JP6168337B2 - Solidified body formation method and steel pipe pile embedding method using the same - Google Patents

Description

  The present invention mainly relates to a solidified body forming method applied when a steel pipe pile having a small pile diameter is embedded in the ground, and a steel pipe pile embedding method using the same.

  From the standpoint of the support mechanism, the pile foundation for supporting the structure consists of a support pile that secures the support force by penetrating the lower end into a good quality support layer, and the surrounding ground when there is no good quality support layer. Friction piles that secure supporting force by friction are broadly classified, but from the viewpoint of construction method, they are classified as driven piles, embedded piles, cast-in-place piles, etc., and from the viewpoint of pile diameter, φ300 mm or less A pile method called a micropile method using embedded piles or driven piles is known.

  Since the micropile method can be implemented with relatively small construction machines, it has proven itself as an effective method when it is not possible to secure sufficient construction space in confined areas, places with limited heads, mountains, slopes, etc. is there.

  In the case of using a steel pipe pile as an embedded pile in the micropile construction method, first, a drill hole is first formed in the ground, and then a steel pipe pile is built in the drill hole and then grouted below and around the steel pipe pile. Fill the material.

  In this way, the filled grout material is solidified below the steel pipe pile to transmit the axial force of the steel pipe pile to the ground in a dispersed state, and is solidified around the steel pipe pile to form the steel pipe pile. It plays the role of transmitting the horizontal force and the frictional force along the peripheral surface of the steel pipe pile with the surrounding ground, and thus the supporting force of the steel pipe pile is sufficiently secured.

JP 2001-81770 A

  Here, if the solidified body of the grout material solidified near the lower end of the steel pipe pile is configured to be larger than the outer diameter of the steel pipe pile, the axial force of the steel pipe pile is further transmitted to the ground in a load-distributed form. Therefore, it is possible to increase the tip bearing capacity of steel pipe piles, and in the mid-boring method and pre-boring method, an excavation method that forms an expanded space in the ground with a cutting head for expanding the diameter is widely adopted. Many cutting heads for diameter expansion have been developed.

  However, in the situation where it is difficult to secure the construction space as described above, there has been a problem that it may be difficult to introduce equipment for using the cutting head for expanding the diameter.

  On the other hand, a small-scale drilling machine such as a boring machine used in the micropile method is equipped with a pump for pumping fresh water or mud water for slime removal or hole wall protection, and the pump is used as a grout pump. As a result, grout material such as cement milk can be press-fitted into the ground, but the discharge pressure is generally low, and in most cases it does not have a discharge capacity capable of expanding the diameter.

  The present invention has been made in consideration of the above-described circumstances. When embedding a small-diameter steel pipe pile, the solidified body formed in the vicinity of the lower end of the steel pipe pile is expanded to increase the tip support force of the steel pipe pile. It is an object of the present invention to provide a method for producing a solidified body and a method for embedding a steel pipe pile using the same.

In order to achieve the above object, the solidified body forming method according to the present invention is solidified in the grout filling region filled with the grout material by filling the ground with the grout material and solidifying as described in claim 1. In the method of forming a solidified body that forms the body,
Before the grout material is solidified, the loading rod is arranged so that the tip is opposed to the vicinity of the boundary of the grout filling region or the tip is positioned inside the grout filling region, and the loading rod is by pressurizing the grouting area at the wood-axis direction is advanced near the center direction of the grouting area along loading means located at the distal end of the placing load rod, grout of the grouting area Is diffused in the periphery to expand the grout filling region .

  Further, in the solidified body forming method according to the present invention, after the grout filling region is pressurized by the advancement of the loading rod described above, the loading rod is retracted or retracted, and then the forward region of the loading rod. In addition, the front region is made a new grout filling region by filling the grout material with the above, and a series of steps consisting of forward and backward movement of the loading rod and filling the front region with the grout material is repeated.

  Further, the solidified body forming method according to the present invention includes the load rod described above configured by a hollow rod whose inner space serves as a flow path for the grout material, the load means described above is attached to the opening of the tip, and the grout material is attached to the load means. Are provided with ejection holes for ejecting water.

