JP2020051046A - Installation method of cofferdam structure used for bridge footing repairing and strengthening work - Google Patents

Abstract

To provide an installation method of a cofferdam structure used for bridge footing repair and strengthening work allowing the cofferdam structure to be stably lowered into water even at a site in a strong stream.SOLUTION: An installation method of a cofferdam structure at a site where two bridge foots 1, 2 are installed adjacent to each other comprises the step of: constructing the cofferdam structure 3 on the bridge footing 1 to be repaired; installing guides 4 for lowering into water on the bridge footing 1 and the cofferdam structure 3 as well as installing auxiliary guides 5 on the bridge footing 2 not to be repaired and the cofferdam structure 3; lowering the cofferdam structure 3 into water below a bridge for the bridge footing 1 to be repaired using a lowering guide function of both of the auxiliary guide 5 and the guide 4 for lowering into water; using water cut-off means to cut off water in a gap between a bottom part of the cofferdam structure 3 and the bridge footing 1 to be repaired; and discharging the water entered into the cofferdam structure 3 after completion of cutting off the water.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of installing a temporary closing structure used for repairing and reinforcing bridge piers provided in water bodies such as rivers and the sea.

  Bridges built over rivers and seas will be repaired and reinforced if the piers are damaged due to aging or earthquakes.

  More specifically, a tubular temporary closing structure is constructed around the pier and lowered into the water, and water is stopped so that water does not enter the temporary closing structure to secure a work space (dry area). (For example, see Patent Document 1).

  In the method of lowering the temporary closing structure into water, a guide for lowering is installed on the pier and the temporary closing structure, and the temporary lowering structure is lowered via the lowering guide. As this descent guide, a descent rail having a length in the vertical direction is installed on the outer periphery of the pier, and an arm protruding from the temporary closing structure is connected to the descent rail so as to be able to move down. The temporary closing structure is configured to move down along the lowering rail.

Japanese Patent No. 6273328

  In pier repair / reinforcement work where water flow is strong, a large temporary closing structure receives a large amount of water flow (water pressure) when falling into the water, so even if a guide for descent is installed, it will be lowered stably It can be difficult.

  In this regard, the present invention provides a method of installing a temporary closing structure used for pier repair / reinforcement work capable of stably dropping the temporary closing structure underwater even at a site where the water flow is strong. is there.

  The gist of the present invention will be described with reference to the accompanying drawings.

  A non-submerged part of one of the two piers 1.2, which is to be constructed at a site where the two piers 1.2 are provided adjacent to each other and which is to be repaired and reinforced by one of the two piers 1.2 Then, a temporary closing structure 3 to be installed to surround the outer periphery of the pier 1 to be constructed is constructed, and a guide 4 for underwater descent is installed on the pier 1 and the temporary closing structure 3 to be constructed. An auxiliary guide 5 is installed on the other non-construction pier 2 adjacent to the pier 1 and the temporary closing structure 3, and the auxiliary guide 5 is provided with a descending auxiliary rail 6 provided on the non-construction pier 2; The temporary closing structure 3 includes a connecting arm 7 protruding toward the non-construction pier 2 and being connected to the lowering auxiliary rail 6 so as to be able to move down. The auxiliary guide 5 and the submersible lowering guide 4 are connected to each other. Using both descent guide functions The temporary closing structure 3 is lowered into the water under the bridge with respect to the pier 1 to be constructed, and the gap between the bottom of the temporary closing structure 3 and the pier 1 to be constructed is stopped by water stopping means. A method of installing a temporary cutoff structure used for pier repair / reinforcement work, characterized by draining water that has entered the temporary cutoff structure 3 after completion and making the temporary cutoff structure 3 a dry area for work. It is related to.

  In addition, it is to be constructed at a site where two piers 1.2 are provided adjacent to each other on the upstream side and the downstream side of the water area, and repair / reinforcement work of the two piers 1.2 is performed. The underwater descent guide 4 is installed on the downstream pier 1 and the temporary closing structure 3 on the downstream side, and the pier 2 and the temporary closing structure 3 on the upstream side adjacent to the pier 1 to be constructed. The method according to claim 1, wherein the auxiliary guide (5) is installed at the same time.

