JP4609627B2 - Joining method of ready-made piles, Joined hardware of ready-made piles - Google Patents

Description

  This invention is a prefabricated pile mainly made of concrete, and a prefabricated pile used for connecting a prefabricated pile to configure a prefabricated pile corresponding to a pile hole of a predetermined depth, and a prefabricated used for this joining method. It relates to joint hardware of piles.

  In concrete-based foundation piles, the ready-made piles used have steel plate end plates attached to the top and bottom, and the end plates of the upper and lower ready-made piles are attached together and overlapped and joined using end plates.

  Generally, the contact surfaces of the attached end plates are welded to join the upper and lower ready-made piles. Since this method has been used for many years, its evaluation has been solidified and can be made inexpensively, so far it has been widely adopted (Non-Patent Document 1).

  However, the welding method has a problem in that welding quality varies due to the skill and experience of the welding operator, and construction management becomes complicated. Welding was one of the factors that increased the construction period due to the influence of the construction conditions depending on the weather.

Accordingly, various mechanical joints have been proposed in order to eliminate such inconvenience of welding. For example, screw holes are formed on the outer peripheral side of the end plate, arc-shaped connection pieces are arranged on the outer peripheral side of the upper and lower end plates, bolts from the connection pieces are screwed into the screw holes, and the upper and lower piles are connected to the connection pieces. There has also been proposed a method of connecting them integrally via a cable (Patent Document 1).
JP 2000-328556 A Geotechnical Society of Japan Foundation Pile Foundation Design Methods and Explanations December 20, 1985, pages 615-617

  In the conventional method in which the connection piece is applied to the outer periphery of the end plate and the bolt is tightened from the outer periphery side, the connection piece and the head of the bolt can be somewhat protruded to the outer periphery side. Further, in the case of a ready-made pile having a large diameter exceeding 120 cm in outer diameter, it is necessary to increase the thickness of the connecting piece and to increase the number of bolts, which causes a problem that the installation work becomes complicated.

  However, the present invention has solved the above-mentioned problems because the joining end portions having the through-hole pieces are overlapped to form the through-hole and the hole-filling member is closely inserted into the through-hole.

That is, this invention is a method for joining ready-made piles in which the upper pile and the lower pile are joined at the joint portion, and is a portion protruding on any of the inner and outer peripheral surfaces of the upper and lower piles. This is a ready-made pile joining method characterized by joining in the following steps without causing any problems.
(1) A first fitting portion formed by alternately providing fitting convex portions and fitting concave portions in the circumferential direction is formed at the joint end portion of one of the upper and lower piles.
The fitting recesses and the fitting protrusions are alternately provided in the circumferential direction at the joint end of the other upper and lower piles to form a second fitting portion. The first fitting portion and the second fitting portion have the same outer diameter D1 and the same inner diameter D2.
A first through hole piece is formed on the fitting convex portion of the first fitting portion, and a second through hole piece is formed on the fitting convex portion of the second fitting portion.
(2) The upper pile is overlapped on the lower pile, the first fitting portion and the second fitting portion are fitted, and the front end surface of the fitting convex portion of the first fitting portion and the second fitting portion The bottom surface of the fitting concave portion contacts, and the tip surface of the fitting convex portion of the second fitting portion contacts the bottom surface of the fitting concave portion of the first fitting portion.
(3) By fitting the first fitting portion and the second fitting portion, the first through-hole piece and the second through-hole piece cooperate to form a through-hole.
(4) The second fitting convex portion is formed with an introduction hole that communicates with the through hole and penetrates outward from the through hole in a tangential direction, and a filling member is inserted from the introduction hole, The hole filling member is closely inserted into the through hole .

Moreover, another invention is a joining hardware comprised from the 1st joining hardware which can be fixed to one of an upper pile or a lower pile, and the 2nd joining hardware which can be fixed to the other, Comprising: The inner peripheral surface of the said upper pile and a lower pile It is a prefabricated pile joint hardware that can be joined without producing a protruding portion on either side of the side and the outer peripheral surface, and has the following characteristics.
(1) The first joint hardware is configured by connecting a first fitting portion having a first through hole piece to a base portion fixed to a ready-made pile . First fitting portion before SL constitutes provided alternately fitting projections and fitting recesses in the circumferential direction.
(2) The second joint hardware is formed by continuously providing a second fitting portion that can be fitted to the first fitting portion on a base portion fixed to a ready-made pile. The second fitting portion is configured by alternately providing the fitting concave portion and the fitting convex portion in a circumferential direction. A second through-hole piece capable of forming a through-hole in cooperation with the first through-hole piece in a straight line or an arc shape was formed in the second fitting portion.
(3) The first fitting portion and the second fitting portion have the same outer diameter D1 and the same inner diameter D2.
(4) the said first through-hole member formed in the fitting convex portion of the first fitting portion, the second through-hole member formed in the fitting convex portion of the second fitting portion, the second In the fitting convex portion, an introduction hole is formed which communicates with the through hole in a straight line or an arc shape and penetrates outward . The introduction hole and the through hole are formed so that a filling member can be inserted from the introduction hole .
(5) When the first fitting portion and the second fitting portion are fitted, the front end surface of the fitting convex portion of the first fitting portion and the bottom surface of the fitting concave portion of the second fitting portion are The fitting convex part and the fitting concave part are formed so that the tip end surface of the fitting convex part of the second fitting part and the bottom surface of the fitting concave part of the first fitting part are in contact with each other .

  The hole-filling member can be inserted by any method such as press-in, push-in, and pull-out.

Moreover, the preferable relationship of the magnitude | size of the hole-filling member and through-hole piece (annular groove) in the above is as follows.
(1) After fitting the fitting parts of the upper and lower piles to each other, when attaching so-called post-filling members, the cross-sectional shape of the through-hole pieces (annular grooves) of the first and second fitting parts is In the case of a hole-filling member that is substantially the same shape and size as the half-section of the hole-filling member and is relatively easy to deform, it is desirable that the annular groove has a smaller cross-sectional shape from the viewpoint of adhesion and adhesion. However, in the case of a high-strength, high-strength hole-filling member, since it is difficult to deform, it is inserted by forcibly pushing it in. Therefore, the cross-sectional shape of the through-hole piece (annular groove) is large, and it is easier to wear And the fixability is also good.
(2) Before the upper and lower piles are fitted to each other, the annular hole filling member is attached to the through hole piece, the diameter is reduced, and the diameter is released by releasing the reduced diameter after fitting. The through hole piece (annular groove) to be attached with a reduced diameter of the hole filling member has a cross-sectional shape dimension that can be just accommodated by the hole filling member. It is desirable that when the elasticity of the hole-filling member is released and the diameter of the hole-filling member is released, the determination surface portion of the hole-filling member has a dimension and shape that can be accommodated. This is because the bonding strength can be realized most efficiently.

