WO2007130667A2 - Fondation d'ancrage à pieux en post-tension et procédé associé - Google Patents

Fondation d'ancrage à pieux en post-tension et procédé associé Download PDF

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Publication number
WO2007130667A2
WO2007130667A2 PCT/US2007/010995 US2007010995W WO2007130667A2 WO 2007130667 A2 WO2007130667 A2 WO 2007130667A2 US 2007010995 W US2007010995 W US 2007010995W WO 2007130667 A2 WO2007130667 A2 WO 2007130667A2
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WO
WIPO (PCT)
Prior art keywords
foundation
pile
cap
post
foundation cap
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Application number
PCT/US2007/010995
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English (en)
Other versions
WO2007130667A3 (fr
Inventor
Allan P. Henderson
Original Assignee
Henderson Allan P
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Henderson Allan P filed Critical Henderson Allan P
Priority to CA2651259A priority Critical patent/CA2651259C/fr
Publication of WO2007130667A2 publication Critical patent/WO2007130667A2/fr
Publication of WO2007130667A3 publication Critical patent/WO2007130667A3/fr

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D27/00—Foundations as substructures
    • E02D27/32—Foundations for special purposes
    • E02D27/42—Foundations for poles, masts or chimneys
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D27/00—Foundations as substructures
    • E02D27/32—Foundations for special purposes
    • E02D27/42—Foundations for poles, masts or chimneys
    • E02D27/425—Foundations for poles, masts or chimneys specially adapted for wind motors masts

Definitions

  • the present invention is related to the field of pile anchor foundations and, more particularly, to a post-tensioned pile anchor foundation including a post-tensioned foundation cap and a plurality of post- tensioned pile anchors extending vertically downward therefrom and a method of constructing such a post- tensioned pile anchor foundation.
  • a post-tensioned concrete foundation is desirable in order to provide improved rotational stiffness, minimized movement from dynamic forces, and increased foundation frequency to approach the frequency of a rigid body.
  • Such concrete foundations are particularly useful for the support of tall, heavy and/or large towers which may be used to support wind turbines, power lines, street lighting and signals, bridge supports, commercial signs, freeway signs, ski lifts and the like.
  • the foundation of the instant invention resists supported structure overturn by a multitude of circumferentially spaced post tensioned pile anchors driven, drilled or otherwise formed into the subsurface soil.
  • the pile anchors are constructed below a foundation concrete cap which is used to support a tower or other structure that is attached to the upper surface of the concrete cap.
  • Each pile anchor includes a post-tensioning element, such as a tendon or bolt, that extends through a pile anchor base plate and the concrete cap, and then centrally into a pile hole.
  • the pile hole can be formed in various ways known in the art, such as drilling, mandrel driving, etc.
  • Each pile hole is filled with cementious material around the tendon or bolt to secure the pile anchors into the ground.
  • the embedded portion of the tendon or bolt includes a lower end and an upper end.
  • the lower end of the bolt is bare, i.e., is in direct contact with the cementious material, for bonding with the cementious material in a bottom- portion of the pile anchor.
  • One or more end nuts may be provided on the bolt lower end to facilitate bonding of the bolt lower end with the cementious material.
  • one or more centralizers center the tendon or bolt in the drilled pile hole.
  • the upper end of the embedded portion of the bolt is encased, preferably in a plastic sleeve or the like, and most preferably in a polyvinyl chloride (PVC) tube, so that the upper end of the bolt does not bond to the cementious material in the upper portion of the drilled pile hole .
  • the sleeve also extends upwardly through the cap so that the tendon or bolt is also prevented from bonding to the cementious material of the cap.
  • a void or space is created above the top of each, filled pile hole or pile anchor and into the adjacent lower surface of the foundation cap or leveling course.
  • One technique to form the requisite void or space is to insert a spacer or void forming element .
  • the spacer or void forming element thus defines a hollow area between the top of each pile anchor and the adjacent bottom of the foundation cap.