  In addition, the auxiliary guide 5 projects from the pair of lowering auxiliary rails 6 provided on opposite side surfaces of the construction target pier 1 and the temporary closing structure 3 toward the construction outside pier 2 from two places. The pair of connecting arms (7) each having a sliding member (8) that is connected to the lower auxiliary rail (6) so as to be slidable and descent movable at a protruding tip end. The method relates to a method of installing a temporary closing structure used for pier repair / reinforcement work described in (1).

  Since the present invention is configured as described above, the temporary closing structure receiving the water flow (running water pressure) when descending into water, a normal underwater descent guide installed on the pier and the temporary closing structure to be constructed, Apart from this, it can be moved down while supporting it with the auxiliary guide installed on the pier and temporary closing structure outside the construction target, and even at the site where the water flow is strong, the temporary closing structure can be established via these two descending guide functions This is an extremely practical method of installing a temporary closing structure used for pier repair / reinforcement work that can stably lower the body into the water.

  Further, in the invention according to claim 2, the temporary closing structure receiving the water flow on the downstream side is provided with a normal underwater descent guide installed on the pier and the temporary closing structure to be constructed on the downstream side, and separately from this. An extremely practical bridge pier repair / reinforcement construction that can be stably lowered into the water while being effectively supported by the non-construction pier on the upstream side and the auxiliary guide installed on the temporary closing structure The installation method of the deadline structure will be used.

  Further, in the invention according to the third aspect, there is provided a method of installing a temporary shut-off structure which is more practical and makes it possible to easily design and realize an auxiliary guide which reliably exerts the above-mentioned functions and effects with a simple configuration.

It is an outline explanatory side view showing the state where the temporary shutoff structure of the present example was lowered into the water via the underwater lowering guide and the auxiliary guide. FIG. 2 is an explanatory plan view of FIG. 1. FIG. 2 is an explanatory partial enlarged plan view showing an auxiliary guide (a connecting structure of a lowering auxiliary rail and a connecting arm) of the present embodiment.

  Preferred embodiments of the present invention will be briefly described with reference to the drawings, showing the operation of the present invention.

  One of the two piers 1 and 2 provided adjacent to each other, which is to be repaired or reinforced. The cutoff structure 3 is constructed.

  Next, an underwater descent guide 4 is installed on the pier 1 to be constructed and the temporary cutoff structure 3, and the other non-construction pier 2 adjacent to the pier 1 to be constructed and the temporary cutoff structure 3 A lowering auxiliary rail 6 provided on the non-target pier 2 and a connecting arm 7 protruding toward the non-target pier 2 from the temporary closing structure 3 and connected to the lowering auxiliary rail 6 so as to be able to move down. An auxiliary guide 5 is installed, and the temporary closing structure 3 is lowered into the water under the bridge with respect to the bridge pier 1 using the lowering guide function of both the auxiliary guide 5 and the underwater lowering guide 4.

  That is, a normal underwater descent guide 4 installed on the pier 1 to be constructed and the temporary closing structure 3 and an auxiliary guide 5 separately installed on the non-construction pier 2 and the temporary closing structure 3. Since the two guides lower the temporary cutoff structure 3 while supporting it, the temporary cutoff structure 3 can be stably lowered into the water by the two descent guide functions even at a site where the water flow is strong.

  Next, the gap between the bottom of the temporary closing structure 3 and the pier 1 to be worked is stopped by a water stopping means, and after the water stopping is completed, the water that has entered the temporary closing structure 3 is drained. The inside of the deadline structure 3 is used as a work dry area, and a worker can repair and reinforce the pier 1 to be worked in the work dry area.

  A specific embodiment of the present invention will be described with reference to the drawings.

  The present embodiment is applied to a method of installing a temporary closing structure used for repair and reinforcement work of a pier constructed on a pier of a bridge bridged over a river (water body). The present invention can be applied (constructed) to a pier of a bridge spanned in a water area other than a river.

