JP5984083B2 - Foundation structure and foundation construction method - Google Patents

Description

  The present invention relates to a foundation structure and a foundation construction method, and in particular, a foundation structure provided with a foundation body connected to an upper structure of a building, and a pile body provided to extend from the foundation body into a lower ground. It relates to the construction method of the foundation related to the foundation structure.

  Conventionally, as a foundation of a relatively small detached house as a building, a direct foundation placed directly on the ground such as a solid foundation, a cloth foundation, and an independent foundation has been generally used. In the case of such a direct foundation, if the ground on which it is placed is a soft ground or a ground that may cause liquefaction in the event of an earthquake, the ground itself loses its supporting force, and the foundation and the building are inclined. May end up. If the entire building including the foundation inclines in this way, the repair becomes large and the repair cost becomes large, so a foundation structure that can handle soft ground and liquefied ground has been proposed ( For example, see Patent Documents 1 and 2).

  The foundation structure described in Patent Document 1 is supported by being connected to a support body (pile part) that penetrates into the ground from the bottom plate of a building (structure), a buoyancy body provided on the support body, and the support body. An anchor body provided in the layer. In this foundation structure, even if the ground is liquefied and the bearing capacity is reduced, and groundwater rises due to excessive pore water pressure, the buoyancy due to this groundwater acts on the buoyant body to obtain the bearing capacity, and the anchor body tilts the building. It is a technology that tries to prevent.

  The foundation structure described in Patent Document 2 includes a foundation that supports a building, a sheet pile that surrounds the side of the foundation and penetrates into the ground, and a lightweight material that is provided in an area surrounded by the sheet pile below the foundation, Is provided. In this foundation structure, when the ground is liquefied and the bearing capacity is reduced, the foundation and the sheet pile are made to behave in an integrated manner, thereby suppressing the inclination of the foundation and the building. It is a technology that tries to secure the supporting force by acting on the foundation of the buoyancy of groundwater.

JP-A-6-240694 JP 2008-101379 A

  However, as in the foundation structure described in Patent Document 1, in order to construct a buoyancy body and an anchor body in the ground, the construction becomes very large, and an increase in cost is inevitable. It is difficult to apply to small-scale detached houses. Moreover, like the foundation structure described in patent document 2, when a foundation is enclosed with a sheet pile and a lightweight material is provided in the enclosed area, groundwater will always stay, and the retained groundwater will rot or May deteriorate. In addition, the buoyancy of the groundwater when the ground is liquefied and the buoyancy of the fluid in which the groundwater and sandy soil are turbid are not mechanically stable. In addition, since the buoyancy varies depending on the planar position of the building, it is difficult to effectively suppress the inclination of the entire building.

  Accordingly, an object of the present invention is to provide a foundation structure and a foundation construction method capable of suppressing the inclination of the building and reducing the seismic response even when the ground is liquefied.

In order to achieve the above object, the foundation structure according to claim 1 includes a foundation body connected to an upper structure of a building, a weight adjustment layer provided between the foundation body and the ground, and the weight adjustment layer. A plurality of pile bodies penetrating and extending into the lower ground, the pile bodies forming an outer surface of the pile body and having a water permeability and laminated inside the outer surface material A plurality of sandbag materials, and the sandbag material is configured by filling a sandbag of a predetermined size having water permeability with a granular material, and a plurality of sandbags between the foundation main body and the weight adjustment layer. A water permeable layer configured by stacking materials is provided, and a pile head of the pile body is continuously provided on a lower surface of the water permeable layer .

