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 disclosed herein are direct to pier assemblies for supporting structures. In an embodiment, the pier assembly comprises a guide member having a base plate and a plurality of tubular guides extending from the base plate. The base plate comprises a plurality of through holes and each tubular guide includes a through passage aligned with one of the through holes of the base plate. In addition, the pier assembly comprises a plurality of elongate members that extend through one through hole in the base plate and the through passage of the corresponding tubular guide.
Embodiments disclosed herein are also directed to methods for installing piers for supporting structures. In an embodiment, the method comprises (a) seating a guide member against the ground. The guide member includes a base plate, a first tubular guide extending downward from the base plate, and a second tubular guide extending downward from the base plate. The method also comprises (b) bending a first elongate member extending through the base plate and the first tubular guide after (a), wherein the first elongate member has a lower end inserted into the ground and an upper end coupled to a driver above the ground. In addition, the method comprises (c) actuating the driver during (b) to (i) advance the first elongate member through the base plate and the tubular guide and (ii) advance the lower end of the first elongate member through the ground. Further, the method comprises (d) bending a second elongate member extending through the base plate and the second tubular guide after (c), wherein the second elongate member has a lower end inserted into the ground and an upper end coupled to the driver above the ground. Still further, the method comprises (e) actuating the driver during (d) to (i) advance the second elongate member through the base plate and the tubular guide and (ii) advance the lower end of the second elongate member through the ground.
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 in accordance with principles described herein for supporting a structure;
FIG. 2 is an enlarged, partial cross-sectional side view of one of the pier assemblies of FIG. 1;
FIG. 3 is a cross-sectional side view of the base and the cap of FIG. 2;
FIG. 4 is a top view of the base of FIG. 2;
FIG. 5 is a flowchart illustrating an embodiment of a method in accordance with principles described herein for installing the pier assembly of FIG. 2;
FIGS. 6a-6d are sequential, schematic illustrations of the blocks of the method of FIG. 5;
FIG. 7 is an enlarged, partial cross-sectional side view of another pier assembly of FIG. 1;
FIG. 8 is a top view of an embodiment of a base in accordance with principles described herein for use with embodiments of pier assemblies described herein; and
FIG. 9 is a schematic 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. 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 with 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 discussed 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 elongate members or rods 130 that extend from a hole 20 excavated below supports 6 to static zone 14. Each elongate member 130 has a first or lower end 130a disposed in static zone 14 and a second or upper end 130b at hole 20. 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. In general, each hole 20 is excavated to provide sufficient clearance 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 includes a guide member 110 seated in the bottom of hole 20, a plurality of elongate rods 130 extending through guide member 110 to static zone 14, and a cap or cover plate 120 seated directly on top of guide member 110. As best shown in FIGS. 2-4, guide member 110 includes a body or base plate 111 and a plurality of tubular guides 114 extending downward from base plate 111. Base plate 111 and guides 114 are made of rigid, durable materials suitable for use below ground 4. Examples of suitable materials include steel, stainless steel, aluminum, rigid polymeric material, concrete, or combinations thereof. In some embodiments, the base plate 111 is formed of one material (e.g., concrete) and the guides 114 are formed by another material (e.g., such as steel tubes) disposed in and/or extending from the base plate 111.
Referring now to FIGS. 3 and 4, base plate 111 has a first or upper planar surface 111a, a second or lower planar surface 111b oriented parallel to surface 111a, and a plurality of spaced through bores or holes 112 extending from upper surface 111a to lower surface 111b. As shown in 4, in this embodiment, base plate 111 is a rectangular plate having a rectangular outer profile 113 in top view, however, in other embodiments, the base plate (e.g., base plate 111) may have other geometries (e.g., triangular, circular, hexagonal, etc.). In addition, base plate 111 has a central axis 115 oriented perpendicular to surfaces 111a, 111b and geometrically centered relative to outer profile 113, a first axis 116a perpendicular to and intersecting axis 115, and a second axis 116b perpendicular to and intersecting axes 115, 116a. Thus, axes 115, 116a, 116b are orthogonal with axes 116a, 116b being disposed in a plane oriented parallel to surfaces 111a, 111b.
Tubular guides 114 are fixably attached to base plate 111 (e.g., welded to or integral with base plate 111) such that guides 114 do not move translationally or rotationally relative to base plate 111, and further, tubular guides 114 extend downward from lower surface 111b. Each guide 114 has a central or longitudinal axis 119, a first or upper end 114a fixably attached to base plate 111, a second or lower end 114b distal base plate 111, and a central through bore or passage 117 extending axially from end 114a to end 114b. In this embodiment, each tubular guide 114 has a radially outer cylindrical surface extending axially between ends 114a, 114b and a radially inner cylindrical surface extending between ends 114a, 114b and defining bore 117. However, in other embodiments, one or more tubular guides (e.g., tubular guides 114) may have radially outer and/or radially inner surfaces with different geometries such as rectangular prismatic, triangular prismatic, etc.
