JP2014040703A - Existent construction ground improvement structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an existent construction ground improvement structure firstly in which damage with local bending distortion of a base structure can be suppressed by improving or recovering bearing power of a bearing ground in a settlement non-correction location and further, to provide an existent construction ground improvement structure secondly in which work efficiency can be improved by simplifying backfill work of a settlement correction member.SOLUTION: When flowable improvement soil is hardened within a working recessed spot 2, a bearing ground recovery body 4 is formed within the working recessed spot 2, and a plurality of settlement correction members 3 and a reinforcement arrangement member 11 are included and restricted within the bearing ground recovery body 4. Then, a base structure 51 is point-supported at a plurality of positions P by the plurality of settlement correction members 3, such that uneven settlement is corrected, and a down face of the base structure 51 is face-supported by the bearing ground recovery body 4 along a planar arrangement of foundation rising parts 51a.

Description

  The present invention relates to an existing building ground improvement structure for improving and reinforcing a supporting ground on which a foundation structure of an existing building is already installed.

  Conventionally, various methods have been proposed as methods for correcting the subsidence of existing buildings, and there are methods using jackup such as a pressure platen method and a steel pipe pile press-in method (underpinning method).

  Here, the pressure platen method excavates a work hole that extends from the outer periphery of the plane of the foundation structure of the existing building to the bottom of the foundation structure, and installs a pressure plate on the bottom ground of the work hole. Using a lifting device such as a jack as a force plane, raise the foundation structure to level the existing building, and insert a support member between the foundation structure and the pressure board in this state. Thus, the work hole is backfilled while the foundation structure is supported from below.

  The steel pipe pile press-in method uses a lifting machine such as a jack that drills a work hole that leads from the outer periphery of the plane of the foundation structure of the existing building to the bottom of the foundation structure and uses the bottom surface of the foundation structure as the reaction surface. Then, the steel pipe pile is driven into the support ground from the bottom ground of the work hole, and the existing structure is leveled by raising the foundation structure through the reaction force accompanying this driving, and in this state the foundation structure and the steel pipe pile A support member is inserted in between, and the work hole is backfilled while the base structure is supported from below by the support member.

JP 2007-100454 A

  However, first, in the above-mentioned pressure plate method and steel pipe pile press-in method, when the foundation structure is point-supported in a plurality of locations on the support ground by a plurality of support members, the portion between the installation locations of the support members Becomes a non-installation location (absence location) of the support member. For this reason, when the supporting force of the supporting ground is insufficient, the foundation structure is locally bent and distorted by the load of the existing building at the point between the supporting points by the supporting member, and breakage such as cracks and breaks There was a problem of generating.

  In particular, in the case where the support ground that has subsided due to liquefaction is accompanied by a decrease in support capacity, the support capacity of the support ground is determined by the support member for the location of the support member for subsidence correction. However, at the non-installation location of the support member, the support ground support capacity to support the building load applied to the foundation structure cannot be obtained, and the foundation structure is locally bent and distorted. There was a risk of damage such as cracks and breaks.

  In addition, secondly, in each of these methods, the supporting force of the supporting ground is recovered or improved by rolling and compacting the backfilling soil put into the working hole. There are a number of excavation points, and in order to backfill all of these, it is necessary to individually load and roll sand into each work hole, which makes the work hole backfilling work complicated. There was a problem of becoming.

  In addition, when the work hole is backfilled, if the gap between the bottom in the work hole and the lower surface of the foundation structure is narrowed, the compactor cannot be brought into the work hole, and the rolling operator cannot enter. For this reason, the gap remaining between the bottom of the work hole and the lower surface of the foundation structure needs to be filled with mortar separately and cured and cured. Therefore, there is a problem that the work of backfilling a plurality of work holes becomes very complicated in this respect as well.

  The present invention has been made to solve the above-described problems. First, in a non-sinking correction location, the support force of the support ground is improved or recovered to reduce the local flexural distortion of the foundation structure. The purpose is to provide an existing construction ground improvement structure that can suppress the accompanying damage, and secondly, an existing construction ground improvement structure that can improve work efficiency by simplifying the backfilling work of subsidence correction members The purpose is to do.

  In order to achieve this object, the existing ground improvement structure of claim 1 is for improving and reinforcing the supporting ground on which the foundation structure of the existing building is laid. Plural subsidence correction members that are installed in a plane and spaced apart from each other, support the substructure from below and correct the inclination of the substructure caused by non-uniform subsidence, and the installation locations of the subsidence correction members A subsidence correction part and a non-settlement correction part between the subsidence correction part and a non-sinking part of the subsidence correction member, and the ground surface portion of the supporting ground along the plane arrangement of the foundation rising part A working recess that is recessed at a predetermined depth, and a fluidity-improved soil that is injected and filled in a fluid uncured state into the working recess and hardened in the working recess. Backfilling and subsidence A positive member enclosing, provided along the planar arrangement of the rising portion in the substructure, and a support ground restoration body to face supporting the substructure from below.