The foundation structure according to claim 2 penetrates into the ground below the foundation body connected to the upper structure of the building, a weight adjustment layer provided between the foundation body and the ground, and the weight adjustment layer. A plurality of pile bodies extending, and the pile body includes an outer surface material that forms an outer surface of the pile body and has water permeability, and a plurality of sandbag materials laminated inside the outer surface material. The sandbag material is configured by filling a sandbag of a predetermined size having water permeability with a granular material, and the entire weight of the building including the upper structure to the plurality of pile bodies, and the foundation body to the and dumping the volume of the underground portion including up to the weight adjustment layer, and the pile body, so that the density is calculated (total weight / earth removal volume) is substantially 1.0t / m ³ ~1.5t / m ³ by The specific gravity of the weight adjusting layer is set in (1).

  The foundation structure according to claim 3 is the foundation structure according to claim 1 or 2, wherein the weight adjustment layer is composed of post-expandable concrete, and the weight adjustment layer has a specific gravity of 0.5 to 0.5. It is characterized by being set to a range of 1.0.

The foundation construction method according to claim 4 is a foundation construction method according to any one of claims 1 to 3 , wherein the ground is excavated according to the dimensions of the pile body, The outer surface material of the pile body is set in the excavated excavation hole, the plurality of sandbag materials are put into the set outer surface material, and the pile body is constructed by stacking the sandbag materials, and the foundation body and the weight adjustment Excavating the ground in the region where the layer is constructed, constructing the weight adjustment layer integrally with the pile head of the pile body exposed by excavation, and placing the pile body on the upper surface of the constructed weight adjustment layer After connecting an outer surface material, the said base main body is constructed | assembled above the said pile body and the said weight adjustment layer, It is characterized by the above-mentioned.

The foundation construction method according to claim 5 is the foundation construction method according to claim 4 , wherein after the outer surface material of the pile body is connected to the upper surface portion of the weight adjustment layer, the pile body and the weight. A plurality of sandbag materials are laminated on the upper side of the adjustment layer to form a water permeable layer, and then the foundation body is constructed on the upper side of the formed water permeable layer.

  According to the invention described in claim 1, by providing a weight adjustment layer between the foundation body and the ground, the buoyancy due to excess pore water pressure when the ground is liquefied and the weight of the entire building are balanced. It is possible to prevent the foundation from being lifted due to excessive buoyancy. In addition, by providing a plurality of pile bodies that extend from the weight adjustment layer into the ground below, even if the normal vertical load is supported by the pile bodies and the buoyancy caused by liquefaction is locally excessive, It can resist buoyancy by pulling resistance of the body, and can suppress the inclination of the building. Furthermore, a pile body is configured by including an outer surface material having water permeability and a plurality of sandbag materials laminated inside, and a sandbag material is configured by packing granular material in a water bag having water permeability. Therefore, the pile body with water permeability can be constructed. In addition, because piles can be constructed by laminating sandbag materials inside the outer surface material, pile bodies can be constructed with cheaper and easier construction procedures compared to reinforced concrete piles (cast-in-place piles or PC piles) or steel pipe piles. Can be built.

In addition, because sandbags are laminated inside the exterior material, the vertical load of the building can be transmitted between the sandbags to exert vertical support, and the ground that has become liquefied and softened during an earthquake When an excessive shear displacement occurs, the upper and lower sandbag materials are shifted to the left and right to exert a seismic isolation effect, and since the laminated sandbag materials are constrained by the outer surface material, The pile body can be deformed following the shear displacement, and damage to the pile body can be prevented. Then, after the earthquake, the pile body returns to the initial state and supports the building with a predetermined vertical supporting force, so that the inclination of the building can be effectively suppressed. In addition, the granular material to be packed in the sandbag bag of sandbag material is not limited to soil, sand, crushed stone, etc., but may be a piece of glass, a piece of resin, etc. Those excellent in properties are preferred. Furthermore, a water permeable layer is provided between the foundation main body and the weight adjustment layer, and the pile head of the pile body is made continuous with this water permeable layer, so that water can flow through the permeable pile body and the water permeable layer. Can be made. Therefore, groundwater generated by liquefaction of the ground can be drained to the ground through pile bodies and permeable layers, preventing excessive buoyancy due to groundwater from acting on the foundation body, etc. The inclination of the building can be suppressed. Furthermore, groundwater does not stay in the ground, and its decay and deterioration can be prevented. In addition, since a water permeable layer is formed by laminating a plurality of sandbag materials, even if the gap between the sandbag materials is filled with earth and sand, water permeability can be secured by the sandbag bags and the internal granular materials, and the groundwater can be put on the ground. It can be drained.

