SYSTEM AND METHOD FOR FOUNDATIONS FOR ROADSIDE SIGNS AND STRUCTURES

Abstract

A ground screw anchor foundation for a roadside sign comprises at least one elongated soil screw defining a longitudinal axis. The soil screw includes a barrel section having an upper end and a lower end and a substantially circular cross-section of a first diameter. A point section is connected to the lower end, the point section tapering from a second diameter at a position along the longitudinal axis proximate to the barrel section to a third diameter at a position along the longitudinal axis distal to the barrel section. A helical thread is disposed on an outer surface of at least a portion of the point section. A first component of a breakaway system is mounted on the upper end of the barrel section of the soil screw. The first component is adapted for releasable connection in a breakaway manner to a second component on a roadside sign.

Description

TECHNICAL FIELD

The following disclosure relates to systems for providing foundations for roadside signs, in particular for providing foundations including a ground screw and an integral slip base, such that the foundation can be installed in the ground without excavation, can be removed intact from the ground after use and/or can be reused in another location after removal.

BACKGROUND

Roadside safety is a controlling element within the roadway signing industry. The most widely accepted safety element for small roadside signs is a breakaway system. The Federal Highway Administration, numerous universities, private inventors, and numerous state Departments of Transportation have crash-tested numerous types of breakaway systems in the past 30 years. There are several breakaway systems approved for use on our national highway system. One of the commonly used breakaway systems is commonly known as the “triangular slip base.” U.S. Pat. No. 4,926,592 to Nehls describes a breakaway sign post coupling comprising a triangular slip base. The entire disclosure of U.S. Pat. No. 4,926,592 is incorporated herein by reference.

Conventionally, a foundation for a roadside sign includes a triangular slip base anchored to the ground with a 12″ diameter×42″ deep drilled shaft concrete foundation. As the name implies, the drilled shaft concrete foundation involves drilling a hole in the ground at the desired location and filling it with concrete. The slip base stub is mounted in the wet concrete before it sets up. This is a “one size fits all” roadside sign foundation that is used in every soil type.

Though widely used, there are several disadvantages to the conventional drilled shaft concrete foundation for roadside signs. One disadvantage is the amount of man hours and physical labor required for a complete sign installation. The typical installation of a sign with a drilled concrete foundation takes two trips by a work crew: one trip to drill and pour the foundation; and a second trip, no sooner than four days later, to install the sign after the concrete has cured. Also, the amount of equipment and physical labor to install the foundation is fairly exhaustive. For example, to install a typical 12″ dia.×42″ deep drilled shaft foundation requires a drilling truck and operator, a trailer or separate truck to haul water, dry concrete mix that will result in a 3,000 psi concrete, a wheel barrel, concrete mixing tools, hand tools to load or spread the spoils from drilling the shaft, and cones/barricades to keep vehicles or pedestrians away from the curing foundation and slip base stub extrusion. In all, the installation of a drilled shaft foundation is labor extensive and exhaustive. A need therefore exists, for an improved foundation system for installation of roadside signs that is more efficient of labor and materials.

Of course, if commercially-mixed (i.e., mixing truck delivered) concrete is used, no hand mixing or lifting is required, except possibly for hauling the concrete by wheel barrel if the foundation location cannot be reached with the concrete chute. However, commercial concrete suppliers typically cannot accurately batch less than a half a truck load of concrete, and typically have a minimum charge for delivery. Thus using commercially-mixed concrete can be extremely expensive when only a few signs are installed at time. A need therefore exists, for an improved foundation system for installation of roadside signs that is economical to use when installing only one sign or only a few signs.

Further, there are numerous locations along almost any roadway that require sign placements in location that are extremely difficult and costly to access with a drilling truck and hand- or commercially-mixed concrete. These locations include steep side slopes and areas protected/separated from the roadway by metal beam guard fence or concrete barrier. These locations can normally be easily accessed by foot but not by large trucks and drilling equipment. A need therefore exists, for an improved foundation system for installation of roadside signs that does not require access by large trucks and drilling equipment.

Another disadvantage of the conventional drilled shaft concrete foundation for roadside sign use is that, once in place, such foundations cannot be moved or reused. Thus, removing a sign installed with such a foundation requires either: pulling up the entire foundation, back-filling the void, and disposal of a 400 pound chunk of concrete; or breaking the existing foundation back to 2′ below the existing ground elevation, removal and disposal of 225 pounds of concrete rubble, and then backfilling the void. Moving the sign requires installation of a new concrete foundation at the new location, in addition to the foundation removal process just described. A need therefore exists, for an improved foundation system for installation of roadside signs that allows removal and/or reuse of the foundation.

SUMMARY

In one aspect thereof, the invention comprises a foundation system that can be used for both permanent and temporary roadside sign installation. The foundation is reusable and meets national safety requirements. As compared to conventional concrete sign foundation systems, this foundation requires less manpower to install, expends less nonrenewable resources to install, is adaptable to all soil types, can be installed in hard to reach locations more easily, does not generate earthen spoils, and allows sign installation up to 350 times faster than conventional foundations.

