JPH10121450A - Binding engineering method of caison and foundation pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binding engineering method of a caison and a foundation pile capable of sufficiently securing binding power while speedily depositing binding concrete of the caison and the foundation pile. SOLUTION: This binding engineering method is to integrate a caison 1 and a foundation pile by depositing pile head binding concrete C2 underwater in a dead space after sinking the caison 1 through the foundation pile in the dead space formed by burying a sleeve pipe 50 in a bottom base concrete C of the caison 1. Thereby, an irregular part is formed by previously fixing band steels 53, 54 on an inner surface of the sleeve pipe 50 and on an outer surface of the foundation pile, and binding power is secured even without arrangement of reinforcing bars. Consequently, work is speedily progressed without arrangement of the reinforcing bars and attachment of seaweeds to reduce binding power of the pile head binding concrete C2 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of joining a caisson and a foundation pile, in particular, a method in which a giant steel shell caisson used for construction of an artificial island or the like is installed on a plurality of foundation piles cast on the seabed ground. Related to fixing technology.

[0002]

2. Description of the Related Art For example, in the construction of a huge marine structure such as an artificial island, a giant steel shell caisson may be used in place of a general concrete caisson used for construction of a quay or a seawall. . This steel shell caisson itself,
It is usually formed in the shape of a hollow box with an open top.

As a conventional caisson installation method, a method of forming a waste stone mound on the sea floor and laying it on the mound is usually employed. However, in places where the water depth is deep and the tide is fast, and the supporting strength of the seabed ground surface is not sufficient, a foundation pile reaching the submarine ground support layer is cast, and a caisson is fixed on the foundation pile. It may be desirable to adopt a construction method. In order to actually fix the caisson on the foundation pile, a plurality of cavities are provided at the bottom of the caisson, and underwater concrete is poured into the vacant space with the foundation pile penetrated, and the foundation pile is pierced. And a caisson.

[0004]

However, usually, when concrete is cast, concrete is cast in places where reinforcing bars for reinforcement are arranged in advance. Can not work because the space is narrow. Furthermore, since it takes days from the placement of the pile to the placement of the pile head joint concrete, seaweed may adhere to the concrete placement surfaces to be integrated with each other. This is a problem that must be avoided because the adhesion of seaweed greatly reduces the bonding strength of concrete. A countermeasure to cover the pile head with a curing sheet is also conceivable, but it takes time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a method of connecting a caisson and a foundation pile which can quickly pour the connection concrete between the caisson and the foundation pile while ensuring a sufficient bonding force. It is an object.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. A caisson having a plurality of cavities at the bottom thereof is provided on a seabed on which a foundation pile is laid. In order to integrate the caisson and the foundation pile by sinking and installing the foundation pile in a state where the foundation pile is penetrated, and then by casting concrete in the void underwater,
A plurality of uneven portions are formed in advance on an inner surface of the caisson facing the void and an outer surface of the foundation pile facing the void. In the above method, it is preferable that the uneven portion has a form in which unevenness is formed in a vertical direction. In addition, the uneven portion can be formed by fixing a mechanical element such as a steel strip. Furthermore, when the caisson is laid down, a lid for sealing the cavity is detachably attached to the cavity in the caisson, and the lid is removed when the underwater casting is performed. It is preferable to do so.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying FIGS. 1 to 5 sequentially show steps showing the outline of caisson (steel shell caisson) installation. Before explaining the process,
First, the structure and fabrication of the caisson will be schematically described with reference to FIG. The caisson denoted by reference numeral 1 is formed of a so-called steel shell caisson using a large number of large and small H steels for the frame and steel plates for the side plates, and is formed in a hollow box shape inside.
The caisson 1 is open at the top and its interior is divided into three chambers by two partition walls 2 parallel to each other. The lower portion of the partition wall 2 is not provided at a portion where the concrete slab C is cast. That is, the partition 2 has a structure rising from the bottom slab concrete C. The size of the caisson 1 is several tens of meters or more in length, width, and height, respectively.