According to the invention described in claim 2, by setting the specific gravity of the weight adjusting layer appropriately, the density obtained by dividing the total weight of the building by the soil volume is approximately 1.0 t / m ^{3 to} 1.5 t / m. By setting to m ³ , it is possible to suppress the inclination of the building without causing buoyancy due to liquefaction and balancing the buoyancy and the building weight. Moreover, even when the surface layer portion of the ground is liquefied, the vertical supporting force and pulling-out of the pile body itself can be obtained by penetrating the tip of the pile body to a non-liquefied layer deeper than this liquefied layer. Resisting force can remain, and the building can be prevented from falling or tilting.

  According to the invention described in claim 3, the weight adjusting layer can be constructed relatively easily and inexpensively by constituting the weight adjusting layer from the post-expandable concrete. Furthermore, by setting the specific gravity of the weight adjustment layer in the range of 0.5 to 1.0, the weight of the weight adjustment layer can be adjusted according to the scale of the upper structure, the structure type, and the like. In other words, if the weight of the superstructure is small, the specific gravity of the weight adjustment layer is set large. If the weight of the superstructure is large, the specific weight of the weight adjustment layer is set small. And adjusting the thickness of the weight adjusting layer appropriately to adjust the volume of soil removed. Therefore, the adjustment range when adjusting the building weight and the soil removal volume so as to balance the buoyancy due to liquefaction can be expanded, and the application range of the basic structure of the present invention can be expanded.

According to the invention described in claim 4 , excavating the ground after constructing the pile body, constructing the weight adjustment layer integrally with the pile head of the pile body, and constructing the foundation main body on the upper side Thus, the pile body and the weight adjusting layer can be connected to raise the floating resistance. Moreover, by inserting and laminating sandbag material on the outer surface material set in the excavation hole, the sandbag materials can be laminated while being compacted by impact of dropping, and a pile body can be constructed easily and in a short construction period. Furthermore, the integrity of a pile body and a weight adjustment layer can be improved by connecting the outer surface material of a pile body to the upper surface part of the constructed weight adjustment layer.

  Depending on the strength and hardness of the weight adjustment layer, after constructing the weight adjustment layer, excavate the ground through this weight adjustment layer, set the outer surface material in this excavation hole and insert sandbag material You may build a pile. That is, for example, when the weight adjustment layer is made of lightweight foamed concrete having a specific gravity of 1.0 or less and a specific gravity of about 0.5 to 0.7, the weight is adjusted using a general excavating machine (eg auger). It can penetrate the layer. Thus, by excavating after constructing the weight adjustment layer, it is possible to implement the marking of the pile core position, the installation of the excavating machine, the excavation work, and the like in a favorable work environment.

According to the invention described in claim 5 , a pile body is formed by laminating a plurality of sandbag materials on the upper side of the pile body and the weight adjustment layer to form a water permeable layer, and then constructing a foundation main body on the upper side. The groundwater can be drained from the pile body through the water permeable layer by securely connecting the water permeable layer and the water permeable layer.

It is a perspective view which shows the foundation structure of the building which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view which shows the lower part of the said building. It is a cross-sectional view of the foundation part of the building. It is an expanded sectional view explaining the effect | action of the said foundation. It is sectional drawing which shows the construction procedure which builds the foundation of the said building. It is sectional drawing which shows the construction procedure of the said foundation following FIG. It is sectional drawing which shows the construction procedure of the said foundation following FIG. It is sectional drawing which shows the construction procedure of the said foundation following FIG. It is sectional drawing which shows the modification of the construction procedure of a foundation.

