United States Patent [191
`Yegge
`
`[54] STRUCTURE AND METHOD OF
`CONSTRUCTING AND TEST-LOADING
`PILE ANCHORED FOUNDATIONS
`
`[76]
`
`Inventor: Lawrence R. Yegge, 139 Via de
`Tesoros, Los Gatos, Calif. 95030
`
`[21] Appl. No.: 707,184
`
`[22] Filed:
`
`July 21, 1976
`
`Int. CI.2 ................................................ E02D 5/74
`[51]
`(52] U.S. CI . ........................................... 61/50; 61/39;
`61/56.5; 52/166; 52/169.1
`(58] Field of Search .................... 61/39, 35, 50, 53.52,
`61/53.5, 56, 56.5, 63, 31; 52/742, 230, 169, 166,
`155
`
`[56]
`
`2,763,464
`3,087,308
`3,256,694
`3,299,644
`
`References Cited
`U.S. PATENT DOCUMENTS
`9/1956 Leonhardt ......................... 52/230 X
`4/1963 Hart et al ............................ 61/50 X
`6/1966 Siedenhans .............................. 61/50
`1/1967 White ................................... 61/39 X
`
`[11]
`
`[45]
`
`4,043,133
`Aug.23, 1977
`
`FOREIGN PATENT DOCUMENTS
`683,898
`4/1964 Canada ..................................... 61/39
`Primary Examiner-Jacob Shapiro
`Attorney, Agent, or Firm-Naylor, Neal & Uilkema
`[57]
`ABSTRACT
`A method of constructing pre-tested concrete pilings
`and pile caps particularly for use in supporting struc(cid:173)
`tures, such as transmission line towers that are subjected
`to large overturning moments. One or more pile holes
`are bored, a small diameter sheathing containing one or
`more steel tendons is inserted and a concrete mixture is
`poured in the pile hole exterior of the tendon sheathing
`with the tendons anchored in the bottom of the pile.
`When the concrete has obtained sufficient strength, the
`tendon is stressed, thereby testing the tension-carrying
`capacity of the pile and its surrounding foundation soil.
`A concrete pile cap is thereafter joined to the pile, the
`tendons are again stressed and anchored to the pile cap
`and the tendon sheathing is filled with concrete grout to
`form a solid post-tensioned foundation that has been
`pre-tested at a force in excess of its design load.
`
`7 Claims, 8 Drawing Figures
`
`12
`
`24 0
`
`Exhibit - 1008
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 1
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`

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`Exhibit - 1008
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 2
`
`

`

`U.S. Patent Aug 23, 1977
`
`Sheet 2 of 2
`
`4,043,133
`
`! ! !
`'' '
`11 I
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`58
`
`50
`
`38
`
`FIG- _ ?_
`
`FIG(cid:173)
`_B_
`
`Exhibit - 1008
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 3
`
`

