JP5383568B2 - Grout injection construction method, pier construction method using this construction method, and foundation pile fixing structure applicable to this construction method - Google Patents

Description

  The present invention relates to a grout injection construction method for joining a foundation pile and a mounted portion, a pier construction method using this construction method, and a foundation pile fixing structure applicable to this construction method.

  A general construction procedure of a conventional jacket type jetty will be described with reference to the drawings. As shown in FIG. 10, a foundation pile (steel pipe pile) 1 is placed on the ground G from the bottom of the water (a), a jacket 2 having a leg 3 is transported (b), and the leg 3 is inserted into the steel pipe pile 1 to cover the jacket. 2 is installed (c). Next, grout is injected and integrated between the steel pipe pile 1 and the leg 3 of the jacket 2, and then the upper concrete is constructed.

  In the construction of the grout injection described above, the grout injection part 4 between the steel pipe pile 1 and the leg 3 is lower than the water surface S and submerged in water as shown in FIG. For this reason, generally, as shown in FIG. 11 (b), the lower end position of the leg 3 as shown in FIG. The grout 9 is injected from the injection port 6. At this time, if the grout injection height is large, the cloth bottom formwork is pushed down by the weight of the grout, and the grout leaks from the gap with the leg, so that as shown in FIG. The primary grout 9 may be launched until the secondary grout 10 is cured, and the secondary grout 10 may be injected from the secondary inlet 7 after the hardening. 11 (c) and 11 (d), the grout is poured into the gap between the leg 3 and the steel pipe pile 1 in a state where seawater is confined, and the grout is required to have a performance that does not separate even in water. Is done.

  In Patent Document 1, in order to improve the water-stopping property at the joint between the steel pipe pile and the leg and prevent leakage of the grout when the grout is injected, the joint between the tubular leg and the steel pipe pile inserted into the leg is used. A steel pipe pile foundation seal that is made of an annular and plate-like sealing material that has elasticity and water-stopping properties, and has different lengths at one end and the other end along the circumferential direction of the sealing material. It is attached to the joint between the tubular leg and the steel pipe pile inserted through the leg, and one end along the circumferential direction of the steel pipe pile foundation seal is elastically attached to either the leg or the steel pipe pile. Disclosed is a steel pipe pile foundation in which the other end is elastically pressed to either the leg or the steel pipe pile, and a filler is filled above the seal for the steel pipe pile foundation.

  Patent Document 2 is easy to mount, has good workability, can inject grout without processing the structure, and in order to prevent the outflow of the injected grout, The base is fastened to the outer peripheral surface of the sheath tube with the upper tightening body, the opposite ends are connected with the watertight connector, and the base is connected with the lower tightening body. A method for injecting grout is disclosed in which a base is attached and fixed by covering the gap at the lower end of the sheath tube and injecting grout from the inlet.

  In Patent Document 3, a work object is surrounded by a work box in which a pair of hollow units are joined by a hinge, and one end portion of a water-stop tube provided at the lower part of the work box is used as a sleeve at the other end part. Disclosed is a water-stopping structure capable of easily joining the cut-off ends of the water-stopping tube and enhancing the adhesion thereof by expanding the water-stopping tube after insertion.

JP 2000-3831 A JP 2006-200328 A JP 2002-242220 A

  Even though the grout has separation resistance in water, it does not separate at all, but it causes separation due to injection in water, resulting in a decrease in quality. It is also conceivable that seawater is involved in the course of launching by injection and uniform quality cannot be ensured. Furthermore, in the two-stage construction of the primary grout injection mainly for water stop and the subsequent secondary grout injection, sufficient adhesion cannot be obtained between the primary grout and the secondary grout. Disadvantages are that it cannot be made and the grout construction period is long.

  In the general construction method of FIG. 11, it is most desirable to inject the grout in a dry state without seawater in order to prevent degradation of the grout quality and to ensure the required strength. In addition, it is possible to improve the efficiency of the construction by performing the injection by one injection without dividing the grout construction into two stages.

  In addition, according to the structure and grout injection method of Patent Documents 1 and 2, a complicated structure seal or a pile and a sheath pipe are wound around the outer periphery to form a cylindrical shape, and the upper clamp body is used as a base for the outer periphery of the sheath pipe. A sheet-like substrate that is fastened to the surface is required, and the construction process is complicated accordingly.

  In the construction of a jacket-type pier, etc., the grout injected into the gap between the mounting part of the jacket leg and the foundation pile and the foundation pile prevents deterioration in quality due to construction in water and shortens the construction period and is efficient. An object of the present invention is to provide a grouting method, a pier construction method using this construction method, and a foundation pile fixing structure applicable to this construction method.

