JP2012001927A - Watertight hardware for underwater cofferdam installation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate harmful influence on a position adjustment bolt when fixing a door stop.SOLUTION: The present invention relates to a hardware 4 which faces a reservoir side concrete surface 1a of a dam weir body 1, where an underwater cofferdam installation 2 is installed to ensure a working space for the concrete surface 1a, and keeps an injection space 4a watertight for injecting load transmitting mortar 7 for transferring a water pressure load received from a support surface from the underwater cofferdam installation 2 to the concrete surface 1a. The hardware has, in an order from the concrete surface 1a, water swelling rubbers 6b and non-swelling rubbers 6a on both internal sides. The hardware also has a stretchable tubes 9 positioned next to the non-swelling rubbers 6a on an opposite side of the water swelling rubbers 6b. An injection device 10 is provided to inject pressurized water into the tubes 9. With these configurations, the invention has an effect of evenly applying pressure due to swelling of the tubes by the pressurized water injected therein to the water swelling rubbers through the non-swelling rubbers, thereby preventing increase of the repelling force of the water swelling rubbers and fluctuation thereof, and evenly transferring the repelling force of the water swelling rubbers to position adjustment bolts.

Description

  The present invention relates to a watertight metal fitting provided at a door of a caisson leg in an underwater temporary cutoff facility to be attached to a reservoir side of a dam weir body so as to separate the dam weir body and a reservoir when improving a dam facility, for example. It is.

  Conventionally, in the case of improvement work for a dam facility, prior to the construction, as shown in FIG. 4, the underwater temporary cutoff facility 2 is temporarily attached to the reservoir-side concrete surface 1 a of the dam weir body 1. The construction part and the reservoir 3 are separated (for example, paragraphs 0002 to 0006 and FIGS. 7 to 10 of Patent Document 1).

  The underwater provisional cutoff facility 2 has a structure in which a watertight hardware 4 is provided on a door-to-door 2b installed on a leg portion of a caisson 2a which is a box-shaped structure. The watertight hardware 4 is disposed relative to the concrete surface 1a of the dam weir body 1, the bearing surface receives a hydraulic load from the underwater temporary cutoff facility 2, and is transmitted to the concrete surface 1a through a load transmitting mortar. (Patent Document 1, paragraph 0008).

  At that time, non-swollen rubber 6a and water-swollen rubber 6b are arranged on both sides of the watertight hardware 4 with the allowance adjustment pillow 5 facing the concrete surface 1a, and both sides of the watertight hardware 4 follow the concrete surface 1a. Thus, the injection space 4a is water-tight (see FIG. 5) to prevent outflow when the load transmitting mortar 7 is injected into the injection space 4a (paragraph 0008 of Patent Document 1).

  However, in the above-mentioned watertight hardware, when the water-swelling rubber expands unexpectedly and the repulsive force of the water-swelling rubber increases, the door contact is made via a fixing member (11 in FIG. 5) attached to the outside of the watertight hardware. The load applied by the position adjustment bolt (8 in FIG. 5) for adjusting the position of is increased.

  Due to this increase, if the actual burden load exceeds the assumed burden load, there is a risk of adversely affecting the tightening and fixing of the position adjusting bolt determined by selecting the material and strength based on the assumed burden load.

  In addition, the burden load of the bolt for position adjustment means the value calculated | required by (the repulsive force of water swelling rubber + the load of the watertight mortar which acts on a concrete surface) / number of bolts. Of these, the repulsive force of the water-swelling rubber is the value obtained by multiplying the contact pressure of the water-swelling rubber by the area where all the water-swelling rubber contacts the concrete surface, and the load of the water-tight mortar acting on the concrete surface is This is a value obtained by multiplying the casting pressure by the area where all watertight mortar contacts the concrete surface.

