JP4022656B2 - How to correct the direction of the sinking box - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a method for setting a submerged box for a submerged tunnel, and more particularly to a method for correcting the direction of a submerged box for correcting a horizontal shift of a rear end of a new box relative to a tunnel normal.
[0002]
[Prior art]
Conventionally, in the submergence box construction method, the submergence box (new box) is submerged and its end face is brought into contact with the existing box via a rubber gasket, and the seawater between the bulkheads of both boxes is drained. The new box is hydraulically joined to the existing box using the water pressure on the back of the box.
In such a sinking method, the direction of the new box often deviates from the tunnel normal due to various factors such as installation error of the new box, dimension error of the sinking box, and dimension error of the rubber gasket. Therefore, in general, after the above-described hydraulic welding, the bulkhead on the joining side is removed and detailed survey (including survey in the box) is performed, and the horizontal deviation from the tunnel normal at the rear end of the new box is calculated. If this deviation is larger than expected, a direction correction jack (hydraulic jack) is installed between the end faces of the new box and the existing box, and the right or left side of the new box is pushed back to correct the direction. I was trying to do it.
However, according to the above-described conventional method for correcting the direction of the submerged box, it is necessary to push back the new box against a large load caused by water pressure. And the jack could not be removed before the backfilling was completed, and there was a problem that the entire construction period was extended.
[0003]
Therefore, for example, in Patent Document 1, a plurality of pairs of stoppers are fixedly provided opposite to the outer wall surfaces of the left and right side walls of the existing box and the new box, and between the wedged surfaces provided on the facing surfaces of each pair of stoppers. The wedge (movable wedge) placed on the outer wall is supported by a jack so that it can move in the normal direction of the outer wall surface, and the amount of drainage when adjusting the water pressure is adjusted, or water is injected between the bulkheads after water pressure bonding, and the load due to water pressure There has been proposed a direction correcting apparatus and method for moving the movable wedge with a jack while reducing the above.
[0004]
[Patent Document 1]
JP-A-10-88597 gazette
[Problems to be solved by the invention]
However, according to the direction correcting device and method of the submerged box described in Patent Document 1, the wedge device including the bracket and the movable wedge is disposed so as to protrude from the side surface of the submerged box (new box, existing box). These become obstacles such as towing and sunk work of the burial box. In particular, in order to finely adjust the return amount of the new box and increase the accuracy of direction correction (in units of several millimeters), the wedge angle (wedge interface tilt angle) must be set to a small value. Not only a long device is required, but also a jack with a large stroke length is required, and these greatly project to the side of the sinking box (new box, existing box) as an obstacle.
[0006]
Accordingly, the present inventors have each of the junction of the left and right side walls of the existing box making and new box making, by positioning inside the rubber gasket wedge device engaged wedge fixed wedge and the movable wedge in the longitudinal direction and A direction correcting device having a driving device for moving the movable wedge has been devised and has already been clarified in Japanese Patent Application No. 2001-236429 (unknown). According to this direction correcting device, since the wedge device is arranged in the joint end surface of the new box and the existing box, it does not protrude as an obstacle to the sides of both boxes, and is described in Patent Document 1 described above. Problems in the invention can be solved.
Recently, demands for reducing the construction cost of the submerged box construction method have become stricter, and as part of this, various cost reduction measures have been studied for rubber gaskets interposed between the submerged boxes. However, in the conventional submerging method using the above-mentioned wedge device as well as the submerging method using the wedge device described above, the total load of hydraulic bonding is applied to the rubber gasket. A large-sized one that does not buckle or break (having a large reaction force resistance) is required, and there is a certain limit to the cost reduction.
In view of such a current situation, the present inventors have focused on the direction correction device of the Hakouchi wedge method described in the above Japanese Patent Application No. 2001-236429, and changed the procedure of the direction correction by the device to change the rubber gasket. It has been found that such a load can be reduced.
The present invention has been made on the basis of the above-described knowledge, and the object of the present invention is to provide a direction correcting method that achieves cost reduction of the rubber gasket while taking advantage of the characteristics of the direction correcting device of the Hakouchi wedge method. It is in.
