column arrangement 213 shown in FIG. 5. Similar to method 400 for installing pier assembly 100 previously described, in this embodiment, elongate members 130 are driven directly into the ground and are not driven through or guided by a guide or other structure. For example, in this embodiment, a rigid guide is not placed in hole 20 or above the ground for guiding elongate members 130 in a particular direction or orientation as they are driven into the ground in block 530. This offers the potential to simplify installation and reduce installation costs.
Referring again to FIG. 6 and moving to block 540, after the desired number of elongate members 130 are installed, a cylinder 260 is positioned atop the upper ends 130b of the elongate members 130 in the bottom of hole 20 such that abutting contact is established therebetween. After placing cylinder 260 on top of upper ends 130b, a jack 140 (e.g., such as a hydraulic cylinder) is then placed on top of cylinder 260 and used to apply compressive forces to cylinder 260, thereby driving cylinder 260 and the plurality of abutting elongate members 130 down and further into ground 4. In some embodiments the compressive forces of jack 140 may be reacted by structure 2, and a distribution block 160 may be used as needed to increase the contact area along structure 2 to reduce the localized forces and stresses applied to structure 2. Additionally, for new construction, where structure 2 is not yet installed, heavy equipment such as a tractor may be used instead of jack 140 to directly apply the downward forces. After the driving of cylinder 260 in block 540, the compressive forces of jack 140 may be released to allow another cylinder 260 to be stacked onto the first cylinder 260. Jack 140 may then again be used to apply compressive forces to the second cylinder 260, thereby repeating block 540 as stack of cylinders 260 (both cylinders 260) and the plurality of elongate members 130 are driven even further into the ground 4. This process may be repeated as many times as necessary to reach a static zone 14 as shown in FIG. 1 or until sufficient support is otherwise provided to structure 2.
Next, in block 550 jack 140 may be used to lift structure 2 in the manner previously described. In particular, the lifting according to block 550 may be performed on one pier assembly 200 at a time or be performed with a plurality of jacks 140 installed on a plurality of pier assemblies 200 concurrently. After the desired lifting or loading of structure 2 is achieved, a support 250 may be installed between the upper most cylinder 260 and structure 2 in block 560 and as shown in FIG. 1. In some embodiments, support 250 may be substantially the same as cylinders 260 or support 250 may be made of different materials and or may have a different length. In particular support 250 may be configured to have a length which is adjustable (e.g., include a threaded segment which may move up or down to meet the height of structure 2) or may be configured such that the overall length may be cut or trimmed to meet the height of structure 2. Although support 250 is shown abutting support 6 in FIG. 1, in other embodiments, support 250 may directly abut structure 2 and/or shims 152 and/or distribution block(s) 160 may be used as needed in the manner previously described for pier assembly 100. Moving now to block 570, jack 140 is lowered to transfer the load of structure 2 onto supports 250 and pier assembly 200, and then jack 140 is removed.
Referring again to FIG. 1, pier assembly 300 is shown. In general, pier assembly 300 can be used in place of any one or more pier assemblies 100, 200 previously described. Pier assembly 300 is similar to pier assemblies 100, 200 previously described, and thus, components of pier assembly 300 that are shared with pier assemblies 100, 200 are identified with like reference numerals, and the description below will focus of features of pier assembly 300 which are different from pier assemblies 100, 200. However, unlike pier assemblies 100, 200 that provide vertical support to structure 2, pier assembly 300 primarily provides lateral support to structure 2 (i.e., limits lateral shifting and movement of structure 2).
In this embodiment, pier assembly 300 includes a plurality of horizontally spaced elongate members 130 with upper ends 130b positioned laterally adjacent a support 6 of structure 2 (e.g., for example along an outer perimeter of structure 2). In particular, in this embodiment, a plurality of elongate members 130 are arranged along a linear path that follows the outer perimeter of a support 6 at an exterior edge of structure 2. Thus, upper ends 130b are disposed in a common plane oriented parallel to the outer perimeter of support 6 and structure 2.
Referring now to FIG. 7, pier assembly 300 also includes a plurality of brackets 350, with one bracket 350 being fixably mounted to upper end 130b of each elongate member 130. In particular, each bracket 350 secures the upper end 130b of one elongate member 130 to structure 2. Bracket 350 may be directly attached to structure 2 (e.g., adhere, bolt, weld, bond, or otherwise attach) or may be indirectly coupled to structure 2 via support 6, distribution block 160, or by another intermediate device not specifically shown. In particular, it is anticipated that a metal plate or bracket encapsulated in poured concrete or epoxy may be used to form bracket 350 and fixably secure each elongate member 130 to structure 2 separately.
Referring now to FIG. 8, an embodiment of a method 600 for installing pier assembly 300 is shown. FIG. 8 will be described in connection with FIGS. 4 and 7, which illustrate select blocks of method 600. In addition, method 600 will be described in the context of lateral stabilization of a pre-existing structure 2, however, in general, embodiments of pier assembly 300 and method 600 can be used to laterally stabilize new construction with pier assembly 300 being installed prior to construction of the structure that pier assembly 300 ultimately supports.
