JP2007327248A - Prefabricated pile for foundation pile and continuous wall using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prefabricated pile for foundation pile, which increases the bearing force of a pile in place of a conventional prefabricated pile for foundation pile made of H-steel. <P>SOLUTION: The prefabricated pile for foundation pile is formed of: a plate B forming a web; and two plates A which are made at both ends forms flanges, and has a generally H-shaped cross section. The two plates A are so bent in a chevron shape in cross section as to be expanded more than the width of the plate material B at its contact point with the plate material B. The angle of each of two bent plate materials A formed with the plate material B is more than 90° and less than 180°. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a prefabricated pile manufactured in advance in a factory or the like before construction on site among foundation piles that support a structure, and further relates to a continuous wall using the prefabricated pile.

  Conventionally, there is a pile foundation as one of the foundations for supporting the structure. Pile foundations are further divided into those that use prefabricated piles manufactured at factories and others, and cast-in-place piles that are built using cement during the excavation process.

  As prefabricated piles, in addition to cylindrical piles such as ordinary concrete piles, steel pipe piles, steel-concrete composite piles, etc., H-shaped steels commonly used for beams and column members were used as building materials. There are H piles.

  The reason why the cylinder is used in the cross-sectional shape as a prefabricated pile is non-directionality in bending load, but it is largely due to restrictions on its manufacturing method. In many steel pipe piles, hot-rolled coils are continuously formed into a spiral shape by a forming apparatus, and it is difficult to manufacture shapes other than cylindrical shapes. In addition, RC piles (Reinforced spun Concrete Piles) and PHC (Pretensioned spun High strength Concrete Piles) piles, which are examples of concrete piles, adopt a manufacturing method that uses centrifugal force. Is hard to manufacture.

  On the other hand, Steel H Piles using H-section steel can be installed easily without the need for dedicated heavy machinery to embed piles required for steel pipe piles or concrete piles. It is a pre-made pile material that has a very high utility value in terms of the characteristic construction surface. As described in Non-Patent Document 1 and Non-Patent Document 2, the H-shaped steel pile using the H-shaped steel is expected to have a supporting force as a retaining wall and an intermediate pile, and receives a vertical load. It is used to support

FIG. 14 is a diagram showing a general H-shaped steel used as a pile, and is composed of a plate material 1 that is two flanges and a plate material 2 that is a web connecting the two, and the angle formed by the plate material 1 and the plate material 2 is as follows. 90 °. This is because H-shaped steel is mainly used as, for example, a beam column for construction, and 90 ° has been the optimum angle in terms of increasing bending resistance and the relationship with the floor and other beam columns. This is because.
Tunnel standard specification [open-cut method], commentary, Japan Society of Civil Engineers pp.152-156 Road earthwork temporary structure work guidelines, Japan Road Association pp.67-73

  The H-section steel has a shape determined with an emphasis on bending resistance at present, and for example, the function as a pile including a supporting force is not considered at all in the shape determination.

  H-section steel is a shaped steel product that forms a slab by rolling with a hole roll or a universal roll, so the shape restriction on the production surface is low, and it is possible to produce the best shape according to various applications. The current situation has not been studied.

  In order to increase the supporting force in the H-section steel, for example, the use of a large type is one means, but in this case, the amount of steel material to be used increases and the material cost increases. That is, if an attempt was made to increase the supporting force by using a large model, the cost of the entire construction was often increased.

  The present invention has been made in view of the above-mentioned problems of the prior art, and is not limited to existing cross-sectional shapes such as a cylindrical shape or an H shape, and in particular, an existing pile made of a conventional H-shaped steel. On the other hand, it aims at providing the ready-made pile for foundation piles which can increase the bearing capacity of a pile.

  The pile support force is generally evaluated by dividing it into a peripheral support force at the pile shaft and a tip support force at the tip of the pile. In the peripheral support force, the pile circumference and the pile are included in the friction stress of the pile material and the surrounding ground. Calculated by multiplying by length. On the other hand, the tip support force is calculated by multiplying the ground strength at the tip of the pile by the tip area, and the support force of the entire pile is determined by appropriately considering the safety factor.

