JP3967872B2 - Pile cutting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inter- pile cutting device between cast-in-place piles, and in particular, efficiently excavates a wall-shaped groove having a predetermined width in a ground between cast-in-place piles formed with a predetermined interval by using a high-pressure jet. The present invention relates to an inter- pile cutting device between cast-in-place piles in which a high water-stopping property and a predetermined strength are obtained between adjacent cast-in-place piles by integrally placing the cast-in-place pile and the wing-like wall.
[0002]
[Prior art]
Conventionally known as a water stop construction that connects the cast-in-place piles created with a predetermined plane interval to form a water stop wall, a water stop column formed by chemical injection or column jet is known. ing. In these water stop works, the injection casting pipe is inserted to a predetermined depth while cutting the ground from the ground, and the water-permeable ground is improved over a predetermined range between cast-in-place piles by chemical injection, column jet, etc. A water-permeable structure is formed. FIG. 12 shows a water stop structure in which a water stop column 110 is formed by a column jet on a natural ground 102 between cast-in-place piles 101. In particular, FIG. 2A shows a nozzle pipe insertion hole 111 for column jet construction drilled from the ground to the side of a cast-in-place pile 101 that is created in advance at a predetermined interval. A column having a predetermined diameter is formed using the nozzle tube insertion hole 111 (see FIG. 12B). According to this column jet method, as shown in the drawing, it is possible to perform a water stop for only the water permeable layer 103 having a predetermined depth.
[0003]
[Problems to be solved by the invention]
However, in the water stoppage by the above-described column jet method, it is necessary to newly drill the nozzle tube insertion hole, which requires an additional period of ground improvement work. In addition, additional construction costs such as chemical injection as a waterstop, column jet, etc. are required. Furthermore, since the column is formed so as to contact each side surface of the adjacent cast-in-place piles, there is a problem that the piles cannot be integrated with each other and the structural strength cannot be improved.
[0004]
By the way, one of the applicants has proposed a well foundation using a composite pile as a composite well foundation applicable to a large pier foundation as a related technique (see Japanese Patent Laid-Open No. 9-256356). This composite well foundation is constructed by adjoining in plan so that a composite pile formed by connecting different types of piles in the vertical direction has a predetermined foundation shape such as a circular shape or an oval shape. Each composite pile is composed of, for example, a steel pipe sheet pile having a large diameter in the upper pile and a cast-in-place concrete pile having a larger outer diameter than the steel pipe sheet pile as the upper pile. There is a need for a structure and construction method that can be applied to the connection structure between cast-in-place concrete piles as these lower piles.
[0005]
Therefore, the object of the present invention is to solve the problems of the conventional technology described above, and among the adjacent cast-in-place piles, along with the construction of the subsequent cast-in-place pile, construct a wing-shaped wall as a connection structure, Connection structure between cast-in-place piles, in which the preceding cast-in-place pile and the subsequent cast-in-place pile are securely integrated to ensure not only the water stop effect but also the prescribed wall structure strength It is providing the pile cutting device which can perform .
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a suspension body member that is suspended so as to be lifted and lowered in a subsequent cast-in-place pile groove , and a pile groove position holding means supported by a part of the suspension body member, A rotating pipe that is coaxially accommodated in the suspension main body member, is moved up and down with respect to the main body member , and is supported so as to be able to rotate forward and backward with respect to a central axis. A high-pressure jet pipe having a plurality of nozzle pipes that are rotatably supported integrally with the moving pipe, and the subsequent cast-in-place pile and the follow-up cast-in-place pile by the high-pressure jet flow from the nozzle pipe A natural ground is cut so as to form a wall-like groove between adjacent cast-in-place piles.
[0010]
Preferably, the pile groove in-position holding means has a reaction force plate, the reaction force plate is brought into contact with the pile groove wall, and the central axis of the suspension body member in the apparatus axial direction is aligned with the pile core.
[0011]
It is preferable that the nozzle pipe is supported by the rotating pipe through a lower mount at an installation angle at which the high-pressure jet stream can be jetted so as to intersect near the surface of the preceding cast-in-place pile.