Japanese Patent No. 3455081

  The problem to be solved by the present invention is that the conventional watertight hardware provided at the door of the underwater temporary shut-off equipment has a door contact when the distance between the water swelling rubber and the concrete surface is smaller than expected and the repulsive force increases. The load of the position adjusting bolt is increased, which may adversely affect the fastening.

The watertight hardware of the underwater temporary cutoff facility of the present invention is
In order not to adversely affect the tightening and fixing of the position adjustment bolts per door,
The underwater temporary cutoff facility that secures work space on the concrete surface of the reservoir of the dam weir body is installed opposite to the concrete surface, and the bearing surface receives the hydraulic load from the underwater temporary cutoff facility and is transmitted to the concrete surface. A hardware that seals the injection space of the load transmission mortar,
Provide water-swelling rubber and non-swelling rubber in this order from the concrete surface side on both sides of the interior, and place an expandable tube on the opposite side of the non-swelling rubber to the water-swelling rubber. The main feature is that an apparatus for injecting pressure water to be injected is provided.

  In the present invention, since the tube is disposed on the opposite side of the concrete surface of the non-swelling rubber disposed on both sides of the watertight hardware, the pressure of the tube that expands due to the injection of pressure water is changed to the water-swelling rubber via the non-swelling rubber. It acts equally and the repulsive force is evenly transmitted to the position adjusting bolt.

  In the watertight hardware of the above-mentioned underwater temporary cutoff facility of the present invention, when an accumulator is installed in the middle of a pipe for supplying pressure water to a tube from a water supply pump constituting a pressure water injection device, The water pressure can be kept almost constant.

  In the present invention, since the tube is disposed on the opposite side of the concrete surface of the non-swelling rubber disposed on both sides of the watertight hardware, the pressure of the tube that expands by injecting the pressure water is transferred to the water-swelling rubber via the non-swelling rubber. Act equally.

  Therefore, the increase and dispersion of the repelling force of the water-swollen rubber can be prevented, the repulsive force of the water-swollen rubber can be evenly transmitted to the position adjusting bolt, and the load acting on the position adjusting bolt can be easily equalized. Can do.

  Moreover, the contact surface pressure between the water swelling rubber and the reservoir-side concrete surface of the dam weir body can be easily controlled by controlling the water pressure in the tube.

(A) is schematic explanatory drawing of the watertight metal fitting of the present invention installed at the door of the underwater temporary cutoff facility, (b) is an enlarged view of the AA portion of (a), (c) is an enlarged view of the watertight hardware. It is. It is the figure which showed the watertight metal object of this invention before the swelling of water swelling rubber | gum. FIG. 2 is a view showing an example of the present invention, and is an enlarged view of a watertight hardware and an injection device. It is a schematic explanatory drawing of the underwater temporary cutoff equipment temporarily attached to the reservoir side concrete surface of a dam weir. It is a figure explaining the conventional watertight hardware installed per door, (a) is the figure which showed the state which inject | poured the mortar for load transmission after swelling of the water swelling rubber, (b) is after swelling of the water swelling rubber. .

  In the present invention, the purpose of not adversely affecting the tightening and fixing of the position adjusting bolt for adjusting the position of the door stop is to expand and contract on the side opposite to the concrete surface of the non-swelling rubber disposed on both sides inside the watertight hardware. Realized by arranging possible tubes.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS.
FIG. 1 (a) is a schematic explanatory view of the watertight metal fitting of the present invention installed at the door of an underwater temporary cutoff facility, (b) is an enlarged view of the AA portion of (a), and (c) is a watertight metal fitting. FIG. 2 and FIG. 3 are views for explaining the watertight hardware of the present invention installed per door.

  When the dam facility is improved, prior to the construction, the door stop 2b of the underwater temporary cutoff facility 2 to be temporarily installed in order to secure a working space on the concrete surface 1a on the reservoir side of the dam weir body 1 is shown in FIG. As shown in FIG. 2, a watertight hardware 4 is installed.