  When H-shaped steel is generally used as a pile, it is also called an H-pile, but when evaluating its bearing capacity, a rectangle circumscribing the H-shaped steel is determined, and the total side length is evaluated as the circumference. A method of evaluating a rectangular area as a tip area is employed.

  This is a method of evaluating only the surface circumference of the H-section steel and the pure cross-sectional area of the tip of the H-section steel by interaction with the soil, based on the accumulation of knowledge that evaluated the bearing capacity in past field tests. This is because it is underestimated, and the method described above has been accepted as an evaluation method based on the actual situation on the premise of interaction with soil.

  As a result of earnestly examining the combined shape of the members that maximize the circumference and tip area when evaluating the bearing force in the existing pile for a foundation pile having a substantially H-shaped cross section, the inventors have a substantially H-shaped cross section. By changing the angle of the member corresponding to the flange, the circumference and tip area can be increased compared to H-shaped steel piles with an angle of 90 °, with almost no change in the amount of steel. We found a prefabricated pile for foundation piles that can be increased. The characteristics are described below.

  In addition, the “prefabricated pile” referred to in the present invention is a pile manufactured at a factory.

(1) A cross-section consisting of a plate B serving as a web and two plate A present at both ends and serving as a flange is a prefabricated pile for a foundation pile having a substantially H shape, and the two plates A are the plate B The cross section is bent in a U-shape so that it is wider than the width of the plate material B, and the angle between the two bent plate materials A and the plate material B is more than 90 ° and less than 180 °. And

(2) In the prefabricated pile for foundation piles described in (1), each of the two plate materials A maintains a straight shape instead of bending in a cross-sectional shape from the contact point with the plate material B to the middle, Further, the section is bent in a U-shape in a direction wider than the width of the plate material B, and the angle formed by the extension line of the bent portion and the plate material B is more than 90 ° and less than 180 °. And

(3) In the prefabricated pile for foundation piles according to (2), each of the two plate materials A is bent into a U-shaped cross section at the point where the linear shape is held, and the extension line of the bent portion and the plate material In addition to being more than 90 ° and less than 180 °, the angle formed with B is further characterized in that the cross section is bent in a dogleg shape at the tip.

(4) In the ready-made pile for foundation piles in any one of (1)-(3), the said board | plate material B is connected with the joint in the middle of the web, It is characterized by the above-mentioned.

(5) The prefabricated pile for foundation piles according to any one of (1) to (4), wherein at least one end of each of the two plate members A has joints.

(6) A continuous wall using the prefabricated pile for the foundation pile according to (5), wherein a plurality of the prefabricated piles for the foundation pile are arranged adjacent to each other, and joints at both ends of the plate material A in the preformed pile are used. The adjacent pre-built piles are connected to each other.

  As described above, the use of a prefabricated pile having a substantially H-shaped cross section as a foundation pile as described above is less than when using an H-shaped steel pile that is a prefabricated pile for a conventional foundation pile. The necessary supporting force can be exhibited by the amount of steel used, and the supporting force can be further increased when the amount of steel is the same as that of these conventional foundation piles.

  Hereinafter, the best mode for carrying out an existing pile for a foundation pile to which the present invention is applied will be described in detail with reference to the drawings.

(1) 1st Embodiment FIG. 1: is a cross-sectional block diagram of the existing pile 51 for foundation piles which is 1st Embodiment of this invention. A cross section consisting of a plate material B4 serving as a web and two plate materials A3 existing at both ends of the web and serving as a flange is a substantially H-shaped pile, and the two plate materials A are in contact with the plate material B, rather than the width of the plate material B. The cross section is bent in a U shape so as to expand. Unlike the H-section steel shown in FIG. 1, the angle 5 formed between each of the two bent plate materials A3 and the plate material B4 is greater than 90 ° and less than 180 °.