[0012]
It is preferable that the wall-like groove forms a groove contour at an outer position of the high-pressure jet flow in which a turning angle of the turning pipe is adjusted and a predetermined deflection angle is set.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an inter- pile cutting device between cast-in-place piles of the present invention will be described with reference to the accompanying drawings. In addition, although this connection structure is applicable also to the lower cast-in-place concrete pile of the composite well-cylinder foundation method mentioned above, in the following description, it demonstrates by the example of the structure which consists of a normal cast-in-place concrete pile row | line | column.
[0014]
First, the configuration of the inter-pile cutting apparatus 10 and the ground cutting operation by the apparatus will be described with reference to the drawings. The inter-pile excavating device 10 (FIG. 1) is arranged in a pile groove 3 of a subsequent cast-in-place pile 2 excavated between a preceding cast-in-place pile 1 and 1 that has been created with a predetermined plane interval in advance. This is an excavator for cutting a wall-like groove 5 in a natural ground in order to form a wing-like wall 4 (see FIGS. 8 and 9) as a connection structure for connecting between cast-in-place piles 1 and 2.
FIG. 1 shows a state in which an inter-pile excavating device 10 according to the present invention is installed in a pile groove 3 excavated as a trailing cast-in-place pile 2. This inter-pile excavator 10 is used for cutting a wall-like groove 5 in a natural ground 6 between a preceding cast-in-place pile 1 and a subsequent cast-in-place pile 2. The entire device 10 is held by a suspension device (not shown) installed on the ground and suspended so as to be lifted and lowered to a predetermined depth in the pile groove 3.
[0015]
The inter-pile excavation apparatus 10 is accommodated in the main body pipe 11 as a suspended main body member having the upper frame 12 and the in-groove position holding means 20 attached to the lower end, and is accommodated in the main body pipe 11 so as to be positioned below the upper frame 12. A rotating pipe 31 that can be rotated by continuously performing forward / reverse switching at a predetermined rotating speed and a rotating pipe 31 that is arranged in the rotating pipe 31, The high-pressure jet pipe 40 is fixedly supported so that the nozzle tip faces the groove wall 7 of the pile groove 3.
[0016]
Hereinafter, each structure mentioned above is demonstrated with reference to FIGS.
As shown in FIG. 1, the main body pipe 11 is made of a circular cross-section steel pipe extending from the ground (not shown) into the pile groove 3, and the upper surface of the upper gantry 12 is fixed to the pipe lower end 11a. The main body pipe 11 suspends the entire inter-pile excavator 10 and holds it at a predetermined depth in the pile groove 3, and also moves the entire inter-pile excavator 10 by the operation of a ground lifting device (not shown). It plays the role of moving up and down in the direction. In addition, although the pipe shape by a steel pipe is shown in this Embodiment, the assembly frame etc. by the shape steel which has torsional rigidity etc. with respect to a predetermined | prescribed longitudinal direction can be used. Moreover, a main body pipe 11 can also be raised / lowered by using a suspension wire etc. as a raising / lowering apparatus, and winding up and down with this winder (not shown) installed on the ground.
[0017]
The upper frame 12 includes inner and outer circumferential frames 13 and 14 and a cruciform frame 15 that stiffens the circumferential frames 13 and 14, and the center upper surface of the inner circumferential frame 13 is fixed to the lower end of the main body pipe 11. Yes. A direction control jack (hereinafter, denoted by reference numeral 20) is installed on the upper frame 12 as a groove position holding means 20 to be described later. By the expansion and contraction of the rod 21 of the direction control jack 20, the position of the upper frame 12, that is, the lower end of the main body pipe 11 is maintained. Usually, the length of the rod 21 of each jack 20 is adjusted so that the tube axis of the main body pipe 11 and the pile core substantially coincide. A bearing portion 16 is formed on the inner surface of the inner peripheral frame 13 to hold a rotating pipe 31 concentrically accommodated in the main body pipe 11 so as to be rotatable in forward and reverse directions. The friction reducing member 17 is attached to the lower surface of the outer peripheral frame 14, and when the lower rotating frame 32 comes into contact with the lower surface of the upper frame 12, the sliding resistance with the lower rotating frame 32 is minimized. It is supposed to be.
