JP2010095907A - Reinforcing structure and reinforcing method for existing foundation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing structure and a reinforcing method for an existing foundation by which an existing foundation, such as bridge leg, can be reinforced without damage. <P>SOLUTION: The reinforcing structure includes a first form 2 disposed at a location close to the existing foundation 1 to encircle the exterior of the existing foundation 1, a second form 3 disposed to encircle the exterior of the first form 2, and concrete 6 placed to fill a gap between the existing foundation 1 and the first form 2 and a gap between the first form 2 and the second form 3. The outer peripheral surface of the first form 2 and the inner peripheral surface of the second form 3 are provided with a plurality of projected studs 4 and 5, respectively. The first form 2 is composed of a steel plate with projections, while the second form 3 is of a plurality of steel pipe sheet piles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a reinforcing structure and a reinforcing method for an existing foundation, and can reinforce an existing foundation such as a pier without damaging it.

  In recent years, in order to improve the superstructure such as the widening of the bridge and to increase the strength of the existing bridge, it has been practiced to reinforce the existing foundation of the pier with a steel sheet pile around it.

  In this construction method, for example, as shown in FIGS. 7 (a) and 7 (b), a plurality of steel pipe sheet piles 11 are driven to the support layer so as to surround the outside of the existing foundation 10 of the pier, and the steel pipe sheet pile 11 and the existing foundation 10 is a method of reinforcing the existing foundation by filling the concrete 12 between the two.

  In this construction method, since it is necessary to have a structure in which the load acting on the existing foundation 10 is transmitted to the surrounding steel pipe sheet pile 11 in particular, the steel pipe sheet pile 11 driven around the existing foundation 10 and the outer periphery of the existing foundation 10 are respectively provided. A number of studs 13 made of reinforcing bars or the like are provided so as to integrate the existing foundation 10 and the surrounding steel pipe sheet pile 11 via concrete 12.

JP 2004-232436 A JP 2001-107319 A JP 2005-107319 A JP-A-2005-290869 JP-A-9-125317 JP 2001-214465 A

  However, in order to project studs on the outer periphery of the existing foundation, it is necessary to open a large number of holes for projecting studs on the surface of the existing foundation with a boring machine, etc., and the surface of the existing foundation is damaged. was there.

  In addition, studs need to be drilled in the surface of the existing foundation, filled with grout material in each hole, and then inserted and installed one by one in each hole, which requires a lot of labor and increases costs. There were problems such as.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a reinforcing structure and a reinforcing method for an existing foundation that can be reinforced without damaging an existing foundation such as a bridge.

  The reinforcing structure of the existing foundation according to claim 1 is installed so as to surround the outer side of the first mold frame and the first mold frame that is installed to surround the outer side of the existing foundation at a position close to the existing foundation. A second mold, and a filler filled between the existing foundation and the first mold and between the first mold and the second mold, and at least the first mold A plurality of protrusions are provided on the outer peripheral surface of the second mold and the inner peripheral surface of the second mold, respectively.

  In the present invention, when reinforcing an existing foundation such as a pier with a steel pipe sheet pile around the existing foundation and reinforcing the existing foundation, a protrusion for integrating the existing foundation and the additional foundation is added to the existing foundation. By projecting on the outer peripheral surface of the first formwork installed in the vicinity, it is possible to reinforce the existing foundation without damaging it.

  Examples of the protrusion include a protrusion of a steel plate with a protrusion having a plurality of protrusions on the surface of the steel plate, a shear connector such as a stud or a reinforcing bar retrofitted to the surface of the steel plate, and the like.

  According to the present invention, the plurality of projections are provided on the outer peripheral surface of the first mold frame installed at a position close to the existing foundation, so that a shear connector such as a stud is not provided on the existing foundation. The integration of the existing foundation and the filler filled in the outer peripheral portion thereof can be achieved.

  In addition, since it is not necessary to project a shear connector such as a stud on the existing foundation, it is possible to save labor, shorten the construction period, and further reduce costs.

  Further, by using a steel plate with protrusions for the first mold, it is not necessary to project studs later on the outer peripheral surface of the first mold, and the construction period can be shortened.

  In addition, if the first mold is made of a steel plate with protrusions having a plurality of protrusions on the inner peripheral surface, and a plurality of studs protrude from the outer peripheral surface, the first mold is reliably integrated with the existing foundation. Further, the expansion foundation on the outer periphery can be reinforced economically and rationally by appropriately adjusting the number and interval of studs according to the scale of the foundation.

  The distance between the existing foundation and the first mold can be determined in consideration of the design load acting on the foundation, the fluidity and workability of the filler filled in this part, About 100 cm is preferable.