  As shown in FIG. 1 (b), the watertight hardware 4 is configured by partitioning a side of the door 2b opposite to the concrete surface 1a with a horizontal member 2ba. In the present invention, The structure is adopted.

  Reference numeral 2bb denotes side walls on both sides of the door stop 2b, and an auxiliary wall surface 4b is provided in parallel to the side wall 2bb toward the concrete surface 1a inside the side walls 2bb of the space defined by the horizontal member 2ba.

  Then, in the space surrounded by the side walls 2bb, the horizontal member 2ba and the auxiliary wall surface 4b, the water swelling rubber 6b, the non-swelling rubber 6a, and the tube 9 are arranged in this order from the concrete surface 1a side. Pressure water can be injected from the injection device 10.

  As shown in FIGS. 1A and 3, for example, the pressure water injection device 10 injects pressure water from the water supply pump 10a to the respective watertight hardware 4 via a pipe 10b and a hose 10c. A pressure gauge 10d is provided at 10b so that the internal pressure of the tube 9 can be measured. In this embodiment, an accumulator 10e is provided in the pipe 10b.

  By the way, in the watertight metal fitting 4 of the present invention, the length L holding the water swelling rubber 6b between the side wall 2bb and the auxiliary wall surface 4b sandwiching the water swelling rubber 6b from both sides is at least 10 mm or more so that the water swelling rubber 6b is at least 10 mm. And the swelling allowance of the water swelling rubber 6b are selected in advance.

  When the length L of the side wall 2bb and the auxiliary wall surface 4b sandwiching the water-swelling rubber 6b from both sides for holding the water-swelling rubber 6b is 10 mm or less, the water-swelling rubber 6b is detached from the watertight metal 4 due to the pressure of the tube 9. Because there is a fear.

  Accordingly, even if the lengths of the side wall 2bb and the auxiliary wall surface 4b are determined so that the end surfaces of the side wall 2bb and the auxiliary wall surface 4b opposite to the concrete surface 1a are not in contact with the concrete surface 1a, the distances C1 and C2 are small. good.

  In the present invention having the above-described configuration, the tube 9 is disposed on the opposite side of the concrete surface 1a of the non-swelling rubber 6a disposed on both sides of the watertight metal fitting 4, so that the pressure of the tube 9 that is expanded by the injection of pressure water is not swollen. It acts equally on the water swelling rubber 6b through the rubber 6a.

  Accordingly, an increase or variation in the repulsive force of the water-swelling rubber 6b can be prevented, and the repulsive force of the water-swelling rubber 6b is evenly transmitted to the position adjusting bolt 8 so that the load acting on the position adjusting bolt 8 can be easily obtained. Can be equalized.

  Further, by controlling the water pressure in the tube 9, the contact surface pressure between the water swelling rubber 6b and the reservoir-side concrete surface 1a of the dam weir body 1 can be easily controlled.

  Further, in the above-described invention example in which the accumulator 10e is installed in the middle of the pipe 10b, the internal pressure change of the tube 9 due to the temperature change can be absorbed by the accumulator 10e even when the temperature changes. It can be held almost constant.

  The underwater temporary cutoff facility 2 provided with the watertight hardware 4 of the present invention having the above configuration is installed in the following construction order.

(1) First, the concrete 1a surface on the reservoir side of the dam weir body 1 where the work space should be secured is measured. Based on the measurement results, the distances C1 and C2 between the end surfaces of the side wall 2bb and the auxiliary wall surface 4b of the door stop 2b in the underwater temporary cutoff facility 2 are as follows. Cut to a predetermined range (for example, about 20 mm).

(2) The tube 9, the non-swelling rubber 6a, and the water-swelling rubber 6b are sequentially installed on both sides of the watertight hardware 4.