A caisson 1 having such a structure and size
Is manufactured, for example, using a dry dock of a shipyard. Thereafter, the caisson 1 is towed and moored to a quay or the like suitable for the concrete placement work, and the bottom concrete C is placed in the caisson 1. The structure and function of the bottom slab concrete C will be described more specifically with reference to FIG. 5. After the bottom slab concrete C is cast, the caisson 1 is towed to a target sunk place and sunk there. . At the time of this submersion, the template 4 is supported by the head part of the support pile 10 previously constructed, and the caisson 1 is set and fixed on the template 4. The template 4 includes a plurality of foundation piles 3 including support piles 10 by casting underwater concrete.
And the head of each foundation pile 3 is inserted into the caisson 1 through the template 4.

Therefore, a large number of cavities 5 are formed in the bottom slab concrete C for drawing in the heads of the respective foundation piles 3. These voids 5 are caisson 1
The caisson 1 is sealed in advance by a water-tight temporary lid so that the caisson 1 itself functions as a hull until completion of the submersion. In FIG. 5, reference numeral 6 denotes a cast-in portion of a pile head joint concrete, 7 denotes a gasket, 8a,
8b is a side wall, 9 is an upper floor beam.

Next, the process of installing the caisson 1 will be specifically described. First, as shown in FIG. 1, a support pile 10 for supporting the template 4 and a guide pile 20 for guiding the template 4 when the template 4 is laid are placed on the seabed ground G. The number of the support piles 10 to be driven is determined according to the size and strength of the template 4. At least four or more support piles 10 are driven so that the template 4 can be stably supported near the seabed. Although the structure and function of the template 4 will be described later, as shown in FIG. 6, the overall structure is a frame steel structure having a plane lattice shape.

On the other hand, at least two guide piles 20 are driven near both ends in the longitudinal direction of the template 4. At this time, it is preferable that both guide piles 20 and 20 be considered so as to be located at the center position in the width direction of template 4. Since the guide piles 20 are used as guides when the template 4 is laid, the heads (upper ends) of the guide piles 20 are set to have a length protruding from the sea surface.

Further, bearing members 11 and 21 for receiving the lower surface of the template 4 are attached to the head of the support pile 10 and the outer peripheral portion of the guide pile 20, respectively. These support members 11 and 21 are at the same level as each other. The support member 21 of the guide pile 20 is fixed to the outer peripheral portion of the guide pile 20 by means such as underwater welding, but the support member 11 of the support pile 10 is
It is preferable to adopt a structure to be fixed on the head of the camera. This is because this is advantageous in terms of structural strength and workability. Each of the support members 11 and 21 is designed to be sufficiently larger in plan than the outer diameters of the support pile 10 and the guide pile 20 located at the center. This is to ensure that a sufficiently large pressure receiving area can be obtained for stably supporting the template 4.

After the support pile 10 and the guide pile 20 have been constructed in this way, the support pile 20 is cut and sand-removed if necessary.
After performing the mounting work of 1, the template 4 is
The guide pile 20 is used as a guide to settle.

As shown in FIG. 6, the template 4 is configured as a frame steel structure having a plane lattice shape. That is, a large H steel or I-type steel is welded and assembled in a lattice shape, and among the many squares, a square square is used when the foundation pile 3 is driven. 3 is designed to be able to be driven while being positioned from above.

On the other hand, the cavity 5 formed in the bottom slab concrete C in the caisson 1 is shown in FIG.
As shown in (b), a sleeve pipe 50 having a larger diameter than the foundation pile 3 is provided by being buried in the bottom concrete C. The sleeve tube 50 is provided in advance when the caisson 1 is manufactured, and a water-tight disk-shaped temporary lid (cover) 51 is provided at the upper end opening so that the caisson 1 itself has a function as a hull until completion of the submersion. Sealed. The temporary lid 51 is placed on an annular bracket 52 provided on the inner peripheral edge of the upper end of the sleeve tube 50, and is fixed by a plurality of bolts (not shown).