  • the spacer or void forming element is provided with an aperture, preferably generally cylindrical, through which the sleeved tendon or bolt extends before passing through the cap .
  • a second technique would be to form a collapsible zone with a highly compressible material similar to Styrofoam or equivalent .
  • the uppermost end of the tendon or bolt which protrudes from the top of the cap is fitted with the pile anchor base plate and a post—tensioning nut threaded thereon to post-tension the pile anchor and the concrete cap after the cementious material of the cap has hardened.
  • the compressible material, spacer or void forming element is compressed or crushed by the post-tensioning, allowing the pile anchor to pull upward until skin friction resistance with the surrounding soils equaling the required tendon tension is achieved.
  • the required bolt or tendon tension should exceed the maximum structure uplift load determined for each pile anchor.
  • a further object of the present invention is to provide a post-tensioned pile anchor foundation in accordance with the preceding objects which includes a void or spacing defining a hollow area between the top of each pile anchor and the adjacent bottom of the foundation cap so that the top of the pile anchor is pulled upwardly toward the adjacent cap bottom and the cap is pulled downwardly against the surrounding soil during the post-tensioning of each anchor tendon or bolt.
  • a still further object of the present invention is to provide a post-tensioned pile anchor foundation in accordance with the preceding object in which the void or spacing is preferably formed by a compressible (including crushable) spacer or void forming element.
  • Still yet another object of the present invention is to provide a pile anchor foundation which has greater flexibility to design for supporting a wide range of towers or other structures, including the addition of further weight components .
  • the number of pile anchors can be easily increased or decreased for any particular design depending upon the design capacity of the foundation, including the addition of an inner circle of separate post-tensioned pile anchors, if desired.
  • a further object of the present invention is to provide a post-tensioned pile anchor foundation in accordance with the preceding objects, which can be constructed and effective in soils with long-term compressibility, where other foundations are inadequate, because long-term settlement can be addressed in the foundation of the present invention by simply re-tensioning the anchor bolts periodically.
  • a further object of the present invention is to provide a post-tensioned pile anchor foundation in accordance with the preceding objects which can be constructed and operate effectively in storm surge, flood, scour, erosion, and seismic zones inasmuch as the foundation of the present invention is anchored and supported deep below the surface and is able to be re- tensioned.
  • Yet another object of the present invention is to provide a method for forming the post-tensioned pile anchor foundations recited in the preceding objects.
  • a final object of the present invention to be set forth herein is to provide a post-tensioned pile anchor foundation and method for construction which may be utilized in a wide range of soils from water-laden sand or clay formations to solid rock, may be formed in situ, in remote locations, and will incorporate a minimum amount of concrete or other cementious materials, while providing at the same time a concrete foundation which can be maintained under heavy post- tension forces.
  • Figure 1 is a schematic perspective and partial sectional view of a complete cap and pile anchor foundation constructed in accordance with a preferred embodiment of the present invention.
  • Figure 2 is a cross-sectional side view of the complete foundation of Figure 1 showing the concrete cap positioned above the concrete pile anchors and the bolts or tendons extending therethrough in accordance with the present invention.
  • Figure 3 is a top plan view of the cap foundation of Figure 1 before concrete is poured.
  • Figure 4A is a top plan view of one embodiment of a void forming element for the completed cap and pile anchor foundation of Figure 1.
  • Figure 4B is a section view of the void forming element of Figure 4A.
  • Figure 5 is a partially sectioned side view of a first step in forming the completed foundation with the concrete cap and pile anchors as shown in Figure 1.
  • Figure 6 is a partially sectioned side view of a second step in forming the completed foundation following the first step of Figure 5.
  • Figure 7 is a partially sectioned side view of a third step in forming the completed foundation following the second step of Figure 6.
  • Figure 8 is a partially sectioned side view of a fourth step in forming the completed foundation following the third step of Figure 7.
  • Figure 9 is a partially sectioned side view of an optional fifth step in forming the completed foundation following the fourth step of Figure 8.