Referring still to FIGS. 3 and 4, guides 114 are positioned and attached to base plate 111 such that passage 117 of each guide 114 is aligned with a corresponding hole 112 (e.g., coaxially aligned), thereby creating a continuous bore or passage extending through base plate 111 and the corresponding guide 114. In this embodiment, upper ends 114a of guides 114 are attached to lower surface 111b of base plate 111. However, in other embodiments, the guides (e.g., guides 114) extend through the base plate (e.g., base plate 111) such that the bore of each guide defines a continuous passage through the base plate and the guide.
In this embodiment, guides 114 are uniformly spaced and arranged in a rectangular matrix as shown in FIGS. 3 and 4. In addition, in this embodiment, a first plurality of guides 114 are oriented parallel to central axis 115 of base plate 111 (e.g., axes 115, 119 are parallel), while a second plurality of guides 114 are oriented at an acute angles α relative to axis 115 of base plate 111 (e.g., axes 115, 119 are oriented at acute angles α) 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 guides 114 are flared outward such that each extends outward and away from axis 115 in both front view and side view moving from upper end 114a to lower end 114b. 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 briefly to FIG. 3, cover plate 120 is a rigid plate having a first or upper planar surface 120a, a second or lower planar surface 120b, and an outer profile that is similar to outer profile 113 of base plate 111. In this embodiment, cover plate 120 has a rectangular outer profile that is substantially the same as outer profile 113 of base plate 111. In general, cover plate 120 is configured to cover and extend across all of the holes 112 in base plate 111, and thus, the dimensions of cover plate 120 (e.g., length and width) sufficiently large to ensure it covers all holes 112.
When pier assembly 100 is installed as shown in FIG. 2, guide member 110 is seated in the bottom of hole 20 with base plate 111 horizontally oriented (axis 115 vertically oriented), surface 111a facing upward, and guides 114 extending downward from base plate 111 into the ground. In addition, one elongate member 130 extends through each aligned bore 112 and passage 117 into the ground below guide member 110. In this embodiment, when installed, each elongate member 130 extends linearly in a direction generally coaxially aligned with axis 119 of the corresponding passage 117. Cover plate 120 is seated on base plate 111 with lower surface 120a abutting and directly engaging upper surface 111a, thereby closing off bores 112 at upper surface 111a and preventing elongate members 130 from extending upwardly above guide member 110.
Although guide member 110 includes base plate 111 and a plurality of tubular guides 114 extending from base plate 111 in this embodiment, in other embodiment, tubular guides 114 may not be included. For example, in one embodiment, the base plate (e.g., base plate 111) includes a plurality of holes (e.g., holes 112) extending therethrough, however, no guides (e.g., guides 114) extend from the lower surface of the base plate. In such embodiments, the elongate members (e.g., elongate members 130) are advanced through and guided by the holes in the base plate. In some such embodiments, the holes in the base plate may be defined by and lined with tubulars such as steel tubulars to enhance wear resistance and integrity of the base plate.
Referring now to FIG. 5, an embodiment of a method 500 for installing pier assembly 100 is shown. FIG. 5 will be described in connection with FIGS. 6a-6d, 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 100 and method 500 can be used to support new construction with pier assembly being installed prior to construction of the structure that pier assembly 100 ultimately supports.
Referring now to FIGS. 5 and 6, method 500 begins at block 520, 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 accommodate 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, where the structure to be supported by pier assembly 100 is not yet constructed.
Moving now to block 530, in embodiments including existing structure 2, guide member 110 is placed in hole 20 and pressed downward into hole 20 with a jack 140 to advance tubular guides 114 into the ground and position base plate 111 in a horizontal orientation against the bottom of the hole 20 as shown in FIG. 6a. With guides 114 advanced into the ground, guide member 110 is generally held static and restricted and/or prevented from moving translationally and rotationally relative to the ground. In this embodiment, jack 140 is a hydraulic ram that urges support 6 of structure 2 (not shown in FIG. 6a) and guide member 110 vertically away from each other to press guides 114 into ground 4 and seat base plate 111 against the bottom of hole 20. In embodiments where structure 2 does not have adequate supports 6, a distribution block 160 may be used to increase the contact area along structure 2, thereby reducing the localized forces and stresses applied to structure 2. Additionally, for new construction, wherein structure 2 is not yet installed, heavy equipment such as a tractor or excavator may be used instead of jack 140 to directly apply downward forces against base plate 111 to sufficient to seat guide member 110 in the hole 20. Still further, in applications where the ground is sufficiently soft, guide member 110 may be manually urged downward and seated against the bottom of hole 20.
