Box type roof and construction method thereof
The expandable box-shaped cylinder with hydraulic jacks addresses the deflection and propulsion challenges of long box roofs, enabling stable and efficient construction by distributing force evenly and allowing for soil passage.
Patent Information
- Application Number
- JP2024045918
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-22
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2044-03-22
AI Technical Summary
Long box-shaped roofs are prone to bending and require excessive force to be pushed out during construction, and existing methods may not provide sufficient propulsion to overcome this issue, especially in long construction lengths.
Incorporating an expandable box-shaped cylinder with the same outer diameter as the unit cylinders, which can expand and contract longitudinally, and using hydraulic jacks at the four corners to evenly distribute propulsion force, allowing the box roof to be pushed out without deflection.
The expandable box-shaped cylinder ensures reliable and stable pushing of the box roof, even in long construction lengths, without causing deflection, and allows for efficient soil passage and reuse of the structure.
Smart Images
Figure 2025145632000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a box-shaped roof used in the construction of underground structures, which allows existing crossing structures to be constructed without interfering with traffic above when excavating and constructing large-width underground structures below the ground such as railways and roads in a transverse direction, and to a construction method for the same. [Background technology]
[0002] In the case of railways, the construction methods for underground crossing structures were initially mainly open-cut construction methods such as temporary track construction and temporary track support construction (construction girder construction method). However, as the number of trains increased, it became difficult to adopt open-cut construction methods, which involve a lot of work inside the tracks.
[0003] Therefore, a trenchless construction method was developed to enable the construction of crossing structures under the tracks while ensuring train service. This method, called the jacking method, involves the construction of large-width precast concrete boxes (box culverts) as underground structures made of reinforced concrete.
[0004] This pushing is done by attaching a cutting edge made of a steel hood to the tip of a precast concrete box culvert, excavating inside the cutting edge to create a gap in front, and then pushing the concrete box forward with a main push jack installed in the starting shaft.
[0005] However, when digging a large precast concrete box culvert in a transverse direction beneath a railway, road, etc., protective work is required to support the traffic above.One example of such protective work is the pipe roof method, which involves installing a pipe roof made of horizontally aligned steel pipes, etc.
[0006] The pipe roof method involves inserting a pipe roof (steel pipes) under the tracks in advance as a protective measure for the tracks. After the tracks are temporarily supported by each steel pipe using shoring, the soil under the pipe roof is excavated and a concrete box is constructed.
[0007] In the pipe roof method, the main structure is excavated inside a roof or wall made of pipes (steel pipes) laid horizontally in an arched or columnar pattern.As a result, in addition to the soil cover and the diameter of the pipes (steel pipes), the top of the concrete box is low, and the excavation must be done at a deep position.
[0008] Furthermore, there is a problem that the pipes that form the pipe roof cannot be removed, which increases the construction costs.
[0009] Therefore, a box roof has been proposed as a protective work when using the concrete box jacking method. A box roof protects railway tracks, etc., instead of a pipe roof, and the box roof method uses a box roof, in which the main structure is installed under the tracks while pushing out the box roof. This method does not require separate construction work for the underground structure being excavated into the ground, but is carried out at the same time as the underground structure is being excavated, so construction can be done safely, reliably, and inexpensively, and the earth cover can be kept shallow.
[0010] As shown in Figure 15, the box-shaped roof is formed to a specified length by connecting unit cylindrical bodies 17a. These unit cylindrical bodies 17a are box-shaped cylindrical bodies with an approximately square cross section of 800 x 800 (mm) or 1000 x 1000 (mm). Unit cylindrical bodies 17a of 3 to 6 m in length can be connected sequentially in the lengthwise direction to bury the required length, and can also be arranged side by side in the horizontal direction via joints.
[0011] The unit cylindrical bodies 17a of the box-shaped roof 17 form connection flanges 17c at the corners of their ends, and these connection flanges 17c are fastened together with bolts and nuts 19, or the fastening with bolts and nuts 19 is carried out at the part of the box cutout 20, where the corners of the end of the unit cylindrical bodies 17a are formed as box cutouts 20 that are open outward.