  • Figure 10 is a schematic perspective and partial sectional view, similar to Figure 1, of a complete cap and pile anchor foundation constructed in accordance with a second embodiment of the present invention.
  • Figure 11 is a cross-sectional side view of the complete foundation of Figure 10, similar to Figure 2.
  • pile anchor foundation according to the present invention is shown in the *281 application using corrugated metal pipes to define the perimeter wall of the anchor piles . It has been found that the pile anchors can be formed in various other ways known to those skilled in the art in order to form a post-tensioned foundation according to the present invention. Such further embodiments are illustrated and described herein.
  • another post- tensioned pile anchor foundation of the present invention has a circular concrete cap, generally designated by reference numeral 10.
  • the cap 10 is made of cementious material 46 and preferably defined by corrugated metal pipe 104 around its periphery and by the soil at the bottom 82 of an excavation in a ground surface.
  • the soil underneath the cap 10 is preferably compacted to a depth of 12 inches or more.
  • the cap is set at or below the ground surface and a plurality of pile anchors, generally designated by the reference numeral 12 extend vertically downward into the soil 100 from the bottom 11 of cap 10.
  • the pile anchors 12 serve to secure the concrete cap 10 into the ground.
  • the foundation cap 10 includes a series of tower anchor bolts 14 spaced circumferentially about the central vertical axis of the foundation cap.
  • the tower anchor bolts 14 are preferably positioned in radial pairs forming two anchor bolt circles, generally designated by the reference numerals 16 and 18.
  • the inner tower anchor bolt circle 16 has a slightly shorter diameter than the outer tower anchor bolt circle 18.
  • the outer tower anchor bolt circle diameter may be about fourteen feet and the inner tower anchor bolt circle diameter may be about thirteen feet.
  • a tower or other supported structure (not shown) can be attached to the concrete cap 10 by the tower anchor bolts 14.
  • Structures which can be supported on the post-tension pile anchor foundation of the present invention include, but are not limited to, transmission towers, electrical towers, communication towers, lighting standards, bridge supports, commercial signs, freeway signs, ski lift supports, solar energy towers, wind turbine towers, large stacks or chimneys, silos, tank structures, airport towers, guard towers, etc .
  • the tower anchor bolts 14 extend through and are nutted atop a typical circular tower base flange at the bottom of the tower or other supported structure positioned and grouted in grout trough 23 in the cap upper surface.
  • the other or bottom end of the bolts 14 extends to an embedment ring 22 near the bottom of the concrete cap.
  • the tower anchor bolts 14 are sleeved in elongated hollow tubes 15, preferably PVC tubes, which cover the anchor bolts except for threaded portions at the top and bottom of the bolts .
  • the anchor bolt sleeves prevent bonding of the bolts to the concrete and grout. This structure allows the tower anchor bolts to be elongated and post-stressed between the tower base flange and the embedment ring to alleviate bolt cycling and fatigue .
  • the lower ends of the tower anchor bolts 14 are anchored near the bottom of the concrete cap foundation with the embedment ring 22 with suitable nuts 102 or the like.
  • the embedment ring 22 is
  • the embedment ring 22 is approximately the same size as and is complementary to the tower base flange 21.
  • the ring 22 contains bolt holes for each of the tower anchor bolts .
  • the tower- base flange 21 is preferably seated in the grout trough 23.
  • Reinforcing steel rebar 24 is positioned radially between the pairs of tower anchor bolts 14 and pile anchor bolts 26.
  • the radial steel rebar is preferably in the shape of rebar hoops extending both near the " top and the bottom of the concrete cap foundation 10.
  • the rebar hoops are lapped vertically and wire tied near and parallel to the cap perimeter.
  • the rebar reinforcement which can also include welded wire mesh 28, is intended to resist bending forces in the concrete cap 10.
  • Other types of reinforcing steel as known by those skilled in the art can be used for the reinforcing steel rebar 24 of the concrete cap 10, such as bent rebar, headed rebar, bolts and nuts, bolts with forged bell ends, etc.