  In this case, the filler may be concrete, but by using an adhesive, the existing foundation and the first formwork can be reliably secured by filling the adhesive particularly between the existing foundation and the first formwork. It can be firmly integrated.

  In addition, the second formwork can be configured by driving a plurality of steel pipe sheet piles outside the position where the first formwork is installed. You can also

  The reinforcement structure of the existing foundation according to claim 2 is the reinforcement structure of the existing foundation according to claim 1, wherein the first mold is a steel plate with a protrusion having a plurality of protrusions on the surface, and the surface having the protrusion is an inner periphery. It is configured by connecting a plurality of surfaces so as to form a surface.

  According to the present invention, the first mold is reliably integrated with the existing foundation by configuring the first mold with the steel plate with protrusions having a plurality of protrusions on the inner periphery thereof, that is, on the side facing the existing foundation. This can ensure the integration of the existing foundation and the extension foundation.

  The reinforcing structure for an existing foundation according to claim 3 is the reinforcing structure for an existing foundation according to claim 1 or 2, wherein a plurality of studs are projected as protrusions on the outer peripheral surface of the first mold. Is.

  According to the present invention, an existing foundation can be reinforced to a required strength by appropriately determining the number and interval of studs on site according to the scale and strength of the existing foundation, so that economical and rational construction can be achieved. In addition to stud bolts, reinforcing bars can be used as studs in this case.

  The reinforcement structure of the existing foundation according to claim 4 is the reinforcement structure of the existing foundation according to claim 1, wherein the first mold is configured by connecting a plurality of steel plates with double-sided protrusions having a plurality of protrusions on both sides. It is characterized by.

  According to the present invention, the first mold is composed of a steel plate with double-sided projections having projections on both opposing surfaces of the existing foundation and the second mold frame, so that a stud or the like is projected from the first mold. No work is required, and construction can be greatly shortened and labor can be saved.

  The reinforcement structure of the existing foundation according to claim 5 is the reinforcement structure of the existing foundation according to any one of claims 1 to 4, wherein a plurality of studs are projected from the inner peripheral surface of the second formwork. It is characterized by.

  The reinforcement structure for an existing foundation according to claim 6 is the reinforcement structure for an existing foundation according to any one of claims 1 to 5, wherein the second form is composed of a plurality of steel pipe sheet piles. To do. According to the present invention, by installing a steel pipe sheet pile foundation around the first formwork, the existing foundation can be reinforced strongly by the strength of the steel pipe sheet pile foundation.

  The method for reinforcing an existing foundation according to claim 7 includes a step of installing a first formwork at a position close to the existing foundation and a step of installing a second formwork outside a position at which the first formwork is installed. And a step of filling a filler between the existing foundation and the first mold and between the first mold and the second mold, and the first mold has a plurality of surfaces on the surface. The steel plate with protrusions having the protrusions is installed so that the surface having the protrusions forms an outer peripheral surface and surrounds the outside of the existing foundation, and the second formwork is provided with the first formwork. And a plurality of studs projecting from the inner peripheral surface of the second mold frame.

  Concrete is generally used as the filler in this case, but it is also possible to integrate the existing foundation and the first mold more firmly and firmly by filling an adhesive between the existing foundation and the first mold. it can.

  In addition, the construction procedure of the first mold and the second mold is to be performed first in the case of underwater construction such as in a river, followed by the second mold. However, in the case of land construction, either may be performed first.

  The method for reinforcing an existing foundation according to claim 8 includes a step of installing a first formwork at a position close to the existing foundation and a step of installing a second formwork outside the position at which the first formwork is installed. And a step of projecting a plurality of studs on the outer peripheral surface of the first mold, and between the existing foundation and the first mold and between the first mold and the second mold, respectively. The first mold is formed by installing a steel plate so as to surround the outside of the existing foundation, and the second mold is a position where the first mold is installed. It is constituted by installing a plurality of steel pipe sheet piles outside, and a plurality of studs project from the inner peripheral surface of the second mold.

  According to the present invention, it is possible to reinforce the existing foundation to the required strength by appropriately determining the number of studs and the distance at the site according to the scale and strength of the existing foundation, so that economical and rational reinforcement is possible. It is. Also, concrete is generally used as the filler in this case, and an adhesive may be filled between the existing foundation and the first mold frame.

  In addition, the construction procedure of the first mold and the second mold will be the first mold, followed by the second mold in the case of underwater construction such as in a river. However, in the case of land construction, either may be performed first.