[0012] When the box cutter 20 is provided in this manner, the bolts and nuts 19 can be fastened or loosened from the outside of the box-shaped roof.
[0013] The box-shaped roof 17 has friction cut plates 21 made of strip-shaped steel plates with a thickness of 9 to 12 mm placed on the outer surfaces such as the top surface.The length of this friction cut plate 21 is approximately the same as that of the unit cylindrical body 17a, and is lengthened by welding when connecting the unit cylindrical body 17a.
[0014] Retaining members such as steel sheet piles are cast beside overhead transportation such as railways to construct a departure shaft and arrival shaft 9, and as shown in Figure 17, a push jack 4 is installed inside the departure shaft 3 as a propulsion device, and this is used to press the box-shaped roof 17 into the arrival shaft, one unit cylindrical body 17a at a time.
[0015] The box roof 17 has a cutting edge pipe 18 attached to the tip, and the face is excavated by hand or by a machine such as an auger and pushed forward. In the figure, 14 is a soil discharge pipe that discharges the excavated soil.
[0016] In addition, a friction cut plate 21 is attached to the upper surface of the box-shaped roof 17 and is disposed underground by being pushed out together with the box-shaped roof 17, and the friction cut plate 21 is fixed to the starting shaft 3 side with a fixing member 26.
[0017] The friction cut plate 21 is extruded together with the box-shaped roof 17 with only its tip welded to the tip of the box-shaped roof 17, for example, the cutting edge pipe 18, and the other parts are simply placed on top without being fixed.
[0018] The box-shaped roof 17 is made by pressing in the unit cylindrical bodies 17a one by one, and each piece is added lengthwise to bury the required length from the departure shaft 3 to the arrival shaft 9, and then the second, third, etc. are buried in sequence in parallel with the first piece thus buried. Next, as shown in Figure 15, a concrete box 1 serving as an underground structure is set inside the starting shaft 3, a push jack 4 is installed between the reaction wall 5 and the concrete box 1, and a cutting edge 2 is provided at the tip of the concrete box 1.
[0019] The earth and sand in the cutting edge 2 and in front of the face are excavated. A box roof 17 acts as a protective structure.
[0020] Since a gap is created by excavation and removal of soil, the main push jack 4 is extended to push forward the concrete box body 1, and at the same time, the box-shaped roof 17 is pushed forward through the concrete box body 1 while leaving the friction cut plate 21 behind.
[0021] The concrete box 1 advances inside the friction cut plate 21, and the friction cut plate 21 cuts friction with the ground when the concrete box 1 is advanced.
[0022] In the figure, reference numeral 6 denotes a strut interposed between the main push jack 4 and the reaction wall 5. In this way, the box roof 17 and the concrete box body 1 are advanced simultaneously, and when one piece of the unit cylindrical body 17a of the box roof 17 has completely emerged into the arrival shaft 9, the bolts and nuts 19 fastening the connecting flanges 17c together are released, the box roof is separated lengthwise, and the pieces are removed one by one.
[0023] Then, when the tip of the concrete box 1 reaches the arrival shaft 9, the cutting edge 2 and the like are removed and backfilling grout is carried out as appropriate to complete the construction.
[0024] In this way, the box roof allows the structure to be shallowly covered with soil, making the slope of the access road gentler and allowing for the installation of a safe and easy-to-use underpass; the access road section can be shortened, making it easier to apply in existing urban areas; the excavation depth for the entire construction is shallower, so the construction costs for the entire underpass are lower; the structure can be manufactured in a light state that is easy to manage; the protective work can be a box-shaped rigid frame structure, so it can be applied even when the cross-sectional length is long; and the box roof can be reused as a protective work, making it economical.
[0025] The following patent document proposes a device and method for preventing subsidence of a roof cylinder in a method for constructing an underground structure, which can prevent the roof cylinder from bending downward and improve workability. [Patent Document 3] Patent No. 3702265
[0026] In a method for constructing an underground structure, a box-shaped roof with a friction cutter plate on top is pressed into the ground from a starting tunnel to be aligned, an underground structure is placed at the rear of the box-shaped roof cylinder that remains in the starting tunnel, and the underground structure is excavated while the friction cutter is left underground, and a lifting cable is passed through the inside of the box-shaped roof cylinder in the length direction to lift up the downwardly bent portion of the roof cylinder.