  The grout injection construction method for achieving the above object includes a step of attaching a flexible tube and a water stop lid to a foundation pile placed, and a water stop lid at a lower end of a mounted portion installed on the foundation pile. The flexible tube is positioned near the lower surface of the water stop lid, and the flexible tube is expanded by air filling and pressed against the foundation pile and the lower surface of the water stop lid. The step of making a water stop structure between the lower end of the attached portion and the water stop lid and between the foundation pile and the attached portion, and discharging water between the attached portion and the foundation pile. And a step of injecting grout between the attachment part and the foundation pile.

  According to this grouting method, the flexible tube is positioned near the lower surface of the water-stopping lid that is in contact with the lower end of the mounted portion, and is pressed against the foundation pile and the lower surface of the water-stopping lid by being expanded by air filling. Thus, a water-stopping structure can be formed between the lower end of the attached portion and the water-stop cover and between the foundation pile and the attached portion. For this reason, even if the attached part and the foundation pile are underwater, water can be discharged between the attached part and the foundation pile as a water-stopped state, and a dry state can be obtained. Water is not mixed into the grout injected into the tank, and it is possible to prevent deterioration of the quality of the grout due to construction in water, and it is not necessary to divide the grout into two stages as in the past, and the construction period can be shortened and efficiently. Can be implemented.

  In the grouting method, the grouting step can be performed by construction from the water or construction from the land.

  The pier construction method for achieving the above object is a jacket leg in which the attached portion is inserted into the foundation pile, and a jacket type pier is constructed by the grout injection construction method described above.

  According to this pier construction method, even if the leg and foundation pile of the jacket are underwater, water can be discharged between the leg and foundation pile as a water-stopped state, so that the leg and foundation pile can be brought into a dry state. The grout poured in between is not mixed with water, and it is possible to prevent the deterioration of the quality of the grout due to construction in water, and it is not necessary to divide the grout into two stages as in the past, and the construction period can be shortened and efficient. Can be implemented.

  A foundation pile fixing structure for achieving the above object is a foundation pile fixing structure for fixing and fixing a mounted portion to a placed foundation pile, and a flexible tube attached to the foundation pile and A water stop lid attached to the foundation pile and in contact with the lower end of the attached portion, and the flexible tube located near the lower surface of the water stop lid is expanded by air filling to form the foundation pile. By pressing against the lower surface of the water stop lid, a water stop structure between the lower end of the attached portion and the water stop lid and between the foundation pile and the attached portion, the attached portion and the The attached portion is fixed to the foundation pile by injecting grout between the foundation pile.

  According to this foundation pile fixing structure, the flexible tube is positioned in the vicinity of the lower surface of the water-stopping lid that is in contact with the lower end of the mounted portion, and is expanded by air filling. By pressing against the foundation pile and the lower surface of the water stop lid, a water stop structure can be formed between the lower end of the attached portion and the water stop lid and between the foundation pile and the attached portion. Furthermore, if the water confined between the foundation pile and the mounted portion is drained, water pressure from the outside is also applied, and the water stoppage is further improved. For this reason, even if the attached part and the foundation pile are underwater, water can be discharged between the attached part and the foundation pile as a water-stopped state, and a dry state can be obtained. Water is not mixed into the grout injected into the tank, and it is possible to prevent deterioration of the quality of the grout due to construction in water, and it is not necessary to divide the grout into two stages as in the past, and the construction period can be shortened and efficiently. Can be implemented.

  In the above-mentioned foundation pile fixing structure, by further including an elastic member disposed between the lower end of the attached portion and the water stop lid, the water stoppage between the lower end of the attached portion and the water stop lid can be improved. .

  In addition, the flexible tube can be integrated with the waterproof cover so that the flexible tube is integrated with the waterproof cover so that the flexible tube is positioned near the lower surface of the waterproof cover. It is not necessary to adjust the position of the flexible tube alone.

  According to the grout injection construction method, the pier construction method, and the foundation pile fixing structure of the present invention, water is not mixed into the grout injected between the attached portion such as a jacket leg and the foundation pile, ) Can prevent deterioration of the quality of the grout, and there is no need for the conventional two-stage grout construction, so that the construction period can be shortened and efficiently implemented.