In another aspect thereof, the invention comprises a ground screw anchor foundation including an anchor plate of a breakaway system and a soil screw foundation. In preferred embodiments, the soil screw is steel. Embodiments of this ground screw anchor foundation can be screwed into and out of the ground with equal ease, and thus are totally reusable; unlike conventional concrete foundations. Embodiments of this ground screw anchor foundation can be installed in any soil type. Embodiments of this ground screw anchor foundation can be installed and ready for sign placement in less than 15 minutes, compared to the 96 hours for a sign placed on a concrete foundation (including cure time for the concrete), i.e., over 350 times faster than concrete foundations.

In other aspects thereof, the invention comprises an installation device and installation methods that require only one piece of installation equipment to install a foundation for the roadside sign. Various embodiments of the installation device are a hand-held, truck-mountable and/or mountable on a compact utility vehicle (UTV) (e.g., “Bobcat” utility vehicle). Various embodiments of the installation device are hydraulic powered and/or electric powered. The UTV-mountable installation device and/or the hand-held installation device allow for easy access to those hard to access locations, cutting down on the need for specialized equipment and the expense to access these locations with large cumbersome drilling equipment needed for drilled shaft foundations.

In still further aspects, the invention includes methods for installing foundations for roadside signs that do not require any heavy, exhaustive lifting and/or concrete mixing as required for the conventional concrete foundations. Embodiments of the invention require only the lifting of a ground screw anchor foundation that weighs, on average, within the range from 18 to 21 pounds (as compared to five, 80 pound bags of concrete and 30 pounds of water that must be loaded, unloaded, and mixed for every drilled shaft).

In another aspect thereof, the invention comprises systems for installing a roadside sign that do not produce earthen spoils like a drilled shaft foundation. Embodiments of the ground screw anchor foundation do not displace soil upward. Instead, as the screw portion of the ground screw anchor foundation is pulled into the soil by the screw threads, the surrounding soil is displaced outward (not upward), thereby compacting/densifying the surrounding soil. Since there are no spoils like a concrete foundation, there is not 350 pounds of earthen spoils to haul away or spread around every foundation location. Such embodiments may save time, money, and labor effort compared to using a conventional concrete foundation.

In still another aspect thereof, the invention comprises a foundation system that is conservative of natural- and nonrenewable-resources and is 100% recyclable. Whereas; no part of a conventional concrete shaft foundation can be economically recycled, embodiments of the invention may be formed from steel (a recyclable material). Preferred embodiments may be formed from recycled steel. Further embodiments conserve resources since a sign crew and equipment are only required to travel to a foundation site one time (instead of twice) to complete installation of a sign foundation and sign. Thus, with respect to the expenditure of nonrenewable fuel resources, installation in accordance with these embodiments is twice as efficient as the installation of a conventional concrete foundation.

In yet another aspect thereof, a ground screw anchor foundation for a roadside sign comprises at least one elongated soil screw defining a longitudinal axis. Each soil screw includes a barrel section having an upper end and a lower end defining a first length therebetween, and a substantially circular cross-section of a first diameter, viewed along the longitudinal axis. Each soil screw further includes a point section connected to the lower end of the barrel section, the point section tapering from a second diameter at a position along the longitudinal axis proximate to the barrel section to a third diameter at a position along the longitudinal axis distal to the barrel section. A helical thread is disposed around the longitudinal axis on an outer surface of at least a portion of the point section. The ground screw anchor foundation further comprises a first component of a breakaway system is mounted on the upper end of the barrel section of the soil screw.

In another embodiment, the first component of the breakaway system further comprises a plate member having a substantially planar upper surface. The plate member is mounted on the upper end of the barrel section such that the plane of the upper surface forms an angle with the longitudinal axis, the angle being within the range from 60° to 90°.

In another embodiment, the plate member of the first component of the breakaway system includes three lateral sides depending from the upper surface, the lateral sides being configured in the form of an equilateral triangle; and each lateral side being configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch at each point of intersection.

In yet another embodiment, the ground screw anchor foundation further comprises a second soil screw disposed in a spaced-apart relation to the first soil screw, the longitudinal axis of the second soil screw being substantially parallel to the longitudinal axis of the first soil screw. The first component of the breakaway system includes a channel member mounted to the respective upper ends of the barrel sections of the first and second soil screws and a plate member having a substantially planar upper surface mounted on the beam such that the plane of the upper surface of the plate member forms an angle with the longitudinal axes of the soil screws, the angle being within the range from 60° to 90°.

In still another embodiment, the plate member of the first component of the breakaway system includes three lateral sides depending from the upper surface, the lateral sides being configured in the form of an equilateral triangle; and each lateral side being configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch at each point of intersection.

In yet another aspect thereof, a method is provided for installing a ground screw anchor foundation for a roadside sign in a soil substrate, the foundation being adapted for supporting a roadside sign including a second component of a breakaway system, a sign post attached to an upper side of the second component, and a sign attached to the sign post. The method comprises the following steps: 1) providing a first elongated soil screw; 2) providing a first component of a breakaway system, the first component being cooperatively engageable in a breakaway manner to a second component of a breakaway system adapted for attachment to a roadside sign; 3) connecting the first component of the breakaway system to the upper end of the barrel section of the first soil screw; 4) releasably connecting a torque-supplying device to the first soil screw; 5) positioning the first soil screw such that the point section is disposed on a surface of a soil substrate and the longitudinal axis is oriented substantially perpendicular to the surface of the soil substrate; 6) rotating the first soil screw about its longitudinal axis with the torque supplying device until the helical thread on the point section engages the soil substrate and draws the point section a predetermined distance into the soil substrate; and 7) disconnecting the torque-supplying device from the first soil screw.