  According to the existing construction ground improvement structure according to the first aspect, the working recess is recessed along the planar arrangement of the foundation rising portion. Inside the work recess, a plurality of settlement correction locations are installed so as to be scattered in a plane, and there are non-settlement correction locations between the installation locations.

  In such a working recess, the fluidity-improving soil in an uncured state of the supporting ground restoration body is filled and filled to the lower surface of the foundation structure, and the fluidity-improving soil is hardened in the working recess, thereby supporting A ground restoration body is formed. At this time, the support ground restoration body is hardened in a state of including a plurality of settlement correction members, and is integrated with the plurality of settlement correction members.

  In addition, the support ground restoration body is formed not only in the repair support location but also in the entire work recess including the non-repair support location, and is provided along the plane arrangement of the foundation rising portion, so only the settlement correction location is provided. In other words, the foundation structure including the part between the subsidence correction parts is supported from below. Accordingly, the foundation structure is suppressed from being sunk and bent at the non-sinking correction location, and the damage to the foundation structure is also suppressed.

  In addition, the support ground restoration body can obtain a compaction degree equal to or higher than that of the sand compacted by rolling by simply hardening the fluidity-improved soil in the work recess, so that it is similar to the conventional method. There is no need to put earth and sand into the work hole and compaction by compaction, and there is no need to separately fill and cure the mortar in the work recess. For this reason, the backfilling operation of the working recess can be performed very easily.

  In addition, the foundation rising part is a place where the base of the building and the pillar are placed thereon, and thus there is a point where the vertical load of the existing building acts (hereinafter referred to as “load point”). In other words, providing the work recess and supporting ground restoration body along the plane arrangement of the foundation rising part is intended to provide the work recess and supporting ground restoration body along the location of the load point of the existing building. ing.

  The existing construction ground improvement structure according to claim 2 is the existing construction ground improvement structure according to claim 1, wherein the work recess is in communication with a plurality of the subsidence correction locations along the plane arrangement of the foundation rising portion. A recess formed in a long groove shape including the non-sinking correction portion, and the support ground restoration body is formed in a continuous body including a plurality of the settlement correction members in the long groove work recess. Yes.

  According to the existing construction ground improvement structure of claim 2, since it functions in the same manner as the existing construction ground improvement structure of claim 1, a plurality of settlement correction points are communicated with each other as work recesses, By pouring the fluidity improving soil into the place, the fluidity improving soil can be poured into another place, and as a result, a plurality of subsidence correction places can be backfilled efficiently.

  In addition, since the working recess is formed in a long groove shape in which a plurality of settlement correction points and non-sinking correction points are communicated along the planar arrangement of the foundation rising portion, naturally, the supporting ground restoration body formed therein Also, it is formed as a continuous body that is continuously connected by connecting a plurality of settlement correction locations and non-sinking correction locations along the planar arrangement of the foundation rising portion. As a result, since the construction of the support ground restoration body can be collectively performed on the subsidence correction place and the non-installation place, there is an effect that the construction work of the support ground restoration body can be made more efficient.

  The existing building ground improvement structure according to claim 3 is the existing building ground improvement structure according to claim 1 or 2, wherein the working recess is formed in a lattice shape in plan view along a part or all of the planar arrangement of the foundation rising portion. It is recessed in a net shape.

  In addition, the plan view lattice shape or the net shape is, for example, a plan view “mouth” shape (square shape) or a combination of two or more thereof (for example, a plan view “field”, “day”, or “eye” shape). Etc.), a triangular shape in plan view, other polygonal shapes (excluding a square shape), or a combination of two or more of these.

  According to the existing construction ground improvement structure according to claim 3, it acts in the same manner as the existing construction ground improvement structure according to claim 1 or 2, and the work recesses are in a lattice shape along the planar arrangement of the foundation rising portion or Since it is stretched in a net shape, for example, it can be constructed by connecting working recesses so as to cover all the load points of the existing building.

  Then, the support ground restoration body formed in such a working recess is formed continuously so as to cover all the load points of the existing building along the plane arrangement of the foundation rising part. It is possible to evenly support the entire portion serving as the load point of the object, and as a result, it is possible to suppress or reduce the occurrence of uneven settlement of the foundation structure.

  The existing construction ground improvement structure according to claim 4 is the existing construction ground improvement structure according to any one of claims 1 to 3, wherein the fluidity improvement soil is a site-generated soil generated by the recess of the work recess, It is manufactured by mixing and adjusting the solid material with the soil generated on site.

  The solidifying material used for the fluidity improving soil may be either a cement-based solidifying material or a lime-based solidifying material, or a solidified material combining these, and the fluidized soil is used as the fluidity improving soil. You may do it.

  According to the existing construction ground improvement structure of this claim 4, in addition to acting in the same way as the existing construction ground improvement structure of any one of claims 1 to 3, the site caused by the recess of the work recess in the fluidity improvement soil Since the generated soil is used, there is an effect that it is possible to reduce the amount of surplus soil generated at the site.

  The existing building ground improvement structure according to claim 5 is the existing building ground improvement structure according to any one of claims 1 to 4, wherein one of the plurality of settlement correction members and the other are connected to each other, and The reinforcing bar member is included in the support ground restoration body.