  As a result, the circumference 7 that is assumed in the calculation of the bearing capacity of the peripheral surface is as follows. In the case of H-section steel, the H-section steel width 8 (corresponding to the flange width) and H-shape as shown in FIG. It is calculated by the total side length of a rectangle composed of steel height 9 (corresponding to web width + flange thickness at both ends).

  The circumferential length 12 in the first embodiment of the present invention is calculated as a total of the side lengths of a rectangle composed of a width 13 and a height 14 as shown in FIG. 3A, and the angle formed by the plate material A and the plate material B is The pile according to the first embodiment of the present invention, which is more than 90 ° and less than 180 °, has a circumferential length of 1.0 compared to a conventional H-shaped steel pile in which the angle between the web and the flange is 90 °. It becomes possible to have a value of about more than double and 1.3 times or less.

  Furthermore, the tip area assumed for the calculation of the tip bearing capacity is generally multiplied by the width 8 of the H-section and the height 9 of the H-section as shown in FIG. Although the rectangular area obtained by this is adopted as the tip area 10, the tip area in the pile of the first embodiment of the present invention is obtained by multiplying the width 13 and the height 14 as shown in FIG. The rectangular area is evaluated as the tip area 16, and compared to the H-section steel pile with an angle of 90 ° between the web and the flange, the area is more than 1.0 times and less than 1.2 times. Can have.

  Fig.4 (a) is a schematic diagram which shows the view of the bearing capacity of a pile. In the present invention, the bearing capacity of the prefabricated pile 51 for the foundation pile is based on the circumferential length 12 and the tip area 16 calculated as described above, and the pile shaft portion 18 in consideration of the friction stress and the pile length with the surrounding ground. The peripheral support force is determined by multiplying the circumference, friction stress, and pile length, and the pile tip 19 is multiplied by the tip area and ground strength after considering the ground strength at the pile tip. Determine the supportive capacity.

In order to compare the bearing capacity of the existing pile for the foundation pile of the present invention determined above with the conventional H-shaped steel pile, the width Y and the plate thickness of the plate B serving as the web, and the extension of the plate A serving as the flange If the width X (extension length of the cross section of the plate A bent in a U-shape: X / 2 + X / 2), the plate thickness, and the total length of the pile are the same, the required amount of steel material becomes substantially equal. Compared to H-section steel with a 90 ° angle, it can exhibit high bearing capacity performance of more than 1.0 times and less than 1.5 times in total bearing capacity, which is the sum of tip bearing capacity and peripheral surface bearing capacity. it can.

In addition, high bearing force performance shows the performance which is hard to sink at the time of the same load action, for example in a load settlement curve. FIG. 4B is a conceptual diagram showing a load-settlement curve of a pile, in which the horizontal axis P represents the load load and the vertical axis δ represents the amount of deformation. As can be seen from this, the load-subsidence curve 21 in the pile of the present invention shows the positional relationship as shown in FIG. The amount of deformation at the time of loading is small, and therefore it is possible to exhibit high bearing capacity performance.

  When a pile is used as a friction pile, that is, the solid stratum that supports the pile tip is very deep, and from the viewpoint of cost, construction, and design, the tip of the pile does not reach the solid stratum, and it is near the middle soft stratum In the case of using with a stop, the support mechanism depends on the peripheral surface support force. Therefore, the target is to increase the peripheral surface support force as much as possible. In this case, the cross-sectional shape should be determined with emphasis on increasing the circumferential length, and it is desirable to adopt an angle of about 135 ° as the angle formed by the plate material A and the plate material B.

  When a pile is used as a support pile in a landfill such as a harbor, where the ground above the support layer is weak and the friction force between the pile and the ground is low, the support mechanism depends on the tip support force. The goal is to increase the tip support as much as possible. In this case, the cross-sectional shape should be determined with emphasis on increasing the tip area, and it is desirable to adopt an angle of about 120 ° as the angle formed by the plate material A and the plate material B.

