JP4535326B2 - Simple foundation - Google Patents

Description

  The present invention relates to a simple foundation that can be easily installed or removed.

  When building a building, it is preferable that the construction required for building the foundation is simple. In the case of a study item for primary use, it is desirable that the foundation can be easily removed. As such a simple basis, for example, the simple basis disclosed in Patent Document 1 can be shown. The simple foundation of patent document 1 is constructed only by installing a pre-manufactured footing on the construction ground. The footing is exemplified by a concrete plate or a steel plate. Moreover, when the construction ground is soft ground, it is shown that ground improvement is performed in advance.

JP 2002-138492 A

  Certainly, as can be seen in Patent Document 1, if a footing is manufactured in advance and a simple foundation can be constructed simply by installing this footing on the construction ground, not only construction will be easy, but also removal will be possible. . However, simply placing a pre-manufactured footing on the construction ground causes a problem that the footing is displaced with respect to the construction ground and the supporting force and horizontal resistance force are reduced. Moreover, when the ground improvement is required separately for the soft ground, the construction takes time. Therefore, we developed a simple foundation to prevent the displacement of the footing, and studied to build a stable simple foundation without requiring ground improvement so as not to impair the ease of construction or removal of the simple foundation.

Was developed result of the examination is, the footing plate for mounting to the construction ground, in the simple basis comprising a bundle pillars for connecting the pillar members of a building erected from the footing plate, footing plate, two or more A positioning hole is opened, and a reinforcing wall that can be used as an annular formwork extending in the circumferential direction of the bundle column or a reinforcing wall extending in the radial direction of the bundle column is erected, and at least two or more through each positioning hole By positioning the positioning piles into the construction ground and engaging the positioning piles with the positioning holes, it is a simple foundation that prevents the positional displacement with respect to the construction ground and increases the rigidity by the reinforcing wall . In the simple foundation of the present invention, the footing plate that expands the horizontal cross-sectional area of the bundle pillar is prevented from being displaced by the positioning piles, thereby preventing the support force and the horizontal resistance force from being lowered.

  Here, the construction ground may be any ground having an N value that does not allow natural footing of the footing plate. From this, if the ground surface is strong, the simple foundation of the present invention can be constructed by placing a footing plate directly on the ground surface. Further, like a conventional foundation, a footing plate may be placed on the excavated construction ground, and may be embedded with a concrete plate or earth and sand on which the footing plate is placed.

  The footing plate may be a concrete plate or a steel plate. When a steel pipe is used for the bundle column, the bundle column can be welded and fixed to a footing plate made of a steel plate, which is convenient. The bundle pillars may be provided with anchor bolts or projecting flanges for connection according to the pillar members to be connected.

The positioning pile can prevent the displacement of the footing plate, but if the footing plate itself is deformed, the supporting force or the horizontal resistance force is also lowered. Therefore, the footing plate may be provided with a reinforcing wall that can be used as an annular mold extending in the circumferential direction of the bundle pillar or a reinforcing wall that extends in the radial direction of the bundle pillar to increase rigidity. In this case, if the footing plate is made of a steel plate, it is convenient because the reinforcing wall of the steel plate can be fixed by welding.

  The size of the footing plate or the shape in plan view may be freely determined by the required support force and horizontal resistance force. However, in reality, a very large footing plate cannot be conveyed. Therefore, it is preferable that the footing plate or the bundle pillar can be divided into module units so that the module units can be coupled to each other at a construction site or the like. In this case, it is preferable that the footing plate and the bundle pillar are detachable into module units having a dividing line along the reinforcing wall as a boundary, and the module units are coupled to each other through the respective reinforcing walls to be abutted.

  Moreover, it is good for a footing board to comprise a group pile by the positioning pile penetrated into the construction ground through many positioning holes. Thereby, if a positioning pile penetrates into a construction ground, the ground improvement of a construction ground can also be aimed at simultaneously. In addition, a large number of positioning piles penetrate into the construction ground in advance to form a group pile, and two or more positioning piles penetrate through this group pile through a footing plate. It may be configured.

