JPH0548812B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> The present invention relates to a method for confirming the water-stopping properties of a curable water-stopping material such as mortar that is injected between steel materials for cofferdam construction.

<<Conventional technology>> As is well known, in foundation work for bridge piers, etc., cofferdams are constructed above the water surface and construction is carried out with the water inside the coffers excluded.As a type of cofferdam, There is a method of construction by sequentially connecting steel materials such as steel pipes or H-shaped steel.

In the steel materials used for such cofferdams, joints that are engaged with each other are usually fixedly installed in each steel material in advance, an example of which is shown in Japanese Patent Publication No. 59-44462, for example.

In the joint structure disclosed in the above publication, annular steel pipe sheet piles are used as the steel material, and a box-shaped joint having a slit-shaped opening is fixed on the side surface of one of the steel pipe sheet piles that are interconnected. A T-shaped joint that is inserted into the box-shaped joint through the opening is fixed on the side surface of the other steel pipe sheet pile,
When the steel pipe sheet pile is penetrated into the ground, these joints are engaged with each other when it is driven.

After this, a hardening water stop material such as mortar is injected into the joint part using an injection pipe, etc.
The water-stop properties of the cofferdam were ensured by hardening the water-stop material.

However, this water stopping method has the following problems.

≪Problems to be solved by the invention≫ In other words, when driving steel pipe sheet piles, a guide such as an H-shaped steel is installed in order to drive the steel pipe sheet piles along a set line, and the driving is performed along this guide. However, since the steel pipe sheet pile is quite long, it tilts forward, backward, left and right in the longitudinal direction.At this time, the joint provided on the steel pipe sheet pile is a box-shaped joint and a T-shaped joint that engages with it, so it is perpendicular to the connection direction. The inclination of the T-shaped joint is regulated by contacting the inner surface of the box-shaped joint.

However, since there is no means to restrict the movement of the T-shaped joint in the connection direction, it moves until it comes into contact with the outer surface of the steel pipe sheet pile, and in this state, the steel pipe sheet pile is installed obliquely in the connection direction. Therefore, there was a problem that the penetration resistance of the steel pipe sheet piles increased.

If the steel pipe sheet piles are installed in an inclined state in this way, it becomes difficult to inject water-stopping material into the joints, making it impossible to obtain sufficient water-stopping properties, and also reducing the water-stopping properties of the water-stopping material. It will also be difficult to confirm.

The present invention was made in view of the above-mentioned conventional problems, and its purpose is to reduce as much as possible the penetration resistance of steel materials cast into the ground, and to stop the penetration. To provide a method for checking water-stopping properties between steel materials for cofferdams, by which water material can be easily injected and its water-stopping properties can be easily confirmed.

≪Means for Solving the Problems≫ In order to achieve the above object, the present invention provides joints of steel materials such as H-shaped steel, I-shaped steel, steel pipes, etc., which are interconnected and penetrated into the ground through joints. In a water stop method in which a hardening water stop material is injected into a box-shaped joint having a slit-shaped opening fixedly fixed to the outer surface of one of the steel materials to be interconnected, and the outer surface of the other steel material. and a T-shaped joint that is fixed to the box-shaped joint and inserted into the box-shaped joint through the opening, and the lower end is closed to either the T-shaped joint or the outer surface of the one steel material, and the shaft A joint pipe is fixedly installed in which through holes are intermittently drilled at predetermined intervals in the direction and covered with a flexible member, and after the water stop material is injected and hardened, the through holes in the joint pipe are By supplying pressurized fluid nearby,
The water-stopping property of the water-stopping material is detected from the pressure change of the pressurized fluid.

<<Operation>> In the confirmation method for the above configuration, since a joint pipe is provided on either the T-shaped joint or the outer surface of one of the steel materials, the movement of the T-shaped joint in the connecting direction is restricted by this joint pipe. , This reduces the penetration resistance of the steel material, and
The joint space for injecting the water stop material is secured, making it easy to inject the water stop material.

In addition, since the joint pipe is intermittently drilled with through holes covered with flexible members in its axial direction, if pressurized fluid is supplied near the through holes after the water stop material has hardened, If there is a defective part such as a cavity, the pressurized fluid will press the flexible member and flow out of the joint tube, so it can be easily confirmed from the pressure change of the fluid whether water-tightness is ensured.

<<Example>> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of the method for confirming water-tightness between steel materials for cofferdams according to the present invention.

The confirmation method shown in the figure is an application of the present invention to steel materials made of H-shaped steel.
The shaped steels are connected to each other via joints 10 and are driven into the ground.

The structure of the joint part 10 includes a box-shaped joint 14 fixed to the outer surface of a flange 12 of one H-shaped steel A that is interconnected, and a T-shaped joint 14 fixed to the outer surface of a flange 16 of the other H-shaped steel B. It is generally composed of a figure-shaped joint 18.

The box-shaped and T-shaped joints 14, 16 extend along the longitudinal direction of the H-beams A, B over their entire lengths.

The box-shaped joint 14 includes a pair of angle members 20,
20, angle members 20, 20 are placed at a predetermined interval, and one end thereof is connected to a flange 1, respectively.
2 to define a joint space 22 having a longitudinal cross section, and a slit-shaped opening 24 is provided on the central axis of the flange 12 in the width direction.