  According to the existing construction ground improvement structure of claim 5, the same function as the existing construction ground improvement structure of any one of claims 1 to 4 is applied, and the inside of the support ground restoration body is coupled to the subsidence correction member. Since the reinforcement member to be included is included, there is an effect that the rigidity of the support ground restoration body can be improved.

  Below, the modification of this invention is shown.

The existing construction ground improvement structure according to the first modification is the existing construction ground improvement structure according to claim 1 or 2,
The working recess is
Subsidence correction recesses recessed in two or more subsidence correction points;
It is provided with an intermediate recess that is separated from the subsidence correction recess and is recessed in a long groove shape along the planar arrangement of the foundation rising portion,
The supporting ground restoration body is
A plurality of dotted repair bodies that are provided in a state of including the settlement correction member in the plurality of settlement correction recesses and are scattered and installed on a support ground along a planar arrangement of a foundation rising portion;
And a continuous restoration body provided in the intermediate recess located between the interspersed restoration bodies and provided continuously along the planar arrangement of the foundation rising portion.

The existing construction ground improvement structure of the second modification is the existing construction ground improvement structure of claim 1 or 2 or the first modification,
The working recess is
An outer peripheral recess that is recessed in the planar outer periphery of the foundation structure along the planar arrangement of the rising portion existing in the planar outer periphery of the foundation structure;
One or more inner peripheral recesses that are recessed in a long groove shape at one or more locations along the planar arrangement of the foundation rising portion on the support ground inside the outer periphery recess and communicate with the outer periphery recesses. And
The supporting ground restoration body is
An outer peripheral restoration body that is provided in a state of including the settlement correction member in the outer peripheral recess and is continuously or intermittently provided along the planar arrangement of the rising portion existing in the planar outer peripheral portion of the foundation structure;
The outer peripheral portion restoration body provided along the plane arrangement of the rising portion provided inside the one or two or more inner peripheral recesses so as to enclose the settlement correction member and existing inside the plane outer peripheral portion of the foundation structure. And an inner peripheral restoration body that is continuously provided.

  According to the existing construction ground improvement structure of the present invention, not only the foundation structure is point-supported by the plurality of settlement correction members but also the plurality of settlement correction sites by the support ground restoration body. Therefore, the foundation structure is also surface-supported at the non-sinking correction points existing between the subsidence correction points. Therefore, it can be suppressed that the foundation structure is locally bent and distorted by the vertical load of the existing building acting on the non-sinking correction location, and as a result, the occurrence of breakage such as cracks and breaks can be suppressed. effective.

  In particular, in the case where the supporting ground of the existing building is subsidized and the ground surface is weakened due to liquefaction, etc., and the supporting power is reduced, by forming a supporting ground restoration body, An effect of improving or recovering the supporting force of the supporting ground can also be expected.

  Moreover, since the support ground restoration body supports the foundation structure at the subsidence correction location, for example, even if the support force of the substructure due to the subsidence correction member malfunctions for some reason, the subsidence correction member Instead, it has the effect of supplementing the support function of the foundation structure.

  In addition, the work recess recessed on the support ground of the foundation structure has a function corresponding to the formwork of the support ground restoration body in addition to the function of setting the settlement correction member. By refilling the place with the fluidity-improving soil, it is possible to double the construction of the support ground restoration body and to improve the work efficiency.

  Furthermore, since the support ground restoration body is formed by inflowing and filling the fluidity improving soil into the work recess and hardening it, it is not necessary to compact the backfill soil by rolling when filling the work recess, Since there is no need to backfill the gap that cannot be rolled with mortar, there is an effect that the construction work of the support ground restoration body and the backfilling work of the work recess can be easily performed.

It is the longitudinal cross-sectional view (vertical sectional view in the II line of FIG. 2) which showed the internal structure of the support ground improvement structure which is one Example of this invention. It is a top view of the support ground improvement structure shown in FIG. It is the top view which showed the site on the support ground where an existing building is constructed, (a) is a top view of the foundation structure of the existing building, (b) is the foundation structure It is a top view of the working recess excavated and formed in the plane of a support ground. It is a top view of a working recess. It is the longitudinal cross-sectional view which showed the state of the working recess and the settlement correction member before formation of a support ground restoration body. It is the figure which showed the modification of the support ground restoration body shown in FIG.1 and FIG.2, (a) is the longitudinal cross-sectional view which showed the internal structure, (b) is the top view. It is a partial top view of the support ground improvement structure of 2nd Example. It is the top view which showed the other modification of the support ground improvement structure.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.

  FIG.1 and FIG.2 is explanatory drawing about the support ground improvement structure 1 which is one Example of this invention. FIG. 1 is a longitudinal sectional view (longitudinal sectional view taken along line I-I in FIG. 2) of a supporting ground improvement structure 1 according to an embodiment of the present invention, and illustrates an internal structure of a supporting ground restoration body 4. . FIG. 2 is a plan view of the support ground improvement structure 1 shown in FIG. 1, and the support ground restoration body 4 is formed in the work recess 2 shown in FIGS. 3B and 4 described later. The state is illustrated.