(3) The distance C3 between the concrete surface side of the fixing member 11 and the concrete surface 1a is 10 mm or more so that the fixing member 11 does not interfere with the concrete surface 1a when the installation position of the door stop 2b is adjusted by the position adjusting bolt 8. The fixing member 11 is installed outside the watertight hardware 4 so that

(4) The watertight hardware 4 completed by the above construction is laid on the reservoir side of the dam weir body 1.
(5) After adjusting the distance C3 between the fixing member 11 and the concrete surface 1a with the position adjusting bolt 8, the liner 12 is interposed therebetween (FIG. 2).

(6) After connecting the opening provided in the tube 9 and the valve 10f provided at the end of the pipe 10b with the hose 10c, the valve 10g provided in the middle of the pipe 10b is opened to start the water supply pump 10a, and the tube Pressure water is injected into the tube 9 until the internal pressure of 9 reaches a predetermined water pressure.

  Here, it is desirable that the internal pressure of the tube 9 is about 1.5 times the water pressure at the maximum water depth. If the maximum water depth is Bm, the internal pressure of the tube 9 is B × 0.01 × 1.5 = 0.015B (MPa). For example, when the maximum water depth is 50 m, since the water pressure is 0.5 MPa, the required contact pressure is 0.75 MPa, and the internal pressure of the tube 9 is 0.75 MPa.

  Although the water pressure decreases from the maximum water depth to the water surface, in the present invention, the tube 9 absorbs an increase in the repulsive force due to the expansion of the water-swelling rubber 6b, which adversely affects the tightening and fixing of the position adjusting bolt 8. There is nothing.

(7) The tube 9 is expanded by injecting pressure water until the expanded water-swelling rubber 6b hits the concrete surface 1a.

(8) After visually confirming how the water-swelling rubber 6b hits the concrete surface 1a, the internal pressure of the tube 9 is determined by the pressure gauge 10d to prevent leakage when a predetermined water pressure (load transfer mortar 7 is injected). Pressure water until the contact pressure is reached. During this time, the valve 10h connected to the accumulator 10e is open, and the valve 10i for releasing the pressure in the tube 9 is closed. And after supply of pressure water is completed, valve 10g is closed.

(9) The load transmitting mortar 7 is injected into the injection space 4 a of the watertight hardware 4. After the placement of the load transmitting mortar 7 is completed, the pressure in the tube 9 may be released by opening the valve 10i.

(10) When the attachment of the watertight hardware 4 is completed, the caisson 2a and the like are attached, and the underwater temporary cutoff facility 2 is completed.

  The present invention is not limited to the above example, and it goes without saying that the embodiments may be changed as appropriate within the scope of the technical idea described in each claim.

  For example, in the above example, the accumulator 10e is installed in the middle of the pipe 10b, but the accumulator 10e may not be installed. Moreover, although the pressure water is supplied by a separate hose 10c for each door 2b, the pressure water may be supplied to all doors by the same hose.

DESCRIPTION OF SYMBOLS 1 Dam dam body 1a Concrete surface 2 Underwater temporary cutoff equipment 4 Watertight metal 4a Injection space 6a Non-swelling rubber 6b Water swelling rubber 7 Load transmission mortar 9 Tube 10 Injection device 10a Water supply pump 10b Piping 10c Hose 10e Accumulator

Claims (2)

The underwater temporary cutoff facility that secures work space on the concrete surface of the reservoir of the dam weir body is installed opposite to the concrete surface, and the bearing surface receives the hydraulic load from the underwater temporary cutoff facility and is transmitted to the concrete surface. A hardware that seals the injection space of the load transmission mortar,
Provide water-swelling rubber and non-swelling rubber in this order from the concrete surface side on both sides of the interior, and place an expandable tube on the opposite side of the non-swelling rubber to the water-swelling rubber. A watertight metal fitting for an underwater temporary cutoff facility, characterized in that an injection device for injecting pressurized water is provided.   The watertight metal fitting of the underwater temporary cutoff facility according to claim 1, wherein an accumulator is installed in the middle of a pipe for supplying pressure water to the tube from a water supply pump constituting the pressure water injection device.

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