On the outer surface of the T-shaped joint 18, there is a joint tube 26 in the form of a hollow pipe extending over the entire length on its central axis.
is fixedly installed, and this joint pipe 26 has a T-shaped joint 18 connected to the box-shaped joint 1 through the opening 24.
When inserted into the joint space 22 of No. 4, it is placed close to and facing the flange 16 of the H-shaped steel A.

The joint tube 26 has ribs 28, 28 protruding in the radial direction at predetermined intervals on its outer periphery, and one of the ribs 28 is connected to the T-shaped joint 18.
is welded to the outer surface of the

Furthermore, through holes 30 are intermittently bored along the axial direction between the ribs 28 of the joint tube 26, and each through hole 30 is covered with a packing 32 made of a flexible rubber material. ing.

The H-beam steels A, B, ... configured as described above are
They are successively connected by joints 10 and then poured into the ground.

In this case, when the T-shaped joint 18 is inserted into the joint space 22 of the box-shaped joint 14 through the opening 24,
Since a pipe-shaped joint tube 26 is provided on the outer surface of the T-shaped joint 18 and is placed close to the flange 16 of the H-shaped steel A to be connected, the T-shaped joint 18 can be connected by the joint tube 26 or the rib 28. This prevents the penetration direction of the H-shaped steel B from being inclined diagonally with respect to the connection direction, reducing penetration resistance and maintaining the joint space 22 at a predetermined interval. .

In addition, the joint tube 26 has a rib 28 that protrudes.
Since the contact area with the flange 14 of the H-shaped steel A becomes a partial line contact, the contact area becomes small and the frictional resistance can also be reduced.

When the required H-beams A, B, etc. are cast, the earth and sand in the joint space 22 is removed with water or the like, and then an injection pipe 34 is placed in the joint space 22 to stop the water from hardening with mortar or the like. Material 36 is injected.

When the injected water stop material 36 hardens, the water stop property of the water stop material 36 is confirmed as shown in FIG.

To check the watertightness, in the joint pipe 26,
The lower end is closed and the through hole 30 of the joint tube 26 is closed.
Rubber packers 38 each having a semicircular cross section are attached to the upper and lower sides at an interval shorter than the drilling interval, and a pipe 40 having a through hole 39 is inserted between these packers 38, 38.

For example, a water supply means equipped with a pressure gauge is connected to the upper end of this pipe 40, and one of the through holes 30 is located between the packers 38, and the outer surface of the packer 38 is connected to the inner surface of the joint pipe 26. Water is supplied only to the vicinity of the through hole 30 in a pressurized state.

If you do this, for example, if you hit the hardened water stop material 3
If there is a defect such as a crack or a cavity in the water stop material 36, water will press against the gasket 32 covering the through hole 30 and flow out to the outside. Water-based can be detected.

The above confirmation operation is performed sequentially for all the through holes, and if a defective part is found, after the confirmation operation is completed, the water stop material 3 is inserted into the joint pipe 26.
You can repair it by injecting it.

FIG. 3 shows another embodiment of the joint tube 26 used in the method of this invention, and only its features will be described below.

In the embodiment shown in the figure, the joint pipe 26
A flexible gasket 3 that covers the through hole 30 drilled in the
2a is formed into a semicircular shape, and this gasket 32a is fixed on the outer surface side of the T-shaped joint 18.

Even if the joint tube 26 configured in this manner is used, the same effects as in the above embodiment can be obtained.

In addition, in the above-mentioned embodiment, H-type steels A and B were illustrated as the steel materials that are interconnected and penetrated into the ground, but the steel material to which this invention is applied may also be steel pipe sheet piles.

In addition, the joint tube 26 shown in the above embodiment,
26a may be attached to the steel material side on which the box-shaped joint 14 is fixed.

≪Effects of the Invention≫ As explained in the examples above, according to the method for confirming the water-tightness between steel materials for cofferdams according to the present invention,
Penetration resistance when pouring the steel material can be significantly reduced, making construction easier, and since the steel material can be placed accurately on the set line, a space for injecting the water stop material is reliably secured.

Moreover, the water-stopping properties of the cured water-stopping material can also be easily confirmed.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 show the first embodiment of the confirmation method according to the present invention, Fig. 1 is a plan view when steel material is cast, and Fig. 2 is a measurement of the water-stopping property of the water-stopping material. FIG. 3 is an explanatory diagram showing another example of the joint tube used in the method of this invention. 10...Joint part, 12...Flange, 14...
Box-shaped joint, 16...Flange, 18...T-shaped joint, 20...Angle material, 22...Joint space, 2
4...opening, 26...joint tube, 30...
Through hole, 32...Packing, 36...Water stop material,
A, B...H type steel.

Claims (1)

[Claims] 1. A water stoppage method in which a curable waterstop material is injected into the joints of steel materials such as H-type steel, I-type steel, and steel pipes that are interconnected and penetrated into the ground through joints,
A box-shaped joint that is fixed to the outer surface of one of the steel materials to which the joint parts are interconnected and has a slit-shaped opening; and a T-shaped joint inserted into the steel member, the lower end of which is closed at either the T-shaped joint or the outer surface of one of the steel materials, and holes are intermittently drilled at predetermined intervals in the axial direction. A joint pipe with a through hole covered with a flexible member is fixed, and after the water stop material is injected and hardened, pressurized fluid is supplied to the vicinity of the through hole in the joint pipe, and the pressurized fluid is A method for confirming water-stopping properties between steel materials for cofferdam work, comprising detecting the water-stopping properties of the water-stopping material from pressure changes.