  Furthermore, in order to improve the supporting force and horizontal resistance of the simple foundation of the present invention, the footing plate opens a pile penetration hole communicating with the bundle column, and allows the steel pipe pile inscribed in the bundle column to penetrate the construction ground. May be. If the steel pipe pile reaches a solid support layer or penetrates into the group pile as described above, the steel pipe pile can be inscribed in the bundle column, so that stress can be transmitted to the footing plate, and the support force as a simple foundation In addition, the horizontal resistance can be improved.

  The present invention provides a simple foundation that exhibits necessary and sufficient support force and horizontal resistance force while being easily constructed or removed. First, a bundle pillar is erected on a footing plate in advance, and a simple foundation simply placing the footing plate on a construction ground is easy to construct or remove. This brings about the effect which suppresses or prevents generation | occurrence | production of residual soil. And since a footing board can be fixed to a construction ground with a positioning pile, the problem of the position shift of the footing board by external force does not arise, and necessary and sufficient support force and horizontal resistance force can be exhibited.

The reinforcing wall provided on the footing plate increases the rigidity of the footing plate and prevents the support force or the horizontal resistance force from being lowered. In addition, by placing a concrete plate inside the reinforcing wall using an annular reinforcing wall extending in the circumferential direction of the bundle column as a formwork, the unity between the simple foundation and the positioning pile is improved, and the bundle protruding from the footing plate The pillars are supported by the concrete plate, and in particular the horizontal resistance can be increased. In this case, the footing plate or the bundle pillar can be divided into module units having a dividing line along the reinforcing wall as a boundary, thereby avoiding a decrease in the rigidity of the footing plate while facilitating handling in particular. it can.

  Moreover, by using the positioning piles to form the group piles, it is possible to improve the ground of the construction ground together with the construction of the simple foundation, so that the ease of construction is not impaired. And if the steel pipe pile inscribed in a bundle pillar can be penetrated into a construction ground, even if a supporting force or a horizontal resistance force is insufficient only with a footing board, it can supplement with a steel pipe pile. Even if such a group pile configuration or steel pipe pile penetration is added, the simple foundation of the present invention has a feature that does not impair the advantage that it is easier to construct or remove than the conventional foundation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a stage of placing the simple foundation 1 on the construction ground 42 set on the ground surface 41, FIG. 2 is an exploded perspective view of the simple foundation 1, and FIG. 3 shows another example of the simple foundation 7. FIG. 4 is a perspective view showing yet another example of the simple foundation 8, and FIG. 5 is a diagram showing a stage where the positioning pile 2 is inserted through the positioning hole 111 provided in the footing plate 11 of the simple foundation 1. 6 is a partially broken perspective view, FIG. 6 is a view corresponding to the arrow A in FIG. 5 showing a state in which the positioning pile head 21 is spot-welded 211 to the footing plate 11 and is prevented from coming off, and FIG. FIG. 8 is a view showing a state in which the positioning pile head 51 is screwed into a female screw portion 612 made of a nut fixed to the positioning hole 611 so as to prevent it from coming off. FIG. 9 is a view corresponding to the arrow A in FIG. 5, and FIG. 9 shows that the lower end of the column member 43 is connected using the bolt hole 151 of the horizontal flange 15 provided in the bundle column 12. FIG. 10 is a perspective view equivalent to FIG. 1 showing the completed stage, FIG. 10 is a perspective view equivalent to FIG. 1 showing the completed stage of the simple foundation 1, and FIG. 11 is a sectional view showing the completed stage of the simplified foundation 1 is there.