  In addition, in FIG. 2, the planar arrangement | positioning of the foundation rising part 51a of the foundation structure 51 is shown with the dashed-two dotted line.

<Supported ground improvement structure>
As shown in FIGS. 1 and 2, the support ground improvement structure 1 mainly includes a work recess 2 that is recessed in the ground surface portion 53 of the support ground 52 and a plurality of locations (P) in the work recess 2. Are installed on a flat surface (see FIG. 2) and used to correct the uneven settlement of the foundation structure 51, and a plurality of settlement correction members 3 are flown through the work recess 2 in a state where the settlement correction members 3 are installed. And a supporting ground restoration body 4 formed by backfilling using the soil with improved property.

  This support ground improvement structure 1 is for improving and reinforcing a support ground 52 provided with an existing building 50 and its foundation structure 51. Here, the support ground 52 refers to the ground that supports the existing building 50 and the foundation structure 51, and a ground surface portion 53 on which the foundation structure 51 is placed and a deep layer portion that is deeper than the ground surface portion 53. 54.

  The foundation structure 51 is a so-called fabric foundation structure, and is formed in an inverted T shape by being connected to a rising portion (hereinafter referred to as “foundation rising portion”) 51a and a lower end portion of the foundation rising portion 51a. And a footing 51b.

  In addition, although a present Example demonstrates using the foundation structure 51 which has cloth foundation structure, this foundation structure is not necessarily limited to this, The thing of a solid foundation structure may be sufficient.

<Work recess>
Here, the working recess 2 will be described with reference to FIGS. 3 and 4. FIG. 3 is a plan view showing a site on the support ground 52 where the existing building 50 is constructed, and FIG. 3A is a plan view of the foundation structure 51 of the existing building 50. 3 (b) is a plan view of the work recess 2 formed by excavation on the plane of the support ground 52 of the foundation structure 51. FIG.

  3 and 4, the illustration of the existing building 50 is omitted, and in FIG. 3B and FIG. 4, the illustration of the footing 51 b of the foundation structure 51 is omitted, and the planar arrangement of the foundation rising portion 51 a is performed. This is illustrated by a two-dot chain line.

  As shown in FIG. 3A, the foundation structure 51 is laid on the support ground 52 of the existing building 50. The foundation structure 51 is provided with a foundation rising portion 51a on which a foundation of the building 50 is placed and a pillar is erected. And as shown in FIG.3 (b), the working recess 2 is excavated and formed in this support ground 52 just under the plane arrangement | positioning location of the foundation rising part 51a.

  As shown in FIG. 3 (b), the work recess 2 in plan view is stretched around the support ground 52 of the foundation structure 51 in a lattice shape or a net shape along the planar arrangement of the foundation rising portion 51 a. Yes. Specifically, the working recess 2 has a planar shape in which a plurality of rectangular frame-shaped long grooves having a substantially “B” shape in plan view are connected in a plane along the basic rising portion 51a. ing.

  If it demonstrates in detail, the plane form of the working recess 2 in a present Example will be the groove | channel of the "day" shape recessed in the both right and left sides of FIG.3 (b), and FIG. A vertically long “B” -shaped groove that is recessed in the center has a form in which the grooves are connected side by side in the horizontal direction in the figure.

  The work recess 2 is a work space for performing the installation work of the settlement correction member 3, and an installation location of the settlement correction member 3 (hereinafter referred to as “sinking correction location”. In the detailed hatching portion in the figure) Corresponding.) A plurality of P are set. Further, the work recess 2 is a long groove-like recess formed so as to connect a plurality of settlement correction points P to each other, and not only the settlement correction point P but also the non-sink of the settlement correction member 3. It is also provided at the installation location Q (hereinafter referred to as “non-sinking correction location”, which corresponds to the rough hatched portion in the figure).

  Here, the non-sinking correction location Q refers to a location where installation of the settlement correction member 3 is unnecessary and absent in the settlement correction work. That is, the working recess 2 of the present embodiment is not only recessed at the settlement correction place P, but also the location of the ground surface portion 53 of the support ground 52 that does not require the installation of the settlement correction member 3 in the first place, that is, non-sinking correction. The part Q is also recessed.

  FIG. 4 is a plan view of the work recess 2 for explaining the function of each part of the work recess 2. FIG. 4 is basically the same as FIG. 3B, but in order to distinguish the function of each part of the work recess 2, each region is divided by a virtual line (two-dot chain line) according to the function. It is shown.

  As shown in FIG. 4, the working recess 2 corresponds to the outer peripheral recess 5 (corresponding to the rough hatched portion in the figure) that is recessed in the planar outer peripheral portion of the foundation structure 51 along the planar arrangement of the foundation rising portion 51 a. ). Further, in the inner region of the outer peripheral recess 5, the work recess 2 is formed in a long groove shape at one or more locations along the planar arrangement of the foundation rising portion 51 a and communicated with the outer peripheral recess 5. The three inner peripheral recesses 6 (corresponding to the fine hatched portions in the figure) are also provided.

