JP4132437B2 - Curve roof construction method and curve pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of constructing a continuous wall-like curved roof by arranging a plurality of curved pipes in the horizontal direction in the ground in the civil engineering field, and a curved pipe used in this method.
[0002]
[Prior art]
Curved pipes having male and female side joints (hereinafter referred to as section joints) on both sides of the pipe are connected in the longitudinal direction to form an arcuate curved pipe array, and adjacent curved pipe arrays are connected to each other. By connecting the joints in the radial direction by meshing the section joints, an arc-shaped continuous wall (curved roof) is formed in the soil, and then the area surrounded by the arc is dug to secure the necessary space. A middle wall construction method has been proposed (for example, Japanese Patent Laid-Open No. 03-147923). The curved pipes constituting the continuous wall are sequentially connected by engaging (fitting) adjacent curved pipes with a section joint, and finally become one continuous wall having a certain curvature. In addition, as an improvement means of this continuous wall construction method, in order to shorten the construction period and reduce the construction cost, a plurality of curved pipes are connected in parallel, and embedded pipes having joints on the side surfaces of the pipes on both ends thereof A construction method for laying the assembly in the ground is proposed by Japanese Patent Laid-Open No. 10-292367. Such a construction method is stronger than the conventional method in which a single curved pipe is installed in the soil at regular intervals and then a chemical solution is injected around the pipe to form a temporary wall. Is excellent in that it can be easily constructed.
[0003]
However, it is formed by boring holes of a certain diameter in the ground with a certain curvature and then drawing curved pipes of a certain length into the hole and joining them in the length direction. It is generally very difficult to perfectly match the curvature of one curved pipe row and the curved pipe row formed next by the same method adjacent thereto.
[0004]
That is, one of the reasons that the shapes of the curved pipe rows do not become constant is that in the process of constructing one curved pipe row, when excavating the ground that is not completely homogeneous by the boring machine, the excavation part of the boring machine The tip is inevitably displaced to avoid the hard ground. In addition, each curved pipe row is not a long curved pipe with one full length, but is formed by adding short curved pipes in the longitudinal direction, so that a slight deviation in curvature occurs each time the curved pipes are connected to each other, This is repeated over and over, and it is inevitable that the joints of the section joints will gradually become tighter in the process of increasing the number of curved pipe rows, and finally it will be difficult to engage the joints of the section joints. It was.
[0005]
In order to avoid such a situation, it is common practice to devise the male / female shape of the section joint to create a certain amount of play in the meshing state. However, making backlash, on the other hand, acts in a direction that helps to further distort the shape of the curved pipe row as the “row”. Therefore, the idea of engaging the male and female sections of the section joint alone does not lead to an essential solution of the above-described problem.
Also, the section joint is fixed to the side of the curved pipe by welding or the like, and the length is the same as the length of the arc drawn by the side of the curved pipe, and the end face of the section joint and the curved pipe are aligned. It is usually fixed as follows. For this reason, the present situation is that the section joint itself does not contribute to the connection in the lengthwise direction of the curved pipe.
[0006]
[Problems to be solved by the invention]
As described above, when curved pipe rows are connected to each other to form a wide curved roof, to the extent that it is difficult to engage and fasten by side joints between adjacent curved pipe rows at any stage of construction. In addition, a phenomenon in which the shape of the curved pipe array is distorted is an unavoidable problem.
[0007]
INDUSTRIAL APPLICABILITY The present invention is a construction method that can stably form a high-strength wide curved pipe roof structure even when a situation where the above-mentioned curved pipe rows are difficult to be connected to each other and suitable for use therein. The object is to provide a curved pipe. It is another object of the present invention to provide a curved pipe having a section joint effective for connecting the longitudinal direction of the curved pipe.
[0008]
[Means for Solving the Problems]
A method for constructing a curved roof according to claim 1 of the present invention for solving the above-mentioned problem is that a new curved pipe row is installed adjacent to a previously installed curved pipe row by meshing with a section joint. In constructing an arc-shaped connecting wall in the ground, when the preceding curve pipe row is bent to an extent that is inconvenient to mesh with the subsequent curve pipe row by the section joint, the subsequent curve pipe is connected to the preceding curve pipe. Without engaging the joints, the following curve pipes are separated from the preceding curve pipe by a distance of L / 5 or more and 2L or less (L: the length of the curve pipe diameter plus the height of the male and female joints). Are separately laid, and at least the chemical solution is injected from the side of the subsequent curved pipe row into the separated portion.