(1) The first fitting part of the first joint hardware fixed to one ready-made pile and the second fitting part of the other ready-made pile are fitted, and a filling member is placed in the through hole formed by the fitting. Since it is inserted closely, welding is not used, so a skilled welder is not required, construction can be performed regardless of the weather, and connection work is reliably and stabilized. Moreover, just by dropping the upper pile into the lower pile and fixing it, both fitting parts fit together and a through hole is formed, so the bolt hole alignment as in the conventional method using bolts This eliminates the need for troublesome adjustment and control work such as positioning by rotating a ready-made pile. Therefore, generally, the joining work of ready-made piles can be simplified and the construction period can be shortened.

(2) Further, since the stress transmission between the first and second joining hardware is performed between the closely attached through hole and the hole filling member, the joining is performed with almost no gap and the joining is performed reliably. By adjusting the insertion length of the through hole and the hole filling member, the diameter of the through hole (namely, the diameter of the through hole piece), the thickness of the hole filling member, etc., it is possible to easily adjust the bonding strength of the ready-made piles. The required joint strength can be easily set for each object or foundation pile.

  In addition, since it is possible to connect by simply inserting and filling a hole filling member into the through hole without using a connecting material such as tightening with a bolt, the connecting work can be done by methods such as push-in, push-in, pull-out, etc. There is no risk of loosening due to aging. In addition, since there are no movable parts, there is little influence of dirt due to earth and sand.

(3) Moreover, since the insertion of the hole filling member is performed after fitting the first and second joint hardwares of the upper and lower ready-made piles, there is no possibility that the connection is shifted. Moreover, when manufacturing a 1st 2nd joining metal fitting, high processing precision like bolt screwing is also requested | required.

(4) The first fitting part of the first joint hardware fixed to one ready-made pile and the second fitting part of the other ready-made pile are fitted, and a filling member is placed in the through hole formed by the fitting. Since it is closely inserted, there is an effect that no protrusions are generated on the inner and outer peripheral sides of the fitting portion. Therefore, if the cross-section of the joint hardware is formed to be the same as the cross-section of the ready-made pile, the joint hardware has no protruding part on either the inner peripheral surface side or the outer peripheral surface side of the ready-made pile. Excavation of pile holes according to the outer diameter of the construction will not affect the construction plan.

  In particular, in the case of a large-diameter ready-made pile, since the wall thickness is also thick, the present invention forms a through-hole piece in the wall thickness and can be easily connected in the wall thickness. This is particularly effective for connecting the piles mentioned above.

(5) Since the through hole of the joint portion is provided at a plurality of locations and the corresponding hole filling members are similarly sewn at the plurality of locations, the proof stress borne by one hole filling member can be reduced. Can be small. Therefore, by reducing the hole filling member, the hole filling member is easily deformed, the insertion work can be easily and reliably performed, and the reliability is improved.

(1) The 1st metal fitting 1 attached to the upper pile 27B consists of the base 3 which has the fixed upper surface 4, and the lower fitting convex part (1st fitting part) 7 (FIG. 1 (a), 2A), the fitting convex portion 7 has an annular groove (first through hole piece) 10 on the outer peripheral surface. Moreover, the 2nd metal fitting 12 attached to 27 A of lower piles consists of the base 14 which has the fixed lower surface 15, and the fitting recessed part (2nd fitting part) 18 which can be fitted with the fitting convex part 7 on the upper side. (FIGS. 1A and 2B), an annular groove (second through-hole piece) 21 is provided on the inner peripheral surface. The first and second joining hardware 1 and 12 constitute a joining hardware.

(2) In the pile hole 31 excavated by a normal method, a ready-made pile 27A (lower pile) with the second joint hardware 12 fixed to the upper end is buried, and the pile head is held in a state protruding from the ground 32 ( FIG. 1 (a)). The ready-made pile 27B (upper pile) to which the second bonded hardware 1 is fixed is lowered from above (FIG. 1 (a)), and the fitting convex portion 7 of the first bonded hardware 1 of the ready-made pile 27B is moved to the ready-made pile 27A. It inserts in the fitting recessed part 18 of the 2nd joining metal fitting 12 (FIG.1 (b)).

  At this time, the annular groove 10 having the semicircular cross section of the first joint metal 1 and the annular groove 21 having the semicircular cross section of the second joint metal 12 face each other, and the annular hole 25 is formed.

  Subsequently, the connecting rod (hole filling member) 34 is inserted from the introduction holes 23, 23 of the second metal fitting 12 (FIG. 1 (c)), and is closely inserted into the annular hole 25 to complete the joining of the upper and lower piles. To do.

  An embodiment of the metal joint according to the present invention will be described with reference to FIGS.

[1] Structure of metal fitting for bonding (first bonding hardware) 1

The first metal fitting 1 has an outer diameter D ₁ that is the same diameter as the upper pile, and has a donut-shaped (tubular) base 3 having a fixed upper surface 4 that can be joined to the lower surface of the upper pile, and an outer side below the base 3. A fitting convex portion (first fitting portion) 7 having a diameter D ₃ (D ₁ > D ₃ ) is provided so as to project (FIGS. 1A and 2A). The inner diameter of the base portion 3 and the fitting projection 7, an inner diameter and the same diameter D ₂ of the upper pile, is formed with a hollow portion 5 and 8 communicating.

  The base portion 3 is formed with a joining surface 6 that is inclined downward in the radial direction at the lower end.

The fitting convex portion 7 forms an annular groove (first through hole piece) 10 having a semicircular diameter (diameter D ₄ ) along the outer peripheral surface at an intermediate height. The annular groove 10 is formed at a distance L ₁ from the inner peripheral edge 6 a of the joint surface 6. Vertical position of the annular groove 10 is located substantially intermediate position in the vertical direction of the outer side surface of the fitting projection 7 (i.e., a substantially intermediate position between L ₁ is the inner circumferential edge 6a and the lower end face 9) .