Moving now to block 540, a plurality of elongate members 130 are driven downward through the bores 112 and aligned passages 117 of guide member 110 into the ground therebelow as shown in FIG. 6b. In this embodiment, one elongate member 130 is advanced through each bore 112 and corresponding passage 117. More specifically, first end 130a of each elongate member 130 is inserted into a corresponding passage 117, while a second 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 as described above. Such flexing allows the elongate member 130 to curve between user 180 when standing on ground 4 and guide member 110. Driver 170 applies continuous, cyclical axial impacts to end 130b and/or vibrations to elongate member 130 during the driving of process in block 540 to advance elongate member 130 through guide member 110 (i.e., through the corresponding passage 117 and bore 112) and into the ground below guide member 110. In general, driver 170 may be any device known in the art for applying 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 540. 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 in guide member 110 (e.g., in the corresponding bore 112 or passage 117) or just above base plate 111. 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. 6b, as elongate members 130 are passed though guide member 110, tubular guides 114 locally straighten the curvature of elongate members 130 and generally direct them along a linear path oriented at the angle established by central axis 119 of the corresponding tubular guide 114 (i.e., the portion of each elongate member 130 extending downward from the corresponding tubular guide 114 is coaxially aligned or substantially coaxially aligned with the corresponding tubular guide 114). Consequently, acute angles α as previously described and shown in FIG. 3 result in the plurality of elongate members 130 forming a bell arrangement 113 that generally expands radially outward relative to axis 115 of guide member 110 moving downward therefrom as shown in FIG. 6c. Namely, in the installed positions, 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 540, or may occur concurrently with the driving of block 540. In particular, in some embodiments, a first elongate member 130 may be at least partially driven into aperture 117, 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 shown in FIGS. 1 and 6b, each elongate member 130 passes through guide member 110 directly into the ground 4. Thus, once installed, each elongate member 130 directly engages 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.
Referring again to FIG. 5 and moving to block 550, after the desired number of elongate members 130 are installed through guide member 110, cover plate 120 is placed onto guide member 110, and more specifically, onto upper surface 111a of base plate 111 as shown in FIG. 6c. If upper ends 130b of one or more elongate members 130 extends slightly above base plate 111 following block 540, cover plate 120 can be placed atop guide member 110 and pressed downward to urge such upper ends 130b into guide member 110 and seat cover plate 120 against guide plate 111 in block 550. As previously described, cover plate 120 closes off and blocks holes 112 in base plate 111, thereby restricting and/or preventing elongate members 130 from moving upward through guide member 110. Next, in block 560, jack 140 is placed on top of cover plate 120, and then in block 570, jack 140 is used to lift structure 2. It should be appreciated that the lifting according to block 570 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 580 as shown in FIG. 6d. Columns 150 may be placed equidistant from axis 115 of guide member 110 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 590, 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 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. 7, 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 includes a guide member 210 seated in the bottom of hole 20, a plurality of elongate members 130 extending through guide member 210 to static zone 14, and a cover plate 120 seated directly on top of guide member 210. Elongate members 130 and cover plate 120 are as previously described. Guide member 210 is similar to guide member 110 previously described. In particular, guide member 210 includes a base plate 211 and a plurality of tubular guides 214 extending from base plate 211. Base plate 211 and guides 214 are made of rigid, durable materials suitable for use below ground 4. Base plate 211 has a first or upper planar surface 211a, a second or lower planar surface 211b oriented parallel to surface 211a, and a plurality of spaced through bores or holes 212 extending from upper surface 211a to lower surface 211b. In addition, base plate 211 has a central axis 215 oriented perpendicular to surfaces 211a, 211b and geometrically centered relative to the outer profile of base plate 211. Unlike holes 112 in base plate 111 previously described, in this embodiment, each hole 212 in base plate 211 is oriented parallel to axis 215.
Tubular guides 214 are fixably attached to base plate 211 (e.g., welded to or integral with base plate 211) such that guides 214 do not move translationally or rotationally relative to base plate 211, and further, tubular guides 214 extend from lower surface 211b of base plate 211. Each guide 214 has a central or longitudinal axis 219, a first or upper end 214a attached to base plate 211, a second or lower end 214b distal base plate 211, and a central through bore or passage 217 extending axially from end 214a to end 214b. Guides 214 are positioned and attached to base plate 211 such that each passage 217 is aligned (e.g., coaxially aligned) with a corresponding hole 212, thereby creating a continuous bore or passage extending through base plate 111 and the corresponding guide 214. Unlike guides 114 previously described, in this embodiment, each guide 214 is oriented parallel to axis 215 (i.e., central axes 219 are oriented parallel to central axis 215).