In another embodiment, the first component of the breakaway system further comprises a plate member mounted on the upper end of the barrel section of the soil screw, the plate member having a substantially planar upper surface, three lateral sides depending from the upper surface, the lateral sides being configured in the form of an equilateral triangle; and each lateral side being configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch at each point of intersection.

In another embodiment, the first component of the breakaway system is connected to the soil screw before the soil screw is releasably connected to the torque-supplying device; and the torque-supplying device includes an adapter, the adapter being configured to releasably connect to the first component of the breakaway mounting member such that torque from the torque-supplying device is transmitted through the adapter and through the first breakaway mounting member to rotate the soil screw around its longitudinal axis and into the soil.

In yet another embodiment, the torque-supplying device comprises an electric motor operatively connected to the soil screw for rotating the soil screw around its longitudinal axis.

In yet another embodiment, the torque-supplying device comprises a hydraulic motor operatively connected to the soil screw for rotating the soil screw around its longitudinal axis.

In still another embodiment, the torque-supplying device comprises an internal combustion engine operatively connected to the soil screw for rotating the soil screw around its longitudinal axis.

In a still further embodiment, the method further comprises the following steps: a) providing a second elongated soil screw; b) releasably connecting a torque-supplying device to the second soil screw; c) positioning the second soil screw such that the point section is disposed on the surface of the soil substrate and the longitudinal axis is oriented substantially perpendicular to the surface of the soil substrate; d) rotating the second soil screw about its longitudinal axis with the torque supplying device until the helical thread on the point section engages the soil substrate and draws the point section a predetermined distance into the soil substrate; e) disconnecting the torque-supplying device from the second soil screw; and attaching the first component of the breakaway system to the respective upper ends of the first and second soil screws

In another embodiment, the first component of the breakaway system further comprises a channel member connected to the respective upper ends of the first and second soil screws and a plate member mounted on the channel member. The plate member has a substantially planar upper surface and three lateral sides depending from the upper surface. The lateral sides are configured in the form of an equilateral triangle; and each lateral side is configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch at each point of intersection.

In still another embodiment, the first component of the breakaway system further comprises a channel member connected to the respective upper ends of the first and second soil screws and a plate member mounted on the channel member. The plate member has a substantially planar upper surface and is mounted on the beam such that the plane of the upper surface of the plate member forms an angle with the longitudinal axes of the soil screws, the angle being within the range from 60° to 90°.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:

FIGS. 1a, 1b and 1c show a ground screw anchor foundation in accordance with a first embodiment having a triangular plate member, wherein FIG. 1a is a perspective view, FIG. 1b is a top view, and FIG. 1c is a side view;

FIG. 1d shows an alternative embodiment having a square plate member;

FIG. 1e shows an alternative embodiment having a rectangular plate member;

FIG. 2 shows a roadside sign mounted on the ground screw anchor foundation of FIGS. 1a, 1b and 1c;

FIG. 3 shows an enlarged partial view of a roadside sign assembly;

FIG. 4 shows a ground screw anchor foundation in accordance with another embodiment having multiple ground screw anchors and a triangular plate member;

FIGS. 5a, 5b, 5c and 5d show additional views of the first component of a breakaway system for the ground screw anchor foundation of FIG. 4, wherein FIG. 5a is a perspective view, FIG. 5b is a top view, and FIG. 5c is an end view (i.e., viewed in the direction of line 408) and FIG. 5d is a side view;

FIG. 5e shows an alternative embodiment having a square plate member;

FIG. 5f shows an alternative embodiment having a rectangular plate member;

FIG. 6 shows a roadside sign mounted on the ground screw anchor foundation of FIG. 4; and

FIG. 7 shows installation of a ground screw anchor using a torque-supplying device and an adapter in accordance with another embodiment.

DETAILED DESCRIPTION

Referring now to FIGS. 1a, 1b, and 1c, there is illustrated a ground screw anchor foundation for a roadside sign in accordance with one embodiment. The ground screw anchor foundation 100 of this embodiment comprises an elongated soil screw 102 defining a longitudinal axis 104. The soil screw 102 includes a barrel section 106 having an upper end 108 and a lower end 110 defining a first length (denoted L₁) therebetween. The barrel section 106 has a substantially circular cross-section of a first diameter (denoted D₁) when viewed along the longitudinal axis 104. In some embodiments, the diameter D₁ of the barrel section 106 is within the range from 3.0 inches to 4.0 inches. In preferred embodiments, the diameter D₁ is within the range from 3.25 inches to 3.75 inches. In some embodiments, the diameter D₁ of the barrel section 106 is about 3.5 inches.

A point section 112 is connected to the lower end 110 of the barrel section 106. The point section has an upper end 113 and a lower end 115 defining a second length (denoted L₂) therebetween. The point section 112 tapers from a second diameter (denoted D₂) at a position along the longitudinal axis 104 proximate to the barrel section 106 to a third diameter (denoted D₃) at a position along the longitudinal axis distal to the barrel section. In the illustrated embodiment, the taper of the point section 112 is a single, constant angle (i.e., conic taper); however, in other embodiments the taper of the point section may include two or more angles (i.e., bi-conic or multi-conic taper) or may change continuously (e.g., secant- or elliptical-ogive taper).