[2] Structure of metal fitting for bonding (second bonding hardware) 12

The second joint metal 12 has the same outer diameter D ₁ as the first joint metal 1 and a base part 14 having a fixed lower surface 15 that can be joined to the upper surface of the lower pile, and the fitting convex part 7 on the upper side of the base part 14. projecting the fitting can internal diameter _{D 2} of the fitting recess (second fitting portion) 18 constituted by (FIG. 1 (a), Figure 2 (b)). The inner diameter of the base portion 14 in the inner diameter and the same diameter D ₂ of the lower pile, hollow portion 19 of the hollow portion 16 and the fitting recess 18 of the base 14 communicates with the hollow portion 30 of the lower pile.

A joint surface 20 is formed on the upper surface of the fitting recess 18 so as to incline downward in the radial direction with the same slope as the joint surface 6 of the first joint metal 12 and overlap the joint surface 6. The fitting recess 18 forms an annular groove (second through-hole piece) 21 having a semicircular diameter (diameter D ₄ ) along the inner peripheral surface at an intermediate height. Similar to the first annular groove 10 of the joining fittings 1, the annular groove 21, is formed at a distance L ₁ from the inner peripheral edge 20a of the bonding surface.

The fitting recess 18 is formed with an introduction hole 23 that communicates with the annular groove 21 and penetrates outward from the annular groove 21 in the tangential direction. Introducing hole 23 is formed in a circular cross section of diameter _{D 4.}

[3] Bonding hardware

  The metal joint according to the present invention is composed of a first metal joint 1 having a fitting convex portion 7 fitted to each other and a second metal joint 12 having a fitting concave portion 18. When both the fittings 1 and 12 are joined and the fitting convex portion 7 and the fitting concave portion 18 are fitted, the annular grooves 10 and 21 face each other to form an annular hole (through hole) 25.

[4] Other embodiments

(1) In the said Example, although the 2nd joining hardware 12 was applied to the lower pile and the 1st joining hardware 1 was applied to the upper pile, conversely, the 1st joining hardware 1 was used as the lower pile, and the 2nd joining hardware 12 was used. Can also be applied to upper piles (not shown)
(2) Although the joint metal object which joins the upper and lower piles of the same diameter was demonstrated, when the diameter of a ready-made pile is different, the outer diameter of the fitting convex part 7 and the inner diameter of the fitting recessed part 18 which mutually fit are the same diameter. If so, the diameters of the bases 3 and 14 can be increased or decreased according to the diameter of the end plate of the ready-made pile (not shown).

(3) Although the introduction hole 23 is formed in a straight line in the tangential direction of the annular groove piece 21, it can also be formed in an arc shape that is gentler (larger radius) than the annular groove 21 in the tangential direction (not shown). . Further, although three introduction holes 23 are formed, it is sufficient that at least one introduction hole 23 is provided (not shown).

Not in).

(4) Although the annular grooves 10 and 21 are formed one by one in the above embodiment, for example, two or more annular grooves can be formed in the vertical direction (not shown). In this case, the bonding strength can be increased according to the number, and the required bonding strength can be easily adjusted.

  Next, a method for burying a ready-made pile using the metal joint of Example 1 will be described.

[1] Composition of ready-made piles

(1) The ready-made pile 27 located in the intermediate portion is welded on the outer peripheral side, with the lower surface aligned with the fixed upper surface 4 of the first joint hardware 1. Moreover, the fixed lower surface 15 of the 2nd joining metal fitting 12 is match | combined with the upper end surface 29 of the ready-made pile 27, and the piled outer peripheral side is welded.

  In addition, the lowermost ready-made pile 27 fixes only the second metal fitting 12 to the upper end surface 29. The uppermost ready-made pile 27 fixes only the first joint hardware 1 to the lower end surface 28.

(2) In the above description, the metal fittings 1 and 12 and the ready-made pile 27 can be fixed in advance by forming a flange, a screw hole, or the like with a bolt or the like (not shown).

  Further, the fixing work with these joint hardware 1 and 12 can be performed either at the foundation pile enforcement site or the ready-made pile production site (factory).

  Moreover, the joining hardware 1 and 12 can also be previously formed integrally with the end plate (not shown). In this case, when manufacturing ready-made piles, it is usually possible to connect the end fitting combined metal fittings 1 and 12 to the formwork and connect them with the reinforcing bars for ready-made piles (PC steel bars, structural reinforcing bars, etc.) The ready-made pile is manufactured by the method.

[2] Joining method

(1) A pile hole 31 having a predetermined outer diameter is excavated and formed by a normal method.

(2) The lowest ready-made pile 27A (lower pile) is buried in the pile hole 31, and the pile head is protruded from the ground 32 and held by a normal method (FIG. 1 (a)).

(3) Subsequently, the next ready-made pile 27B (the ready-made pile located in the middle part. The upper pile in relation to the ready-made pile 27A) is lowered from above (FIG. 1 (a)), and the first ready-made pile 27B The fitting convex portion 7 of the joint metal 1 is fitted into the fitting concave portion 18 of the second joint metal 12 of the ready-made pile 27A (FIG. 1B). The lower end surface 9 of the first metal fitting 1 comes into contact with the upper surface 17 of the base portion 14 of the second metal fitting 12 (the bottom of the fitting recess 18), the bonding surface 6 and the bonding surface 20 come into contact with each other, and the inner peripheral edge thereof. 6a and 20a come into contact with each other and are attached to each other so that they are in close contact with each other.

Further, the first semicircular section of the annular groove 10 of the joining hardware 1 and semicircular section of the annular groove 21 of the second connecting hardware 12 is opposed, substantially circular section annular hole 25 of the outer diameter D ₄ is formed The The introduction hole 23 of the second bonding hardware communicates with the annular hole 25 (FIGS. 1B and 1C).

(4) Subsequently, the connecting rod (hole filling member) 34 is inserted in the direction indicated by the arrow from each of the three introduction holes 23, 23 of the second metal fitting 12 (FIG. 1C). The connecting rod 34 is made of a steel material having a certain degree of flexibility, and is tightly fitted and inserted into the circumference of the annular hole 25 by about “one third” (FIG. 1D). When inserting the connecting rods 34, 34, the connecting rod 34 is closely inserted into the annular hole 25 by pushing or driving in with various jigs, or by drawing a spare wire or the like at the tip. In addition, if the connecting rod 34 is inserted into the introduction hole 23 and fixed, the disconnection of the connecting rod 34 can be easily confirmed, which is convenient for the chuck in the inserted state.