`

`1
`
`4,043,133
`
`STRUCTURE AND METHOD OF CONSTRUCTING
`AND TEST-LOADING PILE ANCHORED
`FOUNDATIONS
`
`2
`FIG. 7 is a detailed elevation view of the lower end of
`the tendon sheath with the extending tendons anchored
`to an anchor plate; and,
`FIG. 8 is a detailed elevation view of the pile top and
`5 illustrates the placement and structure of the tensioning
`jack.
`DESCRIPTION OF THE ILLUSTRATED
`EMBODIMENT
`Turning now to a detailed description of the inven(cid:173)
`tion, FIG. 1 is a sectional elevation view illustrating the
`boring of two diverging pile holes 10 and 12. Prior to
`this boring operation, the ground surface has been exca(cid:173)
`vated to a footing or beam line and a boring template 14
`has been installed. Pile holes 10 and 12 may, in most
`cases, have a diameter of only twelve to fourteen inches
`and their depth will, of course, be dependent upon the
`consistency and nature of the subsoil and the various
`design loading on the structure.
`In FIG. 2, piling holes 10 and 12 have been com(cid:173)
`pletely bored to the design depth. Inserted throughout
`SUMMARY OF THE INVENTION
`the length of hole 10 and extending above the ground
`surface are one or more steel tendons 16. Tendons 16
`Briefly described, the invention includes the steps of
`are loosely encased in a tendon sheathing 18, which
`boring a pile hole to the appropriate design depth, in-
`serting one or more steel cable tendons loosely con- 25 preferably is a galvanized steel conduit that may be
`tained in and extending from, the ends of a tubular metal
`spirally wound to reduce wobble within the piling
`tendon sheath running coaxially through the length of
`holes. The lower end of sheathing 18 is provided with a
`collar 20 from which the tendons 16 extend to be spread
`the bored hole, and then pouring a concrete mixture in
`the hold within one or two feet of the ground surface,
`and anchored to an anchor plate 22. As will be subse-
`but not within the tendon sheath, so that the lower end 30 quently explained in detail, a plastic grout tube 24 enters
`of the tendon is firmly anchored in the bottom of the
`t~~ sheathing collar 20 and e.xtends up through th~
`concrete pile but is loose within the tendon sheath.
`p1bn~ hole and through the bormg template 14 w~ere 1t
`When the concrete has attained sufficient compressive
`remams ~bove ground surface for a future step m the
`strength, the tendon is stressed to approximately 125%
`construc!1on pro.cess.
`of the design load of the pile to test the tension capacity 35 Upo~ mstallat1on of.the tend~ns 16 and t~e tendon
`of the pile and its surrounding soil. The upward force
`s~:athmg 18, c~ncrete 1s poured.mto that portion of the
`applied to the pile by means of the stressing tendon has
`p1hng hol~ outside of the sheathing 18 and up to a level
`r
`· t th t
`·t
`· kin
`d whi h
`26 approximately one foot below the bottom surface of
`1 s r~ac ton agams
`template 14. As will be explained in connection with
`e e~p~rary Jae
`g pa '
`c
`pad is separ?ted from the ~tie m sue~ a way that no part 40 FIG. 7, a mastic is packed in the lower end of collar 20
`of th~ reac!10n ~o !he applied force 1~ t~en ~t the top of
`to prevent the poured concrete from seeping around the
`the pile. Smee 1t 1.s known that a ptle s resistance to a
`tendons 16 and into the tendon sheathing 18.
`downward lo.ad ts at. least e~ual t~ (and n~~ally
`After the concrete has attained a sufficient compres-
`greater tha~) its cap?c1ty. to resist upbft, the m1rum~
`sive strength, the drilling template 14 is removed and is
`value .at which the ptle wtll support down:ward loads 1s 45 replaced with a temporary jacking pad 28, as illustrated
`in FIG. 3. Jacking pad 28 is a large surfaced steel or
`est~bbshed by t~e performance of the pile ~nder the
`~pbft load. appb~d. Thereafter, the te~don 1s ?e-ten-
`concrete structure suitably bored to receive the tendons
`stoned, a pil.e cap .1s poured to connect .with the pile top,
`16, an anchorage trumpet 30 and a bearing plate 32.
`the ~endon 1s agam stre~sed to the design load, t~e ten-
`Jacking pad 28 is provided with two upper surfaces that
`don 1s anchored to the pile cap, ~d cement grout !s the~ 50 are pitched at an angle normal to the longitudinal axes
`pumped into the tendon sheathtng to form a sobd uru-
`of piling holes 10 and 12 to receive a tensioning jack 34.
`The illustrated jack 34 is of the type disclosed in my
`tary pre-tested pile and cap.
`U.S. Pat. No. 3,597,830.
`As will be discussed in detail in connection with FIG.
`8, the tensioning jack 34 is connected to the end of each
`tendon 16 and the tendons are stressed to 125% of the
`design load of the pile. By stressing the tendons in this
`manner, the tension capacity of the pile and its sur(cid:173)
`rounding soil is tested to assure that uplift forces will
`not dislodge the pile. Likewise, the compressive load(cid:173)
`carrying capacity of the pile is also tested as this capac(cid:173)
`ity is at least as great as the tension capacity. Further(cid:173)
`more, the force exerted by the bottom of the jacking
`pad 28 can be used when desired to effectively test the
`vertical downward load-carrying capacity of the sub(cid:173)
`surface soil. Since there is a space of approximately one
`foot between the top level 26 of the poured pile and the
`bottom surface of the jacking pad 28, sub-surface soil
`consolidation may be achieved by continuing the test
`
`BRIEF DESCRIPTION OF THE ORA WINGS
`In the drawings that illustrate the preferred embodi- 55
`ment of the invention:
`FIG. 1 is a proftle view illustrating the boring,
`through a template, of two diverging pile holes;
`FIG. 2 is a proftle view illustrating the placement of 60
`the tendons and the tendon sheath;
`FIG. 3 is a proftle view illustrating the placement of a
`jacking pad and tendon jack;
`FIG. 4 is a proftle view illustrating the pouring and
`connection of a permanent pile cap;
`FIG. 5 is a proftle view illustrating the post-tension(cid:173)
`ing of a completed pile to .. the pile cap;
`FIG. 6 is a profile illustrating the completed pile cap
`with installed stub angle;
`
`BACKGROUND OF THE INVENTION
`This invention relates to the construction of concrete
`piling and more particularly to a method of construct(cid:173)
`ing, on the site, a structure foundation which includes
`one or more concrete piles post-stressed to the pile cap 10
`to form a rigid unitary foundation for a structure, such
`as an electrical transmission line tower, that may be
`subjected to severe overturning moments or uplifting
`forces as well as the downward gravity loads. The in-
`vention is particularly valuable for use in the construc(cid:173)
`tion of transmission line towers in remote areas where
`all construction material may be transported to the site
`by helicopters, thereby obviating the need for costly
`access roads.
`
`15
`
`20
`
`65
`
`Exhibit - 1008
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 4
`
`