  The arrow Y in FIG. 2 indicates the direction of the river water flow. In the drawing, two piers 1.2 are installed adjacent to each other on the upstream side and the downstream side of the river, and one of the two piers 1.2 (downstream side) is repaired and reinforced. And the other (upstream side) pier 2 is a non-construction pier 2 that does not perform repair / reinforcement work.

  In addition, the drawings illustrate the piers 1 and 2 having an elliptical cross section having a length along the water flow, but the method is not limited to the method of installing the piers on the piers of this shape, and the shape of the piers at the site is not limited. Accordingly, the design and the like of the temporary closing structure 3 can be appropriately changed in design.

  Hereinafter, the installation procedure will be described.

  First, a work scaffold (not shown) is installed at a position (non-submerged portion) above the water surface of the pier 1 to be constructed. A floating body (floating pier) may be installed (floated) on the water surface around the pier 1 to be constructed, and this floating body may be used as a work scaffold.

  Next, using this work scaffold, a tubular temporary closing structure 3 is provided so as to surround the outer periphery of the pier 1 to be constructed, and is provided with a through portion 9 at the center portion through which the pier 1 can be disposed. To build.

  Specifically, the temporary closing structure 3 has a cylindrical shape in which a plurality of divided wall members 10 are combined and connected in the circumferential direction and the height direction of the pier 1 to be constructed.

  Next, for example, a balance 11 for balancing is installed above the pier 1 to be constructed, and the descent ropes 12 provided at several places of the balance 11 for balancing are connected to the temporary closing structure 3.

  Specifically, the balance 11 for balance maintenance is formed of a frame, and several places thereof are connected to suspension ropes 13 fixed to several places at the wide upper portion of the pier 1 to be constructed. Is installed horizontally above the pier 1 to be constructed while penetrating the pier 1 to be constructed in the space portion, and furthermore, several places of the balance 11 for balancing and the pier corresponding thereto are provided. By equipping and stretching a pipe support (not shown) between several outer peripheral surfaces of the balance 1 and the balance 11, the balance holding balance 11 is installed so as not to swing with respect to the pier 1 to be constructed.

  Each of the descending ropes 12 is configured to be able to be moved up and down by an elevating device (not shown) such as a chain block, and the temporary closing structure 3 can be moved down with respect to the balance 11 for balance by controlling the elevating device. At this time, the balance 11 for balance is connected to the balance 11 via the descent cable 12 and is fixed in a horizontal state in which it cannot swing, so that the temporary closing structure 3 is hardly inclined. It is configured to be able to descend while being kept in an equilibrium state.

  Next, an underwater descent guide 4 is installed on the pier 1 to be constructed and the temporary closing structure 3.

  Specifically, the underwater descent guide 4 includes a descent rail 14 having a length in the up-down direction, which is installed on the opposite side surface of the pier 1 to be subjected to the construction, and A sliding support arm 15 having a sliding member 16 protruding inward toward the pier 1 and having a protruding tip fitted to the descending rail 14 and slidable.

  More specifically, the descent rail 14 is made of a long metal material (a grooved steel material) having a groove shape (a U-shaped cross section), and the bottom of the groove is formed along the outer peripheral surface of the pier 1 to be constructed. It is fixed vertically to the pier 1 to be constructed.

  The lowering rails 14 are fixed to two flat sides facing each other in parallel with the direction of water flow of the pier 1 to be constructed, and each of the lowering rails 14 is provided with a curved opposed side orthogonal to the direction of water flow of the pier 1 to be constructed. It is also fixed to one side on each side. That is, the descent rails 14 are fixed to a total of six locations on the outer peripheral surface of the pier 1 to be constructed (see FIG. 2).

  On the other hand, although not shown in detail, the sliding support arm 15 is made of a long metal material having an H-shaped cross section, and a roller 16 employed as a sliding member 16 is attached to the tip of the sliding support arm 15. Note that the sliding member 16 is not limited to the roller 16 of the present embodiment, and the design can be changed as appropriate.