  When embedding the foundation pile in the embodiment of the present invention in the ground, it is suspended by a crane or the like at the installation location, and then a vibration exciter capable of giving a specific frequency that is separately lifted by the crane With this member gripping device, the simplest construction means is to grip the plate material B at the upper end in the longitudinal direction of the member and transmit the vibration to the gripped part and construct it by the weight of the foundation pile and the weight of the vibration heavy machine. In general, when vibration is applied to the ground, the friction between the foundation pile and the ground is reduced, and therefore, very simple construction can be performed.

  In addition, as a manufacturing method of the ready-made pile for foundation piles in 1st Embodiment, it can manufacture by hot rolling, the buildup by welding of a flat steel, etc., for example.

(2) Second Embodiment In the first embodiment, the plate material A3 is a straight member having a cross-sectional shape, but in the second embodiment, the plate material A3 is not limited to a cross-sectional shape. FIG. 5 shows a cross-sectional shape of the second embodiment of the present invention.

  The plate material A22 in the second embodiment maintains a linear shape up to a point 25 on the way from the contact point 24 to the plate material B23 toward the end, and bends in a dogleg shape from the tip to the end. That is, the two plate materials A22 are disposed substantially perpendicular to the plate material B23 from at least the contact point 24 with the plate material B23 to the bent portion 25, and 90 to the plate material B23 from the bent portion 25 to the tip 61. It is inclined at an angle θ26 of more than 180 ° and less than 180 °.

  The bent portion 25 may be close to the flange end portion or close to the connection position with the web. However, it is desirable that the bent portion 25 be close to the web for improving the supporting force.

  In addition, the manufacturing method of the existing pile for foundation piles in 2nd Embodiment can also be manufactured similarly to the manufacturing method in 1st Embodiment.

(3) 3rd Embodiment In FIG. 13 (a), the shape of one example of the ready-made pile for foundation piles which concerns on 3rd Embodiment is shown.

  In this embodiment, in the prefabricated pile for foundation piles of the second embodiment, each of the two plate members A bends in a cross-sectional shape at the point where the straight shape is maintained from the contact point with the plate member B. Furthermore, the cross-section is bent in a dogleg shape at the tip. That is, in this embodiment, the cross section in which the two plate materials A22 are formed at both ends of the plate material B23 is a substantially H-shaped pile. The two plate materials A22 are disposed substantially perpendicular to the plate material B23 from at least the joint portion 24 with the plate material B23 to the first bent portion 62, and from the first bent portion 62 to the second bent portion 63. Is inclined at an angle θ26 of more than 90 ° and less than 180 ° with respect to the plate material B23. Furthermore, it extends substantially perpendicularly to the plate material B23 from the second bent portion 63 to the tip 61. Incidentally, not only when extending from the second bent portion 63 to the tip 61 but extending substantially perpendicularly to the web 23, the peripheral length and the tip area are larger than those of the conventional H-section steel. Any shape may be used.

  In addition, the manufacturing method of the ready-made pile for foundation piles in 3rd Embodiment can also be manufactured similarly to the manufacturing method in 1st, 2nd embodiment.

(4) Fourth Embodiment FIG. 6 shows a fourth embodiment of the present invention.

  In the first to third embodiments, the foundation pile has a final shape at the time of completion of the production stage in rolling or build-up processing. May be affected by product size. In 4th Embodiment, in order to solve this subject, the coupling 27 is formed in the middle of the web of the board | plate material B. FIG.

  As a result, in the embodiment of FIG. 6, the manufacturing is performed with a half size of the final product, and the size restriction in manufacturing can be relaxed. In the ground, about half of the final product 28 is first buried in the ground, and then the joint 27 is fitted to each other, and then the remaining members 29 are buried. Configure the final product shape.

  The smaller the number of joints, the more labor can be reduced in the embedding stage. Therefore, it is desirable that the smaller number of joints be located on the web. However, when it is important to alleviate manufacturing constraints, one or more pairs of joints may be arranged.