  Further, the plurality of settlement correction members 3 are installed in a plurality of settlement correction points P provided on the support ground 52 that supports the foundation structure 51, and are supported by supporting the foundation structure 51 from below. This is equipment for correcting the inclination of the foundation structure 51 due to subsidence.

  The subsidence correcting members 3 are scattered on the ground surface portion 53 of the support ground 52 with a space therebetween in a plane, but are not scattered randomly but the basic rising portions 51a. It is installed along the plane arrangement.

  Returning to FIG. 1 and FIG. 2, the settlement correction member 3 will be described. As shown in FIGS. 1 and 2, the plurality of settlement correcting members 3 are facilities for adjusting and leveling the settlement amount of the foundation structure 51, and the foundation structure 51 is locally disposed from below. (Refer to FIG. 1), and are arranged in a flat manner in a scattered manner at a plurality of locations (see FIG. 2) of the support ground 52.

  Here, as shown in FIG. 1, a plurality of settlement correction members 3 are installed in a work recess 2 that is recessed in the support ground 52 at a predetermined depth from the lower surface of the foundation structure 51. The subsidence correcting member 3 mainly includes a support frame 7 installed in the work recess 2 immediately below the foundation rising portion 51a, and a reaction force member 8 installed below the support frame 7.

  Next, the support frame 7 and the reaction force member 8 will be described. The support frame 7 is a conventional frame used for subsidence correction. A top plate 7 a at the upper end of the support frame 7 is in contact with the lower surface of the foundation structure 51, and the base plate 7 b at the lower end of the support frame 7 is a reaction force member 8. The reaction force plate 9 is in contact with the upper surface.

  The support frame 7 is formed so that its height can be variably adjusted in the vertical direction. The support base 7 has a top plate 7a and a base plate 7b that are vertically opposed to each other, and further, four support columns 7c that connect the four corners of the top plate 7a and the support plate 7b, and shafts of the support columns 7c. And an adjusting tool 7d for adjusting the length in the direction (vertical direction).

  An internal space 7e for jack installation having a predetermined height is provided between the top and bottom opposing surfaces of the top plate 7a and the base plate 7b of the support frame 7, and this internal space 7e is a hydraulic jack or the like to be described later. This is a space in which the elevator 16 can be installed (see FIG. 5A).

  The reaction force member 8 is a member that receives a vertical load acting on the support frame 7 from the foundation structure 51 that supports the existing building 50 and transmits the reaction force from the support ground 52 to the support frame 7 to the vertical load. It is. For example, the reaction force member 8 employs a composite structure in which the reaction force plate 9 is placed on the upper end of the steel pipe pile 10 that is press-fitted to the deep layer portion 54 that serves as a support layer.

  In the case of a direct foundation, the support layer in the support ground 52 refers to the ground surface portion 53 immediately below the lower surface of the foundation structure 51. In the case of a pile foundation, a foundation pile such as a steel pipe pile 10 that is press-fitted into the ground. The deep layer part 54 which supports the front-end | tip of this.

  With reference to Fig.5 (a), the settlement correction method by the settlement correction member 3 installed in the working recess 2 is demonstrated. Here, FIG. 5A is a longitudinal sectional view showing a state of the work recess 2 and the settlement correction member 3 before the formation of the support ground restoration body 4.

  As shown in FIG. 5A, the reaction force member 8 of each subsidence correction member 3 is a bottom ground surface 2a in the work recess 2 and a position that becomes a subsidence correction point P (see FIG. 3B). Installed. After each reaction force member 8 is installed, the support frame 7 is installed on the reaction force member 8. At this time, the top 7 a of each support base 7 is opposed to the base structure 51 and the base plate 7 b is placed on the reaction force plate 9 of the reaction member 8.

  After the installation of each support frame 7, the elevator 16 is installed in the internal space 7 e of each support frame 7. At this time, when the fixed state of each support column 7c by the adjusting tool 7d of each support frame 7 is released, each support column 7c can be expanded and contracted. Therefore, when the elevator 16 is driven in this state, the top plate 7a becomes the foundation structure. By being raised toward 51, the distance between the opposing surfaces of the top plate 7a and the base plate 7b is increased, and each column 7c is extended.

  As a result, when the top plate 7 a comes into contact with the lower surface of the foundation structure 51, the foundation structure 51 is supported by the force generated by the elevator 16. Then, while maintaining the state in which the foundation structure 51 is supported by the generated force of the elevator 16, the supports 7 c are fixed again by the adjusters 7 d so that they cannot be stretched. It is fixed.

  Then, each subsidence correcting member 3 comes to support the foundation structure 51 on the support ground 52 even if there is no generating force of the elevator 16. In other words, after that, even if the elevator 16 is lowered to stop driving and removed from the internal space 7e of the support frame 7, it is ensured that the foundation structure 51 is supported from below by each of the settlement correcting members 3. Will come to be.

  In the subsidence correction of the foundation structure 51 by the plurality of subsidence correction members 3, the elevators 16 installed on the support bases 7 of the individual subsidence correction members 3 are simultaneously operated by computer control, so that the substructure 51 The amount of subsidence may be adjusted.