  The present invention provides a first mold frame installed so as to surround the outside of the existing foundation at a position close to the existing foundation, a second mold frame installed so as to surround the outside of the first mold frame, and the existing mold It is composed of a filler filled between the foundation and the first mold and between the first mold and the second mold, and at least the outer peripheral surface of the first mold and the second mold By providing a plurality of protrusions on the inner peripheral surface of the frame, the existing foundation and the filler (extended part) filled on the outside can be integrated, and the existing foundation can be reinforced without damaging it. There are effects such as being able to.

  Moreover, since there is no hole for projecting studs on the existing foundation, labor saving of construction, shortening of construction period, and cost reduction can be achieved.

  Furthermore, by configuring the first mold with a steel plate with protrusions having a plurality of protrusions on the surface, there is no need to project a shear connector such as a stud on the first mold afterwards, saving labor and shortening the construction period. Shortening and cost reduction can be achieved.

  1A to 1C show an embodiment of the present invention. In the figure, reference numeral 1 denotes an existing foundation of a pier constructed on the bottom of a river or the like, and 2 denotes a surrounding of the existing foundation 1 A first mold 3 installed around the existing foundation 1 is a second mold installed around the existing foundation 1 and the first mold 2 so as to surround the existing foundation 1 and the first mold 2. .

  Reference numerals 4 and 5 are studs projecting from the outer peripheral surface of the first mold 2 and the inner peripheral surface of the second mold 3, respectively, and reference numeral 6 is between the existing foundation 1 and the first mold 2. The concrete is filled between the first mold 2 and the second mold 3.

  The first mold 2 is composed of a steel plate with protrusions having a plurality of protrusions 2a on one side, and the steel plate with protrusions is about 10 to 100 cm away from the outer surface of the existing foundation 1 with the protrusion surface facing the existing foundation 1 side. It is installed so as to surround the existing foundation 1 at a certain position.

  Further, the steel plates with protrusions are formed with a certain width in the circumferential direction of the existing foundation 1 so as to be easily handled by heavy construction equipment, are installed adjacent to each other in the circumferential direction of the existing foundation 1, and have adjacent protrusions. The steel plates are joined together by welding or a joint (not shown) formed at the end of each steel plate.

  Further, a stud 4 made of a reinforcing bar or the like is provided on the outer peripheral surface 2 b of the first mold 2 so as to protrude over the entire surface of the first mold 2. As a general rule, the studs 4 having the same diameter and the same length are protruded at equal intervals as a whole, but are appropriately adjusted according to the design load together with the height of the first mold 2.

  The second mold 3 is installed at a position away from the first mold 2 by a predetermined distance so as to surround the existing foundation 1 and the first mold 2. Further, the distance between the first mold 2 and the second mold 3 is set based on the design load in the same manner as the number of the studs 4 and 5, and about 3 to 5 m is often appropriate in practice. Though possible, this may be exceeded depending on conditions.

  On the outside of each steel pipe sheet pile of the second mold 3, a pair of joints protrudes in the diametrical direction, and adjacent steel pipe sheet piles are coupled to each other through this joint.

  Further, a stud 5 made of a reinforcing bar or the like is provided on the inner periphery of the second mold 3 so as to protrude over the entire surface. In principle, the studs 5 having the same diameter and length are projected at equal intervals as a whole, but may be appropriately adjusted according to the design load.

  The concrete 6 is filled between the existing foundation 1 and the first mold 2 and between the first mold 2 and the second mold 3, respectively. With such a configuration, the existing foundation 1, the first mold 2 are filled. The frame 2 and the second mold 3 are integrated, and a new foundation for the pier is constructed. The concrete 6 is also filled in each steel pipe sheet pile of the second mold 3.

  Next, a construction method will be described.

(1) First, a plurality of steel pipe sheet piles are driven outside the position where the first formwork 2 is installed so as to surround the existing foundation 1 to form the second formwork 3. Each steel pipe sheet pile of the second mold 3 is driven in until the tip reaches the support layer, the adjacent steel pipe sheet piles 3 are connected to each other through a joint, and the joint is filled with mortar and the like to stop water. Moreover, the upper end of each steel pipe sheet pile of the 2nd formwork 3 is made to protrude on a water surface, and the part to the part which protrudes on a water surface from a river bottom is utilized as the water stop wall 7. FIG.

(2) Next, the inside of the water blocking wall 7 is drained, and the ground between the existing foundation 1 and the second mold 3 is dug down to at least the bottom of the existing foundation 1.