[0007]
[Means for Solving the Problems]
To solve the above problems, the present invention is, each of the joint portions of the left and right side walls of the existing box making and new box making, by positioning inside the rubber gasket, the inside portion of the rubber gasket, the fixed wedge and the movable wedge A wedge device that wedges in the vertical direction and a drive device that moves the movable wedge are disposed. First, the rubber gasket and the left and right wedge devices are installed while sharing the load of hydraulic bonding. The new box is hydraulically joined to the box, then water is injected between the bulkheads, and the new box is pushed back by the reaction force of the rubber gasket. In this state, only the amount necessary to correct the deviation of the rear end of the new box the movable wedge of the left or right side of the wedge device, moved by corresponding drive device, thereafter, while sharing the load of the pressure bonded to said rubber gasket and said left and right wedging devices, new to the existing box making Characterized by re-pressure bonded to a box.
In the present invention, the initial wedge height of the wedge device is set within a range in which a load lower than the allowable load of the rubber gasket is shared and the waterproofness of the rubber gasket and the allowable return deformation are guaranteed.
In the method of correcting the direction of the sinking box performed in this way, the load applied to the rubber gasket is reduced by sharing a part of the load of hydraulic bonding with the left and right wedge devices, and a small rubber gasket is reduced accordingly. Can be used. In addition, since the wedge device and its driving device are arranged in the same form as the direction correcting device of the box inner wedge method, it does not protrude as an obstacle to the side of the sinking box (new box, existing box).
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIGS. 7-9 shows the direction correction apparatus used for implementation of the direction correction method of the embedding box based on this invention. This direction correcting device 20 is the same as that described in Japanese Patent Application No. 2001-236429, and is a wedge device that sets the joining interval between the existing box 10 and the new box 11 that are hydraulically bonded via the rubber gasket 12. 21 and a drive device 22 for operating the wedge device 21.
[0009]
Here, the existing box 10 and the new box 11 have a rectangular cross section, and the internal space is divided into a plurality of parts by an inner wall 13 (FIG. 10) and left and right partition walls 14 and 15. Before joining, the opening of the existing box 10 with the new box 11 is closed by the bulkhead 16 and both ends of the new box 11 (the rear end side is omitted) are closed by the bulkhead 17. A sealed chamber 18 surrounded by the rubber gasket 12 is defined between the bulkheads 16 and 17 in accordance with the joining of 10 and 11. In addition, the structure type of the existing box 10 and the new box 11 is arbitrary, and can be a reinforced concrete (RC) structure type, a steel shell structure type, a steel concrete composite structure type, or the like.
[0010]
On the other hand, the rubber gasket 12 is configured as a Gina type here, and as shown in FIG. 3, a mountain-shaped nose portion 12b is provided on the upper surface of the trapezoidal body portion 12a, and fibers are formed on the lower surface of the body portion 12a. The reinforcing flange portion 12c is provided. The rubber gasket 12 is tightly fixed to the end surface using a bolt (not shown) through which a through hole 19 provided in the flange portion 12c is inserted with the flange portion 12c aligned with the end surface of the new box 11. Yes. The size of the Gina rubber gasket 12 is defined by the width L of the bottom surface and the height H from the bottom surface to the top surface of the main body 12a.
[0011]
As shown in FIGS. 7 to 9 again, the wedge device 21 used in the present invention is disposed on a pedestal 23 fixed to the stepped portion inside the rubber gasket 12 on the end surfaces of the left and right side walls 10a of the existing box 10. It comprises a fixed wedge 24 and a movable wedge 26 disposed on a pedestal 25 fixed to the stepped portion inside the rubber gasket 12 on the end face of the new box 11. The fixed wedge 24 and the movable wedge 26 are arranged on the corresponding pedestals 23 and 25 so as to extend in the vertical direction, that is, to be wedged in the vertical direction. The wedged surface 24a of the fixed wedge 24 and the wedged surface 26a of the movable wedge 26 are inclined so as to increase the wedged height in accordance with the downward movement of the movable wedge 26. As a result, the joining interval between the existing box 10 and the new box 11 is increased in accordance with the downward movement of the movable wedge 26.
