JP7646452B2 - Wellhead water stop device - Google Patents

Description

Article 30, paragraph 2 of the Patent Act applied. Published in the Proceedings of the 30th Tunnel Engineering Research Presentation Conference (Tunnel Engineering Committee, Japan Society of Civil Engineers) on November 24, 2020.

Application of Article 30, Paragraph 2 of the Patent Act Presented at the 30th Tunnel Engineering Research Symposium hosted by the Tunnel Engineering Committee of the Japan Society of Civil Engineers, held online on November 26, 2020

The present invention relates to a mine entrance water stop device that is installed at the entrance of a departure shaft or arrival shaft and uses a packing to stop the infiltration of groundwater when a propellant such as an element is passed through the entrance.

When pipe roofs or bulkheads are constructed using the pipe jacking method to build underground spaces or tunnels, the construction often involves connecting multiple tubular elements with circular or rectangular cross sections in parallel. These elements are provided with joints that protrude from their outer periphery. These joints are then connected to each other to connect the elements in parallel.

When the tunneling method is used, a packing is typically installed along the tunnel entrance to seal the gap between the tunnel entrance and the element, preventing groundwater from seeping into the departure shaft or arrival shaft.

Multiple gaskets may be stacked and installed at the entrance to the well to improve the water-stopping effect.
In the entrance packing device described in Patent Document 1, a thick packing having a first hole that roughly corresponds to the outer shape of the tunneling machine body and the joint part is stacked on top of a thin packing that is thinner than the thick packing and has a hole smaller than the first hole, and the two are attached to the starting tunnel entrance, and as the tunneling progresses, the thin packing conforms to the outer surface of the tunneling machine body to stop water.

JP 2004-76391 A

As described in Patent Document 1, a packing device that simply combines a thin packing with a thick packing can prevent the thin packing from warping because the thick packing resists high water pressure, but the adhesion of the thin packing is not necessarily high, so a packing with a stronger water-stopping effect is desired. In addition, it is difficult for the thin packing to adequately conform to recessed corners such as the joints formed on the outer periphery of the element, and there is a limit to the water-stopping effect that can be obtained.

In view of the above problems, the present invention aims to provide a wellhead waterstop device with a high waterstop effect. It also aims to provide a wellhead waterstop device with a high waterstop effect even in corners such as the joints of elements.

The invention of claim 1 is a mine entrance water stopping device that is installed at the entrance of a departure shaft or a arrival shaft when a propellant is passed through the entrance and that uses a gasket to stop the infiltration of groundwater, the gasket comprising a first gasket and a second gasket arranged to be overlapped on the first gasket in the direction of propulsion of the propellant, the inner peripheral edge of the first gasket being located radially inward from the outer peripheral edge of the propellant, the inner peripheral edge of the second gasket being the same as or slightly radially inward from the outer peripheral edge of the propellant and located radially outward from the inner peripheral edge of the first gasket, the first gasket having an inner peripheral portion that overlaps with and is in contact with the outer peripheral surface of the propellant, and the second gasket having an inner peripheral portion that expands inward when pressed in the direction of propulsion and presses the inner peripheral portion of the first gasket that overlaps with and is in contact with the outer peripheral surface of the propellant against the propellant to stop the water.
The invention of claim 2 is a mine entrance water stopping device as described in claim 1, characterized in that the thruster has an inside corner portion around the outer periphery of its cross section, and the first gasket and the second gasket are attached so as to stop water at the location corresponding to the inside corner portion.
The invention of claim 3 is a mine entrance water stopping device as described in claim 1 or claim 2, characterized in that the first gasket and the second gasket are attached one on top of the other by bolts, and by tightening the bolts, the second gasket is pressed in the forward direction and expanded inwardly.
The invention of claim 4 is a mine entrance water stopping device described in any one of claims 1 to 3, characterized in that the first gasket and the second gasket have overlapping and contacting surfaces that are bonded together before the second gasket is pressed and expanded inwardly.
The invention of claim 5 is a wellhead water stopping device described in any one of claims 1 to 4, characterized in that the packing set is composed of the first packing and the second packing, the packing sets are provided in two sets, one at the front and one at the back in the propulsion direction, a bolt is provided that penetrates the two sets of packing sets, and by tightening the bolt, the second packing of the two packing sets is pressed in the propulsion direction and expanded inwardly.
The invention of claim 6 is a wellhead water stopping device described in any one of claims 1 to 5, characterized in that the packing set is composed of the first packing and the second packing, the packing sets are provided in two pairs, one at the front and one at the back in the propulsion direction, and sealing material is filled between the two pairs of packing sets.
The following may also be considered as another invention.
Means 1 is a mine entrance water stopping device that is installed at the entrance of a departure shaft or a arrival shaft when a propellant is passed through the entrance and that uses a gasket to stop the infiltration of groundwater, the gasket comprising a first gasket and a second gasket arranged to overlap the first gasket on the propulsion direction side of the propellant, the inner peripheral edge of the first gasket being located radially inward from the outer peripheral part of the propellant, the inner peripheral edge of the second gasket being the same as or slightly radially inward from the outer peripheral part of the propellant and located radially outward from the inner peripheral edge of the first gasket, and when the propellant passes through, the inner peripheral part of the first gasket, which is the rear surface in the propulsion direction, overlaps with and contacts the outer peripheral surface of the propellant, and the second gasket is pressed in the propulsion direction to expand toward the inner peripheral side, thereby pressing the overlapped part of the first gasket against the propellant to stop the water.