  The joint shape is preferably a key claw shape such as a steel sheet pile in rolling production, but is not limited to the key claw shape as long as they can be fitted to each other and cannot be detached. Absent. Moreover, it is not necessary to manufacture all by rolling, and if necessary, a steel pipe with a slit may be processed into a joint, and may be manufactured by being fixed to the end of the web by welding or the like.

(5) Fifth Embodiment In the first to fourth embodiments, it is assumed that a single member is used as a pile, but a plurality of these members may be connected and used as a continuous wall.

  FIG. 7 shows a fifth embodiment. A joint 32 is provided at both ends 31 of at least one of the two plate materials A30. The joint may be provided at both ends of one plate A or may be provided at both ends of both plates A.

  The joint shape is preferably a key claw shape such as a steel sheet pile in rolling production, but is not limited to the key claw shape as long as they can be fitted to each other and cannot be detached. Absent. In particular, since the shape in the present embodiment is a very complicated shape and it is very difficult to manufacture only by rolling, separately manufactured joints are fixed to both end portions of the plate material A serving as a flange by welding or the like. May be produced.

(6) Sixth Embodiment A sixth embodiment of the present invention is shown in FIGS. This is a continuous wall characterized in that a plurality of foundation piles of the present invention which is the fifth embodiment are arranged adjacent to each other and connected by fitting joints to each other. FIG. 8A shows a case where joints are provided at both ends of one of the two plates A, and FIG. 8B shows a case where joints 36 are provided at both ends 34 of the two plates A.

  In FIG. 8, although the several foundation pile 55 is arrange | positioned so that board | plate materials B used as a web may become substantially parallel, it is not restricted to this, The board | plate materials B used as a web are C-shaped. Other arrangements are possible, such as being arranged.

  In the configuration of the continuous wall, a foundation pile 55 having the same shape as the existing pile 54 having a joint according to the fifth embodiment is first embedded in the ground, and one joint 32 of the foundation pile 55 and the adjacent foundation pile are embedded. One of the joints 32 of 55 is fitted and buried in the ground. A method of repeatedly adjoining a plurality of foundation piles by using these joint fitting and underground burying steps is used.

  Under the present circumstances, it is preferable to arrange | position so that the board | plate materials B used as the web of an adjacent foundation pile may become substantially parallel, and to comprise the continuous wall of a single wall. In addition, when attaching a gentle curvature to a continuous wall, as shown in FIG. 8 (a), using a pile having joints only at one end of two plate members A in a single foundation pile, adjacent plate members B It can be made by making each other into a C shape according to the curvature.

  Although 1st Embodiment-4th Embodiment is utilized as a foundation pile which supports a structure, in 6th Embodiment, since the wall in the ground can be comprised, one side of a wall surface is excavated and the other wall surface is comprised. As an underground wall that supports soil pressure and water pressure acting on the ground, an underground wall that suppresses ground fluctuations in the ground and improves the ground strength, and a stationary wall that stops the flow of fluid such as underground water in the ground Can also be used.

An embodiment according to the present invention will be described using a conventional wide series H-section steel (H-300 × 300 × 10 × 15) shown in FIG. 9A as a comparative example. The dimensions of this H-shaped steel are width a300mm, height b300mm, flange plate thickness tf 15mm, web plate thickness tw 10mm, steel cross section 118.4cm ² and steel weight 93kg per pile length Become.

  FIG. 9 shows Example 1 in the first embodiment, and further shows the result of trial calculation of the effect of the invention.

  As an example of the first embodiment of the present invention, the width of the plate B serving as a web is set to 300 mm which is the same as the width of the H-shaped steel web of the comparative example, and the extended width of the plate A serving as a flange is the H-shaped of the comparative example. Assuming that the width of the steel flange is 300 mm, the angle θ formed by the plate material A and the plate material B is changed from 90 ° to 180 ° as a parameter, and the peripheral length and tip area which are the premise for the support force evaluation are calculated.

Conditions other than the angle, plate thickness, web length, and flange extension were not changed, and as a result, the steel weight per 1 m of pile length remained unchanged at 93 kg.