  The sliding support arm 15 is constructed so as to horizontally project inward from two opposing two directions corresponding to the lowering rail 14 on the inner peripheral surface of the temporary closing structure 3. The sliding members 16 at the tips of the six sliding support arms 15 are slidably fitted (coupled) to the six descending rails 14 fixed to the pier 1 to be constructed (see FIG. 2). .

  Although not shown in detail, the six slide support arms 15 are provided in two stages in the temporary closing structure 3.

  Therefore, the temporary closing structure 3 can be smoothly lowered and moved with respect to the pier 1 to be constructed by sliding the six (six) descent rails 14 with the twelve sliding members 16 in total. It is configured so that

  In the figure, reference numeral 17 denotes a reinforcing frame which reinforces the horizontal protruding state of the sliding support arm 15 and also contributes to improving the shape retaining strength of the temporary closing structure 3.

  Next, an auxiliary guide 5 is installed on the other non-construction target pier 2 adjacent to the construction target pier 1 and the temporary closing structure 3.

  More specifically, the auxiliary guide 5 includes a pair of vertical auxiliary rails 6 having a length in the vertical direction installed on the side opposite to the pier 2 and a temporary closing structure 3. A pair of connecting arms 7 projecting toward the pier 2 and having projecting tips connected to the pair of descending auxiliary rails 6 so as to be movable downward.

  More specifically, the pair of lowering auxiliary rails 6 are fixed to the flat opposite sides parallel to the water flow direction of the non-construction pier 2 in a vertically installed state.

  As shown in FIGS. 2 and 3, each of the pair of descending auxiliary rails 6 includes a first rail 6 </ b> A fixed to the upstream side of the non-construction pier 2 and a downstream side of the non-construction pier 2. The first rail 6A and the second rail 6B are fixed vertically so that they are in a parallel relationship with each other.

  The first rail 6 </ b> A is made of a long metal plate, and is located on the upstream side of the flat opposed side surface of the non-construction pier 2 via the first fixing member 19 and outward from the flat opposed side surface. The first rail 6A is fixed in a separated state, and is disposed and fixed such that the plate surface of the first rail 6A is parallel to the flat opposed side surface of the non-construction pier 2 (see FIG. 3).

  The second rail 6 </ b> B is formed of a long metal material (a grooved steel material) having a groove shape (a U-shape) in cross section, and is located downstream of the flat opposed side surface of the non-construction pier 2 via the second fixing member 20. The second rail 6B is fixed so that the open portion of the second rail 6B faces the upstream side (the first rail 6A side). (See FIG. 3).

  On the other hand, although not shown in detail, the connecting arm 7 is formed of a long metal material having an H-shaped cross section, and a pair of the connecting arms 7 is a side surface of the temporary closing structure 3 on the side of the pier 2 outside the construction target. From the two parts of the part to be parallel to the non-construction pier 2, and the distal ends of the respective connecting arms 7 are in an installed state spaced apart from each of the flat opposed side surfaces of the non-construction pier 2. It is arranged. In the figure, reference numeral 21 denotes a reinforcing bar provided between the pair of connecting arms 7.

  Further, a roller 8 employed as a sliding member 8 that slides on the descending auxiliary rail 6 is attached to the tip of each connecting arm 7. Note that the sliding member 8 is not limited to the roller 8 of the present embodiment, and the design can be changed as appropriate.

  More specifically, a base portion 18 is provided inside the distal end of each connecting arm 7 opposite to the distal end thereof, and the roller 8 is provided at the distal end (upstream end) and the proximal end (downstream end) of the base 18. (8A, 8B) are attached.

  The roller 8A at the distal end is provided such that the axial direction of the rotation axis is parallel to the water flow direction, and the roller 8B at the proximal end is such that the axial direction of the rotation axis is orthogonal to the water flow direction. It is provided so that it may become a direction.

  Further, the roller 8A at the tip is disposed so as to slidably abut on the inner plate surface of the first rail 6A fixed on the upstream side of the flat opposed side surface of the non-construction pier 2. By disposing the base roller 8B so as to slidably contact the groove bottom of the second rail 6B fixed to the downstream side of the flat opposed side surface of the non-construction pier 2, A connecting arm 7 is slidably connected to the descending auxiliary rail 6.