  • each pile anchor includes an elongated pile anchor post-tensioning element, preferably a bolt or tendon 26, that extends through a pile anchor base plate 32 on the top surface of or preferably grouted into the concrete cap 10, then through the concrete cap 10, and finally into a drilled pile hole 34 that is filled with pile anchor cementious material 36 to secure the pile anchors in the ground or soil 100.
  • an elongated pile anchor post-tensioning element preferably a bolt or tendon 26 that extends through a pile anchor base plate 32 on the top surface of or preferably grouted into the concrete cap 10, then through the concrete cap 10, and finally into a drilled pile hole 34 that is filled with pile anchor cementious material 36 to secure the pile anchors in the ground or soil 100.
  • the embedded portion of the tendon or bolt 26 includes a lower end 38 and an upper end, generally designated by the reference numeral 40.
  • the lower end 38 of the bolt is bare, i.e., is in direct contact with the cementious material 36, for bonding thereto when the material 36 is poured or pumped to fill the interior of the drilled pile holes 34.
  • the cementious material 36 preferably fills the pile holes 34 to the bottom 82 of the excavation area.
  • An end nut 42 may be provided on the lower end of the bolt 26 (see, for example, Figures 5 and 6) to facilitate bonding of the bolt lower portion 38 with the cementious material 36.
  • the upper end 40 of the embedded portion of the bolt 26 is encased in an elongated hollow tube, preferably in a plastic sleeve 44 or the like, and most preferably by PVC tubing, along a major upper portion of its length, to prevent bonding with the cementious material 46 of the concrete foundation cap 10 and the pile anchor cementious material 36 and to allow for post—tension stretching.
  • a centralizer 84 is preferably mounted around the lower portion 38 of the anchors 26 so as to position the pile anchor bolt 26 centrally within the pile hole 34.
  • the hollow tubes 15 and plastic sleeve 44 for encircling or encasing the anchor bolts 14 and the elongated pile anchor bolts 26, respectively, are preferably made of PVC tubing.
  • the plastic sleeves or tubing shield the bolts and prevent them from adhering to the cementious material.
  • the bolts can be tensioned after the cementious material has hardened and cured in order to post- tension the pile anchors and the foundation cap of the present invention.
  • the bolts can be wrapped in plastic tape, or otherwise sheathed, to prevent the bolts from adhering to the cementious material during curing and allow the bolts to stretch freely under tension over the entire sheathed length of the bolts .
  • a void or highly compressible area 54 is formed between the top of the pile anchor cementious material 36 and the adjacent lower surface 52 of the cementious material 46 of the concrete foundation cap 10.
  • the void 54 is preferably formed using a compressible (including crushable) spacer or void forming element generally designated by the reference numeral 50, which is inserted between the top of each filled pile hole 34 and the adjacent lower surface 52 of the cap 10 to be formed.
  • a compressible spacer or void forming element 50 is representatively shown in Figures 4A and 4B .
  • the void forming element defines a void or hollow area 54 above each pile anchor 12 and is provided with a generally circular aperture 56 through which the sleeved tendon or bolt 26 extends before passing through the cap 10.
  • the void forming element 50 is made to slide down the bolt 26 to sit on the bottom of the excavation area over the top of each filled pile anchor cementious material 36.
  • the void forming element 50 can be a molded plastic form made of any suitable polymer material and having an upstanding peripheral wall 60, an upper surface 62 and an open bottom 63.
  • the void forming element 50 can be constructed as a hollow disc or as a compressible disc, such as a disc made of expanded polyurethane or of styrofoara.
  • the element 50 can be virtually any natural or man-made material that is highly compressible or crushable under 10 psi pressure or greater and which allows the concrete cap foundation 10 to be pulled downwardly compressing and consolidating the underlying soils 100 to the required bearing strengths and allowing the pile anchors 12 to be pulled upwardly to develop the skin friction resistance equal to the pile anchor bolt or tendon post—tension.