It is a flowchart for demonstrating process S01-S08 of the grout injection construction method by this embodiment. It is a side view which shows the state which respond | corresponded to process S02 of FIG. 1, and inserted the flexible tube and the water stop lid into the steel pipe pile. FIG. 3 is a side view / cross-sectional view (a) and a top view (b) of a water stop lid structure using the flexible tube and the water stop lid of FIG. 2. It is sectional drawing which shows the example of attachment of the flexible tube to the water stop lid | cover of FIG. 2, FIG. It is a side view which shows the state (b) with which the leg of the jacket was inserted in the steel pipe pile, and the state (b) which made the water stop lid contact the lower end of a leg corresponding to process S03, S04 of FIG. FIG. 6 is a side view showing a state (a) in which the flexible tube is lifted up to the lower surface of the water stop lid and a state inflated by air filling, corresponding to steps S05 and S06 in FIG. 1. It corresponds to process S07 of FIG. 1, and is a side view which shows the state (a) which discharges seawater from between the leg 3 and the steel pipe pile 1, and the state (b) which drained seawater completely. It is a fragmentary sectional side view for demonstrating the water stop effect in FIG.7 (b) by the water stop structure of this embodiment. It is side view which shows the construction (a) from the sea for the grout injection | pouring between the leg 3 and the steel pipe pile 1, and the construction from the land (b) corresponding to process S08 of FIG. It is a figure for demonstrating the schematic construction process (a)-(c) of the conventional jacket type jetty. It is a figure for demonstrating the conventional general grout construction process (a)-(d) in construction of a jacket type jetty.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a flowchart for explaining steps S01 to S08 of the grout injection method according to this embodiment. FIG. 2 is a side view showing a state in which the flexible tube and the water blocking lid are inserted into the steel pipe pile, corresponding to step S02 of FIG. FIG. 3 is a side view / cross-sectional view (a) and a top view (b) of the water stop lid structure including the flexible tube and the water stop lid of FIG. 2. FIG. 4 is a cross-sectional view showing an example of attachment of the flexible tube to the water stop lid of FIGS.

  As shown in Fig. 1, Fig. 2 and Fig. 10 (a), a steel pipe pile (foundation pile) 1 is placed on the ground G from the bottom of the water (S01), and then the steel pipe pile 1 is used for water stop before installing the jacket. The flexible tube 11 is inserted, and then the waterproof cover 12 is inserted (S02). The water-stopping flexible tube 11 and the water-stopping lid 12 attached in this way are under water under the water surface S.

  Here, with reference to FIG.2, FIG.3, FIG.4, the water stop structure applicable to the grout injection construction method of this embodiment is demonstrated.

  The water stop structure of the present embodiment has a water stop cover structure that includes a water stop flexible tube 11 and a water stop cover 12. The flexible tube 11 for water stop and the water stop lid 12 have a circular closed shape. The water stop flexible tube 11 is configured in a donut shape and inserted into the steel pipe pile 1, and the water stop lid 12 is inserted into the steel pipe pile 1 from its inner hole. That is, as shown in FIGS. 3A and 3B, the inner diameters of the flexible tube 11 and the water blocking lid 12 are slightly larger than the outer diameter of the steel pipe pile 1. Thereby, the insertion into the steel pipe pile 1 of the flexible tube 11 and the water stop lid 12 like FIG. 2 becomes easy.

  As shown in FIGS. 3 (a) and 3 (b), a rubber plate is provided on the upper surface of the water stop lid 12 so that no gap is formed between the water stop lid 12 and the lower end 16 of the leg 3 (see FIGS. 5 to 8). It is preferable to attach an elastic member 13 made of water or the like.

  Moreover, the water stop lid | cover 12 has the protrusion part 12a which protrudes in the downward perpendicular direction from the lower surface 14 of the water stop cover 12 like FIG. 3A, and is flexible between the protrusion part 12a and the steel pipe pile 1. FIG. Since the tube 11 is positioned, the tube 11 is held in the horizontal direction.

  The flexible tube 11 is a hollow tubular member made of a rubber material or the like and has a structure that expands when filled with air, and an air injection valve 11a for injecting high-pressure air (FIG. 6B). (See Fig.).

  3 (a), the flexible tube 11 can be pressed so as to be wound around the outer peripheral surface of the steel pipe pile 1 by expanding the flexible tube 11 by filling with high-pressure air. It can be fixed to the outer peripheral surface of. In the water stop structure of the present embodiment, the lower end 16 of the leg 3 is positioned on the upper surface of the water stop lid 12 via the elastic member 13 as shown in FIG.