  Further, the solidified body forming method according to the present invention is configured such that the hollow rod is constituted by a boring rod and a non-core cutting bit attached to the tip of the boring rod is used as the loading means described above, so that the pressure feeding is performed via the boring rod. The grout material thus discharged is discharged from a discharge hole provided in the non-core cutting bit.

According to the method for embedding a steel pipe pile according to the present invention, as described in claim 5, a drilling hole is formed in the ground and a solidified body is formed in the vicinity of the bottom surface of the drilling hole. In the method of embedding a steel pipe pile, the steel pipe pile is built in the excavation hole so as to be in contact or penetrated.
The solidified body is formed according to the solidified body forming method according to any one of claims 1 to 4.

  Moreover, the embedding method of the steel pipe pile which concerns on this invention WHEREIN: When forming the said solidified body according to the formation method of the solidified body of Claim 4, formation of the said excavation hole by the said boring rod is performed in a casing. The hole wall of the excavation hole is protected, and after forming the excavation hole, the boring rod is penetrated downward from the bottom surface, and then the solidified body is formed, and after the solidified body is formed, the steel pipe pile Is inserted into the excavation hole, the casing is pulled out, and the grout material is filled between the peripheral surface of the steel pipe pile and the hole wall of the excavation hole.

  In order to create a solidified body in the ground using the solidified body forming method according to the present invention, after forming a grout filling region by filling the ground with a grout material, a tip is formed near the boundary of the grout filling region. The loading rod is arranged so that the tip is positioned inside the grout filling region.

  The grout filling area refers to an area in which a grout material is filled in a soil particle gap or other gap existing in the ground and is not yet solidified, and is appropriately formed in the ground using a known grout method. be able to.

  Regarding the relative positional relationship between the grout filling area and the loading rod, the tip of the loading rod does not necessarily have to be positioned inside the grout filling area, and the grout filling area is pressurized by a forward operation of the loading rod described later. As long as it is done, the tip of the loading rod may be separated from the grout filling region.

  Next, the loading rod is advanced along the material axis direction in the vicinity of the center of the grout filling region, so that the grout filling region is pressurized by the loading means arranged at the tip of the loading rod.

In this way, as described above, the grout material in the grout filling region permeates and diffuses to the periphery and the grout filling region expands, so that simple equipment can be installed without introducing equipment for injecting the grout material under high pressure. It becomes possible to build a larger solidified body in the ground.

  Here, after the grout filling region is pressurized by the advancement of the loading rod, the front region is filled with a grout material in the front region of the loading rod after the loading rod is retracted or retracted. Is a new grout filling region, and the series of steps consisting of the forward and backward movement of the loading rod and the filling of the grout material to the front region are repeated, the grout filling region becomes the material axis of the loading rod. It is possible to continuously form in the ground along the direction of the material axis while expanding in the orthogonal direction, thus more solidly forming the solidified body, and also when solidifying the ground over a certain range, Efficient creation is possible.

  The grout material is filled in the gap generated in front of the loading rod by the retraction operation. The filling timing may be after the retraction operation of the loading rod is completed or in parallel with the retraction operation. You may do it.

  It is sufficient that the loading rod is configured to pressurize the grout filling region by advancing it, and the grout material may be filled regardless of the loading rod. The loading rod is constituted by a hollow rod whose inner space is a flow path for the grout material, the above-mentioned loading means is attached to the opening of the tip, and a discharge hole for discharging the grout material is provided in the loading means. Then, it becomes possible to use the loading rod as a supply means for filling the grout material.

  Further, the hollow rod is constituted by a boring rod, and a non-core cutting bit attached to the tip of the boring rod is used as a loading means, so that the grout material pumped through the boring rod is provided in the non-core cutting bit. If it is made to discharge from, it becomes possible to implement this invention using the conventional boring machine, and an installation burden is further reduced.