[0018]
The hydraulically driven direction control jack 20 as the in-groove position holding means is fixed so as to be placed on the upper frame 12. A reaction force plate 23 is attached to the tip of the rod 21 via a pin joint 24. As shown in FIG. 2, the reaction force plate 23 abuts against the pile groove wall 7 by extending the rod 21 in response to a command from a control unit (not shown), The positions can be held so as to substantially match. In addition, although the hydraulic hose for driving the direction control jack 20 is not illustrated, each hydraulic hose is extended to the ground, and the rod 21 of each jack 20 can be operated simultaneously or independently from the ground hydraulic drive source. It can be done. In addition to the direction control jack 20 as the in-groove position holding means, a mechanism in which a solid link is assembled with a steel frame so that the four support positions can move outward from the central axis (device central axis) by an equal distance. May be installed. Further, instead of the reaction force plate 23, a reaction force roller that can roll along the groove wall 7 as the apparatus is moved up and down may be used.
[0019]
The lower rotating pedestal 32 has substantially the same shape as the upper pedestal 12, and the nozzle tube 42 of the high-pressure jet pipe 40 is fixed to the lower surface thereof so as to face the pile groove wall side 7 at a predetermined angle θ. The rotating operation of the rotating pipe 31 is transmitted to the lower rotating frame 32.
[0020]
The rotating pipe 31 is made of a steel pipe concentrically accommodated in the main body pipe 11 via a bearing 34, and a lower rotating mount 32 is fixed to the lower end thereof. For example, a forward / reverse rotation operation with a predetermined rotation angle 2α (α = 90 ° −θ) is given to the rotation pipe 31 by a ground driving device (not shown). As shown in FIGS. 1 and 3 with the height of the nozzle tube 42 changed, the rotating pipe 31 is moved up and down with respect to the main body pipe 11 (upper frame 12) by a ground lifting mechanism (not shown). Can be taken. Thereby, the natural ground cutting by the high-pressure jet flow J mentioned later over a fixed depth range in the pile groove 3 can be performed. In addition, if the lower rotation mount 32 has a rigidity that can hold the reaction force when the high-pressure jet stream J applied to the nozzle tube 42 is injected, the truss only supports the nozzle tube 42 even if it is not ring-shaped. It may be a structure or the like.
[0021]
The configuration and operation of the high-pressure jet pipe 40 will be described.
The high-pressure jet pipe 40 is fixed so as to form a predetermined installation angle between the supply pipe 41 piped in the rotary pipe 31 from the high-pressure jet generator which is a pressure source (not shown) on the ground and the lower surface of the lower rotary mount 32. Nozzle tube 42 formed. As a high-pressure jet generator, a pressure generator such as a normal column jet is used. In the present embodiment, four supply pipes 41 are provided in the rotary pipe 31, each supply pipe 41 is bent at the lower surface position of the lower rotary base 32, and the tip thereof is a nozzle pipe 42. . In addition, instead of the four supply pipes 41, one large-diameter supply pipe (not shown) is piped to the lower rotating mount 32, and is branched into, for example, four narrow pipes in the vicinity of the tip, and an equivalent nozzle pipe 42 is provided. May be configured. Moreover, the air piping used for the high-pressure jet stream J can be supplied by another system. The pressure of the high-pressure jet stream J to be used may be equal to the pressure used in a normal jet grout or the like, and in this embodiment, P is set to about 20 to 40 MPa. In the present embodiment, the supply pipe 41 accommodated in the rotary pipe 31 and the nozzle pipe 42 fixed to the lower rotary mount 32 are configured to rotate integrally. A swivel pipe (not shown) or the like is provided between the supply pipe 41 and the nozzle pipe 42, and the supply pipe 41 is fixedly supported in the rotary pipe 31, while only the nozzle pipe 42 fixed to the lower rotary mount 32 is provided. Can be rotated together with the lower rotation mount 32.