A helical thread 114 is disposed around the longitudinal axis 104 on an outer surface of at least a portion of the point section 112. In some embodiments the thread 114 is disposed entirely on the point section 112, while in other embodiments the helical thread may be disposed on portions of the barrel section 106 and the point section 112. A first component 116 of a breakaway system mounted on the upper end 108 of the barrel section 106 of the soil screw 102.

As best seen in FIG. 1c, in some embodiments, the first component 116 of the breakaway system may further comprise a plate member 118 having a substantially planar upper surface 120. The plate member 118 is mounted on the upper end 108 of the barrel section 106 such that the plane 122 of the upper surface 120 forms an angle (denoted A₁) with the longitudinal axis 104, the angle being within the range from 60° to 90°. Preferably, the plane 122 of the upper surface 120 forms an angle θ₁ with the longitudinal axis 104 within the range from 80° to 90°. In some embodiments, the upper surface 120 of the plate member 118 will be horizontal after installation of the foundation 100.

As best seen in FIG. 1b, in some embodiments, the plate member 118 of the first component 116 of the breakaway system includes three lateral sides 124 depending from the upper surface 120. The lateral sides 124 may be configured in the form of an equilateral triangle; with each lateral side being configured to terminate before reaching an apex 126 with an adjacent lateral side, thereby defining a notch 128 at each point of intersection (of the lines extending from the lateral sides). In other embodiments, the plate member 118 may be configured as a non-equilateral triangle.

Referring now also to FIGS. 1d and 1e, in still other embodiments, the plate member 118 may be configured with its upper surface 120 in the shape of a square, a rectangle or yet another different shape. FIG. 1d illustrates an embodiment of a first component 116 having a plate member 118′ configured in a square shape. FIG. 1e illustrates an embodiment of a first component 116 having a plate member 118″ configured in a rectangular shape. Whether configured as a triangle, a square, a rectangle or other shape, the plate member 118 of some embodiments may include notches 128 formed at each point of intersection of the lateral sides (i.e., at the “corners” of the plate member), whereas the plate members of other embodiments may not include notches.

Referring now to FIG. 2, there is illustrated a roadside sign assembly in accordance with another embodiment. The roadside sign assembly 200 includes a roadside sign 202 mounted on the upper end 204 of a sign post 206. A ground screw anchor foundation as disclosed herein is connected to the lower end 208 of the sign post 206. In the embodiment illustrated in FIG. 2, the ground screw anchor foundation is a foundation 100 substantially identical to the foundation described in connection with FIGS. 1a, 1b and 1c, however, other ground screw anchor foundations as disclosed herein may also be used. The sign post 206 includes on the lower end 208 a second component 210 of a breakaway system. The ground screw anchor foundation 100 is installed such that a majority of the soil screw 102 is substantially engaged in the soil substrate 212 (also referred to as “soil”, “ground” or “earth”) below the ground surface 214 (also referred to as “grade”). For purposes of illustration, the soil substrate 212 is shown in the Figures extending only a short distance below the grade 214; however, it will be appreciated that the soil actually extends downward a substantial distance past the lower end of the soil screw(s).

In preferred embodiments, the soil 212 at the installation site for the roadside sign assembly 200 is unexcavated prior to installation of the soil screw, i.e., the soil screw 102 may be driven directly into unexcavated soil. Alternatively, the soil screw 102 may be driven into compacted soil, loose soil, clay, gravel or other ground substrates. The second component 210 of the breakaway system mounted on the lower end 208 of the sign post 206 is connected to the first component 116 of the breakaway system mounted on the upper end 108 of the soil screw 102. In this manner, the roadside sign 202 and post 206 are securely supported by the ground screw anchor foundation 100 to form the roadside sign assembly 200.

Referring now to FIG. 3, there is illustrated an enlarged partial view of a roadside sign assembly 200. For purposes of illustration, the soil screw 102 is shown “interrupted” such that its overall length (denoted L₃) is not completely shown. In some embodiments, the overall length L₃ of the soil screw is within the range from 30 inches to 60 inches. In preferred embodiments, the overall length L₃ is within the range from 36 inches to 54 inches. In other preferred embodiments, the overall length L₃ is within the range from 39 inches to 52 inches. Selection of the length L₃ for a particular foundation 100 or sign assembly 200 may be dependent on factors such as type of soil substrate and/or size of the sign to be supported. In some embodiments, the overall length L₃ is about 39.37 inches. In some other embodiments, the overall length L₃ is about 51.18 inches. The height (denoted H₁) above the top of the soil level 214 (also called “grade”) of the ground screw anchor foundation 100, measured at the upper surface 120 of the first component 116, is preferably in the range of 4.5 inches to 0.5 inches. In more preferred embodiments, the height H₁ is in the range of 3.9 inches to 4.1 inches. In some embodiments, the height H₁ is about 4 inches.