Means 2 is a wellhead water-stopping device described in Means 1, characterized in that the propellant has an inside corner on the outer periphery of its cross section, and the first gasket and the second gasket are installed so as to stop water at the locations corresponding to the inside corner .

Means 3 is a wellhead water stopping device described in Means 1 or 2, characterized in that the first gasket and the second gasket are attached one on top of the other by bolts, and by tightening the bolts, the second gasket is pressed in the forward direction and expanded inwardly.

Means 4 is a wellhead water stopping device described in any of means 1 to 3, characterized in that the first gasket and the second gasket are bonded at their overlapping and contacting surfaces before the second gasket is pressed and expanded inwardly.

Means 5 is a wellhead water stopping device described in any of means 1 to 4, characterized in that the packing set is composed of the first packing and the second packing, the packing sets are provided in two sets, one at the front and one at the back in the propulsion direction, a bolt is provided that penetrates the two sets of packing sets, and by tightening the bolt, the second packing of the two sets of packing sets is pressed in the propulsion direction and expanded inwardly.

Means 6 is a wellhead water stopping device described in any of means 1 to 5, characterized in that the packing set is composed of the first packing and the second packing, the packing sets are provided in two pairs, one at the front and one at the back in the propulsion direction, and sealing material is filled between the two pairs of packing sets.

According to the present invention, when the object passes through, the inner peripheral portion of the first packing, which is the rear surface in the propulsion direction, contacts and overlaps with the outer peripheral surface of the object, and the second packing is pressed in the propulsion direction to expand toward the inner peripheral side, thereby pressing the overlapped portion of the first packing against the object to stop water, thereby ensuring high water stopping performance.
In particular, even in the case of an inside corner of a propellant such as an element equipped with a joint, the inner peripheral portion of the first packing conforms to the outer surface of the inside corner, making it difficult for gaps to form and preventing the infiltration of groundwater.
In addition, the second packing expands and presses the portion of the first packing that overlaps with the propellant, so that the first packing can be prevented from turning over in the opposite direction to the propelling direction.

In addition, the packing set is composed of a first packing and a second packing, and two sets of packings are provided, one at the front and one at the back in the propulsion direction, and a sealant is filled between them, further enhancing the water-stopping effect.

1 is a front view of a wellhead water stopping device showing an embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 is a perspective view of the essential parts of an inside corner of a wellhead water-stopping device according to an embodiment of the present invention, showing the inside corner of the protruding portion where the female joint shown in FIG. 2 is provided, as viewed from behind. FIG. 2 is a front view of the packing case according to the present invention. FIG. 2 is a front view of a first packing according to the present invention. FIG. 4 is a front view of a second packing according to the present invention. FIG. 3 is a view corresponding to FIG. 2 in another embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 6. It should be noted that the present invention is not limited to the embodiment.
1 to 3 show one embodiment of a wellhead water stop device, and FIGS. 4 to 6 show a packing case, a first packing, and a second packing, respectively, in the embodiment.