  The method for producing a solidified body according to the present invention can be applied to any case where it is desired to create a solidified body by solidifying the grout filling region after expanding the grout filling region formed in the ground, For example, it can be applied when creating a solidified body in the ground as a countermeasure against liquefaction. However, a drilling hole is formed in the ground and a solidified body is formed in the vicinity of the bottom surface of the drilling hole. When the steel pipe pile is built in the excavation hole so as to abut or penetrate, if the solidified body is formed according to the above-described solidified body forming method, a solidified body larger than the outer diameter of the steel pipe pile is obtained. Since it is constructed, the axial force of the steel pipe pile is transmitted to the ground in a load-distributed form, and thus the tip supporting force of the steel pipe pile can be increased.

  Here, when forming a solidified body according to the method for forming a solidified body according to claim 4, it is optional whether or not the hole wall of the drilling hole is protected by forming the drilling hole with the boring rod in the casing. However, when forming a drilling hole using a casing, after forming the drilling hole, after penetrating the boring rod downward from the bottom, to form a solidified body by the above procedure, What is necessary is just to make it build in the excavation hole of a steel pipe pile, pulling out removal of a casing, and filling the grout material between the surrounding surface of a steel pipe pile and the hole wall of an excavation hole.

  The order in which the steel pipe pile is installed in the excavation hole, the casing is pulled out and the grout material is filled between the peripheral surface of the steel pipe pile and the hole wall of the excavation hole is arbitrary, and the steel pipe pile is removed from the excavation hole. After installing the steel pipe pile, the steel pipe pile is built after the grout material is filled in the excavation hole, and then the casing is pulled out and removed. Is possible.

The flowchart which showed the implementation procedure of the formation method of the solidified body which concerns on this embodiment, and the embedding method of the steel pipe pile using the same. The vertical sectional view explaining the implementation procedure of this embodiment. The vertical sectional view which continued the implementation procedure of this embodiment. The vertical sectional view which continued the implementation procedure of this embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a solidified body forming method and a steel pipe pile embedding method using the same according to the present invention will be described with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.

  FIG. 1 is a flowchart showing a method for forming a solidified body and a method for embedding a steel pipe pile using the same according to the present embodiment. As shown in the figure, in order to embed a steel pipe pile in the ground using the steel pipe pile embedding method according to this embodiment, first, as shown in FIG. Meanwhile, the excavation hole 4 is formed in the ground 3 with the loading rod and the boring rod 2 as a hollow rod built in the casing (step 101).

  In forming the excavation hole 4, the casing 1 is attached to the tip opening of the boring rod by rotating the boring rod 2 built in the casing around the material axis while press-fitting the casing 1 into the ground 3. The ground 3 is dug down to a predetermined depth by the non-core cutting bit 5 and fresh water fed from a pressure pump (not shown) is discharged from the discharge hole 6 formed in the non-core cutting bit 5 through the internal space of the boring rod 2. Then, the excavated earth and sand may be discharged to the ground in the form of being entrained in the fresh water.

  The non-core cutting bit 5 can be composed of, for example, a rod bit in which a cemented carbide tip is planted on the end surface of a thick cylindrical body.

  When the excavation hole 4 is formed, the boring rod 2 is penetrated downward from the bottom surface 7 of the excavation hole 4 as shown in FIG.

  Next, the pressure pump connected to the boring rod 2 is switched to supply the grout material, and the pressure pump is operated to supply the grout material into the boring rod 2. Then, the grout material 8 pumped through is discharged from the discharge hole 6 provided in the non-core cutting bit 5 as shown in FIG.

  In this way, a grout filling region 9 filled with the grout material 8 is formed below the excavation hole 4. Incidentally, since the grout filling region 9 is separately expanded in a subsequent process, the discharge capacity of the above-described pressure feed pump connected to the boring rod 2 may be small.

  Next, as shown in FIG. 4 (d), the boring rod 2 is retracted. In this embodiment, the grout material 8 is continuously discharged from the discharge hole 6 of the non-core cutting bit 5 while being pulled up vertically. The front region of the rod 2 is filled with the grout material 8 to make the front region a new grout filling region 9, and the boring rod 2 is disposed so that the tip of the boring rod 2 faces the vicinity of the boundary of the grout filling region 9 (step 104). ).