  Here, the insertion work of the connecting rod 34 is performed from the introduction holes 23 and 23 on the second connecting hardware 12 side of the ready-made pile 27A, and the annular groove 10 is formed in rotational symmetry (axial symmetry). Since the relative position of 12 and the 1st connection metal fitting 1 is arbitrary, adjustment work, such as rotating and aligning the ready-made pile 27 (upper pile) B like the conventional joining metal fitting, can be omitted.

  Further, it is desirable that the groove dimensions of the annular grooves 10 and 21 are substantially the same (shape and size) from the viewpoint of the reliability and stability of the joining force.

  Further, the connecting rod 34 is made of a prefabricated pile against the shearing force when a slight flexibility that can be inserted and inserted along the annular hole 25 and a pushing force or a pulling force are generated in the upper and lower prefabricated piles 27A and 27B. The strength which can hold | maintain joining of 27A and 27B is required.

(5) Subsequently, the holding of the ready-made pile 27A is released, and the connected ready-made piles 27A and 27B are lowered. At this time, since the joint hardware 1 and 12 does not protrude outward from the ready-made piles 27A and 27B, the embedding work of the ready-made piles 27A and 27B is not affected, and the pile hole to be excavated is outside the normal ready-made pile. Pile hole diameter corresponding to the diameter is sufficient.

  Hereinafter, similarly, the ready-made pile 27 </ b> B is held in a state where the pile head is taken out from the ground 32. Similarly, a ready-made pile is connected above it (not shown). The foundation pile structure is constructed by burying the ready-made piles in the following order.

[3] Other embodiments

(1) In the above embodiment, the connecting rod 34 is inserted about “one-third” of the annular hole 25. However, when the required joining strength is low, a short connection such as “one-fourth” is used. A rod 34 can also be used (not shown).

(2) In the above embodiment has been described above drilling method, prefabricated pile 27A for connecting, in 27B, hollow portions 30 are formed in the radial _{D 2,} the hollow portion 5 of the joint hardware 1,12, 8,16,19 since also formed by D _2, since the protrusions or the like by the coupling does not occur inward, inserting the drill rod is facilitated, but also can be used (shown in the middle drilling method Absent).

  Next, another embodiment of the present invention will be described with reference to FIGS.

[1] Structure of metal fittings for bonding (first and second metal fittings) 1 and 12

(1) The first metal fitting 1 is D ₁ having the same diameter as the outer diameter of the ready-made pile (upper pile) 27B and D ₂ having the same diameter as the inner diameter (hollow part diameter), and is below the ready-made pile (upper pile) 27B. A donut-shaped (cylindrical) base 3 having a fixed upper surface 4 that can be joined to the end face 28, and fitting protrusions 36 and fitting recesses 38 are alternately formed on the lower surface side of the base 3 (FIG. 3). (A) (d)).

  The fitting convex portion 36 is formed by alternately dividing the fitting convex portion 36 and the fitting concave portion 38 by equally dividing the entire circumference into 12 portions in the circumferential direction.

  The front end surface (lower surface) 37 of each fitting convex portion 36 is formed so as to incline with an upward gradient toward the center, and the bottom surface (lower surface of the base portion 3) 39 of the engaging concave portion 38 is inclined with a downward gradient toward the center. It is formed so that the propagation of stress on both sides is balanced (FIG. 3 (a)).

  In the above, the 1st fitting part 51 is comprised from the continuous fitting convex part 36 and the fitting recessed part 38 (FIG. 3 (a)).

(2) The second joint metal 12 also has substantially the same outer shape as the first joint metal 1. That is, the fixed lower surface 15 that can be joined to the upper end surface 29 of the ready-made pile (lower pile) 27A with D ₁ having the same diameter as the outer diameter of the ready-made pile (lower pile) 27A and D ₂ having the same diameter as the inner diameter (hollow portion diameter). The doughnut-shaped (cylindrical) base portion 14 and the fitting convex portions 42 and the fitting concave portions 44 are alternately formed on the upper surface side of the base portion 14 (FIGS. 3A and 3C).

  The fitting convex portion 42 is the same as the fitting convex portion 36 of the first metal fitting 1, and the entire circumference is equally divided into 12 parts in the circumferential direction to alternately form the fitting convex portions 42 and the fitting concave portions 44. It is. The front end surface (upper surface) 43 of each fitting convex portion 42 is formed so as to incline with a downward gradient toward the center, and the bottom surface (upper surface of the base portion) 45 of the fitting concave portion 44 is inclined with an upward gradient toward the center. Is formed.

  In the above, the 2nd fitting part 52 is comprised from the fitting convex part 42 and the fitting recessed part 44 which are continuous (FIG. 3 (a)).

(3) Horizontal through-hole pieces 46A and 46B are formed from one fitting convex portion 42A and 42A of the second bonding hardware 12 toward the fitting convex portions 42B and 42B adjacent on one side. The through-hole pieces 46A and 46B are arranged on a straight line. One fitting convex part 42A, 42A is arrange | positioned in the diameter symmetrical position. An introduction hole 47 is formed in the vicinity of the intersection of both through-hole pieces 46A and 46A of the fitting convex portions 42A and 42A (FIG. 3C). In order to propagate the stress acting on the joint in a well-balanced manner, the joint protrusions 42A, 42B and the like are formed to be symmetric in diameter and rotationally symmetric.

  Further, in the first joint hardware 1, the fitting convex portion 36 </ b> A inserted into the fitting concave portion 44 </ b> A between the fitting convex portions 42 </ b> A and 42 </ b> B forming the through hole pieces 46 </ b> A and 46 </ b> B of the second fitting hardware 12, A through-hole piece 40 that communicates with the through-hole pieces 46A and 46B in a straight line is formed (FIG. 3D).

(4) The metal fitting of the present invention includes a first metal fitting having a first fitting portion 51 (fitting convex portion 36, fitting concave portion 38) that fits each other, and a second fitting portion 52 (fitting convex portion). And a second joint metal 12 having a fitting portion 42 and a fitting recess 44). When the fitting convex part 36 and the fitting concave part 44 are fitted to the first joint metal part 1 and the second joint metal part 12 and the fitting concave part 38 and the fitting convex part 42 are fitted, a through hole piece is obtained. 40, 46A and 46B communicate with each other to form a through hole 49 (FIG. 4A).