[0027] By pulling the cable that passes through the length of the inside of the box-shaped roof cylinder in the horizontal direction, the vertical component forces acting on the cable are transmitted to the box-shaped roof cylinder, and the slack portion of the box-shaped roof cylinder is pulled up, eliminating the slack. Summary of the Invention [Problem to be solved by the invention]
[0028] When the construction length of the box-shaped roof is long, the box-shaped roof is more likely to bend as described above, and a large pushing force is required.
[0029] There is a risk that the thrust (propulsion jack or towing jack) used to propel the concrete box may not be enough to push out the box roof with the concrete box.
[0030] In addition, although not shown in the figure, a propulsion tube with a small jack attached is installed at the base of the box-shaped roof, and the box-shaped roof is pushed out using the propulsion force of the small jack, but even this method sometimes does not provide enough force to push out the entire box-shaped roof.
[0031] SUMMARY OF THE INVENTION An object of the present invention is to provide a box roof and a construction method therefor which can eliminate the disadvantages of the above-mentioned conventional examples and can reliably push out the box roof without causing deflection even when the construction length is long. [Means for solving the problem]
[0032] In order to achieve the above object, the box roof of the present invention is, firstly, a box roof formed to a predetermined length by connecting unit cylinders which are box-shaped cylinders of a substantially square cross section, and in the middle of the box roof where the unit cylinders are lined up vertically, an expandable box-shaped cylinder which has the same outer diameter as the unit cylinders and can expand and contract in the length direction is installed, This telescopic box-shaped cylindrical body consists of a front cylindrical body and a rear cylindrical body that fits into it, and jacks are placed at the four corners to span between the front and rear cylindrical bodies. The gist of this is that it has been incorporated.
[0033] Secondly, the expandable box-shaped cylindrical body consists of a front cylindrical body and a rear cylindrical body that fits into it, and one of the cylindrical bodies is reduced in diameter and inserted into the other. Thirdly, the part of the cylindrical body that is reduced in diameter that does not reduce in diameter extends partially to form a rectangular convex part above the reduced diameter part, and this is inserted into the rectangular concave notch of the other cylindrical body.
[0034] The construction method of the box roof of the present invention is to arrange a box roof, which is a box-shaped cylindrical steel pipe with a rectangular cross section, so as to match the outer edge of the concrete box to be installed as a protective work when pushing in a concrete box to be installed as an underground structure, and this box roof is pushed in and penetrated in advance between the departure shaft and the arrival shaft, which is the entire length of the crossing section, and the concrete box is installed behind it, and the box roof is pushed out while the concrete box is pushed in, and when the box roof and the concrete box are replaced and installed, an expandable box-shaped cylinder with the same outer diameter as the unit cylinder and which can expand and contract in the length direction is installed in the middle of the box roof where the unit cylinders are lined up vertically, This telescopic box-shaped cylindrical body consists of a front cylindrical body and a rear cylindrical body that fits into it, and jacks are placed at the four corners to span between the front and rear cylindrical bodies. The gist of this method is that an expandable box-shaped cylinder that has the same outer diameter as the unit cylinder and expands and contracts in the lengthwise direction is incorporated, and during the process of pushing out the entire box-shaped roof, a process of pushing out only the box-shaped roof in the front part by extending the expandable box-shaped cylinder is inserted.
[0035] According to the present invention as set forth in claim 1, by incorporating an expandable box-shaped cylinder with the same outer diameter as the unit cylinders and which can expand and contract in the longitudinal direction in the middle of a box-shaped roof where unit cylinders are lined up vertically, by extending this expandable box-shaped cylinder, the row of unit cylinders in front of it can be pushed out. By adding this pushing force to the box-shaped roof pushed out by the propulsion force that propels the concrete box body, even a box-shaped roof with a long construction length can be pushed out in front and behind, and it can be pushed out reliably without causing deflection of the entire roof.