  Hereinafter, the basic structure concerning one Embodiment of this invention is demonstrated based on FIGS. 1-3. The foundation structure according to the present embodiment supports a building body 2 as an upper structure of the building 1, and the building 1 is used for a detached house, an apartment, or the like. This building 1 is constructed on the ground G, and this ground G is excavated from the surface GL downward in the Z direction, which is a vertical direction, so that a foundation body 3, a permeable layer 4, a weight adjusting layer 5 and a pile body 6 which will be described later are formed. Built. The building body 2 is a relatively small and light 2 to 3 story building such as a wooden structure or a lightweight steel structure, and has a rectangular planar shape along the X and Y directions which are two horizontal directions. It is being fixed to the basic body 3 via.

  The foundation main body 3 is a solid foundation having a foundation rising 31 provided along the base 21 of the building main body 2 and a foundation bottom slab 32 integrally connected to the foundation rising 31 and extending in a horizontal plane. The foundation bottom plate 32 is made of, for example, reinforced concrete having a thickness dimension of 200 mm to 300 mm, and its lower surface is placed on the upper side of the water permeable layer 4 via a crushed stone layer 33 having a thickness dimension of about 200 mm. That is, the penetration depth (the distance from the ground surface GL to the lower surface of the crushed stone layer 33) of the foundation body 3 is set to about 200 mm. The foundation rising 31 is provided so as to protrude upward from the ground surface GL by about 400 mm to 600 mm, and the base 21 of the building body 2 is connected to the upper end of the foundation rising 31 via an anchor bolt and a joint hardware.

  The water permeable layer 4 is configured by laminating a plurality of sandbag materials 4A. As the sandbag material 4A, for example, a glass piece is placed on a sandbag bag made of a woven fabric having water permeability such as polyethylene. And those filled with granular materials such as glass grains can be used. As such a sandbag material 4A, if the dimension is about 400 mm × 400 mm × 100 mm and the weight is about 5 kg to 10 kg, it is preferable in terms of workability related to conveyance and lamination. In addition, since the sandbag material 4A allows both the sandbag bag and the granular material to pass water, the sandbag material 4A itself has water permeability, and an appropriate gap is formed between the stacked sandbag materials 4A. The water permeability can be obtained.

  Such a water permeable layer 4 is provided between the foundation main body 3 and the weight adjustment layer 5 in the same plane range as the foundation main body 3 and the weight adjustment layer 5. Specifically, the water permeable layer 4 is formed by laminating three layers of sandbags 4A on the upper surface of the weight adjusting layer 5, and the layer thickness is set to about 300 mm. Further, around the water permeable layer 4 and the weight adjusting layer 5, a second water permeable layer 41 in which the same sandbag material 4 </ b> A as the water permeable layer 4 is laminated is provided, and the upper part of the second water permeable layer 41 and the periphery of the water permeable layer 4. Are configured to allow water to pass through each other. In addition, a drainage channel 42 including a groove, a drainage pipe, and the like is provided above the second water permeable layer 41. The second water permeable layer 41 is also used as a retaining wall when excavating the ground G to construct the weight adjustment layer 5 and as a mold for forming the side surface of the weight adjustment layer 5.

  The weight adjusting layer 5 is constructed by placing post-expandable concrete on the excavated ground G. This post-expandable concrete is composed mainly of quicklime and cement, and contains a foam material containing a small amount of aluminum powder, a foam accelerator, a foam stabilizer, and other admixtures. After being placed and placed, it absorbs moisture in the ground G and foams and expands, and after solidification, forms lightweight concrete containing air bubbles. Thus, the specific gravity of the weight adjustment layer 5 constructed by solidifying the foamable concrete after the fact can be appropriately set depending on the amount of the foaming material mixed. The specific gravity is in the range of 0.5 to 1.0. Is set. Moreover, the layer thickness of the weight adjusting layer 5 is set to about 1 m, for example. In addition, under the weight adjustment layer 5, the same sandbag material 4A as the water permeable layer 4 is provided, and these sandbag materials 4A remove the pile body 6 part before pouring expandable concrete. They are arranged side by side on the bottom of the ground G.