This embodiment is a wellhead water stopping device 1 that is provided at a wellhead 4 in order to propel an element 2 having a substantially rectangular cross section from a starting shaft 3 into the ground.
In the following description, the direction in which the element 2 is advanced is referred to as the "front" and the opposite direction is referred to as the "rear."

1, protruding portions 2a protruding in the left-right direction are provided at the four corners of the outer peripheral surface in the cross section of the element 2. Joint portions 2b for connecting with elements arranged in parallel are provided at the tips of the protruding portions 2a in the axial direction.
A female joint 2b1 of a joint portion 2b extending from one side of the element 2 and a male joint 2b2 of a joint portion 2b extending from the other side are shaped so as to be engageable with each other.

At the outer periphery of the cross section of the element 2, an inside corner portion 5 is formed at the protruding portion 2a where the joint portion 2b is provided.
Specifically, the inside corner 5 is formed at the intersection of the overhang 2a and the rectangular vertical wall of the element 2, or at the connection between the overhang 2a and the female joint 2b1.

A tunneling machine (not shown) is attached to the front end of the element 2. The tunneling machine has a cross section similar to but slightly larger than that of the element 2, and is provided with a cutter at its tip.
The tunnel is advanced by the tunnel machine and element 2 inserted from the tunnel entrance 4. The trailing element is installed parallel to the preceding element. The joint of the trailing element is connected to the joint of the preceding element and installed side by side. This process is repeated until the elements are installed side by side in sequence.

The wellhead water stopping device 1 is equipped with a packing case 6 and two packing sets 7.
The packing case 6 is used to attach the packing set 7 to the wellhead 4.
As shown in FIGS. 2 and 4 , the packing case 6 is a frame body having an approximately rectangular overall external shape, and is fixed to the inner wall of the starting shaft 3 .

The packing case 6 includes a base portion 6a and a mounting portion 6b as shown in Fig. 2. Both the base portion 6a and the mounting portion 6b are substantially rectangular frames.
The base portion 6a is fixed to the inner wall of the starting shaft 3. The mounting portion 6b is fixed to the base portion 6a.
The base portion 6a and the mounting portion 6b are connected by a bolt 9 that passes through a bolt insertion hole 8a. When connecting, it is possible to fine-tune the position, so that the next element can be installed by connecting it to the previously installed element.

The mounting portion 6b is provided with two packing mounting pieces 10. The two packing mounting pieces 10 are spaced apart in the front-to-rear direction. The inner peripheral edges of the two packing mounting pieces 10 are located inside the inner peripheral edge of the base portion 6a. The inner peripheral edges of the two packing mounting pieces 10 form a through hole 11 that is similar in shape to and slightly larger than the outer shape of the element 2.

Bolt insertion holes 8b are drilled at corresponding positions on the inner periphery of the packing mounting piece 10, surrounding the through hole 11, at least at a number of locations including near the inside corner 5 of the element 2. A reinforcing piece 12 is fixed from the rear surface of the front packing mounting piece 10 to the inner periphery of the mounting portion 6b. Although not shown, a reinforcing piece is also fixed to the front surface of the rear packing mounting piece 10.

Support legs 13 are provided on the lower part of the inner peripheral surface of the base portion 6a to support and guide the element 2. The support legs 13 may be provided as necessary, but are not necessarily required.
1 and 2, an injection pipe 14 is attached to the inner peripheral surfaces of the base portion 6a and the mounting portion 6b. A sealant or the like can be filled between the packing case 6 and the element 2 through the injection pipe 14.

2, each of the two packing sets 7 includes a first packing 15 and a second packing 16, which are elastic and flexible. The second packing 16 is thicker than the first packing 15. The second packing 16 is attached to the packing case 6 so that the second packing 16 overlaps the front surface of the first packing 15. The inner peripheral edge of the first packing 15 is arranged inside the inner peripheral edge of the second packing 16.
In this embodiment, the first packing 15 is made of rubber with a hardness of 45° and a thickness of 10 mm, and the second packing 16 is made of rubber with a hardness of 45° and a thickness of 20 mm.