  The examination results are shown in FIG. 9 (c). In this examination example, the circumference is greater than 90 ° and less than 147 °, and the circumference of the embodiment of the present invention is the comparison object. As a result, it was the largest at an angle of 120 °, which was 1.18 times that of H-section steel.

  On the other hand, in the tip area, when the angle is greater than 90 ° and less than 180 °, the tip area of the embodiment of the present invention exceeds the tip area of the H-section steel to be compared, and becomes the largest at an angle of 135 °. It was 1.30 times that of H-section steel.

  The effect of increasing the bearing capacity of piles varies depending on the influence of the ground and the usage of piles such as friction piles and support piles. For example, if the peripheral support force is 1.18 times and the tip support force is 1.30 times, the total support force is calculated by the sum, so compared to H piles using H-section steel In the embodiment of the present invention, the supporting force is more than 1.0 times and 1.5 times or less.

  FIG. 10 shows the result of trial calculation of the effect of the invention in the second embodiment as Example 2. The comparison target was H-300 × 300 × 10 × 15 among the same wide series H-section steel as described above. In the example of the second embodiment of the present invention, it is assumed that the plate A has a bent portion at a quarter of the flange extension width a from the free end side, and the width of the plate B serving as a web is compared. Considering the angle between the part near the free end and the sheet material called the web as a parameter, assuming that it is the same as the width of the web of the shape steel, and the same width as the flange of the H-shaped steel. Carried out. The steel weight per 1 m of pile length is 93 kg like the Example of 1st Embodiment.

  The results of the examination are almost the same as in the first example, and the effect of increasing the circumference and the tip area is different, but the embodiment of the present invention is excellent in the circumference and the tip area, which are the premise of the bearing capacity evaluation. Was confirmed.

  In addition, for the purpose of verifying that the effect of the invention is obtained even when the position of the bent portion is different, the results of Example 3 in which the effect was calculated by changing two types of positions of the bent portion are shown in FIGS. FIG. 11 shows a case where the plate A has a bent portion at 1/8 of the flange extension width a from the free end side, and FIG. 12 shows a portion of the plate A at 3/8 of the flange extension width a from the free end side. This is a case having a bent portion. The results of the examination are almost the same as in the first and second examples, and the effect of increasing the circumference and the tip area is different, but the embodiment of the present invention is excellent in the circumference and the tip area, which are the premise of the bearing capacity evaluation. It was confirmed that

  Further, for the purpose of verifying that the effect of the invention is also obtained in the case of the third embodiment having a bent portion ahead of the bent portion, the result of calculating the effect by changing the angle of the bent portion is shown in FIG. Show. FIG. 13 shows a case where the plate A has bent portions at 1/6 and 2/6 of the flange extension width a from the free end side, and the member between them has an angle of 90 ° to 180 ° with the plate B This is the case. The result of the examination is almost the same as in the first to third embodiments. The increase effect in the circumference and the tip area is different, and the improvement effect is relatively small compared to Examples 1 to 3, but the embodiment of the present invention is excellent in the circumference and the tip area which are the premise of the bearing capacity evaluation. It was confirmed that

In addition, since the four types of examinations use only the angle as a parameter, there is no change in the pure cross-sectional area and steel weight of the steel material. In the embodiment of the present invention, the cross-sectional area is 118.4 cm ² and the steel weight is the pile length. Since it is 93 kg per meter, it indicates that it is possible to increase the bearing capacity only at the same material cost.