[0036] Furthermore, when the telescopic box-shaped cylindrical body is fully extended, if the box-shaped roof at the rear portion is pushed out, the telescopic box-shaped cylindrical body will contract and be ready for further pushing out.
[0037] Furthermore, the telescopic box-shaped cylinder can be reliably extended and retracted by using a jack to slide the front cylinder and the rear cylinder that fits into it, and since the jacks are located at the four corners, space is secured in the center for workers and earth-removal carts to pass through.Furthermore, by using the jacks at the four corners, the propulsive force of the jacks is transmitted evenly to the box-shaped roof at the front of the telescopic box-shaped cylinder, allowing the front box-shaped roof to be pushed out stably without any deviation.
[0038] According to the present invention as set forth in claim 2, the expandable box-shaped cylindrical body is composed of a front cylindrical body and a rear cylindrical body that fits into it, and one of the cylindrical bodies is reduced in diameter and inserted into the other, so that no gap is created between the front cylindrical body and the rear cylindrical body when the expandable box-shaped cylindrical body is extended or contracted, and there is no risk of soil or sand getting mixed inside.
[0039] According to the present invention described in claim 3, the portion of the cylindrical body that is being contracted that does not contract extends to form a rectangular convex portion above the contracted portion, and this is inserted into the rectangular recess notch of the other cylindrical body, so that the rectangular convex portion acts as a guide when the expandable box-shaped cylindrical body contracts and expands, allowing it to contract and expand smoothly.
[0040] According to the present invention as set forth in claim 4, a box roof is constructed by incorporating an expandable box-shaped cylinder with the same outer diameter as the unit cylinders, which can expand and contract in the longitudinal direction, in the middle of the box roof where unit cylinders are lined up vertically, and by inserting a process in which the expandable box-shaped cylinder extends to push out only the box roof in front of it during the process of pushing out the entire box roof, it is possible to push out the row of unit cylinders in front of it, and by adding this pushing out to the pushing out of the box roof with the propulsion force that propels the concrete box body, even a box roof with a long construction length can be pushed out in front and back parts, and the entire roof can be pushed out reliably without deflection. [Effects of the Invention]
[0041] As described above, the box-shaped roof and the construction method of the present invention can reliably push out the box-shaped roof without causing deflection even when the construction length is long. [Brief explanation of the drawings]
[0042] [Figure 1] FIG. 2 is a side view showing the first step of the box roof construction method of the present invention. [Figure 2] FIG. 2 is a side view showing the second step of the box roof construction method of the present invention. [Figure 3] FIG. 10 is a side view showing the third step of the box roof construction method of the present invention. [Figure 4] FIG. 10 is a side view showing the fourth step of the box roof construction method of the present invention. [Figure 5] FIG. 10 is a side view showing the fifth step of the box roof construction method of the present invention. [Figure 6] FIG. 10 is a side view showing the sixth step of the box roof construction method of the present invention. [Figure 7] FIG. 1 is a side view showing the final step of the box roof construction method of the present invention. [Figure 8] FIG. 1 is a cross-sectional plan view of the telescopic box-shaped cylindrical body of the box-shaped roof of the present invention when it is contracted. [Figure 9] FIG. 1 is a cross-sectional plan view of the telescopic box-shaped cylindrical body of the box-shaped roof of the present invention when extended. [Figure 10] FIG. 1 is a front view of a telescoping box-shaped cylindrical body of a box-shaped roof of the present invention. [Figure 11] FIG. 9 is a view taken along the line BB in FIG. 8. [Figure 12] 9 is a view taken along the line CC in FIG. 8. [Figure 13] FIG. 1 is a plan view of the telescopic box-shaped cylindrical body of the box-shaped roof of the present invention when contracted. [Figure 14] FIG. 1 is a plan view of the telescopic box-shaped cylindrical body of the box-shaped roof of the present invention when extended. [Figure 15] FIG. 1 is a side view showing an overview of a box roof construction method. [Figure 16] FIG. 10 is a perspective view showing the box roof connection. [Figure 17] FIG. 10 is a side view showing the launch of the box roof. DETAILED DESCRIPTION OF THE INVENTION
[0043] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Figures 1 to 7 are side views showing each step of the construction method for a box-shaped roof of the present invention, in which 17 is a box-shaped roof formed to a predetermined length by connecting unit cylindrical bodies 17a, which are box-shaped cylindrical bodies with a substantially square cross section. The details of this box-shaped roof 17 are as explained in the conventional example.