  5 (b) and 5 (c) are longitudinal sectional views showing modifications of the settlement correction member 3, and the working recess 2 and the settlement correction member 3 before the formation of the support ground restoration body 4 are shown. The state is illustrated. For example, instead of the reaction force member 8 shown in FIG. 5A, the reaction force member 8 is applied to the bottom ground 2a of the work recess 2 excavated in the ground surface 53 of the support ground 52 as shown in FIG. 5B. Only the reaction plate 9 or only the steel pipe pile 10 that is press-fitted from the bottom ground 2a of the working recess 2 to the deeper layer 54 that is the support layer as shown in FIG. 5C is used. May be.

<Supported ground restoration body>
Returning to FIGS. 1 and 2, the support ground restoration body 4 will be described. As shown in FIG. 1, the support ground restoration body 4 supports the foundation structure 51 from below, and is formed of a hardened material of fluidity improved soil injected and filled in the work recess 2. The fluidity improved soil used for the support ground restoration body 4 is soil and sand having both uncured fluidity that can be injected and filled into the work recess 2 and curability that hardens in the work recess 2. It is.

  As shown in FIG. 2, the fluidity improving soil is supplied into the working recess 2 through a pressure feeding hose 17 by a pressure feeding device (not shown). This fluidity-improving soil is produced mainly by mixing and adjusting earth and sand and a solidifying material, and additives such as a predetermined amount of admixture and fine aggregate are added as necessary.

  As such fluidity improved soil, for example, it may be produced by mixing and adjusting the solidified material in the field generated soil generated from the site by excavation for the recess of the work recess 2, By doing so, the soil generated in the field can be used as a raw material, and it becomes possible to effectively use the stratum and surplus residual soil.

  For example, fluidized soil may be used as the fluidity improved soil. If the above-mentioned soil generated from the fluidized soil is used, there is no need to temporarily install a fluidized soil production device at the site, and simple production of fluidity-improved soil of a certain quality is achieved by manual labor. You can also

  The solidifying material used for the fluidity improving soil may be either a cement-based solidified material or a lime-based solidified material, or a solidified material obtained by combining these.

  The support ground restoration body 4 is formed in the work recess 2 by filling the work recess 2 back to the lower surface of the foundation structure 51 as shown in FIG. 1, and as shown in FIG. It is formed along the recessed portion of the place 2. For this reason, the support ground restoration body 4 is a continuous body provided continuously along the planar arrangement of the foundation rising portion 51a. The work recess 2 also has a function as a mold for forming the support ground restoration body 4.

  Further, as shown in FIG. 2, the support ground restoration body 4 includes an outer circumference restoration body 12 and an inner circumference restoration body 13 made of a cured product of the above-described fluidity-improving soil, and these outer circumference restoration bodies. The body 12 and the inner peripheral restoration body 13 are a continuous body formed integrally and continuously.

  Here, the outer peripheral restoration body 12 is a hardened material of fluidized improved soil formed in the outer peripheral recess 5 (see FIG. 4) of the work recess 2, while the inner peripheral restoration body 13 is a work piece. This is a hardened material of fluidized improved soil formed in three inner peripheral recesses 6 (see FIG. 4) in the recesses 2.

  The outer peripheral portion restoration body 12 is continuously provided in a ring shape having a rectangular shape in plan view along the planar arrangement of the foundation rising portion 51 a existing on the outer peripheral portion of the foundation structure 51. On the other hand, the inner peripheral part restoration body 13 is formed in a planar inner region from the outer peripheral part restoration body 12, and follows the planar arrangement of the foundation rising part 51 a existing in the planar inner peripheral part of the foundation structure 51. It is connected continuously.

  Incidentally, as shown in FIG. 4, the inner peripheral recess 6 serving as the mold of the inner peripheral repair body 13 communicates with the outer peripheral recess 5 serving as the mold of the outer peripheral repair body 12. When the liquefied soil is poured into the outer peripheral recess 5, the fluidized soil is poured into the inner peripheral recess 6 through the outer peripheral recess 5.

  In particular, each of the inner circumferential recesses 6 is not a groove-like recess in which one end portion in the extending direction becomes a so-called dead end shape, but both end portions in the extending direction are different. Since the inner circumferential recess 6 or the outer circumferential recess 5 communicates with both sides of the inner circumferential recess 6 in the extending direction, the flow of the fluidity improving soil becomes better.

  Here, with reference to FIG. 6, the modification of the support ground restoration body 4 is demonstrated. FIG. 6 is a view showing a modified example of the supporting ground restoration body 4 shown in FIGS. 1 and 2, and FIG. 6 (a) is a longitudinal sectional view showing the internal structure (of FIG. 6 (b)). This corresponds to a longitudinal sectional view taken along the line A-A.), And FIG. 6 (b) is a plan view thereof.

  As shown in FIG. 6, in the modified example of the support ground restoration body 4, a plurality of settlement correction members 3 and reinforcing members 11 are included therein, and these members 3 and 11 are made of fluidity improving soil. It may have a structure in which the inclusion is restrained by a cured product. In such a case, the settlement correction member 3 and the reinforcing member 11 function as a reinforcing body of the support ground restoration body 4.