[0022]
In the present embodiment, the set angle θ in the horizontal plane of the nozzle pipe 42 is set so that the two high-pressure jet streams J are in a preceding location in a state where the two nozzle pipes 42 eject the high-pressure jet streams J as shown in FIG. It is set to intersect near the surface 1 a of the pile 1. Thereby, the natural ground crushing ability by the two high-pressure jet streams J ejected from the tip of the nozzle tube 42 is overlapped, and is maximized in the vicinity of the surface 1a of the preceding cast-in-place pile 1 which is the tip position where the natural ground is cut.
[0023]
Next, the ground cutting process by the high-pressure jet stream J ejected from the nozzle pipe 42 will be described with reference to FIGS. FIGS. 5A to 5C show the deflection direction when the nozzle tube 42 rotates forward and backward and the ground cutting state in that state. FIG. 5A shows a state where the high-pressure jet stream J injected from the nozzle tube 42 intersects in the vicinity of the center 1b of the groove width on the surface of the adjacent cast-in-place pile. FIG. 5 (b) shows a state in which it is rotated from the initial position (FIG. 5 (a)) by the maximum deflection angle (α) counterclockwise in the drawing. FIG. 5 (c) shows a state where it is rotated clockwise in the drawing by the maximum deflection angle (−α). Accordingly, the deflection angle during operation of the nozzle tube 42 is about 2α.
[0024]
First, as shown in FIGS. 5 (a) to 5 (b), the high-pressure jet stream J ejected from one of the two nozzle tubes 42 in a state of being rotated counterclockwise when viewed from above. The outer side surface is at a position along the planned excavation contour 5 a of the wall-like groove 5. Thereby, the outline 5a on one side of the wall-shaped groove 5 can be cut. At this time, the other pair of two nozzle tubes 42 in a symmetrical position across the rotating pipe 31 also intersect at the surface of one preceding cast-in-place pile 1, and the high-pressure jet flow ejected from one nozzle tube 42 The outer surface of J is at a position where the planned excavation contour 5 a of the wall-like groove 5 is formed. Thereby, one outline 5a of the wall-like groove 5 on the other side is also formed. As shown in FIG. 5 (c) from this state, when rotated clockwise, the contour 5b of the wall-like groove 5 on the opposite side to that in FIG. 5 (b) can be formed. The groove contour 5b is also cut by the high-pressure jet stream J ejected from the nozzle tube.
[0025]
When cutting the wall-like groove 5 portion in the natural ground by the nozzle pipe 42 configured in this way, the high-pressure jet stream J is jetted so as to intersect in the vicinity of the surface 1a of the preceding cast-in-place pile 1, so in this portion The maximum cutting ability by high pressure jet is demonstrated. Further, the contours 5a and 5b of the wall-shaped groove 5 are set along the deflection angle of the nozzle tube 42, and the wall-shaped groove 5 having a predetermined width is obtained. As described above, the wall-like groove 5 is formed in the lower rotary frame 32 to which the nozzle tube 42 is fixed over a predetermined depth range as the rotary pipe 31 is lowered. When the cutting of the wall-shaped groove 5 within a certain descent range is completed, the wall-shaped groove 5 can be cut within a range in which the main pipe 11 is lowered by a predetermined amount and the rotating pipe 31 is lowered as the next cutting step. it can. By repeating this cutting process of the wall-shaped groove 5, the wall-shaped groove 5 can be cut between the preceding cast-in-place pile 1 and the subsequent cast-in-place pile 2 over a predetermined depth range. In each figure, the surface 1a of the preceding cast-in-place pile 1 is shown with its concavo-convex shape enlarged to show a rough state.
[0026]
The construction method of the connection structure between adjacent cast-in-place piles 1 and 2 including the cutting of the wall-like groove 5 by the inter-pile excavating apparatus 10 described above will be described with reference to FIGS.