[2] Joining method of ready-made piles 27 and 27

(1) As in the second embodiment, the ready-made pile 27 located at the intermediate portion is aligned with the upper surface 4 of the first joint hardware 1 at the lower end surface 28 and the overlapped outer peripheral side is fixed by welding or bolts or the like. . Moreover, the fixed lower surface 15 of the 2nd joining metal fitting 12 is match | combined with the upper end surface 29 of the ready-made pile 27, and the piled outer peripheral side is fixed with welding or a volt | bolt. In addition, the lowermost ready-made pile 27 fixes only the second metal fitting 12 to the upper end surface 4. The uppermost ready-made pile 27 fixes only the first joint hardware 1 to the lower end surface 28.

(2) In the same manner as in the above embodiment, the ready-made pile (lower pile) 27A is held by a normal method with the pile head protruding from the ground in the pile hole 31 (FIG. 3A). Subsequently, the next ready-made pile (upper pile) 27B is lowered from above (FIG. 3A), and the first joint 51 of the first joint hardware 1 of the ready-made pile 27B is connected to the second joint of the ready-made pile 27A. The second joint portion 52 of the metal piece 12 is overlapped, and the joint convex portion 36, the fitting concave portion 44, the fitting concave portion 38, and the fitting convex portion 42 are fitted to each other (FIG. 3B). At this time, the front end surface 37 of the fitting convex portion 36 of the first metal fitting 1 comes into contact with the bottom (upper surface) 45 of the fitting concave portion 44 of the second metal fitting 12, and the first metal fitting 1 The bottom surface 39 of the fitting recess 38 comes into contact with the tip surface 43 of the fitting projection 42 of the second metal fitting 12 so that the whole is closely attached.

  Moreover, the through-hole piece 40 of the 1st joining metal fitting 1 and the through-hole pieces 46A and 46B of the 2nd joining metal fitting 12 are connected on a straight line, and the through-hole 49 is formed (FIG. 4 (a)).

(4) Subsequently, the connecting rod 34 is inserted in the direction indicated by the arrow from the introduction hole 47 of the second metal fitting 12 (FIG. 4A). The connecting rod 34 is made of a rigid steel material, and is pushed or driven, or attached with a pull-out spare wire and pulled out, etc., so that the through-hole piece 46A of the second joint hardware 12 and the adjacent fitting convex portion It penetrates the through hole 40 of 36A, reaches the through hole piece 46B of the fitting convex portion 42B, and is inserted into the through hole 49 (FIG. 4B). Further, the connecting rod 34 needs to have a strength capable of holding the joint of the ready-made piles 27A and 27B against each stress generated when a pulling force or a horizontal force is applied to the upper and lower ready-made piles 27A and 27B.

[3] Other embodiments

  In the above embodiment, the through-hole 49 (through-hole pieces 40, 46A, 46B) and the connecting rod 34 to be inserted into the through-hole 49 are formed in a straight line, but may be formed in a curved line (FIG. 5). In this case, the through-hole 49 is formed in an arc shape so as to be convex outward in a horizontal plane (along the outer or inner circle) (FIG. 5A). Thus, by forming the through-hole 49 and the connecting rod 34 in an arc shape, there is no possibility that the connecting rod 34 inserted into the through-hole 49 will come off, and a stable coupling force can be maintained.

  Next, another embodiment of the present invention will be described. In the first to third embodiments, the connecting rod 34 is connected to the annular holes 25 and 49 formed after the ready-made piles 27A and 27B are connected, that is, after the fitting convex portion 7 and the fitting concave portion 18 are fitted. Is an example in which a connecting rod is attached to one annular hole piece in advance (FIGS. 6 to 10).

[1] Structure of bonding hardware (first bonding hardware) 1

(1) The first metal fitting 1 has an outer diameter D ₁ having the same diameter as the upper pile, a donut-shaped (tubular) base portion 3 having a fixed upper surface 4 that can be joined to the lower surface of the upper pile, and a lower portion of the base portion 3. A fitting convex portion (first fitting portion) 7 having an outer diameter D ₃ (D ₁ > D ₃ ) is provided to protrude on the side (FIGS. 6A and 7). The inner diameter of the base portion 3 and the fitting projection 7, an inner diameter and the same diameter D ₂ of the upper pile, is formed with a hollow portion 5 and 8 communicating.

  The base portion 3 is formed with a joining surface 6 that is inclined downward in the radial direction at the lower end.

The fitting convex portion 7 has an annular groove (first through hole piece) 10 having a semicircular diameter (diameter D ₄ ) and a deep opening at the intermediate height of the outer surface along the outer peripheral surface. Form. Therefore, the cross-section of the annular groove 10 is composed of a semi-circular portion 10b of the rectangular portion 10a and the bottom side of the opening side (Fig. 8), the annular groove 10, a size that the connecting rod 34 of diameter D ₄ is accommodated (FIGS. 6, 7, and 8B).

The annular groove 10 is formed at a distance L ₁ from the inner peripheral edge 6 a of the joint surface 6, and is positioned approximately in the middle of the distance from the inner peripheral edge 6 a to the lower end surface 9.

(2) A connecting rod (elastic ring) 34 having a shape obtained by cutting a part of the annular shape is attached to the annular groove 10.

Connecting rod 34, an annular bar is a circular annular groove (first through-hole piece) geometry and cross section diameter D ₄ that can be exactly housed in 10, and cut into a predetermined length dimension and configuration. Connecting rod 34 is in the normal position, the outer diameter is larger inner diameter than the D ₃ is formed to be smaller than D _3. The connecting rod 34, since the gap portion 35 is formed in the cutting position (Fig. 7), it is possible diameter while maintaining the elasticity, with reduced diameter state and an outer diameter smaller than D _3, an annular groove 10 can be accommodated.

[2] Structure of bonding hardware (second bonding hardware) 12

The second metal fitting 12 has the same outer diameter D ₁ as the first metal fitting 1 and has a base portion 14 having a fixed lower surface 15 that can be bonded to the upper surface of the lower pile, and the fitting convex portion 7 and the upper portion of the base portion 14. the mating recess in the inner diameter _{D 3} that can focus (second fitting portion) 18 configured by projecting (Fig. 6 (a)). The inner diameter of the base portion 14 in the inner diameter and the same diameter D ₂ of the lower pile, hollow portion 19 of the hollow portion 16 and the fitting recess 18 of the base 14 communicates with the hollow portion 30 of the lower pile.