As shown in FIG. 5, the outer shape of the first packing 15 has a size and shape that surrounds the outer periphery of the cross section of the element 2. The first packing 15 has a first element insertion hole 17 that is smaller than the outer shape of the element 2. The inner peripheral edge of the first packing 15 is located approximately 3 cm radially inward from the outer periphery of the square (1 m x 1 m) of the element 2 to be inserted into the wellhead 4. Note that in this embodiment, the inner peripheral edge of the first packing 15 is located approximately 3 cm inward from the outer periphery of the square of the element 2, but this is not limited to this and may be longer as appropriate, for example approximately 10 cm.

The first element insertion hole 17 is substantially rectangular, and slit-like holes 17a are formed from its four corners to fit the shapes of the protrusion 2a and the joint portion 2b so as to pass the protrusion 2a and the joint portion 2b through.
The first packing 15 is provided with a bolt insertion hole 8b. The bolt insertion hole 8b is provided at a position corresponding to the bolt insertion hole 8b provided in the mounting portion 6b of the packing case 6.

6, the outer shape of the second packing 16 is approximately the same as the outer shape of the first packing 15. The second packing 16 is formed with a second element insertion hole 18 that is approximately the same shape as or similar to the outer shape of the element 2, is slightly smaller, and is larger than the first element insertion hole 17. The inner peripheral edge of the second packing 16 is located at the same position as the outer periphery of the element 2 or slightly radially inward, and radially outward of the inner peripheral edge of the first packing 15.
The second packing 16 is provided with a bolt insertion hole 8b. The bolt insertion hole 8b is provided at a position corresponding to the bolt insertion hole 8b provided in the first packing 15.

As shown in FIG. 2, two packing sets 7 are attached to the front surface of the front packing mounting piece 10 of the mounting portion 6b of the packing case 6 and two packing sets 7 are attached to the rear surface of the rear packing mounting piece 10.
Presser plates 19 are provided to sandwich from the front and rear the fixed portions of the two packing sets 7. The presser plates 19 are also provided with bolt insertion holes (not shown), and the two packing sets 7 are attached to the packing case 6 by one through-bolt 20 inserted through the bolt insertion holes 8b of the packing mounting pieces 10, the first packing 15, and the second packing 16.

Between the two packing sets 7, the inner circumference of the packing case 6 is filled with sealing material 21 via an injection tube 14.

As shown in Figures 2 and 3, when the element 2 is advanced, the inner peripheral portion of the thin and flexible first packing 15 located at the rear abuts against the outer peripheral surface of the element 2 and is pulled forward, so that the rear surface of the inner peripheral portion overlaps with the outer peripheral surface of the element 2. The overlapped portion of the first packing 15 is located forward of the inner peripheral edge of the second packing 16.

In this state, by tightening the through bolt 20 that secures the first packing 15 and the second packing 16, the thick and flexible second packing 16 is pressed by the pressing plate 19 and expanded toward the inner periphery. As a result, the inner periphery of the first packing 15 that is in contact with and overlaps the outer periphery of the element 2 is pressed against it.
The first packing 15 is thin and flexible, and can therefore adhere closely to the shape of the inside corner 5 of the element 2. The second packing 16 is less flexible than the first packing 15, but has a certain degree of flexibility, and can therefore press the first packing 15 while following the first packing 15's adherence to the inside corner 5.

In particular, as shown in FIG. 3, by tightening the through bolt 20 inserted near the inside corner 5 of the element 2 and pressing and expanding the second packing 16, the first packing 15 is pressed against the shape of the inside corner 5 of the element 2, which is prone to gaps, thereby reliably preventing water leakage.
It is preferable to place the through bolt 20 as close as possible to the inside corner portion 5. If this is difficult due to space restrictions, the pressing plate 19 can be placed as close as possible to the inside corner portion 5.

In Figure 3, the pressure plate 19 is omitted to make it easier to understand the relationship between the tightening of the through bolt 20 and the deformation of the packing set 7.