  The pile body 6 extends from the lower surface of the water-permeable layer 4 through the weight adjusting layer 5 and penetrates into the lower ground G and extends in the X and Y directions within the range corresponding to the planar shape of the foundation body 3. A plurality are provided at appropriate intervals. Specifically, a total of 12 pile bodies 6 of 3 rows along the X direction and 4 rows along the Y direction are provided. As shown in FIG. 4, the pile body 6 includes a bag 61 as an outer surface material that forms the outer surface of the pile body 5 and has water permeability, and a sandbag material laminated inside the bag 61. 62. The bag 61 is made of a woven fabric having water permeability such as made of polyethylene, for example. As the sandbag material 62, the sandbag material 62, which is made of a woven cloth having water permeability made of polyethylene or the like, can be used as the sandbag material 62 is filled with granular materials such as glass pieces and glass particles. As the shape and size, for example, a diameter of about 600 mm and a thickness of about 200 mm can be used. The upper edge of the bag 61 extends to the upper surface of the weight adjustment layer 5 and is fixed to the weight adjustment layer 5, and a sandbag material 62 is laminated so as to contact the lower surface of the water permeable layer 4.

  In such a pile body 6, since both the bag 61 and the sandbag 62 pass water, the pile body 6 itself has water permeability, and the upper end of the pile body 6 and the lower surface of the water permeable layer 4 are provided continuously. Therefore, the water that has passed through the inside of the pile body 6 can be drained from the water permeable layer 4 to the second water permeable layer 41 and the drainage channel 42. Moreover, since the sandbag material 62 is laminated | stacked inside the bag 61, when the sandbag material 62 moves so that it may shift | deviate to right and left, the pile body 6 can be shear-deformed, and soft ground or liquefied ground The pile body 6 can follow the displacement of the ground G during the earthquake. Furthermore, since the sandbag materials 62 move so as to be shifted from side to side, the seismic motion input from the ground G is hardly transmitted upward via the pile body 6, and the seismic isolation effect by the pile body 6 can be obtained. At this time, since the laminated sandbag material 62 is restrained by the bag 61, the sandbag materials 62 are not separated from each other even if they are shifted left and right, and the pile body 6 can be returned to the initial state after the earthquake. It has become.

As described above, in the foundation structure of the present embodiment, the base penetration depth (distance from the ground surface GL to the lower surface of the weight adjustment layer 5) of the foundation body 3, the water permeable layer 4, and the weight adjustment layer 5 is, for example, , About 1.5 m. Here, the penetration depth of the foundation is the buoyancy acting on the lower surface of the weight adjustment layer 5 due to the groundwater pressure generated during liquefaction, the building body 2, the foundation body 3, the water permeable layer 4, the weight adjustment layer 5 and the pile body. It is sufficient that the weight is set by comparing the weight of 6. Specifically, the total weight W of the building 1 including the building body 2, the foundation body 3, the water permeable layer 4, the weight adjustment layer 5 and the pile body 6 is divided by the soil volume V excavated to the lower surface of the weight adjustment layer 5. The specific gravity and the layer thickness of the weight adjusting layer 5 are set so that the density P (P = W / V) is in the range of 1.0 to 1.5 (t / m ³ ). Therefore, even when the groundwater generated by liquefaction rises to the ground surface GL, the buoyancy acting on the lower surface of the weight adjustment layer 5 does not exceed the overall weight W of the building 1 and can prevent the building 1 from being lifted. It is like that.