  • the void forming element 50 may also be constructed as an inflatable or pressurized bladder which will allow the pile anchor 12 to be pulled upwardly and the foundation cap 10 be pulled downwardly by tensioning the anchor bolts 26.
  • the void forming element 50 can be made of a material that will develop great compressive strength when contacted with a catalyst after tensioning the anchor bolt or tendon. This embodiment includes materials in which the development of such compressive strength can be retarded for days.
  • the void forming element 50 is preferably provided with a generally cylindrical coupling component 64 that defines the circular aperture 56 and which assists in enabling the void forming element to slide down the anchor bolt 26.
  • this coupling component 64 may be embodied as a piece of PVC pipe approximately four inches in diameter and two inches in length. According to the embodiment shown in Figures
  • At least one and preferably two smaller generally cylindrical tube couplers 66 may be located adjacent the coupling component 64. These smaller tube couplers 66 communicate with the hollow space 54 created by the void forming element 50 and are each attached to a grout tube 68, one tube acting as an inlet and the other tube acting as an outlet .
  • the grout tubes 68 extend upwardly from the tube couplers 66 along the length of the sleeved bolt or tendon 26 to its uppermost end. Following post-tensioning, grout or other cementious material may be forced into the inlet grout tube to fill any remaining void space not eliminated by the crushing of the void form. When grout is forced through the inlet tube to the void space and begins to exit from the grout outlet tube, this indicates that any remaining void space has been filled.
  • This grout tube construction is optional, however, and is not necessary to the effectiveness of the present invention.
  • the uppermost end of the tendon or bolt 26 which protrudes from the top of the cap 10 is fitted with a pile anchor base plate 32 and a post—tensioning nut 70 is threaded onto the tendon or bolt to post- tension the pile anchor 12 and the concrete cap 10 after the cementious material 46 of the cap has hardened.
  • the void created by the void forming element 50 is compressed and element 50 is crushed by the post- tensioning, allowing the pile anchor 12 to pull upwardly until skin friction resistance with the surrounding soils equaling the required tendon tension is achieved.
  • the required bolt or tendon tension exceeds the maximum structure uplift load determined for each pile anchor.
  • an area 80 is excavated having a depth generally corresponding with the intended thickness of the cap 10 and leveling course. Representatively, this area 80 has a depth of about 4 feet.
  • a plurality of spaced pile holes 34 are drilled or driven. These pile holes 34 typically have a diameter of about 18-36 inches and a depth from about 30 feet to about 50 feet. In the representation illustrated in the drawings, the pile holes are 24 inches in diameter and 40 feet deep, and twenty pile holes 34 are formed. After the pile holes 34 are formed, pile anchor bolts or tendons 26 are inserted therein.
  • the pile anchor bolts or tendons 26 are preferably fitted with centralizers 84 to maintain their position in the center of the pile holes in preparation for the pouring of the cementious grout or material therein.
  • cementious material 36 is poured or pumped therein up to the bottom 82 of the excavation area 80.
  • the bolts 26 and centralizers 84 can be inserted after the cementious material 36 is in the pile holes 34.
  • the void forming element or plastic void form 50 is inserted over the top of the bolt 26 and positioned over the top of the anchor pile cementious material 36 at the bottom 82 of the excavation area 80.
  • FIG. 6 The next step in forming the foundation is illustrated in Figure 6.
  • a concrete leveling. course 86 is laid on the bottom 82 of the excavation area 80.
  • the leveling course 86 is approximately four inches in depth to correspond with the height of the void forming element 50 as shown.
  • different thicknesses of the leveling course 86 can be used to accommodate void forming elements of different thicknesses.
  • the top surface 110 of the void forming elements 50 should be substantially flush with the upper surface 88 of the leveling course 86.
  • the tower anchor bolts 14, embedment ring 22, foundation steel rebar reinforcement 24 and wire mesh 28 are then installed, after which the concrete 46 is poured for the cap foundation 10 within corrugated metal pipe 104.
  • the cap is 5 feet thick.