`

`4,043,133
`
`4
`through the trumpet 30 and the bearing plate 32, which
`overlies both the trumpet 30 and the top surface of the
`pile cap 38. Atop the upper surface of bearing plate 32
`is anchor head 40, which is a thick steel disc drilled to
`5 receive tendons 16. The tendon holes on the top surface
`of anchor head 40 are conically counterbored to receive
`gripper jaws 42.
`Tensioning jack 34 is installed on the bearing plate 32
`and is aligned with the anchor head 40 so that tendons
`16 extend through the center open portion of jack 34
`where they are anchored by a second set of gripper
`jaws 44 connected to a hydraulic piston assembly in the
`tensioning jack 34. This piston assembly includes an
`annular piston 46 adapted to slide within an annular
`cylinder 48 coaxially located in the housing of the jack
`34. An intake port 50 admits an hydraulic fluid under
`force into the cylinder area, forcing the annular piston
`46 to apply tension to the tendons 16. Installed within
`tensioning jack 34 and adjacent the anchor head 40 is a
`second piston 52 which, when activated by the applica(cid:173)
`tion of pressure through intake port 54, will apply a
`downward locking force against gripper jaws 42 to
`insure that the jaws lock tendons 16. When presure is
`applied to the intake port 56 of the piston 52, the piston
`releases its force against the gripper jaws 42. This re(cid:173)
`leasing function is necessary when it is desired to de(cid:173)
`tension tendons 16 as described in connection with FIG.
`3. When it is desired to remove tensioning jack 34 after
`tendons 16 have been tensioned, pressure is admitted to
`intake port 54, forcing piston 52 to lock the gripper jaws
`42. Pressure is then admitted to the intake port 58 to
`force the main tensioning piston 46 back down to its
`non-tensioning position. At this point, the gripper jaws
`44 are loose and may be removed so that the entire
`tensioning jack 34 may be lifted from the bearing plate
`32, thereby leaving the tendons 16 firmly anchored in
`the gripper jaws 42 of the a1:.chor head 40.
`
`30
`
`3
`load until the desired consolidation is obtained. When
`the test has been completed and any desired soil com(cid:173)
`paction has been obtained, tendons 16 are de-tensioned
`and the tensioning jack 34 and the temporary jacking
`pad 28 are removed.
`FIG. 4 is a sectional elevation view illustrating that
`after removal of the temporary jack pad 28, a concrete
`form is placed, a bearing plate 32 and trumpet 30 assem(cid:173)
`bly is attached to the top of the tendon sheathing 18, the
`desired stub angle 36 is installed and the lower portion 10
`of the bearing cap 38 is poured from the top of the
`existing concrete piles and the ground surface to the
`lower surface of the bearing plate 32.
`After the lower portion of the piling cap has attained
`sufficient strength, the tendons 16 are threaded through 15
`a suitable anchor head 40, as illustrated in FIG. S. The
`tensioning jack 34 is reinstalled and the tendons 16 are
`stressed to their design load and permanently anchored
`to anchor head 40. This post-stressing step renders the
`pile cap 38 and each of the pilings into a solid unitary 20
`structure so that compressive loads applied downward
`upon the piling cap 38 will be carried by the pilings 10
`and 12, as well as by the cap 38.
`After tendons 16 have been stressed and anchored to
`the anchor head 40, a cement grout is pumped through 25
`the plastic grouting tube 24 and the interior of the ten(cid:173)
`don sheathing 18 and anchor head 40 is filled with
`grout. This grouting prevents corrosion of the steel
`tendons 16 and further adds to the solidarity of the
`pilings.
`FIG. 6 illustrates that, upon completion of the posts(cid:173)
`tressing and anchoring step described above, the piling
`cap form is again installed and the concrete piling cap is
`completed by pouring an upper portion 42 that covers
`the anchor head 40 and the exposed ends of the ten- 35
`sioned tendons 16 which now become thoroughly and
`permanently anchored. Thereafter, the desired struc(cid:173)
`ture 44 may be installed.
`FIG. 7 illustrates in detail the lower end of the tendon
`sheathing 18 with the attached collar 20 from which the 40
`tendons 16 extend. In most instances it is necessary to
`anchor the lower ends of the tendons 16 to an anchor
`plate 22 which effectively separates the ends of the
`tendons and prevents them from being pulled through
`the sheathing during the tensioning step described in 45
`connection with FIG. 3. It has been found that, if the
`pile hole is sufficiently deep so that the length of the
`exposed tendons 16 extending from the collar 20 is five
`feet or greater, there is adequate anchorage by the ten(cid:173)
`dons themselves and a bottom anchorage plate 22 may 50
`be omitted. FIG. 7 also illustrates that tendons 16 are
`sealed in the lower end of the collar 20 by a mastic seal
`44, which is installed prior to inserting the sheathing 18
`into the piling hole 20 to prevent the poured concrete of
`the pile from entering the sheathing 18. After the post- 55
`tensioning of the tendons 16, as described in connection
`with FIG. 5, cement grout is forced through the plastic
`grouting tube 24 that is connected to the collar 20 and
`the interior portion of the sheathing 18 is then filled
`with the cement grout to prevent corrosion of the cable 60
`and to add additional strength and rigidity to the sheath(cid:173)
`ing section of the piling.
`FIG. 8 is a detailed elevation view of the top end of
`the tendon sheathing 18 connected in a trumpet 30 that
`is embedded in the lower portion of the pile cap 38. The 65
`tensioning jack 34 is installed in its position for the
`post-tensioning operation described in connection with
`FIG. 5. As shown in FIG. 8, the tendons 16 extend
`
`CONCLUSION
`Although a preferred embodiment has been illus(cid:173)
`trated and described, it should be understood that the
`invention is not limited to the specifics of this embodi(cid:173)
`ment, but rather is defined by the following claims. For
`example, it is possible that the separate jacking pads
`illustrated in FIG. 3 might be omitted and that a pile cap
`with voids between the cap and the piles might be em(cid:173)
`ployed for use in the load-testing step. In such an ar(cid:173)
`rangement, the voids between the cap and piles would
`be filled after load testing and prior to the final stressing
`step.
`What is claimed is:
`1. A method of making a pre-tested anchored founda(cid:173)
`tion structure in which the anchor members carry com(cid:173)
`pressive loads and resist upward loads including the
`steps of:
`boring at least one pile hole into the sub-surface soil;
`inserting into each pile hole a sheath containing one
`or more tendons, said tendons extending from the
`lower end of said sheath into the bottom end of said
`pile hole, and extending from the top end of said
`sheath above the surface of the soil;
`forming a pile by pouring a concrete mixture into said
`hole to the exterior of said sheath, whereby the
`tendons extending from the lower end of said
`sheath become anchored to the bottom end of said
`pile but remain free for movement within said
`sheath;
`
`Exhibit - 1008
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 5
`
`