A joint surface 20 is formed on the upper surface of the fitting recess 18 so as to incline downward in the radial direction with the same slope as the joint surface 6 of the first joint metal 1 and overlap the joint surface 6. The fitting recess 18 forms an annular groove (second through-hole piece) 21 having a semicircular diameter (diameter D ₄ ) along the inner peripheral surface at an intermediate height. Annular groove 21 is formed in the same dimensions as the first annular groove 10 of the fitting portion 1, is formed at a distance L ₁ from the inner peripheral edge 20a of the bonding surface.

[3] Bonding hardware

  The metal joint according to the present invention is composed of a first metal joint 1 having a fitting convex portion 7 fitted to each other and a second metal joint 12 having a fitting concave portion 18. When both the fittings 1 and 12 are joined and the fitting convex portion 7 and the fitting concave portion 18 are fitted, the annular grooves 10 and 21 face each other to form an annular hole (through hole) 25.

[4] Composition of ready-made piles

(1) The ready-made pile 27 located in the intermediate portion is welded on the outer peripheral side, with the lower surface aligned with the fixed upper surface 4 of the first joint hardware 1. Moreover, the fixed lower surface 15 of the 2nd joining metal fitting 12 is match | combined with the upper end surface 29 of the ready-made pile 27, and the piled outer peripheral side is welded.

  In addition, the lowermost ready-made pile 27 fixes only the second metal fitting 12 to the upper end surface 29. The uppermost ready-made pile 27 fixes only the first joint hardware 1 to the lower end surface 28.

(2) In the above description, the metal fittings 1 and 12 and the ready-made pile 27 can be fixed in advance by forming a flange, a screw hole, or the like with a bolt or the like (not shown).

  Further, the fixing work with these joint hardware 1 and 12 can be performed either at the foundation pile enforcement site or the ready-made pile production site (factory).

  Moreover, the joining hardware 1 and 12 can also be previously formed integrally with the end plate (not shown). In this case, when manufacturing ready-made piles, it is usually possible to connect the end fitting combined metal fittings 1 and 12 to the formwork and connect them with the reinforcing bars for ready-made piles (PC steel bars, structural reinforcing bars, etc.) The ready-made pile is manufactured by the method.

[5] Joining method

(1) A pile hole 31 having a predetermined outer diameter is excavated and formed by a normal method.

(2) The lowest ready-made pile 27A (lower pile) is embedded in the pile hole 31, and the pile head is protruded from the ground 32 and held by a normal method (FIG. 6 (a)).

(3) Then, the next ready-made pile 27B (the ready-made pile located in the middle part. The upper pile in relation to the ready-made pile 27A) is lowered from above (FIG. 6A). In this state, the outer peripheral side of the connecting rod 34 protrudes from the outer peripheral surface 7a of the fitting convex portion 7, and the inner peripheral side is accommodated in the annular groove 10 (FIGS. 6A and 8A).

  Subsequently, when the ready-made pile 27B is lowered, the fitting convex portion 7 of the first joint hardware 1 of the ready-made pile 27B is inserted into the fitting concave portion 18 of the second joint hardware 12 of the ready-made pile 27A. At this time, the outer peripheral surface 7a of the fitting convex portion 7 abuts on the inner peripheral surface 18a of the annular recess 18, and the connecting rod 34 attached to the annular groove 10 is pressed by the inner peripheral surface 18a of the annular recess 18 to be contracted. The diameter is accommodated in the annular groove 10 (FIG. 8B).

(4) When the ready-made pile 27B continues to descend, the connecting rod 34 reaches the annular groove 21 of the fitting recess 18 and expands in diameter by elastic restoring force, and the outer peripheral side 34a is fitted into the annular groove 21. (FIG. 8 (c)). At the same time, the lower end surface 9 of the first metal fitting 1 comes into contact with the upper surface 17 of the base 14 of the second metal fitting 12 (the bottom of the fitting recess 18), and the bonding surface 6 and the bonding surface 20 come into contact with each other. The inner peripheries 6a and 20a come into contact with each other, and the whole comes into close contact with each other, so that the first joint metal 1 and the second joint metal 12 are connected.

  Moreover, the annular groove 25 of the 1st joining metal fitting 1 and the annular groove 21 of the 2nd joining hardware 12 oppose, and the annular hole 25 is formed (FIG.6 (b)).

  At this time, it is possible to omit complicated adjustment work such as rotating the ready-made pile 27 (upper pile) B like a conventional metal fitting and aligning the bolt holes, and dropping and fixing the upper ready-made pile 27B. It can be easily joined.

(5) Subsequently, the holding of the ready-made pile 27A is released, and the connected ready-made piles 27A and 27B are lowered. At this time, since the joint hardware 1 and 12 does not protrude outward from the ready-made piles 27A and 27B, the embedding work of the ready-made piles 27A and 27B is not affected, and the pile hole to be excavated is outside the normal ready-made pile. Pile hole diameter corresponding to the diameter is sufficient.

  Hereinafter, similarly, the ready-made pile 27 </ b> B is held in a state where the pile head is taken out from the ground 32. Similarly, a ready-made pile is connected above it (not shown). The foundation pile structure is constructed by burying the ready-made piles in the following order.

[6] Other embodiments

(1) Further, in the above-described embodiment, an operation hole (introduction hole) 54 that opens from the annular groove 21 of the fitting recess 18 to the outer peripheral surface can be formed (FIG. 6 (a), indicated by a chain line 54). If the gap 35 of the connecting rod 34 is positioned corresponding to the operation hole 54, the connecting rod 34 is pressed from the operation hole 54 to reduce the diameter, and the fitting convex portion 7 that has been once fitted is fitted. The fitting of the joint recess 18 can also be released.

(2) In the embodiment described above, one set of the annular groove 10 and the connecting rod 34 is formed, but it can also be arranged in multiple stages vertically. In this case, the diameter of each annular groove 10 and the connecting rod 34 can be different. For example, is formed in three stages, in order from the top to the fitting projection 7 "annular groove 10A of diameter _{D 41,} connecting rod 34A""annular groove 10B of the diameter _{D 42,} connecting rod 34B""annular groove 10C of the diameter _{D 43} , The connecting rod 34C ”is formed. Correspondingly, to form the "annular groove 21A of diameter _{D 41"} "annular groove 21B of the diameter _{D 42"} "annular groove 21C of the diameter _{D 43} 'from the top to the fitting recess 18 (FIG. 9 (a) In this case, D ₄₁ <D ₄₂ <D _43. The structures of the annular grooves 10, the connecting rods 34, and the annular grooves 21 are the same as described above.