In FIG. 8, method 600 begins at block 620, where a hole 20 is excavated beside structure 2 at the desired installation location for pier assembly 300. As previously described for pier assembly 100 and method 400, hole 20 may provide vertical clearance for personnel to work beneath structure 2, to accomodate supporting equipment used to install pier assembly 300, and to accomodate components used in connection with pier assembly 300 as will described in more detail below. The depth of hole 20 may be varied as needed and may be omitted in some embodiments. For example, hole 20 may not be required for new construction, wherein the structure to be supported is not yet constructed. In addition, hole 20 may be omitted or the depth of hole 20 may be greatly reduced for an installation position along the perimeter of structure 2 as shown in FIG. 1. In both instances the vertical clearance for installation is less obstructed by an overhead structure.
Moving next to block 630, a plurality of elongate members 130 are driven downward into the bottom of hole 20 and into the ground 4 therebelow as shown in FIG. 4. As shown in FIGS. 1 and 7, elongate members 130 are driven into the ground 4 along the outer perimeter of structure 2. The driving of the plurality of elongate members 130 is performed in the same manner as previously described for pier assembly 100, as the installation angle α can be adjusted by the degree of curvature imparted by user 180 into each elongate member 130. In some embodiments, the driving of block 630 will result in the upper end 130b of each elongate member 130 being positioned above the lower most surface of at least one of structure 2 or support 6. Angle α may be the same between each of the plurality of elongate members 130 or may be different.
Moving now to block 640 in FIG. 8, after the desired number of elongate members 130 are installed, the upper ends 130b of each elongate member 130 are secured to structure 2. In this embodiment, the upper end 130b of each elongate member 130 is separately and independently secured to structure 2 or support 6 with a bracket 350. However, in other embodiments, the upper ends 130b of multiple elongate members 130 may be secured to structure 2 or support 6 with a single bracket (e.g., bracket 350). In the manner described, pier assembly 300 provides lateral stability to structure 2 and is generally not configured to impart lifting or leveling forces thereto as described for pier assemblies 100, 200.
Referring now to FIG. 9, another embodiment of a pier assembly 700 is shown. In general, pier assembly 700 can be used in place of any pier assembly 100, 200, 300 previously described. Pier assembly 700 is the same as pier assembly 100 previously described with the exception that elongate members 130 do not extend linearly into the ground, but rather curve to form a flared column arrangement 703. Flared column arrangement 703 may be formed independent of the initial angle of elongate members 130 enter ground 4 as established by the curvature imparted by user 180 in the manner previously described to establish angle α. For example, as shown in FIG. 9, despite the initially parallel arrangement of the plurality of elongate members 130, one of the elongate members 130 progressively curves radially outwardly relative to axis 115 as user 180 advances elongate member 130 into ground 4 using driver 170. Such steering may be achieved by using a pre-bent elongate member 130 (e.g., having a radius of curvature in the relaxed state rather than a linear profile). In addition, it is anticipated that elongate members 130 may be steered by modifying the tip shape of elongate members 130 (e.g., a beveled tip or flared tip). Such steering may be advantageous in some embodiments as the shape of flared column arrangement 703 may be tailored for the specific installation site and ground 4 conditions, and thus may offer selectable attributes from both column arrangement 213 and bell arrangement 113 as shown in FIG. 1. As previously described above, the spacing and arrangement of elongate members 130 may contribute to soil stabilization within dynamic zone 8, increased bearing load capacity of the soil adjacent to and captured within the arrangement of elongate members 130, and may transfer the compressive loading on pier assembly 700 over a larger volume of soil. In addition, such steering of elongate members 130 may offer practical installation advantages as user 180 may steer elongate members 130 away from pre-existing structures (e.g., plumbing or electrical lines) beneath or adjacent to structure 2.
In the manner described, embodiments disclosed herein include pier systems and methods of installing pier systems which may be used with a pre-existing structure, or may be used independently of a structure. For example, embodiments of pier assemblies disclosed herein (e.g., pier assemblies 100, 200, 300) are configured to provide and do provide vertical, upward forces sufficient to support the weight (or portion thereof) of a structure (e.g., pre-existing structure 2). The disclosed systems and methods allow piers to be installed while applying no force or only a relatively small force to the pre-existing structure, and thus may be used to preserve the mechanical integrity of such structures. In addition, systems and methods disclosed herein include systems which can achieve pier depths which are independent of the pre-existing structure weight, and as a result may be used for variable weight structures, for new construction where no structure is present, or installed beside a structure to provide lateral stabilization rather than lifting support.
As shown in FIG. 1, some structures 2 may include a plurality of supports 6 that are laterally spaced along a perimeter of structure 2, however, supports 6 may also be positioned in other locations for example under central regions of structure 2. Thus, in some embodiments, user 180 may operate driver 170 while inside of or under structure 2. In addition, different quantities of supports 6 may be used, for example a singular support 6 that spans across the bottom of structure 2 (e.g., a monolithic concrete slab). Thus, in some embodiments, pier assemblies (e.g., pier assembly 100) may be installed by first tunneling or drenching beneath the monolithic concrete slab. In addition, a through hole may be created in a monolithic concrete slab to allow the installation of the disclosed pier assemblies (e.g., pier assembly 100).
While exemplary embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.
Patent Application
20220042273