Further, a large number of steel strips (mechanical elements) 53 and 54 are fixed to the inner and outer peripheral surfaces of the sleeve tube 50 and the inner and outer peripheral surfaces of the foundation pile 3, respectively. Are formed. A large number of these steel strips 53 and 54 are fixed to the sleeve tube 50 and the foundation pile 3 along the circumferential direction and the axial direction. Note that reference numeral 55 in FIG.
This is a reinforcing steel bar buried in the bottom slab concrete C.

A plurality of guide devices 40 are provided around the template 4 so as to function as guides for setting the caisson 1 when the caisson 1 is set. As shown in FIGS. 7 and 8, the guide device 40 has a configuration including a slope 40 a that guides around the bottom of the caisson 1. Further, as shown in FIG. 8, a suitable portion of a square other than the space 5 in the template 4 is reinforced by a cross member 4b and a diagonal member 4c. The template 4 is laid on land and, for example, lifted by a large crane ship and transported by sea to a submerging site. Template 4 for lifting
It is preferable to use a large number of lifting wires in order to reduce the bending of the wire.

When the template 4 is settled, the template 4 is aligned with the guide pile 20 in a state of being lifted by a crane ship. Thereafter, the template 4 is gradually lowered and settled on the support pile 10 while being settled by its own weight. do it. In this way, the template 4 becomes the support pile 1
0 and the support members 11 and 21 of the guide pile 20 are firmly supported near the seabed. Therefore, in this state, the template 4 is fixed to the support pile 10 and the guide pile 20.

After the fixing work of the template 4 is completed, the upper part of the guide pile 20 is cut next, as shown in FIG.
After that, a large number of foundation piles 3 are set using the template 4 as a ruler. At the time of placing the foundation pile 3, by matching the grids, it is possible to place the foundation pile 3 at a required interval with high accuracy at a target position.

After completing the work of placing the foundation piles 3, as shown in FIG. 3, the outer periphery of the template 4 is filled with the filling sand S if necessary, and the template underwater concrete work C1 is driven. Set up. The filling sand S also serves as a leveling operation before the underwater concrete work C1 is performed, and the underwater concrete C1 is integrated with a large number of foundation piles 3 including the support pile 10 and the guide pile 20 and the template 4 by concrete. Responsible for the role. The thickness of the underwater concrete work C1 is determined in consideration of the caisson 1 being set on the template 4.
Care is taken not to protrude above the upper surface of the.

After completing the basic steps necessary for laying the caisson 1 as described above, the caisson 1 is then towed to the laying position, as shown in FIG.
Settle down just above. When the caisson 1 is submerged, seawater is injected into the caisson 1 as ballast water. In order to cause the caisson 1 to sink vertically to the target position, a sinking attitude control and measurement system using a computer-based analysis and image display is used in addition to the hoisting ship, although not specifically shown here. Do it.

In this manner, the caisson 1 is settled accurately and sequentially, so that the bottom of the caisson 1 is set down on the template 4. FIG. 5 shows this state. If the relative position of the caisson 1 with respect to the template 4 is slightly shifted from the design position immediately before the bottom of the caisson 1 is placed on the template 4, the template The caisson 1 is guided to a predetermined position by the action of the guide device 40 provided around the periphery 4, that is, by the action of the inclined surface 40a.

When the bottom of the caisson 1 rests on the template 4 and is so-called landed, the guide device 4
The caisson 1 is firmly positioned with respect to the template 4 by the action of the whole zero. That is, the caisson 1 is restrained by the guide device 40 so as not to move in the horizontal direction. Therefore, caisson 1 has template 4
It will be supported in a stable state above. As a result, even if the caisson 1 itself is affected by a tidal current or the like, the caisson 1 does not become unstable due to this. Of course, by fixing the template 4 and the caisson 1 with bolts or the like,
Further, it can be supported on the foundation pile 3 in a stable state.