  As shown in FIG. 4, a holding member 12 b having an L-shaped cross section is attached to the lower surface 14 of the water blocking lid 12, and the flexible tube 11 is disposed between the lower surface 14 of the water blocking lid 12 and the holding member 12 b in the horizontal direction. It is good also as a structure previously stored so that it may hold | maintain in a perpendicular direction. By using such a structure in which the waterproof cover 12 and the flexible tube 11 are integrated in advance, the positions of the waterproof cover 12 and the flexible tube 11 in the steel pipe pile 1 can be adjusted integrally. It is. Moreover, it is preferable that the water stop lid | cover 12, the protrusion part 12a, and the holding member 12b consist of steel materials.

  Next, steps S03 to S08 of the grouting method according to the present embodiment will be described with further reference to FIGS.

  FIG. 5 is a side view showing a state (a) in which the jacket leg is inserted into the steel pipe pile and a state (b) in which the waterstop is brought into contact with the lower end of the leg, corresponding to steps S03 and S04 in FIG. is there. FIG. 6 is a side view showing the state (a) in which the flexible tube is lifted up to the lower surface of the water stop lid and the state inflated by air filling, corresponding to steps S05 and S06 in FIG.

  Next, after step S02 of FIG. 1, the jacket 2 is installed by inserting the leg 3 of the jacket 2 into the steel pipe pile 1 as shown in FIGS. 5 (a) and 10 (b) (S03). Next, as shown in FIG. 5A, the water stop lid 12 is lifted and brought into contact with the lower end 16 of the leg 3, and in that contact state, temporarily fixed to the leg 3 by known fixing means such as a bolt (S04).

  Next, as shown in FIG. 6A, the flexible tube 11 is lifted up to the lower surface 14 of the water blocking lid 12 and grounded at a predetermined position (S05). Next, as shown in FIG. 6 (b), the flexible tube 11 is filled with high-pressure air from the air injection valve 11a (S06), and the flexible tube 11 is expanded, so that the outer peripheral surface of the steel pipe pile 1 is expanded. Press and fix as if winding.

  7 corresponds to step S07 in FIG. 1 and is a side view showing a state (a) in which seawater is discharged from between the leg 3 and the steel pipe pile 1 and a state (b) in which seawater is completely drained. FIG. 8 is a partial side cross-sectional view for explaining the water stop effect in FIG. 7B by the water stop structure of the present embodiment. FIG. 9 is a side view corresponding to step S08 of FIG. 1 and showing construction from the sea (a) and construction from the land (b) for injecting grout between the leg 3 and the steel pipe pile 1.

  Next, water (seawater) W confined between the leg 3 and the steel pipe pile 1 is removed by using a drainage valve 3a installed in advance on the lower end 16 side of the leg 3 as shown in FIG. Finally, the water is completely discharged as shown in FIG. 7B (S07).

  As shown in FIG. 8, the water stop structure is completed by the expanded flexible tube 11 and the water stop lid 12 positioned above the tube. According to the water stop structure, the flexible tube 11 does not fall by being fixed to the steel pipe pile 3, and buoyancy acts on the flexible tube 11 for filling and expanding high-pressure air. In addition, since the flexible tube 11 itself expands, a force for pushing up the water stop lid 12 on the upper side acts, and between the lower end 16 of the leg 3 and the water stop lid 12 and between the water stop lid 12 and the steel pipe pile 3. Can be secured.

  Further, the water pressure acting from the inside is eliminated by drainage between the leg 3 and the steel pipe pile 1, and the flexible tube 11 and the water blocking lid 12 are connected to the upper leg 3 and the steel pipe pile 1 by the water pressure from the outside. Therefore, the water stoppage between the lower end 16 of the leg 3 and the waterstop cover 12 and between the waterstop cover 12 and the steel pipe pile 1 is remarkably improved.

  Next, when seawater is discharged from the gap D between the leg 3 and the steel pipe pile 1 in FIG. 7 (b) so that the gap D is in a dry state in which no water is present, In this manner, the grout is injected into the gap D in FIG. 7B from the grout injection valve 3a at the lower end 16 of the leg 3 (S08). Thereby, the grout 15 is filled between the leg 3 and the steel pipe pile 1, and the leg 3 and the steel pipe pile 1 are combined and integrated. As the grout material, a cement-based material can be mainly used, and examples thereof include cement milk and cement mortar.

  In addition, although grout injection | pouring can be performed by construction from the sea like above-mentioned Fig.9 (a), the inside of the clearance gap D of FIG.7 (b) has already been in a dry state, and a cloud is seawater. Since there is no fear of mixing, it can be performed from the upper end side of the gap D between the leg 3 and the steel pipe pile 1 as shown in FIG. 9B, and construction from the land is possible.

  Further, the valve 3a is a drainage / grout injection valve, which serves as both drainage and grout injection in the gap D, but may be provided separately.