  In this example, as shown in FIG. 1, in order to obtain a high supporting force and horizontal resistance force when constructing the simple foundation 1 on which the footing plate 11 is placed on the construction ground 42 set on the ground surface 41, the footing This is an example in which a group pile 22 is configured by penetrating a large number of positioning piles 2 into a construction ground 42 from positioning holes 111 opened in a plate 11. Although illustration is omitted, the construction ground may be dug down similarly to the footing plate of the simple foundation 1. The footing plate 11 of the simple foundation 1 in this example is made of a steel plate having a circular shape in plan view provided with a large number of positioning holes 111 at substantially equal intervals. The shape of the footing plate 11 in plan view is not limited to a circle, but the footing plate 11 having a circular shape in plan view coaxial with the axis of the bundle column 12 is preferable from the viewpoint that stress on the bundle column 12 of the footing plate 11 is uniform in the circumferential direction. .

  The simple foundation 1 can be easily manufactured, for example, by the configuration shown in FIG. First, the footing plate 11 is cut out circularly in plan view from a steel flat plate having positioning holes 111 provided at substantially equal intervals, and a pile penetration hole 112 is opened at the center. The footing plate 11 may be made of punched metal or expanded metal, for example, as long as a large number of positioning holes 111 are opened. The bundle column 12 uses a steel pipe having a size surrounding the pile penetration hole 112, and is fixed to the footing plate 11 by welding and is erected. The bundle pillar 12 of this example has a steel horizontal flange 15 projecting radially outward from the upper end. The column member 43 is firmly connected to the horizontal flange 15 of the bundle column 12 by bolt joining using a bolt hole 151 provided in the horizontal flange 15. Further, in this example, in order to improve the rigidity of the footing plate 11, a reinforcing wall 13 made of steel strip is fixed to the periphery of the footing plate 11 by welding.

  The reinforcing wall is a reinforcing member that increases the section modulus of the footing plate and improves the rigidity of the footing plate. From this point, for example, as shown in FIG. 3, a simple foundation 7 in which a reinforcing wall 73 extending in four directions in the radial direction from the bundle pillar 72 is erected on the footing plate 71 may be used. As shown in FIG. 4, a reinforcing wall 83 made of steel strip is erected on the periphery of the footing plate 81, and the reinforcing wall 84 that extends in four directions in the radial direction is formed by connecting the bundle pillar 82 and the reinforcing wall 83. It is good also as the simple foundation 8 which erected. In this case, if the simple foundation 8 is enlarged, the module unit 85 obtained by dividing the footing plate 81 and the bundle pillar 82 along the reinforcing wall 84 extending in the radial direction can be coupled to each other via the reinforcing wall 84. Good. As a result, the enlarged simple foundation 8 can be easily transported by being divided into module units 85.

  As shown in FIG. 5, the simple foundation 1 penetrates the positioning pile 2 into the construction ground 42 through the positioning holes 111 to prevent positional displacement. In this example, a large number of positioning piles 2 are inserted into the construction ground 42 to form a group pile 22 and the construction ground 42 is reinforced. The positioning pile 2 of this example is a steel bar having an outer diameter of about 20 to 30 mm, and it is easy to penetrate the construction ground 42 through the positioning hole 111. The amount of protrusion of the positioning pile head 21 from the footing plate 11 may be such that the positioning pile head 21 can be engaged with the positioning hole 111 and displacement of the footing plate 11 can be prevented.

  Since the positioning pile 2 only needs to prevent the displacement of the footing plate 11 and prevent the support force and horizontal resistance of the simple foundation 1 from being lowered, the positioning pile head 21 protruding from the footing plate 11 is fixed to the footing plate 11 do not have to. However, since the large number of positioning piles 2 constituting the group pile 22 are integrated with the footing plate 11, the support force and horizontal resistance force of the simple foundation 1 can be improved. From this, for example, as shown in FIG. 6, the positioning pile head 21 may be spot-welded 211 to the footing plate 11 and the positioning pile 2 may be fixed to the footing plate 11. In this case, the positioning pile 2 with respect to the simple foundation 1 after construction is basically inseparable, and when removing it, the simple foundation 1 and the positioning pile 2 are integrally removed.