  The bar arrangement member 11 is formed of, for example, a material having rigidity such as a reinforcing bar or a steel single pipe. After the settlement correction processing of the foundation structure 51 is performed as described above, the reinforcement member 11 is formed in the work recess 2. The support subsidence restoration body 4 is reinforced by connecting the subsidence correction members 3 and 3 adjacent to each other or by connecting the subsidence correction support member 3 and another reinforcing bar arrangement member 11 to each other. .

  Note that a tie fitting (not shown) such as a tie wire or a joint is used for connection between one reinforcing member 11 and the subsidence correcting member 3 or another reinforcing member 11.

<Construction method for supporting ground improvement structure>
Next, the construction method of the support ground improvement structure 1 comprised as mentioned above is demonstrated. First, as a premise for constructing the support ground improvement structure 1, it is necessary to install the subsidence correcting member 3 on the support ground 52 in order to correct the subsidence amount due to the uneven subsidence of the existing building 50 and the foundation structure 51. . For this reason, the settlement correction point P (see FIG. 3) is selected in advance.

  The subsidence correction point P is a load point at which the vertical load of the existing building 50 acts (hereinafter simply referred to as “load point”) based on the amount of subsidence at each point on the supporting ground 52 in the existing building 50 and its foundation structure 51. It is determined so as to match.

  However, in general, the vertical load of the existing building 50 is transmitted to the foundation structure 51 by a pillar, and this pillar is erected on the foundation rising portion 51a via the base. A load point will exist along the plane arrangement of foundation rising part 51a.

  The subsidence correction point P is not limited to any location as long as it is directly below the load point existing along the plane arrangement of the foundation rising portion 51a. As long as it is for adjusting the sinking amount of the substructure 51, it is needless to say that it is a point on the supporting ground 52 where the sinking amount exceeds the allowable range.

  Then, as shown in FIGS. 3 and 4, the working recess 2 is formed in the support ground 52 so that all of the settlement correction points P are continuously communicated. At this time, the work recess 2 is formed by excavation along the planar arrangement of the foundation rising portion 51a. This is because the support ground restoration body 4 formed in the work recess 2 supports the portion of the foundation structure 51 in the non-subsidence correction portion Q where the subsidence correction member 3 is absent.

  After excavation of the work recess 2, a plurality of settlement correction members 3 are installed in the work recess 2. At this time, the settlement correction member 3 is installed in each of the settlement correction locations P determined in advance. In the construction of the subsidence correcting member 3, the reaction force member 8 is installed on the bottom ground 2 a of the work recess 2, and then the support frame 7 is placed on the reaction force member 8, and the internal space 7 e of the support frame 7 The elevator 16 is accommodated in the housing, and the elevation of the substructure 51 is adjusted by changing the height of the support frame 7 by driving the elevator 16.

  After the installation of the plurality of subsidence correction members 3 and the subsidence correction of the substructure 51 using them, the elevator 16 is removed, and then the fluidity improving soil is supplied by a pressure feeding device (not shown). Then, it is poured into the working recess 2. The fluidity improving soil poured into the work recess 2 is poured into the entire work recess 2 and filled from the bottom ground surface 2 a of the work recess 2 to the lower surface of the foundation structure 51.

  By completing the filling and filling of the fluidity improving soil, each subsidence correcting member 3 installed in the work recess 2 is buried in the fluidity improving soil. Then, it is allowed to stand for a predetermined time until the fluidity-improved soil is cured.

  When the fluidity-improving soil is hardened, a support ground restoration body 4 is formed in the work recess 2, and a plurality of settlement correction members 3 are constrained within the support ground restoration body 4. Then, the foundation structure 51 is point-supported by the plurality of settlement correcting members 3 to correct the uneven settlement, and the support ground restoration body 4 follows the planar arrangement of the foundation rising portion 51a along the plane arrangement of the foundation structure 51. The lower surface is surface-supported.

<Modified example of support ground improvement structure>
A modification of the above embodiment will be described with reference to FIG. FIG. 7 is a partial plan view of the support ground improving structure 20 of the second embodiment. The support ground improvement structure 20 of the second embodiment is obtained by changing the planar shape of the working recess and the support ground restoration body with respect to the support ground improvement structure 1 of the first embodiment described above. In the following, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.

  As shown in FIG. 7, according to the support ground improvement structure 20 of the second embodiment, the outer peripheral recess 5 in the work recess 2 includes a settlement correction recess 5a and an intermediate recess 5b. The subsidence correction recess 5a is a recess provided in a plurality of subsidence correction places P, and the subsidence correction member 3 is installed in each of the subsidence correction recesses 5a.

  On the other hand, the intermediate recess 5b is recessed in the shape of a long groove along the planar arrangement of the foundation rising portion 51a in the planar outer peripheral portion of the foundation structure 51, but the recessed portion of the subsidence correction recess 5a. This is a recess that is recessed in the excluded non-sinking correction point Q. Further, the intermediate recess 5b is not communicated with each of the settlement correction recesses 5a, and is intermittently connected to a portion between the settlement correction recess 5a and the settlement correction recess 5a in the outer periphery of the plane of the foundation structure 51. Is recessed.