  That is, the temporary closing structure 3 is supported by the roller 8A and the first rail 6A so as to prevent swinging of the temporary closing structure 3 in a direction orthogonal to the water flow, and the temporary closing structure 3 receives the water flow by the roller 8B and the second rail 6B. The auxiliary guide 5 is employed, which supports the load of the cutoff structure 3 and prevents the temporary cutoff structure 3 from swaying in the water flow direction, thereby enabling the temporary cutoff structure 3 to move down stably.

  Further, as shown in FIG. 1, the pair of connecting arms 7 project upward and downward from the temporary closing structure 3 in two stages.

  Therefore, the total of eight sliding members 8 slide on the lowering auxiliary rail 6, so that the temporary closing structure 3 can smoothly move down to the non-construction pier 2 via the connecting arm 7 while maintaining the posture. Therefore, the normal underwater descent guide 4 installed on the pier 1 to be constructed and the temporary cutoff structure 3, and the auxiliary guide 5 separately installed on the pier 2 not to be constructed and the temporary cutoff structure 3 Since the two guides are lowered while supporting the temporary cutoff structure 3, the two descent guide functions allow the temporary cutoff structure 3 to be stably lowered into the water even at a site where the water flow is strong. It is configured to be able to.

  Reference numeral 22 in the figure denotes a position adjusting mechanism for adjusting the position between the rollers 8A and 8B according to the fixed interval between the first rail 6A and the second rail 6B.

  The submersible descent guide 4 may be installed after the auxiliary guide 5 is installed.

  Next, the gap between the bottom of the temporary closing structure 3 and the pier 1 to be worked is stopped by a suitable water stopping means (not shown), and water that has entered the temporary closing structure 3 after the completion of water stopping. After draining, the inside of the temporary closing structure 3 becomes a work dry area, and the construction is completed.

  Note that the present invention is not limited to the present embodiment, and a specific configuration of each component can be appropriately designed.

DESCRIPTION OF REFERENCE NUMERALS 1 Construction target pier 2 Non-construction pier 3 Temporary closing structure 4 Underwater descent guide 5 Auxiliary guide 6 Descent auxiliary rail 7 Connecting arm 8 Sliding member

Claims (3)

  The pier is to be constructed at the site where two piers are located adjacent to each other. A temporary deadline structure to be installed to surround the outer circumference is constructed, a guide for underwater descent is installed on the pier and the temporary deadline structure, and the other non-target pier adjacent to the target pier and the An auxiliary guide is installed on the temporary closing structure, and the auxiliary guide includes a lowering auxiliary rail provided on the non-construction pier, and a lowering auxiliary rail protruding from the temporary closing structure toward the non-construction pier. And a connecting arm movably connected to the underwater descent guide. The gap between the bottom of the temporary closing structure and the pier to be constructed is stopped by a water stopping means, and water that has entered the temporary closing structure after the completion of the water stopping is drained, and the temporary closing structure is lowered. A method of installing a temporary closing structure used for pier repair / reinforcement work, wherein the inside of the body is a dry area for work.   It is to be constructed at the site where two piers are provided adjacently on the upstream side and the downstream side of the water area, and the construction target pier on the downstream side performing repair / reinforcement work of the two piers and The underwater descent guide is installed on the temporary closing structure, and the auxiliary guide is installed on the upstream non-construction pier and the temporary closing structure adjacent to the pier to be constructed. Item 1. A method for installing a temporary closing structure used for pier repair / reinforcement work according to item 1.   The auxiliary guide includes a pair of lowering auxiliary rails provided on opposing side surfaces of the construction target pier, and a pair of the lowering auxiliary rails protruding from two locations of the temporary closing structure toward the non-construction pier and projecting to the projecting tip. The pier repairing / reinforcing work according to any one of claims 1 and 2, comprising a pair of the connecting arms having a sliding member that is slidably connected to a rail so as to be slidable. Installation method of temporary closing structure.

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