  • the pile anchor base plates 32 are installed over the pile anchor bolts 26 atop or preferably grouted into the concrete foundation cap 10 and the post—tensioning nuts 70 are lifted by jacking, or torqued by threading snugly against the pile anchor base plates 32, during the post—tensioning of the pile anchor bolts 26, as illustrated in Figure 8.
  • pressurized grout can be forced through the inlet grout tube 68 and into any remaining void areas, as at 112 in Figure 9, not eliminated by the post- tensioning process.
  • pile anchor foundation 208 is generally designated by reference numeral 208. Since the components of pile anchor foundation 208 of the second embodiment are identical or very similar to corresponding embodiments of the first embodiment illustrated in Figures 1-9, the components will be similarly numbered in Figures 10-11 except in the "200" series, i.e., foundation 8 in Figures 1-9 and foundation 208 in Figures 10-11. There are several differences as described below
  • the concrete cap 210 includes horizontal upper bolts or headed rebar 215 and lower bolts or headed rebar 217 extending radially between the tower anchor bolts 214 and 216 at one end and adjacent the pile anchor bolts 226 near their other end.
  • the lower rebar bolts or headed rebar 215 rest on top of the embedment ring 222 and are secured to the sleeve 244 of anchor bolts 226 by rebar hoops, as will be readily understood by those skilled in the art .
  • the upper reinforcing steel rebar bolts or headed rebar 217 are secured to the tower anchor bolts 214 and 216, and to sleeve 244 of pile anchor bolt 226 by similar rebar hoops.
  • the central portion of the foundation cap 210 does not have to be the full cap thickness as shown at 219.
  • the excavation for the foundation cap need only be annular at 221, leaving soil 223 in the central portion 219.
  • the pipe 252 provides circumferential steel and reduces possible bursting of the concrete at the top of the pile anchor 212.
  • the pile anchors 12 and 212 of the pile anchor foundation are tension members only.
  • the pile anchors pull the concrete foundation cap 10 and 210 downwardly compressing the underlying bearing soils with such a compression force that the concrete foundation cap is always bearing on the underlying soils even under the greatest overturning and uplift forces transferred to the concrete foundation cap from the tower structure by the tower anchor bolts atop the foundation cap.
  • the pile anchor bolts or tendons 26 and 226 are sleeved as by PVC tubing 44 and 244 to eliminate stress reversals and fatigue while the bolts are stretched by jacking or torquing (post-tensioning) .
  • the post-tensioned pile anchor bolts are shielded from bonding with the reinforced concrete of the concrete foundation cap, allowing the bolts or tendons to elongate when pulled upwardly by jacks or torquing to the required post—tension.
  • the post—tensioned bolts or tendons are secured in tension by a nut 70 and 270 thereon threaded atop the pile anchor base plate 32 and 232 preferably grouted into the top of the concrete foundation cap 10 and 210, thus pulling the cap downwardly with great compression against the underlying soils .
  • Pile anchor bolts or tendons 26 may be re-tensioned periodically as necessary to eliminate long term consolidation and creep.
  • a further advantage of the present invention is that the pull down/hold down force of the pile anchors 12 and 212 results from post—tensioning of the pile anchor bolts 26 and 226 against the pile anchor base plate 32 and 232 atop or preferably grouted into the concrete foundation cap 10 and 210.
  • the pile anchor 12 and 212 is pulled upwardly toward the adjacent bottom 52 and 252 of the concrete foundation cap until the resisting skin friction against the soil equals the post-tension of the tension bolt centered in the pile hole and restrained by the grout.
  • the post—tension downward force atop the concrete foundation cap should exceed the determined maximum uplift by a factor of 1.5 or greater.
  • the post- tensioned pile anchor foundation of the present invention achieves greater rotational stiffness when compared to prior known foundations.
  • the foundation of the present invention also minimizes movement from dynamic forces and increases the foundation frequency to more closely approach that of a rigid body.