[0012]
On the other hand, the drive device 22 is arranged extending in the vertical direction on the side of the pedestal 25 on the side of the new box 11 and is fixed to the pedestal 25, and an output shaft 27a of the hydraulic cylinder 27. The upper and lower brackets 28 are attached to the upper end of the upper and lower ends of the bracket 28, and a connecting bar 29 having the upper end fixed to the bracket 28 and the lower end connected to the movable wedge 26 (FIG. 7). The hydraulic cylinder 27 has a small diameter and a long length so that a sufficient stroke length can be secured although the output is low, and the operation thereof is an oil from a supply / discharge oil device (not shown) disposed in the new box 11. It is controlled by liquid supply / discharge.
[0013]
Various methods such as the tower pontoon method, the placing barge method, and the floating crane method can be adopted as the method for laying the new box 11, but when the tower pontoon method is adopted, as shown in FIG. On the box 11, one or two control towers 30 (one in the illustrated example) and two pontoons 31 are installed. A surveying and command room 32 is provided in the upper part of the control tower 30, and an access shaft (not shown) for allowing workers to enter and leave the new box 11 is provided in the survey tower. In addition, a wire 34 having a tip connected to a sinker 33 installed on the sea floor is routed around the new box 11. The new box 11 is operated by operating a winch (not shown) mounted on the control tower 30. It can be operated horizontally. Each pontoon 31 is provided with a wire 35 for supporting the new box 11 in a suspended manner. The new box 11 includes a sinking winch (not shown) mounted on each pontoon 31 and a ballast in the new box 11. Settling with water injection into a tank (not shown).
[0014]
The new box 11 also includes a sinking box position surveying system (not shown) that takes in GPS signals from the GPS antenna 36 on the control tower 30 and performs overall position management, and position management relative to the existing box 10. End surface exploration device (not shown), a distance meter 37 for measuring the compression amount of the rubber gasket 12 with high accuracy, a measurement device (laser measurement device) 38 for measuring the horizontal and vertical inclinations of the new box 11, etc. The surveying means is installed. The new box 11 further includes an injection / drainage pump for draining seawater in the sealed chamber 17 between the bulkheads and pouring seawater into the sealed chamber 18, a supporting jack, a mortar pump, A vertical shearing key (bracket) or the like for mounting is mounted, but illustration of these is omitted.
[0015]
When the new box 11 is set, the sink box 11 after the above-mentioned mounting of various types of fittings is towed to the set position, and the necessary number of sinkers 33 are installed on the seabed at that position and necessary wiring is performed. After completion of this preparation, the new box 11 is guided to the existing box 10 while performing position management by the submerged box position survey system, the end surface exploration device, etc., and a vertical shear key (not shown) at the tip of the new box 11 is provided. And a rear end thereof is seated on a temporary support base installed on an excavation bottom of the seabed through a support jack (not shown). Next, the new box 11 is pulled toward the existing box 10 by the operation of the drawing jack 39 (FIG. 1) provided in the existing box 10, and thereafter, the joining process including the direction correcting method according to the present invention is executed. .
[0016]
FIGS. 1 and 2 show a joining process including a direction correcting method according to the present invention. First, as shown in FIG. The nose portion 12b of the rubber gasket 12 attached to the joining end surface of the container 10 is compressed, and a sealed chamber 18 surrounded by the rubber gasket 12 is formed between the bulk head 16 of the existing box 10 and the bulk head 17 of the new box 11. It is formed. At this time, the movable wedge of the wedge device 21 constituting the direction correcting device 20 is the original wedge height S which is included in the maximum compression amount δ1 (FIG. 3) of the rubber gasket 12 described in detail later. At this stage, the fixed wedge 24 and the movable wedge 26 are kept in a non-wedge state as shown in FIG.