Therefore, when the ready-made pile 27B to which the first joint hardware 1 is attached is lowered from above the ready-made pile 27A to which the second joint hardware is attached, the fitting convex portion 7 is inserted into the fitting concave portion 18, and first the connecting rod 34C. but, the annular groove 21A of the fitting recess 18, but corresponding to _21B, since it is _{D 41 <D 42 <D 43} , connecting rod 34C passes the annular groove 21A, the 21B. Similarly, the connecting rod 34B can also pass through the annular groove 21A. When the ready-made pile 27B is further lowered, the connecting rods 34A, 34B, and 34C are expanded and inserted into the annular grooves 21A, 21B, and 21C, and the fitting convex portion 7 and the fitting concave portion 18 are fitted. Thus, the joining of the ready-made piles 27A and 27B is completed (FIG. 9B).

In this case, since the connection is maintained by being divided by the three connecting rods 34A, 34B, and 34C, the burden on one connecting rod 34 is reduced, and the joining strength can be increased. Moreover, if the joint strength is the same, the diameters D ₄₁ , D ₄₂ , and D ₄₃ of each connecting rod 34 can be reduced.

  In this case, since the relatively small diameter connecting rod 34 is easily deformed, the adhesion within the annular groove is good. It is effective to use the connecting rod 34 properly, for example, to give the connecting rod 34 a function of bearing a large stress.

(3) In the case (2), further, the annular groove 10A, 10B, although the outer diameter D ₃ of the fitting convex portion provided to 10C, by changing the outer diameter corresponding to form increasingly shape that You can also.

In this case, in order from the top to the fitting projection 7 "on the outer peripheral surface of the outer diameter _{D 31,} the annular groove 10A of diameter _{D 41,} connecting rod 34A""annular groove 10B of the diameter _{D 42} to the outer peripheral surface of the outer diameter _{D 32} coupling rod 34B "" annular groove 10C of the diameter _{D 43} to the outer peripheral surface of the outer diameter _{D 33,} forms a connecting rod 34C ". Correspondingly, in order from the top to the fitting recess 18 'on the inner peripheral surface of the diameter _{D 31,} the annular groove 21A of diameter _{D 41} "," the inner peripheral surface of the diameter _{D 32,} the annular groove 21B of the diameter _{D 42} ""the inner peripheral surface of the diameter _{D 33,} the annular groove 21C of the diameter _{D 43"} is formed (FIG. 10 (a)). In this case, D ₃₁ > D ₃₂ > D ₃₃ is satisfied, and the fitting convex portion 7 is formed in a shape with a diameter reduced downward, and the fitting concave portion is also formed with a diameter reduced downward.

  When formed in this way, when inserted, the connecting rod 34C of the annular protrusion 7 reaches the annular groove 21C without contacting the annular grooves 21B and 21A of the annular recess 18, and the connecting rod Since 34B reaches the annular groove 21B without coming into contact with the annular groove 21A, the connecting operation can be performed smoothly. Moreover, since the diameter of each annular groove 10, 21 (that is, the diameter of each connecting rod 34) can be set independently, the degree of freedom in design can be expanded.

(4) Further, in the embodiment, covers 56 and 57 can be attached to prevent the dust from adhering to the fitting convex portion 7 and the fitting concave portion 18 during construction (FIG. 6 (a)). ) Chain line shown). The covers 56 and 57 are removed during the connection work.

(5) Moreover, in the said Example, since the connecting rod 34 was inserted beforehand by the annular groove 10 of the fitting convex part 7, it is preferable that excavation mud does not adhere, but the annular groove 21 of the fitting recessed part 18 is preferable. Can also be inserted in advance (not shown).

(6) Further, in the above-described embodiment (embodiment 4), the connecting rod 34 (hole filling member) is enlarged and reduced in diameter, and the fitting protrusion 7 of the first fitting 1 and the second fitting 12 are fitted. Since the connecting rod 34 is moved or deformed after being mounted and the joint is loosened because it is positioned between the concave portion 18, so-called rattling may occur. Therefore, in the embodiment, in order to prevent this and realize more reliable and stable joining, the joining rod 34 can be fixed in the fitting groove 10 or the fitting groove 21 (not shown). ).

  For example, the annular groove 10 and / or the annular groove 21 can form a protrusion (for example, a knife shape) at the position of one end of the annular connecting rod 34. In this case, the reduced diameter of the connecting rod 34 is released, the connecting rod is accommodated in the annular groove 21, and the side to which the connecting rod is attached, that is, the annular groove on which the protrusion is formed, with the upper and lower piles joined. The first or second metal fitting on the side having 10 and 21 is slightly rotated to forcibly press the connecting rod 34 in the rotational direction, press down, and fix the connecting rod 34 to be plastically deformed. Therefore, it becomes a locked state, the rattling of the joint portion is eliminated, the connecting rod 34 is securely fixed in the annular grooves 10 and 21, and stable fixing without change with time can be realized.

  Further, by pressing as described above, the connecting rod 34 can be further rotated as it is together with the reduced diameter, the release of the mounting, and the expanded diameter, screwed and pressed, and similarly locked and continuously fixed. It is.

  In addition, the annular grooves 10 and 21 can be formed in a spiral shape. In this case, similarly to the bolt tightening, the joining can be easily fixed and the joining can be stabilized by screwing the connecting rod 34 a little. . The above-described method for reliably and stabilizing the joining, that is, the diameter reduction / release and pressing / fixing of the connecting rod 34 can be similarly realized by deforming the annular grooves 10 and 21.

(7) Other embodiments are the same as those of the first embodiment.