  • the pile anchor base plate 32 and 232 are preferably grouted into the top surface of the concrete foundation cap 10 and 210. This can be readily accomplished by blocking out an indentation slightly larger than the dimensions of the base plate, such as by using a Styrofoam or other easily removable form, similar to making the tower flange grout trough 23.
  • the pile anchor base plate should be grouted into the top surface of the foundation cap so that the upper surface of the base plate coincides with the upper surface of the foundation cap . Having the top surface of the base plate at the same level as the top surface of the foundation cap facilitates using the jacking mechanism when post-tensioning the pile anchor bolts.
  • the post-tensioned pile anchor foundation of the present invention provides significant flexibility in designing a foundation for a wide range of applications, including variation in the height, weight and overturning moment of the supported tower or other structure, including additional equipment to be supported thereon. This greater flexibility arises from the fact that the number and size of pile anchors can be varied over a wide range, and can even include an inner circle of separate post-tensioned pile anchors if a greater rotational stiffness is required.
  • the pile holes 34 and 234 and pile anchors 12 and 212 for the concrete foundation 8 and 208 of the present invention can be formed in. the soil below the excavation 80 and 280 in a variety of ways and using differing equipment, depending upon the condition of the soil, as known to those skilled in the art.
  • the pile hole 34 may be simply formed by a driven mandrel or formed by a screw auger in generally stable soils, by driven pile pipes or pipes drilled, jetted or vibrated in place in unstable soils, such as in the l 281 application, and/or by percussion drilling in rock, or combinations of the foregoing, before positioning the tendon or bolt 26 therein, followed by the addition of the cementious material 36.
  • the pile holes may be drilled and the concrete pressure cast with hollow stemmed augers in wet sands and clays or the hole filled with the cementious material through a tube which then serves as the anchor bolt.
  • Other methods and equipment to form the pile anchors known to those skilled in the art can be used without departing from the present invention.
  • void or hollow area 54 is not absolutely necessary.
  • the concrete foundation of the present invention has the foundation cap set directly into a rock formation, it may not be necessary to utilize the void or hollow area; the post-tensioning of the pile anchors and foundation cap may be sufficient to achieve the requisite stiffness for the foundation.
  • tower anchor bolts separate and apart from pile anchor bolts
  • cementious and cementious-type materials can be utilized in constructing the post-tensioned pile anchor foundation of the present invention as would be utilized by those skilled in the art . These materials include, but are not limited to, sand, cement slurrys, grouts , and epoxys .
  • post-tensioning elements and of the present invention have been described as anchor bolts or tendons, those skilled in the art will appreciate that other forms of tension elements, such as cables, rods, pipes, or the like, could be used in accordance with the present invention.

Abstract

L'invention concerne une fondation d'ancrage à pieux en post-tension et un procédé associé, consistant à créer un vide ou un espace fortement compressible entre un ancrage à pieux forés ou foncés entourant un boulon d'ancrage ou une armature sous post-tension et le fond d'une coiffe de fondation. Le vide ou l'espace peut être formé au moyen d'entretoises compressibles ou d'éléments formateurs de vide placés entre le sommet de l'ancrage à pieux et la coiffe de béton. Du fait que le boulon ou l'armature d'ancrage est mis sous post-tension contre la coiffe, l'élément formateur de vide est comprimé ou écrasé, de sorte que l'ancrage est tiré vers le haut en direction de la coiffe, produisant une résistance à l'arrachement, et la coiffe est tirée vers le bas contre le sol environnant, constituant ainsi une fondation résistante pour un pylône ou une autre structure destinée à être montée sur cette fondation.