The front packing mounting piece 10 has a reinforcing piece 12 on its rear surface, and the rear packing mounting piece 10 has a reinforcing piece (not shown) on its front surface, so even if the through bolts 20 that pass through the front and rear packing mounting pieces 10 are tightly tightened, the packing mounting pieces 10 will not deform.

The following describes a water stopping method using the wellhead water stopping device of the above embodiment.

First, the base portion 6 a of the packing case 6 is attached to the entrance 4 formed in the wall surface of the starting shaft 3 .
Next, the mounting portion 6b of the packing case 6 to which the two packing sets 7 have been attached is attached to the base portion 6a. At this time, the mounting portion 6b is attached to the base portion 6a while adjusting the position of the mounting portion 6b so that the element 2 to be installed can be connected to the previously installed element.

Next, the tunneling machine and element 2 are advanced from the packing case 6 to the minehead 4 .
The inside of the female joint 2b1 of the element 2 is appropriately waterproofed by filling it with a sealant or the like.

When the element 2 reaches the forward packing set 7, the through bolt 20 is tightened from the inside of the starting shaft 3. The inner periphery of the second packing 16 is pressed and expanded inward. The expanded inner periphery of the second packing 16 presses the part of the inner periphery of the first packing 15 that overlaps with the outer periphery of the element 2 against the outer periphery of the element 2, and they come into close contact.
Since the first packing 15 is in close contact with the outer circumferential surface of the element 2, water is stopped reliably from the wellhead 4. In particular, no gaps are generated at the inside corner 5, so water is stopped effectively and reliably. This intimately contacted portion comes into sliding contact with the outer circumferential surface of the element 2 as the pipe is advanced.

The gap between the two packing sets 7 is filled with a suitable amount of sealing material 21 through an injection pipe 14 provided in the mounting portion 6b of the packing case 6 to further improve watertightness. Note that a suitable amount of sealing material may also be filled through an injection pipe 14 provided in the base portion 6a of the packing case 6.

After the elements 2 are thrust-buried in this manner, the elements that are arranged side by side are connected to each other via the joints 2b, and a structure is constructed using the multiple elements 2 that have been buried in sequence.

[Other Modifications]
The present invention is not limited to the above-mentioned embodiment, and may also include the following, for example.

In this embodiment, two packing sets are installed at a distance from each other along the wellhead, but only one packing set may be installed. In this case, as shown in Fig. 7, one packing set 7 is attached to the packing mounting piece 10 by passing it through a through bolt 20 whose head side is fixed to the rear packing mounting piece 10 and a retaining plate 19, and the second packing 16 is pressed and expanded inward by tightening it with a nut. As a result, the inner peripheral portion of the first packing 15 that is in contact with and overlaps the outer peripheral surface of the element 2 is pressed.
Also, three packing sets may be installed along the wellhead at intervals in the front-rear direction as a front packing set, a middle packing set, and a rear packing set. In this case, the rear packing set and the middle packing set are assembled, and a through-bolt is inserted through the packings and tightened to press the second packing of the rear packing set against the second packing of the middle packing set. Also, the rear packing set and the front packing set are assembled, and a through-bolt is inserted through the middle packing set between the packings and tightened to press the second packing of the rear packing set against the second packing of the front packing set (since the middle packing set only has a through-bolt inserted through it, the second packing of the middle packing set is not pressed).
In addition, the portion through which the through bolt 20 passes is appropriately waterproofed with packing or the like as necessary. Similarly, four or more packing sets may be provided.

In this embodiment, two packing sets of a first packing and a second packing are provided as a wellhead water stop device, and in the modified example, one or three or more packing sets are provided. However, the present invention is not limited to this, and may be, for example, a combination of a conventional entrance packing that does not have a structure in which the second packing is pressed and expanded inwardly against which the first packing is pressed. For example, in addition to the embodiment in which one packing set 7 is provided on the rear packing mounting piece 10 as shown in FIG. 7, a conventional entrance packing is combined with the front packing mounting piece 10, and a sealant is filled between the two.

In this embodiment, the first and second packings are attached around the entire circumference of the wellhead (the entire exterior shape of the element), but it is also possible to attach the first and second packings only to the portion where the inside corner of the element, which is prone to gaps, is inserted, and attach conventional packings to the other portions.