[0017]
Next, the pouring / draining pump in the new box 11 is drained, and the seawater in the sealed chamber 18 between the bulkheads is drained. Then, as shown in FIG. 1 (2), the new box 11 is pushed toward the existing box 10 by the water pressure P applied to the back surface of the new box 11, and is hydraulically joined. At this time, the left and right wedge devices 21 are wedged at the above-mentioned initial wedge height S as shown in FIG. 2 (2), so that the rubber gasket 17 is shown by a one-dot chain line in FIG. The deformation is stopped with a compression amount smaller than the maximum compression amount δ1. In other words, the load due to the water pressure P is shared and received by the wedge device 21 and the rubber gasket 12. The amount of compression of the rubber gasket 12 is monitored by the end face distance meter 37 (FIG. 10).
[0018]
Simultaneously with the completion of the water pressure welding, the measuring device 38 performs a survey in the box through an access shaft (not shown) disposed in the control tower 30. Then, as shown in FIG. 5, if the rear end of the new box 11 is shifted by C to one side of the tunnel normal, for example, and if the shift amount C is larger than planned, The water injection pump in the new box 11 is switched to the water injection operation, and seawater is injected into the sealed chamber 18 between the bulkheads as shown in FIG. Then, the rubber gasket 12 restores its main body portion 12a to its original height, and the new box 11 is pushed back by the restoring force (reaction force), and as shown in FIG. The distance between the fixed wedge 24 and the movable wedge 26 in the tunnel normal direction also increases.
[0019]
After that, as shown in FIG. 2 (3), the movable wedge 26 of the wedge device 21 arranged on the side where the rear end of the new box 11 is displaced in the left and right wedge devices 21 is operated by the hydraulic cylinder 27. To move it down from its original position. The moving amount (shift amount) α of the movable wedge 26 at this time is an amount suitable for eliminating the shift amount C of the new box 11, and the wedge height of the wedge device 21 is reduced by the downward movement of the movable wedge 26. As shown in FIG. 4, it increases from h1 (initial wedge height) to h2. The movement (downward movement) of the movable wedge 26 is performed in a free state where it does not come into contact with the fixed wedge 24. Therefore, a small and low output hydraulic jack 27 that constitutes the drive means 22 can be used. .
[0020]
Next, the injection / drainage pump is switched to the drainage side, and the seawater in the sealed chamber 18 between the bulkheads is drained again by the drainage operation. With this drainage, the new box 11 is again hydraulically joined to the existing box 10 as shown in FIG. 1 (4). At this time, as shown in FIG. 2 (4), the left and right wedge devices 21 are configured. The fixed wedge 24 and the movable wedge 26 come into contact with each other, and the new box 11 is restricted from moving toward the existing box 20 by the wedge device 21. Thus, the wedge device 21 on the side where the rear end of the new box 11 has shifted increases the wedge height by shifting the movable wedge 26 described above. As shown in (4), a predetermined amount (return amount) δ is returned to the existing box 10, and the direction is corrected.
[0021]
After that, surveying in the box is performed again to check whether the deviation from the tunnel normal is within the schedule. If it is within the schedule, water is poured into a ballast tank (not shown) to the new box 11. The ballast water load is increased, and then the bulkhead 16 of the existing box 10 and the bulkhead 17 of the new box 11 are removed, and a crushed stone stopper is installed around the new box 11 in parallel with this. After that, according to the normal method of sinking the burial, filling the bottom of the mortar, lowering the support jack, and backfilling, the installation of one burial is completed.
[0022]
Here, as shown in FIG. 5, the return amount δ of the new box 11 with respect to the existing box 10 is C, the amount of deviation of the new box 11, the total length of the new box 11, and the distance between the left and right wedge devices 21. Assuming B, the following equation (1) is given.
δ = B × C / A (1)
On the other hand, as shown in FIG. 4, the shift amount α of the movable wedge 26 for obtaining the return amount δ is the inclination angle (wedge angle) of the wedge surfaces 24a, 26a of the wedges 24, 26 constituting the wedge device 21. ) Is given by the following equation (2), and when the above equation (1) is substituted into this, the following equation (3) is obtained.