Referring still to FIG. 3, in preferred embodiments, the first and second components 116, 210 of the breakaway system are connected to one another in a breakaway manner such that the sign post 206 will shear off the ground screw anchor foundation 100 if struck by a vehicle that has left the road. In the illustrated embodiment, the first component 116 comprises a triangular slip base mounted on the ground screw 102, and the second component 210 comprises a complementary triangular slip base. Each component 116, 210 has a plurality of notches 128 that are configured to align with the notches on the counterpart so as to receive a bolt 130 therein. The two components 116, 210 may be secured in a breakaway manner by the bolt 130, nuts 132 and washers 134 as shown in FIG. 3. A bolt keeper plate 136 may be used to hold the bolts 130 in position during installation.

Referring now to FIG. 4, there is illustrated another embodiment of a ground screw anchor foundation for a roadside sign. The ground screw anchor foundation 400 comprises a plurality of spaced-apart soil screws and a first component of a breakaway system connected to the plurality of spaced apart soil screws. The ground screw anchor foundation 400 is adapted to provide improved resistance to twisting moments imposed on the foundation by the sign being supported. Such twisting moments may be moments (denoted M₁) perpendicular to the longitudinal axis 401 of the sign post 206 (e.g., produced by wind load against the face of the sign) and/or moments (denoted M₂) parallel to the longitudinal axis of the sign post (e.g., produced by the edge of the sign “weather-vaning” into the wind). For purposes of illustration, only the lower portion of the sign, namely, sign post 206 and second component 210 of the breakaway system are shown in FIG. 4.

The ground screw anchor foundation 400 of this embodiment comprises a first soil screw 402 that may be substantially similar to soil screw 102 previously disclosed. The ground screw anchor foundation 400 further comprises a second soil screw 404 disposed in a spaced-apart relation at a distance (denoted S₁) to the first soil screw 402. The second soil screw 404 may be identical to the first soil screw 402, or it may be different. In some embodiments, the second soil screw 404 may have the same diameters D₁, D₂ and/or D₃ and/or the same lengths L₁, L₂ and/or L₃ as the first soil screw 402. The longitudinal axis 104′ of the first soil screw 402 is preferably oriented parallel to the longitudinal axis 104″ of the second soil screw 404. In preferred embodiments, the soil screws 402 and 404 are disposed such that a horizontal line 406 between their respective longitudinal axes 104′ and 104″ is oriented parallel to the direction of travel (denoted by arrow 408). It will be appreciated that the face of a roadside sign is typically oriented perpendicular to the direction of travel 408, therefore, the maximum wind load against the face of the sign (for a given wind speed) will occur in the direction of travel.

Referring still to FIG. 4, and now also to FIGS. 5a, 5b, 5c, 5d, 5e and 5f, the first component 410 of the breakaway system is connected to the plurality of soil screws 402 and 404. The first component 410 includes an elongated channel member 412 defining a lateral axis 413 and having a vertical length (denoted L₄), a plate member 418 and a substantially planar upper surface 420. The plate member 418 is mounted on the channel member 412 so as to position the plate member a predetermined distance (denoted H₂) above the upper surface of the channel member. In the illustrated embodiment, a stub pipe 422 is connected between the channel member 412 and the plate member 418 to mount the plate member at the desired height H₂. In preferred embodiments, the height H₂ is 4 inches or less. The channel member 412 is preferably installed such that its upper surface is no higher than, or preferably below, the prevailing grade 214. In such installations, only the plate member 418 and any mounting components (such as stub pipe 422) will project above the prevailing grade 214.

The plate member 418 may be mounted on the channel member 412 such that the plane 424 of the upper surface 420 forms an angle (denoted θ₂) with the longitudinal axis of the sign post 401 (which will be vertical), the angle being within the range from 60° to 90°. Preferably, the plane 424 of the upper surface 420 forms an angle θ₂ within the range from 80° to 90°. In some embodiments, the upper surface 420 of the plate member 418 is parallel to the upper surface of the channel member 412 (see, e.g., FIG. 5d), such that the upper surface of the plate member will be horizontal after level installation of the foundation 400.

In some embodiments (see, e.g., FIGS. 5a-5d), the plate member 418 of the first component 410 of the breakaway system includes three lateral sides 426 depending from the upper surface 420. The lateral sides 426 may be configured in the form of an equilateral triangle (see, e.g., FIG. 5b); with each lateral side being configured to terminate before reaching an apex 428 with an adjacent lateral side, thereby defining a notch 430 at each point of intersection (of the lines extending from the lateral sides). In other embodiments, the plate member 418 may be configured as a non-equilateral triangle.

Referring now also to FIGS. 5e and 5f, in still other embodiments, the plate member 418 may be configured with its upper surface 420 in the shape of a square, a rectangular or yet another different shape. FIG. 5e illustrates an embodiment of a first component 410 having a plate member 418′ configured in a square shape. FIG. 5f illustrates an embodiment of a first component 410 having a plate member 418″ configured in a rectangular shape. Whether configured as a triangle, a square, a rectangle or other shape, the plate member 418 of some embodiments may include notches 430 formed at each point of intersection of the lateral sides (i.e., at the “corners” of the plate member), whereas the plate members of other embodiments may not include notches.