  Next, the boring rod 2 as a loading rod is advanced in the direction of the center of the grout filling region 9 along the material axis direction of the boring rod as shown in FIG. The grout filling area 9 is pressurized with a non-core cutting bit 5 which is a loading means arranged at the tip (step 105).

  In this way, the grout material 8 in the grout filling region 9 permeates and diffuses into the surrounding ground, and as a result, the grout filling region 9 expands.

  Next, as shown in FIG. 3B, the grout material 8 is continuously discharged from the discharge hole 6 of the non-core cutting bit 5 while the boring rod 2 is retracted, so that the grout material 8 is disposed in the front region of the boring rod 2. And the front region becomes a new grout filling region 9, and the boring rod 2 is arranged so that the tip thereof faces the vicinity of the boundary of the grout filling region 9 (step 104). By moving the boring rod 2 forward in the direction of the center of the grout filling region 9 along the material axis direction of the boring rod as shown in FIG. 3 (c), the loading means disposed at the tip of the boring rod is used. The grout filling region 9 is pressurized with a certain non-core cutting bit 5 (step 105).

  Hereinafter, the process consisting of step 104 to step 105 is repeatedly performed until the grout filling region 9 is continuously formed in a desired length range along the material axis direction of the boring rod 2 (step 106, NO).

  The boring rod 2 can be moved forward and backward using an elevating mechanism (not shown) provided in the boring machine.

  FIG. 3 (d) shows the formation state of the grout filling region 9 when the process consisting of step 104 to step 105 is repeated only once.

  When the formation of the grout filling region 9 is completed, the solidified body 41 is formed in the ground 3 as shown in FIG. 4A by curing it for a predetermined period (step 107).

  Next, the steel pipe pile 42 is built in the casing 1 (step 108), and then the grout material 43 is filled between the peripheral surface of the steel pipe pile 42 and the hole wall of the excavation hole 4 while the casing 1 is pulled out. (Step 109), the embedding of the steel pipe pile 1 into the ground 3 is completed.

  As described above, according to the solidified body forming method according to the present embodiment, the boring rod 2 that is a loading rod is disposed so that the tip thereof is opposed to the vicinity of the boundary of the grout filling region 9. Since the boring rod is advanced in the direction near the center of the grout filling region 9, the grout filling region 9 is pressurized by the non-core cutting bit 5 which is a loading means arranged at the tip of the boring rod 2. The grout material 8 in the filling region 9 penetrates and diffuses into the surrounding ground, and as a result, the grout filling region 9 expands.

  Therefore, it is possible to create a larger solidified body 41 in the ground 3 with simple equipment without introducing equipment for injecting the grout material 8 under high pressure.

  Moreover, according to the embedding method of the steel pipe pile according to the present embodiment, the solidified body 41 formed near the bottom surface of the excavation hole 4 in which the steel pipe pile 42 is built is formed using the above-described solidified body forming method. As a result, the solidified body 41 becomes larger than the outer diameter of the steel pipe pile 42, and the axial force of the steel pipe pile is transmitted to the ground 3 in a load-distributed form, thus greatly increasing the tip support force of the steel pipe pile 42. Can be increased.

  In addition, according to the solidified body forming method according to the present embodiment, a series of steps (step 104 to step 105) including the forward and backward movement of the boring rod 2 and the filling of the grout material 8 to the front region are repeatedly performed. Therefore, it is possible to continuously form the grout filling region 9 in the ground 3 along the material axis direction while expanding the grout filling region 9 in the direction orthogonal to the material axis of the boring rod 2, and thus the solidified body 41 can be formed in a predetermined length direction. It is possible to create a wide and expanded shape.

  Further, according to the solidified body forming method according to the present embodiment, the loading rod of the present invention is configured by the boring rod 2 as a hollow rod whose internal space serves as a flow path for the grout material 8, and is formed at the opening of the tip. Since the non-core cutting bit 5 as a loading means is attached and the discharge hole 6 for discharging the grout material 8 is provided in the non-core cutting bit, the boring rod 2 as the loading rod is supplied for filling the grout material. It can be used as a means, and the present invention can be implemented using a conventional boring machine, further reducing the equipment burden.