(1) Creation of preceding cast-in-place pile 1 and excavation of pile groove 3 in subsequent cast-in-place pile 2 As shown in FIG. Every other pile 1 is constructed. The preceding cast-in-place pile 1 is constructed by a known cast-in-place pile construction method. The preceding cast-in-place piles 1 and 1 are set at a distance so that the follow-up cast-in-place pile 2 can be created between them, but ensure an appropriate distance depending on the excavation accuracy of the pile groove 3 and the ground conditions. is required. Then, the pile groove 3 of the subsequent cast-in-place pile 2 is excavated between the preceding cast-in-place piles 1. FIG. 6 shows a state where the excavation of the pile groove 3 of the trailing cast-in-place pile 2 is completed and the pile groove 3 is filled with the stabilizing liquid 8.
[0027]
(2) Cutting of the wall-like groove 5 FIG. 7 is a schematic view showing a state in which the wall-like groove 5 that connects the adjacent cast-in-place piles 1 and 2 is being cut using the above-described excavating apparatus 10 between piles. It is explanatory drawing. An unillustrated inter-pile excavator is suspended at a predetermined depth in the pile groove 3 of the trailing cast-in-place pile 2 and rotates the nozzle tube 42 at a predetermined deflection angle by rotating forward and backward at a predetermined rotation angle. The wall-like groove 5 having a predetermined width is formed in the natural ground between the preceding cast-in-place pile 1 by injecting the high-pressure jet stream. At this time, cutting of the surface of the preceding cast-in-place pile 1 and peeling and roughening of the weak part can be performed by the high-pressure jet stream J. For this reason, it is possible to reliably connect the concrete 18 of the subsequent cast-in-place pile 2 and the wing-like wall 4 to the advanced cast-in-place pile 1 (see FIG. 9). Note that the wall-shaped groove 5 may be cut with a predetermined interval in the depth direction so that a part of the natural ground remains, and then the remaining portion may be cut. In this case, since the wall-like groove cutting can be carried out in such a manner that it is supported by a relatively healthy portion of the natural ground where there is a possibility of collapse, the risk of natural ground collapse at the time of wall-like groove cutting is reduced. .
[0028]
The attached figure does not show the earth and sand discharge facility, but the cut earth and sand is known to be installed on the ground together with stable mud by a known air lift equipment and the like through the earth pipe installed in the pile groove 3. Discharge to the treatment plant and separate the sediment and muddy water at the treatment plant.
[0029]
(3) Construction of the following cast-in-place pile 2 and the wing-shaped wall 4 After forming the wall-shaped groove 5 between the pile groove 3 of the follow-up cast-in-place pile 2 and the preceding cast-in-place pile 1, the reinforcing bar is placed in the pile groove 3. Build a basket 9. FIG. 8 shows a situation in which a reinforcing bar 9 is inserted into the pile groove 3. The rebar cage 9 can be performed by a known lifting means such as a crane (not shown). When the installation of the reinforcing bar 9 is completed, the pile concrete 18 is placed by a tremy pipe (not shown) or the like in the same manner as the normal cast-in-place pile construction. As shown in FIG. 9, the concrete 18 is simultaneously placed on the main body of the subsequent cast-in-place pile 2 and the wing-like wall 4. Further, since the surface of the preceding cast-in-place pile 1 is sufficiently roughened, the advanced cast-in-place pile 1 and the wing-like wall 4 are surely integrated, and a firm connection structure having high water-stopping properties is obtained.
[0030]
FIG. 10 shows a reinforced concrete structure that exhibits the wall rigidity and strength of the wing-like wall 4 for the purpose of being applied to the above-described composite well foundation structure and the like, and realizes an integral behavior with the subsequent cast-in-place pile 2. A modification is shown. In this case, only the wing-shaped wall 4 may be independently arranged, or a reinforcing bar cage in which the pile reinforcing bar 9 and the wing reinforcing bar 19 are integrated is manufactured and the reinforcing bar cage is installed in the process shown in FIG. You may make it do.
[0031]
FIG. 11 shows an application example in which the wing-like wall 4 is formed only in the permeable layer located at a predetermined depth in the depth direction of the cast-in-place piles 1 and 2. As shown in the figure, depending on the natural ground conditions and structural conditions, it may be necessary to shield only the permeable layer portion located at a predetermined depth without requiring connection between the entire piles. In such a case, as shown in FIG. 11, the cutting of the wall-like groove by the inter-pile excavator can be performed only at the target depth, and the additional work at the time of construction can be minimized.