  As described above, according to the grout injection method of the present embodiment, since the water stop structure including the flexible tube 11 and the water stop lid 12 as shown in FIG. 8 is used, the lower end 16 of the leg 3 and the water stop lid are used. 12 and the gap between the water blocking lid 12 and the steel pipe pile 1 can be eliminated. Therefore, it is possible to ensure the water stoppage in these gaps.

  Furthermore, the water pressure acting from the outside accompanying the discharge of seawater from the gap between the leg 3 and the steel pipe pile 1 is used, and the buoyancy acting on the flexible tube 11 expanded by filling with air is used. Thereby, the water stop of a water stop structure can further be raised.

  Since the water-stopping structure as described above allows the water to be completely discharged from between the leg 3 and the steel pipe pile 1 in the water, and the space between the leg 3 and the steel pipe pile 1 can be made dry, Water (seawater) is not mixed in the grout 15 injected between the leg 3 and the steel pipe pile 1, and the grout is not mixed with water (seawater). For this reason, in addition to eliminating quality deterioration due to material separation caused by construction in water (in the sea), seawater is not involved, so that it is possible to obtain a uniform quality grout and prevent deterioration of the grout quality.

  In addition, since a special admixture is used to give the grout non-separability in water, the material price increases. However, according to the present embodiment, such a special admixture is unnecessary and a normal grout material may be used. , Can prevent the cost of materials.

  Moreover, according to the grout injection method of this embodiment, since water can be completely discharged from between the leg 3 and the steel pipe pile 1 as a water stop state, the primary grout injection for the purpose of conventional water stop is unnecessary. In addition, it is not necessary to divide the grout injection operation as shown in FIG. 11D into a plurality of times, so that the construction period can be shortened.

  As described above, the modes for carrying out the present invention have been described. However, the present invention is not limited to these, and various modifications can be made within the scope of the technical idea of the present invention. For example, the lifting step S05 of the flexible tube 11 in FIG. 1 can be omitted when the integrated structure of the water stop lid 12 and the flexible tube 11 as shown in FIG. 4 is adopted. When the lid 12 is brought into contact with the lower end 16 of the leg 3, the flexible tube 11 is positioned in the vicinity of the lower surface 14 of the water blocking lid 12.

  The foundation pile fixing structure having the grout injection method and the water stop structure of the present invention is suitable for construction of a jacket-type pier constructed by inserting a leg of a jacket assembled by factory manufacture etc. into a foundation pile placed on the bottom of the water, for example. It is preferable to apply.

1 Steel pipe pile (foundation pile)
2 Jacket 3 Leg (Mounted part)
3a Drain / grout injection valve 11 Flexible tube 12 Water stop lid 12a Protruding portion 12b Holding member 13 Elastic member 14 Lower surface 15 of water stop lid 12 Grout 16 Lower end D of leg 3 G gap between steel pipe pile and leg 3 Ground S Water surface

Claims (6)

Attaching a flexible tube and a waterstop to the placed foundation pile;
The step of bringing the water stop lid into contact with the lower end of the mounted portion installed on the foundation pile, and positioning the flexible tube in the vicinity of the lower surface of the water stop lid;
The flexible tube is inflated by air filling and pressed against the foundation pile and the lower surface of the water-stopping lid, and between the lower end of the attachment portion and the water-stopping lid, and the foundation pile and the attachment portion. A process of making a water stop structure between
Discharging water between the mounted portion and the foundation pile;
And a step of injecting grout between the attachment portion and the foundation pile.   The grout injection construction method according to claim 1, wherein the grout injection step is performed by construction from underwater or construction from the land.   A pier construction method for constructing a jacket-type pier by the grout injection construction method according to claim 1, wherein the attached portion is a leg of a jacket inserted into the foundation pile. It is a foundation pile fixing structure for installing and fixing the mounted part to the foundation pile placed,
A flexible tube attached to the foundation pile;
A water stop lid attached to the foundation pile and in contact with the lower end of the attached portion,
The flexible tube located in the vicinity of the lower surface of the water stop lid is inflated by air filling and pressed against the foundation pile and the lower surface of the water stop lid so that the lower end of the attached portion and the water stop lid And fixing the attached portion to the foundation pile by injecting a grout between the attached portion and the foundation pile, and between the foundation pile and the attached portion. The foundation pile fixed structure characterized by.   The foundation pile fixing structure of Claim 4 further provided with the elastic member arrange | positioned between the lower end of the said to-be-attached part, and the said water stop lid.   The foundation pile fixing structure according to claim 4 or 5, wherein the flexible tube is integrated with the water stop lid so as to be positioned near the lower surface of the water stop lid.

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