As best seen in FIGS. 5a and 5c, the channel member 412 may include a pair of side plates 414 connected to either side of a connecting web 416. The side plates 414 preferably project from the connecting web 416 in the opposite direction from the plate member 418. For example, when oriented for installation on the ground, the plate member 418 is positioned above the connecting web 416 and the side plates 414 are positioned below the plate member. This configuration allows the side plates 414 to more easily penetrate into the ground to a lower level than the connecting web 416 when the foundation is installed.

Referring now to FIG. 6, there is illustrated a roadside sign assembly in accordance with another embodiment. The roadside sign assembly 600 includes a roadside sign 202 mounted on the upper end 204 of a sign post 206. A ground screw anchor foundation 400 having multiple soil screws as disclosed herein is connected to the lower end 208 of the sign post 206. In the embodiment illustrated in FIG. 6, the ground screw anchor foundation 400 is substantially identical to the foundation described in connection with FIGS. 4, 5a, 5b, 5c and 5d, however, other ground screw anchor foundations as disclosed herein may also be used. The sign post 206 includes a second component 210 of a breakaway system connected to the lower end 208. The ground screw anchor foundation 400 is installed such that the soil screws 402 and 404 are substantially completely engaged in the soil substrate 212 below the ground surface 214. The ground screw anchor foundation 400 comprises a plurality of spaced-apart soil screws 402, 404 and a first component 410 of a breakaway system connected to the plurality of spaced apart soil screws. The roadside sign assembly 600 is adapted to provide improved resistance to wind loads.

A ground screw anchor foundation for a roadside sign, for example, a foundation 100 according to the embodiment of FIGS. 1a-1c or FIG. 3, may be installed in a soil substrate 212 in accordance with the following procedure: 1) providing a first elongated soil screw 102; 2) providing a first component 116 of a breakaway system, the first component being cooperatively engageable in a breakaway manner to a second component of a breakaway system adapted for attachment to a roadside sign; 3) connecting the first component 116 of the breakaway system to the upper end 108 of the first soil screw 102; 4) releasably connecting a torque-supplying device (702, FIG. 7) to the first soil screw 102; 5) positioning the first soil screw 102 such that the point section 112 is disposed on a surface of a soil substrate 212 and the longitudinal axis 104 is oriented substantially perpendicular to the surface 214 (i.e., grade) of the soil substrate; 6) rotating the first soil screw 102 about its longitudinal axis 104 with the torque supplying device 702 until the helical thread 114 on the point section 112 engages the soil substrate 212 and draws the point section a predetermined distance (e.g., a distance equal to L₃ minus H₁ in FIG. 3) into the soil substrate; and 7) disconnecting the torque-supplying device 702 from the first soil screw 102. Following this installation of the foundation, a sign assembly having a second component 210 of the breakaway system can be attached to the first component 116.

Connection of the first component 116 to the soil screw 102 is typically performed using a permanent joining method such as welding, brazing, soldering or the like. In some embodiments, however, non-permanent connection methods such as threading or bolting may be used. In preferred embodiments of the installation method just described, the first component 116 is connected to the soil screw 102 prior to installing the soil screw in the ground; however, this is not required. In some embodiments, the first component 116 may be connected to the soil screw 102 after installation of the soil screw in the ground.

In some embodiments, the torque-supplying device 702 described herein may comprise an electric motor operatively connected to the soil screw 102 for rotating the soil screw around its longitudinal axis 104. In other embodiments, the torque-supplying device 702 may comprise a hydraulic motor or internal combustion engine operatively connected to the soil screw 102 for rotating the soil screw around its longitudinal axis 104. In preferred embodiments, the torque-supplying device 702 is a hydraulic- or electric-powered auger attachment mounted on a small utility vehicle (e.g., a Bobcat® utility vehicle) or utility truck (not shown). However, in other cases the torque-supplying device 702 may be a hand-held (motor-driven) auger drive, or even hand tools such as wrenches equipped with suitable torque-enhancing handles (i.e., “cheater bars”).

In another embodiment of the installation method, the first component 116 of the breakaway system further comprises a plate member 118 mounted on the upper end of the barrel section 106 of the soil screw 102. In preferred embodiments, the plate member 118 may have a substantially planar upper surface 120 and three lateral sides 124 depending from the upper surface, the lateral sides being configured in the form of an equilateral triangle. In some such embodiments, each lateral side 124 may be configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch 128 at each point of intersection.

Referring now to FIG. 7, in another embodiment, the first component 116 of the breakaway system is connected to the soil screw 102 before the soil screw is releasably connected to the torque-supplying device 702; and the torque-supplying device includes an adapter 700. The adapter 700 may be configured to releasably connect to the first component 116 such that torque from the torque-supplying device 702 is transmitted through the adapter and through the first breakaway mounting member to rotate the soil screw 102 around its longitudinal axis 104 and into the soil 212. The adapter 700 may include a drive plate 704 that is configured to be releasably connectable to the first component 116 using removable fasteners such as bolts 130 and nuts 132.