In an embodiment of the present invention, (a) is a longitudinal sectional view of an upper and lower ready-made pile before joining, (b) is a longitudinal sectional view of an upper and lower ready-made pile after joining, and (c) and (d) are those of FIG. It is sectional drawing in CC line, (c) represents before attachment of a connecting rod, (d) represents after attachment of a connecting rod, respectively. (A) is sectional drawing in the AA line of Fig.1 (a), (b) is sectional drawing in the BB line of Fig.1 (a). In Example 3 of this invention, (a) is a vertical cross-sectional view of the upper and lower ready-made piles before joining, (b) is a vertical cross-sectional view of the upper and lower ready-made piles after joining, and (c) is a D- in FIG. Sectional drawing in D line, (d) represents sectional drawing in the EE line of Fig.3 (a). Similarly, FIG. 3B is an enlarged cross-sectional view taken along the line FF in FIG. 3B, in which (a) shows the state before the connecting rod is attached, and (b) shows the state after the connecting rod is attached. FIG. 3B is an enlarged cross-sectional view taken along the line FF in FIG. 3B. FIG. 3B is an enlarged cross-sectional view taken along the line F-F in FIG. 3B, and FIG. To express. In Example 4 of this invention, (a) is a longitudinal sectional view of the upper and lower ready-made piles before joining, and (b) is a longitudinal sectional view of the upper and lower ready-made piles after joining, respectively. It is an expanded sectional view in the GG line of FIG. Similarly, in Example 4, a partial longitudinal sectional view schematically showing the fitting process of the first and second joining hardware, (a) before fitting, (b) during fitting, (c) fitting completed. Represents each after. Similarly, in another example of Example 4, (a) is a longitudinal sectional view of an upper and lower ready-made pile before joining, and (b) is a longitudinal sectional view of an upper and lower ready-made pile after joining, respectively. Similarly, in another example of Example 4, (a) is a longitudinal sectional view of an upper and lower ready-made pile before joining, and (b) is a longitudinal sectional view of an upper and lower ready-made pile after joining, respectively.

Explanation of symbols

1 First Bonding Hardware 3 Base (First Bonding Hardware)
4 Fixed upper surface (first joint hardware)
5 Base hollow part (first joint hardware)
6 Base joint surface (first joint hardware)
7 Fitting projection (first joint hardware)
7a Outer surface 8 of fitting convex part Hollow part (1st metal fitting)
10 Annular groove (first joint hardware)
12 Second Bonding Hardware 14 Base (Second Bonding Hardware)
15 Fixed bottom surface (2nd metal fitting)
16 Base hollow part (2nd metal fitting)
17 Upper surface of the base (second bonding hardware)
18 Fitting recess (second joint hardware)
18a Inner side surface 19 of the fitting recess hollow portion of the fitting recess (second bonding hardware)
20 Bonding surface (second bonding hardware)
21 annular groove (second joint hardware)
23 Introduction hole 25 Annular holes 27, 27A, 27B Ready-made pile 28 Lower-end surface 29 of ready-made pile Upper-end surface 30 of ready-made pile Hollow portion 31 of ready-made pile Pile hole 32 Ground 34 Connecting rod 34a Outer side 34b of connecting rod Inside of connecting rod Peripheral side 35 Connecting rod gaps 36, 36A Fitting protrusion (first joint hardware)
38 Fitting recess (first joint hardware)
40 Through-hole piece (first joint hardware)
42, 42A, 42B Fitting convex part (second joint hardware)
44 Fitting recess (second joint hardware)
46 Through-hole piece (2nd metal fitting)
47 Introduction hole 49 Through-hole 51 1st fitting part (1st metal fitting)
52 2nd fitting part (2nd metal fitting)
54 Operation hole

Claims (2)

It is a joining method of a ready-made pile that joins the upper pile and the lower pile at the joint portion, without causing a portion protruding on any of the inner peripheral surface side and the outer peripheral surface side of the upper pile and the lower pile, A method for joining ready-made piles characterized by joining in the following steps.
(1) A first fitting portion formed by alternately providing fitting convex portions and fitting concave portions in the circumferential direction is formed at the joint end portion of one of the upper and lower piles.
The fitting recesses and the fitting protrusions are alternately provided in the circumferential direction at the joint end of the other upper and lower piles to form a second fitting portion. The first fitting portion and the second fitting portion have the same outer diameter D1 and the same inner diameter D2.
A first through hole piece is formed on the fitting convex portion of the first fitting portion, and a second through hole piece is formed on the fitting convex portion of the second fitting portion.
(2) The upper pile is overlapped on the lower pile, the first fitting portion and the second fitting portion are fitted, and the front end surface of the fitting convex portion of the first fitting portion and the second fitting portion The bottom surface of the fitting concave portion contacts, and the tip surface of the fitting convex portion of the second fitting portion contacts the bottom surface of the fitting concave portion of the first fitting portion.
(3) By fitting the first fitting portion and the second fitting portion, the first through-hole piece and the second through-hole piece cooperate to form a through-hole.
(4) The second fitting convex portion is formed with an introduction hole that communicates with the through hole and penetrates outward from the through hole in a tangential direction, and a filling member is inserted from the introduction hole, The hole filling member is closely inserted into the through hole . A joint hardware composed of a first joint hardware that can be fixed to one of the upper pile and the lower pile and a second joint hardware that can be fixed to the other, whichever of the inner peripheral surface side and the outer peripheral surface side of the upper pile and lower pile A prefabricated pile metal fitting that can be joined without producing a protruding part on the surface of the steel and has the following characteristics.
(1) The first joint hardware is configured by connecting a first fitting portion having a first through hole piece to a base portion fixed to a ready-made pile . First fitting portion before SL constitutes provided alternately fitting projections and fitting recesses in the circumferential direction.
(2) The second joint hardware is formed by continuously providing a second fitting portion that can be fitted to the first fitting portion on a base portion fixed to a ready-made pile. The second fitting portion is configured by alternately providing the fitting concave portion and the fitting convex portion in a circumferential direction. A second through-hole piece capable of forming a through-hole in cooperation with the first through-hole piece in a straight line or an arc shape was formed in the second fitting portion.
(3) The first fitting portion and the second fitting portion have the same outer diameter D1 and the same inner diameter D2.
(4) the said first through-hole member formed in the fitting convex portion of the first fitting portion, the second through-hole member formed in the fitting convex portion of the second fitting portion, the second In the fitting convex portion, an introduction hole is formed which communicates with the through hole in a straight line or an arc shape and penetrates outward . The introduction hole and the through hole are formed so that a filling member can be inserted from the introduction hole .
(5) When the first fitting portion and the second fitting portion are fitted, the front end surface of the fitting convex portion of the first fitting portion and the bottom surface of the fitting concave portion of the second fitting portion are The fitting convex part and the fitting concave part are formed so that the tip end surface of the fitting convex part of the second fitting part and the bottom surface of the fitting concave part of the first fitting part are in contact with each other .

Images