  The construction procedure of the foundation structure as described above will be described with reference to FIGS. First, according to the construction position of the pile body 6 and the pile length, as shown in FIG. 5 (A), the ground G is excavated from the ground surface GL using the excavating device M1 such as an earth drill to form the excavation hole D. . Next, as shown in FIG. 5B, the bag 61 is inserted into the excavation hole D, and the upper end of the bag 61 is temporarily fixed to the ground surface. Next, as shown in FIG. 6A, the sandbag material 62 is put into the bag 61, and the sandbag material 62 is stacked upward from the front end portion of the bag 61. At this time, the sandbag material 62 is deformed so as to be crushed in the vertical direction and spread in a plane due to the impact of the drop, the upper and lower sandbag materials 62 are brought into close contact with each other, and the bag 61 is expanded in the radial direction of the excavation hole D. Laminated. Here, when a predetermined number of sandbag materials 62 are inserted, as shown in FIG. 6B, a compacting device M2 such as a vibrator is inserted into the bag 61 as necessary, and the sandbag material is inserted by the compacting device M2. The particles 62 and the granular material in the sandbag material 62 are vibrated and compacted. In this manner, the sandbag material 62 is repeatedly charged, and the sandbag material 62 is stacked up to the lower surface position of the water permeable layer 4 to construct the pile body 6.

  Next, as shown in FIG. 7A, after excavating the ground G and exposing the upper part of the pile body 6 from the root cutting bottom D1, the bottom surface position of the permeable layer 4 (upper surface position of the weight adjustment layer 5). The bag 61 is cut and the cut bag 61A is removed. Further, the sandbag material 4A is arranged on the root cutting bottom D1, and the sandbag material 4A is laminated along the rooted side surface D2 to form the second water permeable layer 41. Next, as shown in FIG. 7 (B), post-expandable concrete is placed in the space surrounded by the sandbag material 4A of the root cut bottom D1 and the second water permeable layer 41 of the side surface D2, and the post-expandable concrete is grounded. The weight adjustment layer 5 is constructed by absorbing the moisture in the inside and foaming. At this time, water may be supplied to the post-expandable concrete by watering or the like so that a predetermined foaming state is obtained, and when there is a lot of groundwater, the root cutting bottom D1 and the side surface D2 are blocked and the post-foaming is performed. You may make it adjust the moisture content which a property concrete absorbs. After the foamable concrete is foamed and cured, the bag 61 of the pile body 6 is fixed to the upper surface of the constructed weight adjustment layer 5 with a fixing material 63 such as a screw, and the weight adjustment layer 5 and the pile body 6 are integrated. Connect to.

  Next, as shown in FIG. 8, the sandbag material 4 </ b> A is arranged and laminated on the upper surface of the weight adjusting layer 5 to form the water permeable layer 4. This stacking operation may be performed manually, or may be performed using an appropriate apparatus or heavy equipment. Next, when the foundation body 2 is constructed on the upper side of the water permeable layer 4 and the construction of the foundation structure is completed, the building body 2 is constructed on the foundation rising 31 to complete the building 1.

  According to this embodiment, the weight adjustment layer 5 is provided between the foundation body 3 and the water permeable layer 4 and the ground G, and the total weight W of the building 1 is adjusted by appropriately adjusting the specific gravity of the weight adjustment layer 5. The density P (= W / V) of the underground part based on can be set to a predetermined value. Therefore, when the buoyancy due to excess pore water pressure when the ground G is liquefied acts on the lower surface of the weight adjustment layer 5, the buoyancy and the overall weight W of the building 1 are balanced to lift the building 1 due to excessive buoyancy. Can be prevented. In addition, since a plurality of pile bodies 6 penetrating into the ground G are provided, a normal vertical load is supported by the pile bodies 6 and even if buoyancy due to liquefaction acts locally excessively, the pile bodies 6 The resistance to buoyancy can be resisted by the pulling-out resistance, and the inclination of the building 1 can be suppressed. Further, since the pile body 6 is composed of the bag 61 and the sandbag material 62 laminated inside, the upper and lower sandbag materials even if excessive shear displacement occurs in the ground G that has been liquefied and softened during the earthquake. Since the seismic isolation effect is exhibited by shifting 62 to the left and right, and the laminated sandbag material 62 is constrained by the bag 61, the pile body 6 deforms following the shear displacement of the ground G. It is possible to prevent the pile body 6 from being damaged. Then, after the earthquake, the pile body 6 returns to the initial state and supports the building 1 with a predetermined vertical supporting force, so that the inclination of the building 1 can be effectively suppressed.