  By the way, the inner peripheral recess 6 communicates with the intermediate recess 5b of the outer peripheral recess 5, and the fluidity improving soil is poured into the intermediate recess 5b, whereby the inner peripheral recess 6 is also fluid. Improved soil is introduced. However, as described above, each subsidence correction recess 5a of the outer periphery recess 5 is separated from the intermediate recess 5b, and thus it is necessary to individually fill and fill the fluidity improving soil.

  Therefore, the outer periphery restoration body 12 of the support ground restoration body 4 includes a plurality of spot repair bodies 12a formed in the plurality of settlement correction recesses 5a, and each spot repair body in each intermediate recess 5b. A plurality of continuous restoration bodies 12b that are formed separately from 12a and that are also connected to the inner circumference restoration body 13 are provided.

  Here, each of the scattered repair bodies 12a is formed in a state in which the settlement correction member 3 is contained and restrained, and is scattered on the ground surface portion 53 of the support ground 52 along the planar arrangement of the foundation rising portion 51a. Installed. Moreover, each continuous restoration body 12b is provided in the intermediate | middle recessed part 5b in the part between dotted | restored restoration bodies 12a, and is provided along the planar arrangement | positioning of the foundation rising part 51a.

  The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.

  For example, the planar form of the working recess 2 of the first embodiment is not necessarily limited to a planar view shape and a lattice shape, and may be appropriately changed according to the planar arrangement of the basic rising portions 51a. For example, it may be a lattice shape or a mesh shape combining a circular shape or other polygons.

  Moreover, in the said Example, the three internal peripheral part restoration bodies 13 of planar view linear form are provided in the inner peripheral part of the outer peripheral part restoration bodies 12 and 12, These inner peripheral part restoration bodies 13 are other internal peripheral part restorations. Although it has a planar configuration that intersects with the body 13 or the outer peripheral restoration bodies 12 and 12b, the arrangement state of the inner peripheral restoration body 13 is not necessarily limited to this, and of course. The base rising portion 51a may be changed as appropriate according to the manner of arrangement.

  For example, depending on the arrangement form of the foundation rising part 51a, the inner peripheral recess 6 and the inner peripheral part restoration body 13 formed therein may be one, two, or four or more.

  FIG. 8 is a plan view showing a support ground improvement structure 30 which is another modified example of the support ground improvement structure 1. Here, in the first embodiment, the outer peripheral restoration body 12 is continuous in an annular shape in plan view, but the planar form of the outer peripheral restoration body 12 is not necessarily limited to this, for example, As shown in FIG. 8, the dividing portion 12 c may be provided at an arbitrary position in the circumferential direction and intermittently provided in the circumferential direction of the planar outer peripheral portion of the foundation structure 51.

1, 20, 30 Support ground improvement structure 2 Work recess 3 Settlement correction member 4 Support ground restoration body 5 Outer recess 5a Settlement correction recess 5b Intermediate recess 6 Inner recess 11 Reinforcement member 12 Outer periphery repair body 12a Interspersed restoration body 12b Continuous restoration body 13 Inner circumference restoration body 50 Existing building 51 Foundation structure 51a Rising part (foundation rising part)
52 Support ground 52a Ground surface 52b Deep layer P Subsidence correction point Q Non-subsidence correction point

Claims (5)

In the existing building ground improvement structure for improving and reinforcing the support ground on which the foundation structure of the existing building is laid,
Plural subsidence correction members that are installed in a plurality of locations on the support ground of the substructure in a plane and spaced apart from each other, and support the substructure from below to correct the inclination of the substructure due to non-uniform subsidence. When,
It has a subsidence correction point where the subsidence correction member is installed and a non-subsidence correction point between the subsidence correction point and the non-settling point of the subsidence correction member. Working recesses that are recessed at a predetermined depth along the ground surface of the supporting ground,
The working recess is filled with fluidity improved soil that is injected and filled in a fluid uncured state and hardened in the working recess, backfilling the working recess and enclosing the plurality of settlement correction members, An existing construction ground improvement structure comprising a support ground restoration body provided along a planar arrangement of a rising portion in a foundation structure and supporting the foundation structure from below. The working recess is a long groove-like recess in which a plurality of the settlement correction locations are communicated along the planar arrangement of the foundation rising portion.
2. The existing ground improvement structure according to claim 1, wherein the supporting ground restoration body is formed in a continuous body including a plurality of the settlement correction members in a long groove-like working recess.   3. The existing construction ground improvement according to claim 1, wherein the working recess is recessed in a lattice shape or a net shape in plan view along a part or all of the planar arrangement of the foundation rising portion. Construction.   The fluidity-improving soil is manufactured by mixing and adjusting a site-generated soil generated by the concave formation of the work recess and a solidifying material in the site-generated soil. The existing building ground improvement structure according to any one of 3 above.   5. The reinforcing member for connecting one of the plurality of subsidence correcting members and the other member to each other and having a reinforcing member included in the support ground restoration body. The existing construction ground improvement structure as described in any one of.

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