(3) Next, a steel plate with protrusions is installed around the existing foundation 1 so as to surround the existing foundation 1 to constitute the first mold 2. The steel plate with protrusions is installed with the surface with protrusions facing the existing foundation 1 side and vertically standing at a position about 10 to 100 cm away from the outer surface of the existing foundation 1. In addition, the steel plates with protrusions are formed with a certain width in the circumferential direction of the existing foundation 1 so as to be adjacent to each other in the circumferential direction of the existing foundation 1, and the adjacent steel plates are welded or formed at the end of each steel plate. They are connected through a joint (not shown).

(4) Next, studs 4 and 5 made of reinforcing bars or the like are provided on the outer peripheral surface of the first mold 2 and the inner peripheral surface of the second mold 3, respectively. The stud 4 protrudes over the entire surface of the first mold 2, and the stud 5 protrudes over the entire surface of the second mold 3. The studs 4 and 5 are projected by welding.

(5) Next, concrete 6 is filled between the existing foundation 1 and the first mold 2 and between the first mold 2 and the second mold 3. The concrete 6 is also filled in each steel pipe sheet pile of the second mold 3.

(6) When the concrete 6 reaches a certain strength, the portion that is the water blocking wall 7 of the second mold 3 is cut from the river bottom and removed. This completes the construction.

  The present invention can reinforce an existing foundation such as a strong leg by using a steel pipe sheet pile.

The existing foundation of the reinforced pier is shown, (a) is a longitudinal sectional view, (b) is a transverse sectional view, and (c) is a partially enlarged view of (a). It is a longitudinal cross-sectional view which shows the construction procedure of the reinforcement method of the existing foundation of a pier. It is a longitudinal cross-sectional view which shows the construction procedure of the reinforcement method of the existing foundation of a pier. It is a longitudinal cross-sectional view which shows the construction procedure of the reinforcement method of the existing foundation of a pier. It is a longitudinal cross-sectional view which shows the construction procedure of the reinforcement method of the existing foundation of a pier. The construction procedure of the reinforcement method of the existing foundation of the pier is shown, (a) is a longitudinal sectional view and (b) is a transverse sectional view. The conventional example of the existing foundation of the reinforced pier is shown, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Existing foundation of pier 2 1st formwork 2a Protrusion 3 Second formwork 4 Stud 5 Stud 6 Concrete (filler)
7 Water barrier

Claims (8)

  A first mold frame installed to surround the outside of the existing foundation at a position close to the existing foundation; a second mold frame installed to surround the outside of the first mold frame; and And a filler filled between the first mold and between the first mold and the second mold, and at least the outer periphery of the first mold and the inner periphery of the second mold A reinforcing structure for an existing foundation, wherein a plurality of protrusions are provided on the surface.   The first mold frame is configured by connecting a plurality of steel plates with protrusions having a plurality of protrusions on the surface so that a surface having the protrusions becomes an inner peripheral surface. Reinforcement structure of existing foundation.   The reinforcing structure for an existing foundation according to claim 1 or 2, wherein a plurality of studs are projected as protrusions on the outer peripheral surface of the first mold.   The reinforcing structure for an existing foundation according to claim 1, wherein the first mold is configured by connecting a plurality of steel plates with double-sided protrusions having a plurality of protrusions on both sides.   The reinforcing structure for an existing foundation according to any one of claims 1 to 4, wherein a plurality of studs are protruded from the inner peripheral surface of the second formwork.   The reinforcing structure for an existing foundation according to any one of claims 1 to 5, wherein the second mold is composed of a plurality of steel pipe sheet piles.   A step of installing the first mold at a position close to the existing foundation, a step of installing a second mold outside the position where the first mold is installed, the existing foundation and the first mold And a step of filling a filler between the first mold and the second mold, respectively, and the first mold has a protruding steel plate having a plurality of protrusions on the surface. The surface having the outer peripheral surface is configured to be installed so as to surround the outside of the existing foundation, and the second mold is provided with a plurality of steel pipe sheet piles outside the position where the first mold is installed. A method for reinforcing an existing foundation, characterized in that a plurality of studs project from the inner peripheral surface of the second mold.   A step of installing the first mold at a position close to the existing foundation, a step of installing the second mold outside the position where the first mold is installed, and a plurality of outer peripheral surfaces of the first mold And a step of filling a filler between the existing foundation and the first mold frame and between the first mold frame and the second mold frame, respectively. One mold is configured by installing a steel plate so as to surround the outside of the existing foundation, and the second mold is configured by installing a plurality of steel pipe sheet piles outside the position where the first mold is installed. A method for reinforcing an existing foundation, comprising: forming and projecting a plurality of studs on an inner peripheral surface of the second formwork.

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