[0032]
【The invention's effect】
As described above, according to the present invention, when cutting a wall-shaped groove using a high-pressure jet flow in an inter-pile excavator, the high-pressure jet flow is made to intersect near the outer surface of the preceding cast-in-place pile. Since the arrangement of the nozzle tube etc. has been set, the surface of the preceding cast-in-place pile can be roughened, and the concrete end face of the wing-shaped wall and the advanced cast-in-place pile that are cast integrally with the subsequent cast-in-place pile are securely integrated As a result, the finished connection structure is solid and has high water-stopping properties. Further, since the outer side of the high-pressure jet flow is made to coincide with the contour of the wall-shaped groove, only the contour of the wall-shaped groove can be cut reliably.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a vertical cross-sectional view of a pile showing an embodiment of an inter-pile excavating apparatus used for a connection structure between cast-in-place piles according to the present invention.
FIG. 2 is a cross-sectional plan view of the pile when the pile excavating apparatus shown in FIG. 1 is viewed from the direction of arrow A.
3 is a vertical cross-sectional view of the pile excavation apparatus shown in FIG. 2 as viewed from the direction of arrow B. FIG.
4 is a device end view of the inter-pile excavator shown in FIG. 1 as viewed from the direction of arrow C. FIG.
FIG. 5 is a state explanatory diagram schematically showing a ground cutting state by an inter-pile excavating device.
FIG. 6 is a state explanatory diagram (No. 1) showing a construction state of a connection structure between cast-in-place piles.
FIG. 7 is a state explanatory diagram (2) showing a construction state of a connection structure between cast-in-place piles.
FIG. 8 is a state explanatory diagram (No. 3) showing a construction state of a connection structure between cast-in-place piles.
FIG. 9 is a state explanatory view (No. 4) showing a construction state of a connection structure between cast-in-place piles.
FIGS. 10A and 10B are a plan sectional view and a longitudinal sectional view showing a modified example of a connection structure between cast-in-place piles.
FIGS. 11A and 11B are a plan sectional view and a longitudinal sectional view showing another modified example of a connection structure between cast-in-place piles.
FIG. 12 is a cross-sectional plan view and a vertical cross-sectional view showing an example of a water stop connection structure between conventional cast-in-place piles.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Precede cast-in-place pile 2 Follow-up cast-in-place pile 3 Pile groove 4 Wing-like wall 5 Wall-like groove 6 Ground mountain 7 Groove wall 10 Pile excavator 11 Main body pipe 12 Upper mount 20 Groove position holding means (direction control jack)
31 Rotating pipe 32 Lower rotating base 40 High-pressure jet pipe 41 Supply pipe 42 Nozzle pipe

Claims (4)

A suspension main body member that is suspended so as to be able to move up and down in a subsequent cast-in-place pile groove , a pile groove position holding means supported by a part of the suspension main body member, and coaxially accommodated in the suspension main body member , A rotating pipe that is raised and lowered with respect to the main body member and supported so as to be rotatable forward and backward with respect to the central axis , and is accommodated in the rotating pipe and is supported so as to be rotatable integrally with the rotating pipe. A high-pressure jet pipe having a plurality of nozzle pipes, and the subsequent cast-in-place pile formed adjacent to the follow-up cast-in-place pile by the high-pressure jet flow from the nozzle pipe; A pile-to-pile cutting apparatus characterized by cutting a natural ground so as to form a wall-like groove between the piles. The in-pile groove position holding means has a reaction force plate, the reaction force plate is brought into contact with the pile groove wall, and the central axis of the suspension body member in the apparatus axial direction is aligned with the pile core. The inter-pile cutting device according to claim 1. The nozzle tube according to claim 1, wherein the high pressure jet stream is supported on the pivot pipe through the lower frame in jettable installation angle so as to intersect near the surface of the preceding place pile The inter-pile cutting device described in 1. The wall-like groove, by adjusting the rotation angle of the rotating pipe, in claim 1, characterized in that so as to form a groove contour outside position of the high-pressure jets predetermined deflection angle is set The inter-pile cutting device described.

Images