  Moreover, since the pile body 6 itself comprised of the bag 61 having water permeability and the plurality of sandbag materials 62 has water permeability, and the water-permeable layer 4 is continuously provided on the upper side thereof, the ground during an earthquake is provided. Even when G is liquefied and the groundwater rises, the groundwater can be sent to the permeable layer 4 through the pile body 6 and drained to the ground surface GL. Accordingly, it is possible to prevent the excessive buoyancy due to the groundwater from acting and to suppress the inclination of the building 1 due to the nonuniform buoyancy, and the groundwater does not stay in the ground G, and its decay and deterioration can be prevented. Can be prevented. Furthermore, since the pile body 6 can be constructed by putting and laminating the sandbag material 62 in the bag 61, the pile body 6 can be constructed by an inexpensive and easy construction procedure, and the construction cost is suppressed and the construction period is shortened. Can be planned. Furthermore, since the sandbag material 62 can be compacted by the impact of the dropped sandbag material 62 during the construction of the pile body 6, the degree of restraint of the sandbag material 62 by the bag 61 is increased, and the pile body 6 in the event of an earthquake. The deformation following ability can be improved, and the vertical supporting force of the pile body 6 can be secured by easily returning to the initial state after the earthquake.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

  For example, in the said embodiment, although the water permeable layer 4 was provided between the whole lower surface of the foundation main body 3, and the weight adjustment layer 5, it does not restrict to this but the water permeable layer 4 is provided in the pile body 6 continuously. It is only necessary to be provided through a route that can drain the groundwater that has risen inside the pile body 6 to the ground. Moreover, in the said embodiment, the sandbag material 4A of the water permeable layer 4 and the sandbag bag of the sandbag material 62 of the pile body 6, and also the bag 61 of the pile body 6 were comprised with the woven fabric made from polyethylene etc., but the material of a bag, etc. Is not particularly limited as long as it has water permeability. Moreover, as an outer surface material which comprises the pile body 6, not only what was comprised by the bag 16 like the said embodiment, but it is comprised by what processed the punching metal, the expanded metal, the wire net, etc. into the bottomed cylindrical shape. Alternatively, it may be composed of a net or cylinder other than metal. Furthermore, regarding the granular material of the sandbag materials 4A and 62, any material such as crushed stone or resin granular material can be used without being limited to glass pieces or glass particles. Moreover, in the said embodiment, although the weight adjustment layer 5 was constructed | assembled by the post-expandable concrete, the material which comprises the weight adjustment layer 5 is not specifically limited, Specific gravity is about 1 or less and the material which can be adjusted suitably And what is necessary is just to have the intensity | strength of the grade which hold | maintains the form of the weight adjustment layer 5 and the integrity with the pile body 6 is acquired.