In this embodiment, the propellant is an element, but this is not limited to this and it may be a tunneling machine.

In this embodiment, the device is a water stop device for a tunnel jacking element, but this is not limited to this. It may also be applied to a water stop device for a tunneling machine for a shield tunneling method.

In this embodiment, the element serving as the propulsion has a rectangular cross section, but it may have other shapes, such as a circle.

In this embodiment, it is the entrance of the departure shaft, but it may also be a water stop device used at the entrance of the arrival shaft.

In this embodiment, the first packing 15 and the second packing 16 are attached in an overlapping manner, but in addition to this, before the second packing 16 is pressed and expanded inward, the surfaces where the first packing 15 and the second packing 16 overlap and come into contact may be glued to prevent water from entering between the first packing 15 and the second packing 16. If water enters between the first packing 15 and the second packing 16, the first packing 15 will separate from the second packing 16, and when the second packing 16 is pressed and expanded inward, the overlap of the first packing 15 between the outer surface of the propellant will disappear, and the first packing 15 may not be pressed. By bonding the two together in this way, water is prevented from entering between the first packing 15 and the second packing 16, and the first packing 15 does not separate from the second packing 16, so that when the second packing 16 is pressed and expanded inward, the overlap of the first packing 15 between it and the outer circumferential surface of the propellant can be secured.

The technical aspects of any embodiment may be applied to other embodiments as examples.

1 Wellhead water stop device 2 Element 2a Projection portion 2b Joint portion 3 Starting shaft 4 Wellhead 5 Corner portion 6 Packing case 6a Base portion 6b Mounting portion 7 Packing set 8a, 8b Bolt insertion hole 9 Bolt 10 Packing mounting piece 11 Through hole 12 Reinforcement piece 13 Support leg 14 Injection pipe 15 First packing 16 Second packing 17 First element insertion hole 17a Slit-shaped hole 18 Second element insertion hole 19 Pressing plate 20 Through bolt 21 Sealing material

Claims (6)

A water-stopping device for a starting shaft or a reaching shaft, which is provided at the entrance of the starting shaft or the arrival shaft and stops the infiltration of groundwater with a packing when a propellant passes through the entrance of the starting shaft or the arrival shaft,
The packing is
A first packing;
A second packing is disposed on the first packing in the propelling direction of the propellant,
The inner peripheral edge of the first packing is located radially inward from the outer peripheral portion of the propellant,
The inner peripheral edge of the second packing is located at the same position as or slightly radially inward from the outer peripheral portion of the propellant, and is located radially outward from the inner peripheral edge of the first packing,
The first packing has an inner peripheral portion that contacts and overlaps with an outer peripheral surface of the propellant,
The second packing has an inner peripheral portion that expands inwardly when pressed in the propelling direction and presses the inner peripheral portion of the first packing, which overlaps with the outer peripheral surface of the propelling object, against the propelling object to stop water.
A wellhead water stopping device characterized by the above. The propellant has an internal corner on a cross-sectional outer periphery,
The wellhead water-stopping device according to claim 1, characterized in that the first gasket and the second gasket are attached so as to stop water from entering the area corresponding to the inside corner portion. The first packing and the second packing are attached to each other by bolts,
The wellhead water stopping device according to claim 1 or 2, characterized in that, by tightening the bolt, the second packing is pressed in the forward direction and expanded inwardly. A wellhead water stopping device as described in any one of claims 1 to 3, characterized in that the first gasket and the second gasket have overlapping and contacting surfaces bonded together before the second gasket is pressed and expanded inwardly. a packing set including the first packing and the second packing,
The packing set is provided in two pairs, one at the front and one at the rear in the propulsion direction,
There are bolts that penetrate the two packing sets, front and rear.
A water stopping device for a wellhead as described in any one of claims 1 to 4, characterized in that by tightening the bolts, the second packings of the two packing sets are pressed in the forward direction and expanded inwardly. a packing set including the first packing and the second packing,
The packing set is provided in two pairs, one in front and one in back, in the propulsion direction.
The wellhead water stopping device according to any one of claims 1 to 5, characterized in that a sealant is filled between the two front and rear packing sets.

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