A ground screw anchor foundation for a roadside sign, for example, a foundation 400 having multiple soil screws according to the embodiments shown in FIGS. 4, 5a-5d and 6, may be installed in a soil substrate 212 in accordance with the following procedure: 1) providing a first elongated soil screw 402; 2) releasably connecting a torque-supplying device 702 to the first soil screw 402; 3) positioning the first soil screw 402 such that the point section 112 is disposed on a surface of a soil substrate 212 and the longitudinal axis 104 is oriented substantially perpendicular to the surface 214 (i.e., grade) of the soil substrate; 4) rotating the first soil screw 402 about its longitudinal axis 104 with the torque supplying device 702 until the helical thread 114 on the point section 112 engages the soil substrate 212 and draws the point section a predetermined distance (e.g., a distance equal to L₃ plus L₄) into the soil substrate; 5) disconnecting the torque-supplying device 702 from the first soil screw 402; 6) providing a second elongated soil screw 404; 7) releasably connecting a torque-supplying device 702 to the second soil screw 404; 8) positioning the second soil screw 404 such that the point section 112 is disposed on the surface 214 of the soil substrate 212 and the longitudinal axis 104 is oriented substantially perpendicular to the surface of the soil substrate and spaced-apart from the longitudinal axis of the first soil screw; 9) rotating the second soil screw 404 about its longitudinal axis 104 with the torque supplying device 702 until the helical thread 114 on the point section 112 engages the soil substrate 212 and draws the point section a predetermined distance into the soil substrate; 10) disconnecting the torque-supplying device 702 from the second soil screw 404; 11) providing a first component 410 of a breakaway system, the first component being cooperatively engageable in a breakaway manner to a second component of a breakaway system adapted for attachment to a roadside sign; 12) connecting the first component 410 to the upper end 108 of the first soil screw 402; and 13) connecting the first component 410 to the upper end 108 of the second soil screw 404.

In one embodiment of the method just described, the first component 410 of the breakaway system further comprises a channel member 412 connected to the respective upper ends 108 of the first and second soil screws 402 and 404 and a plate member 418 mounted on the channel member. The plate member 418 may have a substantially planar upper surface 420 and three lateral sides 426 depending from the upper surface. The lateral sides 426 may be configured in the form of an equilateral triangle; and each lateral side may be configured to terminate before reaching an apex 428 with an adjacent lateral side, thereby defining a notch 430 at each point of intersection.

Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A ground screw anchor foundation for a roadside sign having a second component of a breakaway system, the ground screw anchor foundation comprising:

at least one elongated soil screw defining a longitudinal axis, each soil screw including a barrel section having an upper end and a lower end defining a first length therebetween, and a substantially circular cross-section of a first diameter, viewed along the longitudinal axis, a point section connected to the lower end of the barrel section, the point section tapering from a second diameter at a position along the longitudinal axis proximate to the barrel section to a third diameter at a position along the longitudinal axis distal to the barrel section; and a helical thread disposed around the longitudinal axis on an outer surface of at least a portion of the point section; and

a first component of a breakaway system mounted on the upper end of the barrel section of the soil screw, the first component being adapted for releasable connection in a breakaway manner to a second component on a roadside sign.

2. A ground screw anchor foundation in accordance with claim 1, wherein the first component of the breakaway system further comprises:

a plate member having a substantially planar upper surface; and

wherein the plate member is mounted on the upper end of the barrel section such that the plane of the upper surface forms an angle with the longitudinal axis, the angle being within the range from 60° to 90°.

3. A ground screw anchor foundation in accordance with claim 2, wherein the plate member of the first component of the breakaway system includes:

three lateral sides depending from the upper surface, the lateral sides being configured in the form of an equilateral triangle; and

each lateral side being configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch at each point of intersection.

4. A ground screw anchor foundation in accordance with claim 1, further comprising:

a second soil screw disposed in a spaced-apart relation to the first soil screw, the longitudinal axis of the second soil screw being substantially parallel to the longitudinal axis of the first soil screw; and

wherein the first component of the breakaway system includes a channel member mounted to the respective upper ends of the barrel sections of the first and second soil screws and a plate member having a substantially planar upper surface mounted on the beam such that the plane of the upper surface of the plate member forms an angle with the longitudinal axes of the soil screws, the angle being within the range from 60° to 90°.

5. A ground screw anchor foundation in accordance with claim 4, wherein the plate member of the first component of the breakaway system includes:

three lateral sides depending from the upper surface, the lateral sides being configured in the form of an equilateral triangle; and

each lateral side being configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch at each point of intersection.

6. A method for installing a ground screw anchor foundation for a roadside sign in a soil substrate, the foundation adapted for supporting a roadside sign including a second component of a breakaway system, a sign post attached to an upper side of the second component, and a sign attached to the sign post, the method comprising the following steps:

providing a first elongated soil screw defining a longitudinal axis, the first soil screw including a barrel section having an upper end and a lower end defining a first length therebetween, and a substantially circular cross-section of a first diameter, viewed along the longitudinal axis, a point section connected to the lower end of the barrel section, the point section tapering from a second diameter at a position along the longitudinal axis proximate to the barrel section to a third diameter at a position along the longitudinal axis distal to the barrel section; and a helical thread disposed around the longitudinal axis on an outer surface of at least a portion of the point section; and

providing a first component of a breakaway system, the first component being cooperatively engageable in a breakaway manner to a second component of a breakaway system adapted for attachment to a roadside sign;

connecting the first component of the breakaway system to the upper end of the barrel section of the first soil screw;

releasably connecting a torque-supplying device to the first soil screw;

positioning the first soil screw such that the point section is disposed on a surface of a soil substrate and the longitudinal axis is oriented substantially perpendicular to the surface of the soil substrate;

rotating the first soil screw about its longitudinal axis with the torque supplying device until the helical thread on the point section engages the soil substrate and draws the point section a predetermined distance into the soil substrate; and

disconnecting the torque-supplying device from the first soil screw.