α = δ / tanθ (2)
α = (B × C) / (A × tan θ) (3)
[0023]
By the way, in order to increase the adjustment accuracy of the return amount δ of the new box 11 relative to the existing box 10, the return amount per unit shift amount of the movable wedge 26 is made as small as possible, that is, the effective movement amount (shift amount) of the movable wedge 26 is reduced. It needs to be as large as possible. In this case, since the total length A of the new box 11 and the distance B between the left and right wedge devices 21 are constant, the wedge device 21 can be used to obtain the maximum shift amount α of the movable wedge 26 from the above equation (3). It can be seen that it is desirable to set the wedge angle θ as small as possible. In this respect, the wedge device 21 according to the present invention is provided in such a manner as to be wedged in the vertical direction at the joint between the left and right side walls 10a and 11a of the existing box 10 and the new box 11 as described above. Even if set to a small value, the shift amount α of the movable wedge 26 can be made sufficiently large, and the adjustment accuracy of the return amount of the new box 11 can be greatly increased. As a result, the direction correction accuracy of the new box 11 is remarkably high. improves.
[0024]
Further, even when the wedge device 21 receives the hydraulic pressure P when the new box 11 is hydraulically bonded to the existing box 10, the condition for stably maintaining the wedged state, that is, the movable wedge 26 is the fixed wedge 24. Similarly, as shown in FIG. 4, the condition of not sliding on the top is based on the relationship between the component force P × sin θ in the direction along the wedge surfaces 24a and 26a and the component force P × cos θ in the normal direction of the wedge surfaces 24a and 26a. Or, it is necessary to satisfy the following expression (4) or (5) from the relationship with the friction coefficient μ of the wedges 24 and 26.
P × sinθ <P × cosθ × μ (4)
tanθ <μ (5)
[0025]
In this case, the coefficient of friction μ is naturally determined because the fixed and movable wedges 24 and 26 are made of steel. Therefore, in order to prevent the movable wedge 26 from sliding, the above (4) or (5) is used. From the equation, it is necessary to set the wedge angle θ as small as possible. In this respect, the wedge device 21 according to the present invention can set the wedge angle θ sufficiently small as described above. Therefore, even if the final hydraulic bonding is performed after the direction of the new box 11 is corrected, The movable wedge 26 is not slid by the joining force P, and the joining state is stably maintained. This means that even if the hydraulic cylinder 27 is removed at the same time as the bulkhead removal described above, the new box 11 maintains its position (hydraulic joining position), and a subsequent stabilization work for the new box 11 was awaited. Even if not, the hydraulic cylinder 27 can be removed, and the construction period is shortened accordingly.
[0026]
On the other hand, the allowable return deformation amount δS of the rubber gasket 12 required for correcting the direction of the new box 11 is the maximum compression amount δ1 at the time of hydraulic joining when the wedge device 21 is omitted, and the height of the nose portion 12b of the rubber gasket 12. From the correlation between the deformation amount δ2 satisfying the water stoppage, the manufacturing error δ3 of the end surfaces of the submerged boxes 10 and 11, the manufacturing accuracy and temperature shrinkage amount δ4 of the rubber gasket 12, and the unexpected deformation allowance δ5. It is determined based on the following equation (6).
δS = δ1- {δ2 + δx (= δ3 + δ4 + δ5)} (6)
Therefore, the wedge device 21 needs to be set in its original position within a range that does not hinder the water stoppage (δ2 to δ5) of the rubber gasket 12 and sufficiently guarantees the allowable return deformation amount δS. In FIG. 3, each element required for the rubber gasket 12 is added, and accordingly, the original position S of the wedge device 21 is preferably set within the range of δx (= δ3 + δ4 + δ5). It can be said.