  Moreover, as a construction procedure of the foundation structure in the said embodiment, after constructing the pile body 6, the ground G was rooted and the weight adjustment layer 5 was constructed, but not limited to this, FIG. A construction procedure as shown may be adopted. Specifically, before the pile body 6 is constructed, the ground G is excavated to the root cutting bottom D1, surrounded by the sandbag material 4A of the root cutting bottom D1 and the second permeable layer 41 of the side surface D2, and then after the space. The weight adjusting layer 5 is constructed by placing foaming concrete. Then, after marking on the upper surface of the weight adjustment layer 5 and determining the position of the pile body 6, as shown in FIG. 9A, the weight adjustment layer 5 and the ground G are removed using the excavator M1. The excavation hole 51 and the excavation hole D are formed by excavation. Next, as shown in FIG. 9B, the bag 61 is inserted into the insertion hole 51 and the excavation hole D, and the upper end of the bag 61 is fixed to the upper surface of the weight adjustment layer 5 with the fixing material 63. The material 62 is put into the bag 61, and the sandbag material 62 is stacked from the tip of the bag 61 upward. In this manner, the sandbag material 62 is repeatedly inserted, and the sandbag material 62 is stacked up to the upper surface position of the weight adjustment layer 5 to construct the pile body 6. Thereafter, the water-permeable layer 4 and the foundation main body 3 are constructed, and the construction of the foundation structure is completed. According to such a construction procedure, it is possible to perform the marking work, the excavation work of the pile body 6, the loading work of the sandbag material 62, and the like on the upper surface of the weight adjustment layer 5 formed flat. Can be improved.

1 Building 2 Building body (superstructure)
3 foundation body 4 permeable layer 4A sandbag material 5 weight adjustment layer 6 pile body 61 bag (outer surface material)
62 Sandbag Material

Claims (5)

A foundation body connected to the superstructure of the building;
A weight adjusting layer provided between the foundation body and the ground;
A plurality of pile bodies extending through and penetrating from the weight adjustment layer into the ground below,
The pile body includes an outer surface material that forms an outer surface of the pile body and has water permeability, and a plurality of sandbag materials laminated inside the outer surface material, and the sandbag material has water permeability. It is made by packing granular materials in sandbags of the specified dimensions ,
Between the foundation main body and the weight adjustment layer, a water permeable layer configured by laminating a plurality of sandbag materials is provided, and a pile head of the pile body is continuously provided on a lower surface of the water permeable layer. substructure, characterized by that. A foundation body connected to the superstructure of the building;
A weight adjusting layer provided between the foundation body and the ground;
A plurality of pile bodies extending through and penetrating from the weight adjustment layer into the ground below,
The pile body includes an outer surface material that forms an outer surface of the pile body and has water permeability, and a plurality of sandbag materials laminated inside the outer surface material, and the sandbag material has water permeability. It is made by packing granular materials in sandbags of the specified dimensions ,
The density calculated by the total weight of the building including the upper structure to the plurality of pile bodies, and the earth removal volume including the foundation body to the weight adjustment layer and the pile bodies (the whole weight / earth removal volume) foundation structure you characterized in that the specific gravity of the weight adjustment layer is set to be substantially ^{1.0t / m 3 ~1.5t / m 3} .   3. The weight adjusting layer according to claim 1, wherein the weight adjusting layer is composed of post-expandable concrete, and the specific gravity of the weight adjusting layer is set in a range of 0.5 to 1.0. Foundation structure. It is the construction method of the foundation which concerns on the foundation structure as described in any one of Claims 1-3 ,
The ground is excavated according to the dimensions of the pile body, the outer surface material of the pile body is set in the excavated excavation hole, the plurality of sandbag materials are thrown into the set outer surface material, the sandbag materials are stacked, Build a pile,
Excavating the ground in the region where the foundation main body and the weight adjustment layer are constructed, constructing the weight adjustment layer integrally with the pile head of the pile body exposed by excavation, A foundation construction method, comprising: connecting an outer surface material of the pile body to an upper surface portion; and constructing the foundation body above the pile body and the weight adjustment layer. After connecting the outer surface material of the said pile body to the upper surface part of the said weight adjustment layer, after forming a water permeable layer by laminating | stacking a plurality of sandbag materials on the said pile body and the said weight adjustment layer, this water permeability formed The foundation construction method according to claim 4 , wherein the foundation body is constructed on an upper side of a layer.

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