After the caisson 1 is settled as described above, the sleeve tube 50 is removed next so that the creep deformation of the gasket 7 due to the caisson load does not affect the concrete hardening when the pile head is joined. The gap between the template and caisson is filled with special mortar. Then, the pile head joint concrete C according to the present invention
Move on to 2 underwater casting.

In placing the pile head joint concrete C2 underwater, first, as shown in FIG. 10, all bolts fixing the temporary lid 51 to the annular bracket 52 of the sleeve tube 50 are divers. Worker P cuts underwater.
As a result, the temporary lid 51 simply rests on the annular bracket 52. Next, as shown in FIG. 11, a wire 60 engaged with a suspension tower crane or the like is hooked on a suspension hole formed in advance using a shackle or the like. Next, the wire 60 is raised by a tower crane, and the temporary lid 51 is lifted.
Is lifted and removed as shown in FIGS. At this time, care is taken not to damage the reinforcing bar 55 in the bottom slab concrete C.

After the temporary lid 51 is removed as described above, the tremee pipe 61, which is a pile head-joined concrete casting pipe, is introduced into the sleeve pipe 50. The tremee pipe 61 is lowered into the caisson 1 from the crane 71 of the concrete mixer ship 70 moored on both sides of the caisson 1 as shown in FIG. It is guided between the sleeve pipe 50 and the foundation pile 3 by P, and the pile head connection concrete C2 is cast here. When the pile head connection concrete C2 reaches the upper end of the foundation pile 3 between the sleeve pipe 50 and the foundation pile 3, the driving is temporarily stopped, and as shown in FIG. The pile is guided into the inside of the pile 3, and the pile head combined concrete C2 is poured into the inside.

The pile head joint concrete C2 is a non-separable underwater concrete. Its composition is as follows.
For example, it is as shown in Table 1 below. As shown in FIG. 17, the pile head joint concrete C2 is cast to a position at a predetermined height between the upper end of the foundation pile 3 and the upper end of the bottom slab concrete C. The top position is determined by the worker P while confirming the hit setting rule 62, and is, for example, up to the annular bracket 52 to which the temporary lid 51 is fixed.

◎

[Table 1]

When the pile head-joined concrete C2 is cast as described above, the caisson 1, the support pile 10, and the guide pile 2
Integration with the foundation pile 3 including 0 is achieved via the pile head connection concrete C2. Here, as shown in FIG. 9, irregularities are formed on the inner and outer peripheral surfaces of the sleeve pipe 50 and the inner and outer peripheral surfaces of the foundation pile 3 by fixing a number of strips 53 and 54 respectively. , Pile head combined concrete C
The bond to both of the two becomes stronger. As a result, the caisson 1 and the supporting pile 10 via the pile head joint concrete C2
And the integration with the foundation pile 3 including the guide pile 20 is further strengthened. In particular, since the unevenness of the steel strip is vertically arranged, there is no possibility that the pile head joint concrete C2 will fall out of the empty space 5. Further, the steel strips 53 and 54 can be easily fixed by welding, and the irregularities can be easily formed without performing complicated processing on the sleeve pipe 50 and the foundation pile 3.

As described above, when the pile head connection concrete C2 is poured underwater, if necessary, the sleeve pipe 50 is usually used to strengthen the connection between the caisson 1 and the foundation pile 3.
Reinforcing bars such as reinforcing bars are to be arranged inside or inside the foundation pile 3. However, rebar arrangement work in a narrow space is almost impossible, and time for attaching seaweed to the surface of the sleeve tube 50 and the foundation pile 3 is given. If the seaweed adheres in this way, the bonding force of the pile head-bound concrete C2 will be extremely reduced. However, in the present embodiment, a large number of steel strips 53, 54 are provided on the sleeve pipe 50 and the foundation pile 3.
As a result, there is no need to arrange reinforcing bars because the unevenness is formed and the joining force of the pile head connection concrete C2 is secured. The reduction in the bonding force of the concrete C2 can be eliminated.