PCT/US2007/010995 2006-05-05 2007-05-07 Fondation d'ancrage à pieux en post-tension et procédé associé WO2007130667A2 (fr)

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Application Number Priority Date Filing Date Title
CA2651259A CA2651259C (fr) 2006-05-05 2007-05-07 Fondation d'ancrage a pieux en post-tension et procede associe

Applications Claiming Priority (2)

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US79774606P 2006-05-05 2006-05-05
US60/797,746 2006-05-05

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WO2007130667A3 WO2007130667A3 (fr) 2008-02-28

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EP2192238A1 (fr) * 2008-11-26 2010-06-02 Vestas Wind Systems A/S Fondation et procédé de formation de fondation pour tour d'éolienne
EP3219879A1 (fr) * 2016-03-17 2017-09-20 Senvion GmbH Procédé d'installation d'une tour d'éolienne et éolienne correspondante
EP2427603B1 (fr) 2009-05-05 2018-03-14 Ahmed Phuly Engineering & Consulting, Inc. Fondation résistant à la fatigue
EP3336260A1 (fr) * 2016-12-19 2018-06-20 Siemens Gamesa Innovation & Technology, S.L. Procédé de construction d'une fondation de tour
CN108677992A (zh) * 2018-05-21 2018-10-19 上海勘测设计研究院有限公司 海上风力发电机组预应力重力式基础及其安装方法
ES2726248A1 (es) * 2018-04-02 2019-10-02 Structural Concrete & Steel S L Cimiento prefabricado para postes
WO2020187574A1 (fr) * 2019-03-19 2020-09-24 Max Bögl Wind AG Base à fondation plate
CN113373953A (zh) * 2021-06-09 2021-09-10 中国水利水电第十四工程局有限公司 一种高边坡长锚筋桩接长的工艺
CN114134882A (zh) * 2021-11-12 2022-03-04 中国华能集团清洁能源技术研究院有限公司 风电预制板桩及其应用结构、施工方法
CN115198783A (zh) * 2022-07-08 2022-10-18 中交第二航务工程局有限公司 隔仓式地连墙锚碇基础的施工控制方法

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WO2010060866A1 (fr) * 2008-11-26 2010-06-03 Vestas Wind Systems A/S Fondation et procédé de réalisation d'une fondation pour tour éolienne
CN102224301A (zh) * 2008-11-26 2011-10-19 维斯塔斯风力系统集团公司 基座和用于形成风力涡轮机塔架的基座的方法
EP2192238A1 (fr) * 2008-11-26 2010-06-02 Vestas Wind Systems A/S Fondation et procédé de formation de fondation pour tour d'éolienne
EP2427603B1 (fr) 2009-05-05 2018-03-14 Ahmed Phuly Engineering & Consulting, Inc. Fondation résistant à la fatigue
EP3219879A1 (fr) * 2016-03-17 2017-09-20 Senvion GmbH Procédé d'installation d'une tour d'éolienne et éolienne correspondante
EP3336260A1 (fr) * 2016-12-19 2018-06-20 Siemens Gamesa Innovation & Technology, S.L. Procédé de construction d'une fondation de tour
ES2726248A1 (es) * 2018-04-02 2019-10-02 Structural Concrete & Steel S L Cimiento prefabricado para postes
CN108677992A (zh) * 2018-05-21 2018-10-19 上海勘测设计研究院有限公司 海上风力发电机组预应力重力式基础及其安装方法
WO2020187574A1 (fr) * 2019-03-19 2020-09-24 Max Bögl Wind AG Base à fondation plate
CN113373953A (zh) * 2021-06-09 2021-09-10 中国水利水电第十四工程局有限公司 一种高边坡长锚筋桩接长的工艺
CN114134882A (zh) * 2021-11-12 2022-03-04 中国华能集团清洁能源技术研究院有限公司 风电预制板桩及其应用结构、施工方法
CN114134882B (zh) * 2021-11-12 2023-11-07 中国华能集团清洁能源技术研究院有限公司 风电预制板桩及其应用结构、施工方法
CN115198783A (zh) * 2022-07-08 2022-10-18 中交第二航务工程局有限公司 隔仓式地连墙锚碇基础的施工控制方法
CN115198783B (zh) * 2022-07-08 2023-09-08 中交第二航务工程局有限公司 隔仓式地连墙锚碇基础的施工控制方法

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