`

`4,043,133
`
`5
`mounting a tensioning jack to a jacking pad supported
`on the soil surface out of bearing engagement with
`the pile to position the jack in spaced relationship
`above the top of said pile, and connecting said jack s
`to said tendons extending from the top end of said
`sheath; and
`actuating said tensioning jack to apply a tension to
`said tendons, whereby said pile and its surrounding 10
`soil is pre-tested to withstand a measured force thus
`applied, and whereby the soil beneath the bottom
`surface of said jacking pad is loaded.
`2. The method claimed in claim 1 further including 15
`the steps of;
`de-tensioning said tensioning jack and removing said
`jack and said jacking pad;
`forming and pouring a permanent concrete pile cap 20
`above and connected to the tops of said concrete
`piles;
`
`6
`re-installing a tensioning jack to the surface of said
`pile cap and attaching said jack to said extending
`tendons; and
`actuating said jack to apply tension to said tendons,
`whereby said pilings and said pile cap are com(cid:173)
`pressed into a unitary member.
`3. The method claimed in claim 2 further including
`the step of permanently anchoring said stressed tendons
`to said pile cap, and removing said tensioning jack.
`4. The method claimed in claim 3 further including
`the step of pumping cement grout into said sheath ex(cid:173)
`tending throughout the center of each of said pilings.
`5, The method claimed in Claim 4 further including
`the step of forming and pouring a top concrete section
`to said pile cap for sealing said anchored tendons within
`said pile cap.
`6. The method claimed in claim 2 further including
`the step of installing a stub angle during said step of
`forming and pouring a permanent concrete pile cap.
`7. The method claimed in claim 1 wherein at least two
`diverging holes are bored into the sub-surface soil.
`• • • • •
`
`25
`
`30
`
`35
`
`40
`
`4S
`
`so
`
`55
`
`60
`
`65
`
`Exhibit - 1008
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 6
`
`