[0044] In the present invention, an expandable box-shaped cylinder 40 that has the same outer diameter as the unit cylinders 17a and can expand and contract in the longitudinal direction is incorporated into the box-shaped roof 17 where the unit cylinders 17a are lined up in a vertical row. The expandable box-shaped cylinder 40 is also a box-shaped cylinder with a substantially square cross section.
[0045] As shown in Figures 10 to 14, this expansion box-shaped cylindrical body 40 consists of a front cylindrical body 41 and a rear cylindrical body 42 that fits into it, and hydraulic jacks 43 that span between the front cylindrical body 41 and the rear cylindrical body 42 are arranged at the four corners.
[0046] Either the front cylinder body 41 or the rear cylinder body 42 that fits thereto (rear cylinder body 42 in the illustration) consists of an outer cylinder wall 42a and an inner cylinder wall 42b that is smaller in diameter than the outer cylinder wall 42a and protrudes forward, the outer cylinder wall 42a having the same outer diameter as the front cylinder body 41, and the inner cylinder wall 42b is inserted into the front cylinder body 41.
[0047] The rear cylinder 42, which is the cylinder that is contracted, has a portion of its outer cylinder wall 42a that does not contract, which extends to form a rectangular protrusion 45 on the inner cylinder wall 42b, which is the contracted portion, and this is inserted into a rectangular recess notch 46 of the other front cylinder 41 as a guide for expansion and contraction.
[0048] Both the front cylinder body 41 and the rear cylinder body 42 form a jack base 44, and a hydraulic jack 43 is axially attached to a flange protruding from the jack base 44 by a pin.
[0049] The hydraulic jacks 43, including the jack bases 44, are arranged at the four corners, top, bottom, left and right, and a space is secured in the center of the telescopic box-shaped cylindrical body 40 to allow passage of a truck 47 for discharging soil.
[0050] Next, we will explain the construction method for the box roof of the present invention. As shown in Figure 1, earth retaining members 13 such as steel sheet piles are cast next to overhead transportation such as a railway, and a starting shaft 3 and an arrival shaft 9 are constructed. A main thrust jack 4 is installed in the starting shaft 3 as a propulsion device, and this is used to press the box roof 17, unit cylindrical body 17a at a time, into the arrival shaft 9.
[0051] A cutting edge pipe 18 is attached to the tip of the box roof 17, and the face is excavated by hand or by a machine such as an auger and pushed forward.
[0052] The box-shaped roof 17 is formed by pressing in the unit cylindrical bodies 17a one by one, and each piece is added lengthwise until the required length from the departure shaft 3 to the arrival shaft 9 is buried.
[0053] The box-shaped roof 17 is positioned to match the outer edge of the concrete box to be installed as a protective measure when pushing the concrete box to be installed as an underground structure, and an expansion box-shaped cylinder 40 is incorporated in the middle of the vertically arranged unit cylinders 17a of the box-shaped roof 17 (see Figure 4 and subsequent figures), and this expansion box-shaped cylinder 40 is also pushed forward using the main jack 4.
[0054] Then, when the box-shaped roof 17 has been constructed to a certain length, a process of pushing out only the front part of the box-shaped roof 17 by extending the telescopic box-shaped cylindrical body 40 is interposed between the processes of pushing out the entire box-shaped roof 17.
[0055] That is, by extending the hydraulic jack 43, the extension box-shaped cylindrical body 40 extends as shown in FIG. 8 and FIG. 9, thereby pushing out the box-shaped roof 17 at the front portion.
[0056] Furthermore, once the telescopic box-shaped cylindrical body 40 has been extended, the hydraulic jack 43 is set free to push the rear box-shaped roof 17, thereby returning the telescopic box-shaped cylindrical body 40 to its original contracted state.