  In order to separate the positioning pile 2 from the simple foundation 1 while removing the positioning pile 2 and the footing plate 11 as one body, as shown in FIG. As shown in FIG. 8, a simple foundation 6 having a female screw portion 612 as a nut fixed to each positioning hole 611 of the footing plate 61 by welding is used, and the positioning pile head 51 is attached to the female screw portion 612. It is good to screw together. Although illustration is omitted, a thread groove may be formed over the entire positioning pile. However, if it is the positioning pile 5 which engraved the thread groove 52 only in the positioning pile head 51 like this example, most will penetrate the construction ground 42 by driving in, and only at the time of integration with the footing board 61, Since the positioning pile head 51 may be screwed into the female screw portion 612, there is an advantage that the working efficiency is improved.

  When the penetration of the positioning pile 2 into the construction ground 42 is thus completed, the installation of the simple foundation 1 is completed. The column member 43 of the structure is connected to the horizontal flange 15 of the bundle column 12 with the connecting plate 431 attached to the lower end, and is connected by bolt coupling through the bolt hole 151 as seen in FIG. In order for the bundle column 12 to reliably receive the load from the column member 43, it is desirable that the connection plate 431 attached to the lower end of the column member 43 is a disc that blocks the lower end of the column member 43.

  Thus, as shown in FIGS. 10 and 11, the simple foundation 1 for supporting the column member 43 is completed. As is apparent from the procedures so far, the construction of the simple foundation 1 of this example has the advantage that there is no discharge of residual soil and no environmental problems are caused. Moreover, in this example, since the group pile 22 is comprised by many positioning piles 2, the construction ground 42 is reinforced, the footing board 11 does not sink, but supports the column member 43 stably. be able to. However, since the positioning pile 2 only penetrates the construction ground 42, the simple foundation 1 can be easily obtained by releasing the bolt joint of the column member 43 to the bundle column 12 and pulling out each positioning pile 2 from the construction ground 42. Can be removed.

  The simple foundation 1 of the present invention is an integration of the positioning pile 2 and the simple foundation 1 by penetrating the steel pipe pile 3 inscribed in the bundle column 12 into the construction ground 42 or placing a concrete plate in the reinforcing wall 13. As a result, the supporting force and the horizontal resistance force can be improved. FIG. 12 is a perspective view equivalent to FIG. 1 showing a stage where the steel pipe pile 3 is penetrated through the bundle column 12 and the pile penetration hole 112 of the simple foundation 1, and FIG. 13 is a cross-sectional view showing the stage of completion of the construction of the simple foundation 1 FIG. 14 is a perspective view corresponding to FIG. 1 showing the simplified foundation 1 in which the concrete plate 14 is placed in the reinforcing wall 13.

  A pile penetration hole 112 communicating with the bundle pillar 12 is opened in the footing plate 11, so that the positioning pile 2 penetrates the construction ground 42, and then the steel pipe pile 3 is connected to the bundle pillar 12 as shown in FIG. It is possible to penetrate the construction ground 42 by inscribed in the ground. Thereby, as seen in FIG. 13, the simple foundation 1 with improved support force and horizontal resistance force can be constructed. If necessary, the steel pipe pile 3 may be integrated with the bundle column 12 by welding. Moreover, since the group pile 22 is comprised by many positioning piles 2 in this example, the support force and horizontal resistance force of steel pipe pile 3 itself are raised. The steel pipe pile 3 of this example can be easily rotationally press-fitted by providing a saw blade 31 at the tip. Moreover, even if this steel pipe pile 3 penetrates into the construction ground 42, no residual soil is discharged.