Similar to pier assembly 100, in this embodiment of pier assembly 200, one elongate member 130 is installed within each hole 212 and corresponding passage 217 and extends from upper surface 211a into ground 4. Each elongate member 130 extends in a direction generally parallel to axis 215, thereby forming a column arrangement 213.
When pier assembly 200 is installed as shown in FIG. 7, guide member 210 is seated in the bottom of hole 20 with base plate 211 horizontally oriented (axis 215 vertically oriented), surface 211a facing upward, and guides 214 extending downward from base plate 211 into the ground. In addition, one elongate member 130 extends through each aligned bore 112 and passage 117 and into the ground. In this embodiment, when installed, each elongate member 130 extends linearly in a direction generally parallel to axes 215, 219. Cover plate 120 is seated on base plate 211 with lower surface 120a abutting and directly engaging upper surface 211a, thereby closing off bores 212 at upper surface 211a and preventing elongate members 130 from extending upwardly above guide member 210. Pier assembly 200 is installed and functions in the same manner as pier assembly 100 previously described.
Referring again to FIG. 1, another embodiment of a 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 assembly 100 previously described, and thus, components of pier assembly 300 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 300 includes a plurality of elongate members 130 but does not include a guide member (e.g., guide member 110, 210) or a cover plate (e.g., cover plate 120). Rather, elongate members 130 are installed in a column arrangement 213 as described for pier assembly 200, and distribution block 260 is seated on the upper ends 130b of the elongate members 130 in hole 20.
Elongate members 130 may be installed in the manner previously described for pier assemblies 100, 200 using a guide member 110, 210 that may then be removed (e.g., after block 540). Because the guide member (e.g., guide member 110, 210) is removed following installation of elongate members 130, the guide member may be installed onto ground 4 in an inverted orientation. This inverted orientation results in the tubular guides (e.g., guides 114, 214) extending upwards, thereby eliminating the need to advance the tubular guides into the ground. In addition, the guides may be made removable from the base plate (e.g., base plate 111, 211), which may aid in the removal of the guide member as binding between the guides and the plurality of elongate members 130 may be reduced or eliminated once the guides are removed from the constrained positions along the base plate. Thus in some embodiments, the tubular guides (e.g., tubular guides 114, 214) may be releasably coupled to base plate 111, 211, respectively. For example, in some embodiments, guides 114, 214 are threadably attached to base plate 111, 211, respectively.
Referring still to FIG. 1, distribution block 360 may be installed on top of the plurality of elongate members 130 of pier assembly 300, and may support the compressive loads between pier assembly 300 and supports 6 of structure 2. In some embodiments, one distribution block 360 may be used and sized such that it abuts with the upper ends 130b of elongate members 130. In other embodiments, distribution block 360 may be sized smaller than the arrangement of elongate members 130 and a cover plate 120 may be positioned against upper ends 130b between distribution block 360 and elongate members 130. Further, in some embodiments, a plurality of distribution blocks 360 may be used to abut with the upper ends 130b of elongate members 130.
In the embodiments of guide members 110, 210 previously described, the base plates 111, 211, respectively, had a rectangular outer profile. However, in other embodiments, the outer profile of the base plate may have a different geometry. For example, referring now to FIG. 8, an embodiment of a guide member 410 is shown. In general, guide member 410 can be used in place of guide member 110, 210 previously described. Guide member 410 is substantially the same as guide member 110 previously described, with the exception that guide member 410 includes a base plate 411 with a hexagonal outer profile 413 and holes 112 are not arranged in a rectangular pattern.
Referring now to FIG. 9, another embodiment of a pier assembly 400 is shown. In general, pier assembly 400 can be used in place of any pier assembly 100, 200, 300 previously described. Pier assembly 400 is the same as pier assembly 200 previously described with the exception that elongate members 130 do not extend linearly into the ground below guide member 210, but rather curve to form a flared column arrangement 203. Flared column arrangement 203 may be formed independent of the initial angle of elongate members 130 as established by guide member 210. For example, as shown in FIG. 9, despite the parallel arrangement of guides 214, elongate members 130 progressively curve radially outwardly relative to central axis 215 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 pre-determined radius of curvature 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 203 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 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 assemblies 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 and for new construction where no structure is present.
As shown in FIG. 1, some structures 2 may include a plurality of supports 6 which 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 which 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).
Referring again to FIGS. 4 and 7, it is anticipated that cover plate 120 may be omitting in some embodiments and elongate members 130 by be fixably attached to guide member 110, 210 after elongate members 130 are installed according to block 540. For example, elongate members 130 may be fixed at upper ends 130b to portions of guide member 110, 210 using welding, locking sleeves, pins, crimp connectors, concrete, or epoxy.
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
20220018080