It is a figure which shows the cross-sectional shape of the existing pile for foundation piles concerning the 1st Embodiment of this invention. It is a figure which shows the pile circumference and pile tip area which should be evaluated in the case of using H-section steel as a foundation pile. It is a figure which shows the pile circumference and pile tip area which should be evaluated in the existing pile for foundation piles concerning the 1st Embodiment of this invention. (a) is the schematic for demonstrating the view of the bearing capacity of a foundation pile, (b) is a conceptual diagram showing the load-settlement curve of a pile. It is a figure which shows the cross-sectional shape of the existing pile for foundation piles concerning the 2nd Embodiment of this invention. It is a figure which shows the cross-sectional shape of the existing pile for foundation piles concerning the 4th Embodiment of this invention. It is a figure which shows the cross-sectional shape of the existing pile for foundation piles concerning the 5th Embodiment of this invention. It is a figure which shows the cross-sectional shape of the continuous wall which concerns on the 6th Embodiment of this invention, (a) is a case where a unit foundation pile has a joint in the both ends in one of two flanges, (b) This is a case where the unit foundation pile has joints at both ends of both of the two plate materials A. (a) is a figure which shows the shape of the pile using the conventional H-section steel of the comparative example 1, (b) is a figure which shows the shape of the pile of Example 1 which concerns on 1st Embodiment of this invention. (C) is a diagram showing the effect of the first embodiment. (a) is a figure which shows the shape of the pile of Example 2 of this invention, (b) is a figure which shows the effect of invention in Example 2. FIG. (a) is another figure which shows the shape of the pile of Example 2 of this invention, (b) is a figure which shows the effect of invention in Example 2. FIG. (a) is a figure which shows the shape of the pile of Example 3, (b) is a figure which shows the effect of invention in Example 4. FIG. (A) is a figure which shows the shape of the pile of Example 4, (b) is a figure which shows the effect of invention in Example 4. FIG. It is sectional drawing which shows the H-section steel generally used as a conventional pile for conventional foundation piles.

Explanation of symbols

1 Plate material that is flange 2 Plate material that is web 3 Plate material A
4 Plate material B
5 Angle 6 H-section steel 7 Perimeter 8 Width 9 Height 10 Tip area 11 Foundation pile 12 in the present invention Perimeter 13 Width 14 Height 15 Angle 16 Tip area 18 Pile shaft 19 Pile tip 20 Load-sink curve 21 Load-sink curve 22 in foundation pile 23 Flange 23 Web 24 Contact point between flange and web 25 Bend point 26 Angle 27 Joint 28 One member 29 Other member 30 Flange 31 Both ends 32 Joint 34 Both end portions 36 Joint 39 Web 51, 52, 53, 54, 55 Prefabricated pile 61 Tip 62 First bent portion 63 Second bent portion

Claims (6)

  A cross-section consisting of a plate B serving as a web and two plate A present at both ends and serving as a flange is a prefabricated pile for a foundation pile having a substantially H shape, and the two plates A are contact points with the plate B In which the cross section is bent in a U-shape so as to be wider than the width of the plate material B, and the angle between each of the two bent plate materials A and the plate material B is more than 90 ° and less than 180 ° Prefabricated pile for pile.   Each of the two plate materials A maintains a straight shape instead of bending in a cross-sectional shape from the point of contact with the plate material B in the middle, and the cross-sectional shape is in a direction wider than the width of the plate material B at the tip. The prefabricated pile for foundation piles according to claim 1, wherein an angle formed by an extension line of the bent portion and the plate material B is more than 90 ° and less than 180 °.   Each of the two plate materials A bends in a U-shaped cross-section at the point where the straight shape is held, and an angle formed by an extension line of the bent portion and the plate material B is more than 90 ° and less than 180 °. In addition to the above, the prefabricated pile for foundation piles according to claim 2, wherein the cross-section is bent in a U-shape at the tip.   The prefabricated pile for foundation piles according to any one of claims 1 to 3, wherein the plate material B is connected by a joint in the middle of the web.   The prefabricated pile for foundation piles according to any one of claims 1 to 4, wherein joints are provided at both ends of at least one of the two plate materials A.   It is a continuous wall using the existing pile for foundation piles of Claim 5, Comprising: It arranges the existing piles for the said foundation pile adjacently, and the said adjacent by the joint of the both ends of the board | plate material A in the said existing pile A continuous wall using prefabricated piles for foundation piles, characterized by connecting prefabricated piles.

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