Furthermore, as can be seen in FIG. 14, the concrete plate 14 may be placed inside the reinforcing wall 13 by using the reinforcing wall 13 as an annular mold extending in the circumferential direction of the bundle column . As a result, the integrity of the simple foundation 1 and the positioning pile 2 is enhanced, and the bundle column 12 protruding from the footing plate 11 is supported by the concrete plate 14, and in particular, the horizontal resistance can be enhanced. Although illustration is omitted, a reinforced concrete plate may be formed by arranging bars in the reinforcing wall 13, or conversely, the reinforcing wall 13 may be simply filled with earth and sand. In this way, whether to select only earth or sand, placement of the concrete plate 14 or placement of the reinforced concrete plate is determined by the necessity for removal, the supporting force and the horizontal resistance force required as a foundation.

  In order to confirm the bearing capacity and horizontal resistance force of the simple foundation of the present invention, a test ground having a soft ground surface is created, and a foundation according to the present invention is constructed on this test ground to apply a vertical load and a horizontal load. When applied, the amount of vertical displacement (the amount of settlement) and the amount of horizontal displacement were measured. It can be said that the smaller the settlement amount and the horizontal displacement amount, the better the supporting force and horizontal resistance force are exhibited.

  As shown in FIG. 15, the test ground has a structure in which a soft ground is formed by embankment on the ground surface. The range of the embankment is 10000mm wide, 5000mm deep and 1000mm thick enough to build the foundation. In this test, when confirmed by a flat plate loading test, the N value = 20 where the ground surface can be supported by steel pipe piles, and the soft ground of the surface layer formed by embankment had an N value = 10.

  The basis used for the test conforms to the configuration seen in the above example (see FIGS. 1 to 7). First, the footing plate constituting the simple foundation is made of a steel plate having a thickness of 9 mm and an outer diameter of 1000 mm, and a group pile hole having an inner diameter of 30 mm is opened at a grid interval of 150 mm. The peripheral wall erected on the peripheral edge of the footing plate is made of 9 mm thick steel strip and has a height of 200 mm. The pile penetration hole at the center of the footing plate is 200mm, and the bundle column that stands up around the pile penetration hole is composed of a steel pipe with an inner diameter of 200mm and a thickness of 9mm. The height is 300mm, the width is 100mm, and the thickness is 9mm. A horizontal flange is attached. The positioning pile is a steel bar with an outer diameter of 25 mm and a length of 1100 mm, the steel pipe pile is a round steel pipe with an outer diameter of 178 mm, a thickness of 9 mm and a length of 1500 mm, and the lower end is machined into a saw blade.

  In the comparative example, the steel pipe pile was penetrated to the ground surface only by placing the footing plate on the test ground without using the positioning pile among the steel foundations. On the other hand, the Example constituted the group pile by the positioning pile other than penetrating the steel pipe pile to the ground surface. That is, neither the comparative example nor the example digs up the soft ground in particular. Thereby, only the effect of the improvement of the supporting force and horizontal resistance force by synergy of a steel pipe pile and a simple foundation can be confirmed.

  In the comparative example, stress is distributed in the range of 45 degrees below the footing plate range, and in the examples, the stress is distributed in the range of 45 degrees below the copying surface at the bottom of the positioning pile constituting the group pile. A foundation was constructed on each test ground so that the stress distributions in the examples did not overlap. And the lower end of the column member was connected through the horizontal flange, respectively, and a vertical load 5t and a horizontal load 5t were applied to the column member.

  First, on the basis of the comparative example, the amount of horizontal displacement due to the application of the vertical load was infinite, and the amount of settlement due to the simultaneous application of the vertical load and the horizontal load was 30 mm. On the other hand, on the basis of the example, the horizontal displacement amount by the application of the vertical load was 15 mm, and the settlement amount by the simultaneous application of the vertical load and the horizontal load was 10 mm. From this, it has been clarified that the supporting force and the horizontal resistance force are improved in the configuration of the example including the simple foundation in which the group pile is configured by a large number of positioning piles.