As described above, the pile head combined concrete C
After completion of the submerged casting of 2, the concrete casting of the partition wall 2 and the side walls 8a and 8b is performed while draining the caisson 1 to the extent necessary. The drainage operation is performed in accordance with the progress of the concrete placing operation of the partition wall 2 and the side walls 8a and 8b, and is performed while taking care not to generate buoyancy at least in the caisson 1.

[0032]

As described above, according to the present invention, a plurality of concavities and convexities are formed on the inner surface of the caisson facing the space through which the foundation pile penetrates and on the outer surface of the foundation pile facing the cavity. In addition, concrete is poured into the void and the caisson and the foundation pile are integrated, so that concrete can be quickly poured without arranging reinforcing steel heads in the void, and the concrete has sufficient bonding strength Is secured.

Further, by forming the irregularities in a form in which irregularities are formed in the vertical direction, the concrete is prevented from coming off and the bonding force is promoted.

In addition, by forming the uneven portion by fixing a mechanical element such as a steel strip, the uneven portion can be easily formed without performing complicated processing on the inner surface of the space or the foundation pile. .

Further, when the caisson is laid, a cover for sealing the cavity is detachably attached to the space in the caisson, and the cover is removed when concrete is poured into water. By doing so, seawater does not enter the caisson, so that the caisson can function as a hull and be towed to the site for transport.

[Brief description of the drawings]

FIG. 1 is a side view showing Step 1 of a method of connecting a caisson and a foundation pile according to the present invention.

FIG. 2 is a side view showing step 2 of the method.

FIG. 3 is a side view showing step 3 of the method.

FIG. 4 is a side view showing step 4 of the method.

FIG. 5 is a side view showing step 5 of the method.

FIG. 6 is a schematic plan view of a template.

FIG. 7 is a side view of the guide device.

FIG. 8 is a perspective view of a main part of the template.

FIG. 9 is an explanatory view showing a connection state of a caisson and a foundation pile.

FIG. 10 is a side view showing step 1 of removing a temporary lid.

FIG. 11 is a side view showing the same step 2;

FIG. 12 is a side view showing the same step 3;

FIG. 13 is a side view showing the same step 4;

FIG. 14 is a schematic side view showing a state where a pile head combined concrete is poured.

FIG. 15 is a side view showing a placing process 1 of the pile head combined concrete.

FIG. 16 is a side view showing the same step 2;

FIG. 17 is a side view showing the same step 3;

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 caisson 3 foundation pile 5 void 10 support pile 11 support member 20 guide pile 21 support member 21a H-section steel 21b diagonal material 21c support bracket 40 guide device 40a slope 50 sleeve pipe 51 temporary lid (lid) 52 annular bracket 53, 54 Strip steel (uneven part, mechanical element) 55 Reinforcing bar 60 Wire 61 Ptolemy tube 62 Striking set rule 70 Concrete mixer ship C2 Pile head joint concrete G Submarine ground

Claims (4)

[Claims] 1. A caisson having a plurality of cavities at the bottom is laid down and installed on the seabed ground on which a foundation pile is cast, with the foundation pile being penetrated into the cavity, and In order to integrate the caisson and the foundation pile by placing concrete underwater in a place, in advance, an inner surface part facing the void in the caisson and an outer part facing the void in the foundation pile A method of connecting a caisson and a foundation pile, characterized by forming a plurality of uneven portions. 2. The method according to claim 1, wherein the uneven portion is formed with unevenness in a vertical direction. 3. The method of connecting a caisson to a foundation pile according to claim 1, wherein the uneven portion is formed by fixing a mechanical element such as a steel strip. 4. When the caisson is laid down, a lid for sealing the cavity is detachably attached to the cavity in the caisson, and the lid is used when the underwater casting is performed. The method of connecting a caisson and a foundation pile according to any one of claims 1 to 3, wherein