7. A method for installing a ground screw anchor foundation in accordance with claim 6, wherein the first component of the breakaway system further comprises:

a plate member mounted on the upper end of the barrel section of the soil screw, the plate member having a substantially planar upper surface, three lateral sides depending from the upper surface, the lateral sides being configured in the form of an equilateral triangle; and each lateral side being configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch at each point of intersection.

8. A method for installing a ground screw anchor foundation in accordance with claim 6, wherein:

the first component of the breakaway system is connected to the soil screw before the soil screw is releasably connected to the torque-supplying device; and

the torque-supplying device includes an adapter, the adapter being configured to releasably connect to the first component of the breakaway mounting member such that torque from the torque-supplying device is transmitted through the adapter and through the first breakaway mounting member to rotate the soil screw around its longitudinal axis and into the soil.

9. A method for installing a ground screw anchor foundation in accordance with claim 7, wherein the torque-supplying device comprises an electric motor operatively connected to the soil screw for rotating the soil screw around its longitudinal axis.

10. A method for installing a ground screw anchor foundation in accordance with claim 7, wherein the torque-supplying device comprises a hydraulic motor operatively connected to the soil screw for rotating the soil screw around its longitudinal axis.

11. A method for installing a ground screw anchor foundation in accordance with claim 7, wherein the torque-supplying device comprises an internal combustion engine operatively connected to the soil screw for rotating the soil screw around its longitudinal axis.

12. A method for installing a ground screw anchor foundation in accordance with claim 6, wherein the method further comprises:

providing a second elongated soil screw defining a longitudinal axis, the second soil screw including a barrel section having an upper end and a lower end defining a first length therebetween, and a substantially circular cross-section of a first diameter, viewed along the longitudinal axis, a point section connected to the lower end of the barrel section, the point section tapering from a second diameter at a position along the longitudinal axis proximate to the barrel section to a third diameter at a position along the longitudinal axis distal to the barrel section; and a helical thread disposed around the longitudinal axis on an outer surface of at least a portion of the point section;

releasably connecting a torque-supplying device to the second soil screw;

positioning the second soil screw such that the point section is disposed on the surface of the soil substrate and the longitudinal axis is oriented substantially perpendicular to the surface of the soil substrate;

rotating the second soil screw about its longitudinal axis with the torque supplying device until the helical thread on the point section engages the soil substrate and draws the point section a predetermined distance into the soil substrate;

disconnecting the torque-supplying device from the second soil screw;

wherein the first component of the breakaway system is attached to the respective upper ends of the first and second soil screws

13. A method for installing a ground screw anchor foundation in accordance with claim 12, wherein the first component of the breakaway system further comprises:

a channel member connected to the respective upper ends of the first and second soil screws; and

a plate member mounted on the channel member, the plate member having a substantially planar upper surface, three lateral sides depending from the upper surface, the lateral sides being configured in the form of an equilateral triangle; and each lateral side being configured to terminate before reaching an apex with an adjacent lateral side, thereby defining a notch at each point of intersection.

14. A method for installing a ground screw anchor foundation in accordance with claim 12, wherein the first component of the breakaway system further comprises:

a channel member connected to the respective upper ends of the first and second soil screws; and

a plate member mounted on the channel member, the plate member having a substantially planar upper surface and being mounted on the beam such that the plane of the upper surface of the plate member forms an angle with the longitudinal axes of the soil screws, the angle being within the range from 60° to 90°.

15. A ground screw anchor foundation for a roadside sign having a second component of a breakaway system, the ground screw anchor foundation comprising:

a first elongated soil screw defining a first longitudinal axis;

a second elongated soil screw defining a second longitudinal axis;

each soil screw including a barrel section extending along the longitudinal axis and having an upper end and a lower end defining a first length therebetween, and a substantially circular cross-section of a first diameter, viewed along the longitudinal axis, a point section connected to the lower end of the barrel section, the point section tapering from a second diameter at a position along the longitudinal axis proximate to the barrel section to a third diameter at a position along the longitudinal axis distal to the barrel section; and a helical thread disposed around the longitudinal axis on an outer surface of at least a portion of the point section;

an elongated channel member defining a lateral axis and mounted to the upper ends of the first and second soil screws such that the respective longitudinal axes of the soil screws are oriented substantially parallel to one another, substantially perpendicular to the lateral axis of the channel member and spaced apart from one another along the lateral axis; and

a plate member having a substantially planar upper surface, the plate member rigidly connected to an upper surface of the channel member such that the planar upper surface is disposed at a predetermined height above the channel member;

wherein the plate member is configured as a first component of a breakaway system, the first component being adapted for releasable connection in a breakaway manner to a second component on a roadside sign.

16. A ground screw anchor foundation in accordance with claim 15, wherein the channel member further comprises:

a connecting web;

a pair of side plates connected to either side of the connecting web;

wherein the side plates project from the connecting web in the opposite direction from the plate member.