  Although not specifically mentioned in the present embodiment, when pressurizing the grout filling region 9 with the boring rod 2, if the boring rod 2 is advanced at a predetermined speed or more, as with the speed proportional type damper mechanism, the non-core It is possible to prevent the grout material 8 from flowing backward from the discharge hole 6 of the cutting bit 5. If the forward speed of the boring rod 2 cannot be increased, the boring rod may be advanced while pumping the grout material 8 into the boring rod 2.

  In this embodiment, the excavation hole 4 is formed by excavation with a so-called double pipe drilling hole. However, if there is no need to protect the hole wall, the casing 1 may be omitted and a single pipe drilling hole may be used. In the first place, the excavation method for forming the excavation hole 4 in the ground 3 is arbitrary.

  Further, in the present embodiment, the method for forming a solidified body according to the present invention has been described as an example in which the steel pipe pile 42 is embedded in the ground 3. However, for the purpose of ground improvement such as liquefaction countermeasures and strength improvement, 3 can also be applied to the case where the solidified body 41 is simply formed.

  Further, in this embodiment, when the steel pipe pile 42 is built, the grout filling region 9 is solidified, that is, the formation of the solidified body 41 is waited, but the lower end of the steel pipe pile 42 is penetrated into the solidified body 41. If it is embedded in the ground 3 as described above, the steel pipe pile 42 is built before the grout material 8 filled in the grout filling region 9 is solidified, and the lower end of the steel pile pile 42 is maintained while being penetrated into the grout filling region 9. The grout filling area 9 may be solidified.

1 Casing 2 Boring rod (hollow rod, loading rod)
3 Ground 4 Drilling hole 5 Non-core cutting bit (loading means)
6 Discharge hole 7 Bottom surface 8 Grout material 9 Grout filling area 41 Solidified body 42 Steel pipe pile

Claims (6)

In the method for producing a solidified body, a solidified body is formed in a grout filling region filled with the grout material by filling the ground with the grout material and solidifying.
Before the grout material is solidified, the loading rod is arranged so that the tip is opposed to the vicinity of the boundary of the grout filling region or the tip is positioned inside the grout filling region, and the loading rod is by pressurizing the grouting area at the wood-axis direction is advanced near the center direction of the grouting area along loading means located at the distal end of the placing load rod, grout of the grouting area A method for producing a solidified body, characterized in that the grout filling region is expanded by infiltrating and diffusing to the periphery . After pressurizing the grout filling area by advancing the loading rod as described above, the front area is revealed by filling the front area of the loading rod with the grout material while retracting or retracting the loading rod. The method for producing a solidified body according to claim 1, wherein a series of steps consisting of a forward and backward movement of the loading rod and a filling of the grout material into the front region are repeated while the grout filling region is formed. 2. The load rod according to claim 1, wherein the load rod is formed of a hollow rod whose inner space is a flow path for the grout material, the load means is attached to a front end opening thereof, and a discharge hole for discharging the grout material is provided in the load means. Or the manufacturing method of the solidified body of Claim 2. The hollow rod is constituted by a boring rod, and the non-core cutting bit attached to the tip of the boring rod is used as the loading means described above, so that the grout material pumped through the boring rod is provided in the non-core cutting bit. The solidified body forming method according to claim 3, wherein the solidified body is discharged from the discharge hole. An embedding of a steel pipe pile that forms a drilling hole in the ground, forms a solidified body near the bottom of the drilling hole, and builds a steel pipe pile in the drilling hole so that the lower end abuts or penetrates into the solidified body In the method
A method for embedding a steel pipe pile, wherein the solidified body is formed according to the solidified body forming method according to any one of claims 1 to 4. 5. When forming the solidified body according to the solidified body forming method according to claim 4, the borehole of the borehole is protected by forming the borehole with the boring rod in a casing, and the borehole is formed. After the boring rod is penetrated downward from the bottom surface, the solidified body is formed, and after the solidified body is formed, the steel pipe pile is built into the excavation hole, and the casing is pulled out. 6. The steel pipe pile embedding method according to claim 5, wherein the grout material is filled between the peripheral surface of the steel pipe pile and the hole wall of the excavation hole.

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