  The reason can be considered as follows. First, it is considered that the shear failure that occurs in the test ground, particularly the soft ground that becomes the surface layer, due to the vertical load was suppressed or prevented by the group piles in the examples. Moreover, in an Example, since a group pile reinforces a soft ground and stress distributes in the range of 45 degree | times downward from the copying surface of the positioning pile lower end which comprises a group pile, it was supported by the ground surface with high N value. It is considered a thing. Further, in the embodiment, the footing plate of the direct foundation that constitutes the group pile resists horizontal load, and the horizontal resistance force of the direct foundation and the horizontal resistance force of the steel pipe pile are synergistic. It is thought to have improved.

It is a perspective view showing the step which mounts a simple foundation on the construction ground set up on the ground surface. It is a disassembled perspective view of a simple foundation. It is a perspective view showing the simple foundation of another example. It is a perspective view showing the simple foundation of another example. It is a partially broken perspective view equivalent to FIG. 1 showing the stage which has penetrated the positioning pile through the positioning hole provided in the footing board of the simple foundation. FIG. 6 is a view corresponding to an arrow A in FIG. 5 showing a state where the positioning pile head is spot-welded to the footing plate to prevent the positioning pile head from coming off. It is a perspective view of the positioning pile which carved the thread groove in the positioning pile head. FIG. 6 is a view corresponding to an arrow A in FIG. 5 showing a state in which a positioning pile head is screwed into a female thread portion made of a nut fixed to a positioning hole to prevent the pin from coming off. It is a perspective view equivalent to FIG. 1 showing the stage which connected the lower end of the pillar member using the bolt hole of the horizontal flange provided in the bundle pillar. It is a perspective view equivalent to FIG. 1 showing the stage of completion of construction of a simple foundation. It is sectional drawing showing the stage of construction completion of a simple foundation. It is the perspective view equivalent to FIG. 1 showing the step which has penetrated the steel pipe pile through the bundle pillar and pile penetration hole of a simple foundation. It is sectional drawing showing the stage of construction completion of a simple foundation. FIG. 2 is a perspective view corresponding to FIG. 1 showing a simple foundation in which a concrete plate is placed in a reinforcing wall. It is a perspective view showing the construction state of the foundation of the comparative example with respect to the ground for a test, and an example.

Explanation of symbols

1 Simple foundation
11 Footing plate
111 Positioning hole
112 Pile penetration hole
12 Bunch pillars
13 Reinforcement wall 2 Positioning pile
22 Group pile 3 Steel pipe pile
42 Construction ground
43 Pillar member 5 Exceptional positioning pile 6 Exceptional simple foundation 7 Exceptional simple foundation 8 Exceptional simple foundation

Claims (4)

In a simple foundation consisting of a footing plate to be placed on the construction ground, and a bundle pillar that stands upright from the footing plate and connects the pillar members of the building,
The footing plate is provided with two or more positioning holes , standing up a reinforcing wall that can be used as an annular mold extending in the circumferential direction of the bundle column or a reinforcing wall extending in the radial direction of the bundle column,
At least two or more positioning piles are inserted into the construction ground through each positioning hole, and each positioning pile is engaged with the positioning hole to prevent positional displacement with respect to the construction ground, and the rigidity is enhanced by the reinforcing wall. A simple basis. Footing plate or Tababashira is to freely divide the dividing line along the reinforcing walls each module bounded, simplified cross formed by bonding to claim 1, wherein via the respective reinforcing walls each module unit match Basic. The footing board is a simple foundation according to claim 1 or 2 , wherein the footing plate comprises a group pile by positioning piles penetrating into the construction ground through a number of positioning holes. The simple foundation according to any one of claims 1 to 3 , wherein the footing plate is formed by opening a pile penetration hole communicating with the bundle pillar and penetrating a steel pipe pile inscribed in the bundle pillar into the construction ground.

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