[0057] Once the box roof 17 has been installed in this way, the concrete box 1 serving as the underground structure is set inside the departure shaft 3 (in the arrival shaft 9 in the illustration), a push jack is installed, and a cutting edge 2 is provided at the tip of the concrete box 1. Earth and sand are excavated inside the cutting edge 2 and at the front face. The box roof 17 acts as a protective work.
[0058] Since a gap is created by excavation and removal of soil, the main push jack is extended to push forward the concrete box body 1, and at the same time, the box-shaped roof 17 is pushed forward through the concrete box body 1 while leaving the friction cut plate 21 behind.
[0059] When pushing forward this box-shaped roof 17, a small jack 22 may be interposed between the concrete box body 1 and the box-shaped roof 17. A jack housing pipe 24 containing the small jack 22 is disposed on the installation side of the box-shaped roof 17 where the concrete box body 1 is installed.
[0060] The small jack 22 is extended and the concrete box body 1 is used as a reaction force to push forward the box roofs 17 one by one while leaving the friction cut plates 21, and once all the box roofs 17 have advanced, the small jack 22 is retracted and the concrete box body 1 is excavated using the main push jack.
[0061] During the process of pushing forward the box-shaped roof 17 together with the concrete box 1, a process of pushing out only the box-shaped roof 17 at the front portion by extending the telescopic box-shaped cylindrical body 40 can be interposed. [Explanation of symbols]
[0062] 1...Concrete box 2…Blade mouth 3...Departure shaft 4... Push jack 5…Reaction wall 6...Strut 7...Base concrete 9…Achievement shaft 13...Earth retaining member 14...Soil removal pipe 17...Box roof 17a...Unit cylinder 17c...Connection flange 18…Blade mouth tube 19...Bolts and nuts 20...Unboxing 21...Friction cut plate 22...Small jack 24...Jack housing tube 26...Fixing member 40…Extendable box-shaped cylinder 41...Front barrel 42...Rear cylinder 42a...Outer cylinder wall 42b...inner cylinder wall 43...Hydraulic jack 44...Jack base 45...Rectangular convex part 46...Rectangular recessed notch 47...Cart
Claims
1. This box roof is formed to a predetermined length by connecting unit cylinders, which are box-shaped cylinders with a substantially square cross section, and is characterized in that an expandable box-shaped cylinder with the same outer diameter as the unit cylinders and expandable in the length direction is incorporated in the middle of the box roof where the unit cylinders are lined up vertically.
2. 2. The box roof according to claim 1, wherein the telescopic box-shaped cylindrical body comprises a front cylindrical body and a rear cylindrical body fitted thereto, and jacks are disposed at the four corners to bridge between the front cylindrical body and the rear cylindrical body.
3. 3. The box-shaped roof according to claim 2, wherein the telescopic box-shaped cylindrical body comprises a front cylindrical body and a rear cylindrical body fitted thereto, and either one of the cylindrical bodies is reduced in diameter and inserted into the other.
4. 4. A box-shaped roof according to claim 3, wherein the cylindrical member to be reduced in diameter has a portion that does not reduce in diameter extended to form a rectangular convex portion above the reduced diameter portion, which is inserted into the rectangular concave notch of the other cylindrical member.
5. This method of construction involves arranging a box roof, which is a box-shaped cylindrical steel pipe with a rectangular cross section, to match the outer edge of the concrete box to be installed as a protective measure when pushing in a concrete box to be installed as an underground structure. This box roof is previously pushed in between the departure shaft and arrival shaft, which is the entire length of the crossing section, and the concrete box is installed behind it. The box roof is then pushed out while the concrete box is pushed in. When the box roof and the concrete box are replaced and installed, an expandable box-shaped cylinder with the same outer diameter as the unit cylinders is incorporated into the box roof, which is made up of vertically arranged unit cylinders, and which can expand and contract in the lengthwise direction. During the process of pushing out the entire box roof, a process of pushing out only the front part of the box roof by extending the expandable box-shaped cylinder is inserted.