[0027]
Further, the rubber gasket 12 exhibits specific compression characteristics depending on its size (L, H) and hardness. As an example, the compression characteristics of a rubber gasket having L = 155 mm, H = 109 mm, and hardness 40 are shown in FIG. It is as follows. In this case, the allowable load Pf is at a level (about 65 × 9.8 kN / m) lower than the total load Po (about 87 × 9.8 kN / m) of the hydraulic joint, and the wedge device 21 is subjected to the hydraulic joint. If the load is not shared, the rubber gasket may buckle or break. Even when the wedge device 21 shares the load, if the shared load Pk of the wedge device 21 is set to a level higher than the allowable load Pf, the rubber gasket similarly buckles or breaks. there is a possibility. Therefore, when setting the initial wedge height S of the wedge device 21, it is necessary to set the shared load Pk of the wedge device 21 to a level lower than the allowable load Pf. In the example shown in FIG. 6, the shared load Pk of the wedge device 21 is set to about 45 × 9.8 kN / m. In this case, of course, buckling and breakage of the rubber gasket can be prevented. In addition, the waterproofness of the rubber gasket (δ2 to δ5) and the allowable return deformation amount δS are sufficiently ensured.
[0028]
Here, in the conventional construction method in which the total load Po (about 87 × 9.8 kN / m) of hydraulic bonding is borne on the rubber gasket, a rubber gasket having an allowable load Pf at a level higher than the total load Po must be selected. A large-sized one is necessary. Incidentally, the size of the rubber gasket having an allowable load Pf of 95 × 9.8 kN / m level is L = 190 mm and H = 148 mm, where the hardness is 40, and the rubber gasket 12 usable in the above-described method of the present invention. Is considerably larger than the size (L = 155 mm, H = 109 mm).
[0029]
【The invention's effect】
As described above, according to the method for correcting the direction of the sinking box according to the present invention, a part of the load of the hydraulic bonding is shared by the left and right wedge devices, so the load on the rubber gasket is reduced, As a result of the reduction, a small rubber gasket can be used, which is advantageous in terms of cost. In addition, the wedge device and its driving device do not protrude as an obstacle to the side of the sinking box, and it is possible to remove the driving means at an early stage, so that the installation workability is improved and the construction period is shortened. The effect which contributes greatly to is produced.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a joining process including a method for correcting the direction of a sinking box according to the present invention.
FIG. 2 is a schematic view showing an operating state of the wedge device in the joining step shown in FIG.
FIG. 3 is a cross-sectional view showing a cross-sectional shape and a deformed state of a rubber gasket used for a junction of a submerged box.
FIG. 4 is a schematic diagram showing the principle of direction correction by a wedge device.
FIG. 5 is a schematic diagram showing a state of horizontal displacement of a new box.
FIG. 6 is a graph showing compression characteristics of a rubber gasket that can be used in the present invention.
FIG. 7 is a front view showing the installation structure of the direction correcting device used in the present invention.
FIG. 8 is a longitudinal sectional view showing the installation structure of the direction correcting device.
FIG. 9 is a cross-sectional view showing the installation structure of the direction correcting device.
FIG. 10 is a perspective view schematically showing a tower pontoon type construction method in which a new box is sunk.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Existing box 11 New box 12 Rubber gasket 16 Bulk box 17 of existing box Bulk head 18 of new box 20 Sealing chamber 20 between bulk heads Direction correction device 21 Wedge device 22 Drive device 24 Fixed wedge 26 Movable wedge 27 Hydraulic cylinder 39 jack

Claims (2)

Each junction of the left and right side walls of the existing box making and new box making drive, and is positioned inside the rubber gasket, a wedge device engaged wedge fixed wedge and the movable wedge in the longitudinal direction, for moving the movable wedge First, a new box is hydraulically bonded to the existing box while sharing the load of hydraulic bonding between the rubber gasket and the left and right wedge devices, and then water is injected between the bulkheads. Then, the new box is pushed back by the reaction force of the rubber gasket, and in this state, the movable wedge of the left or right wedge device is moved by the corresponding drive unit by the amount necessary to correct the deviation of the rear end of the new box. Then, the direction correction method of the submerged box is characterized in that the new box is again hydraulically bonded to the existing box while the load of hydraulic bonding is shared between the rubber gasket and the left and right wedge devices.   The initial wedge height of the wedge device is set within a range in which a load lower than the allowable load of the rubber gasket is shared, and the waterproofness and allowable return deformation amount of the rubber gasket are guaranteed. The method of correcting the direction of the described sinking box.

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