The invention according to claim 2 is the curved pipe used for connecting the longitudinal direction of the curved pipes in the method of claim 1, and the section joints fixed to both side surfaces of the pipe body have the same length as the pipe body. And a curved pipe attached in an axial direction shifted by D / 2 or more (D: outer diameter of the pipe body) on the extension of the side surface of the pipe body.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the curved roof is formed by integrating curved pipe rows 1A, 1B, 1C,... In the ground so as to form a wall structure, and later digging a portion surrounded by the curved roof. It is used for the purpose of building a space in the ground. Each curved pipe row is formed by joining a plurality of short curved pipes in the longitudinal direction, and the joint is fastened by a shape memory alloy joint or welding. Thus, when a plurality of pipe rows 1A, 1B, and 1C whose side surfaces are connected to each other by the section joints 2a and 2b are constructed in the ground, any of them may be caused by the above-described displacement of the pipe row or deviation of curvature. It becomes difficult to engage the section joints with each other. In such a case, the construction method of the present invention is applied. In FIG. 1, the three pipe rows 1A, 1B, and 1C can be connected to each other by meshing the section joints. However, the next pipe row 1D is assumed to be unable to be connected by the section joints.
[0010]
That is, another new curved pipe row 1D (hereinafter referred to as a straightening pipe row) is constructed at a location separated from the already constructed curved pipe row to some extent without meshing the section joint. However, the following pipe row again builds the wall by meshing with the section joint. Each of the curved pipes constituting the straightening pipe row 1D has normal section joints 2a and 2b on both sides of the pipe body 1 as shown in FIG. 2 as an example. Two small-diameter pipes 3 having a plurality of small holes 4 for injecting a chemical solution are attached to the side surface opposite to the section joint 2a. In the gap between the straightening pipe row 1D and the preceding pipe row 1C, the chemical solution supplied through the small-diameter pipe 3 (having the function of increasing the waterstop or strength of the ground) There are turbid liquid type cement system and water glass system), which are ejected through the small holes 4 and filled, and this solidifies to integrate both pipe rows.
[0011]
FIG. 3 shows an enlarged cross section of the connected pipe row and the straightening pipe row of FIG. 1, and the chemical solution 5 ejected from the small diameter pipe 3 provided in the pipe row 1C and the straightening pipe row 1D fills the gap between them. Shows the integrated state. In the illustrated example, the pipe row having the small diameter pipe 3 on the pipe row 1C side is shown. However, in some cases, the small diameter pipe 3 may not be attached to the pipe row 1C.
[0012]
The straightening pipe row may be laid away from the previous curved pipe row by a distance d of L / 5 or more and 2L or less (L: the length of the curved pipe diameter plus the height of the male and female joints). desirable. If the interval between the two pipe rows is less than L / 5, the efficiency becomes poor when the chemical solution is injected, and depending on the position in the longitudinal direction of the pipe row, the opposing joints may come into contact with each other depending on the bending direction. On the other hand, if the distance exceeds 2L, it is difficult to deal with normal chemical injection, and the costly freezing method must be adopted. In practice, it is common to construct a correction row at the next position by skipping one or two pipes in the normal case.
[0013]
Further, the diameter s of the small diameter pipe 3 attached to the straightening pipe row is 1 / 4D or less of the curved pipe outer diameter D and is usually about 30 to 50 mmφ. It is preferable to provide a nozzle that is directed in three directions, that is, a direction that faces the pipe row opposite to the right direction and a direction that is perpendicular to the pipe row, and that has a diameter of about several millimeters and that prevents the injected drug solution from flowing backward as necessary. In order to inject a chemical solution, an appropriate amount is injected by a method such as observing the movement of the preceding pipe row, but in order to inject evenly along the entire length, it may be necessary to prepare a packer in the small diameter pipe. The In the case of using a packer, it is desirable that the number of fine holes for injection of the small diameter pipe is not opened as many as in the example of FIG. 2, but about one place (3 directions) per 1 m length of the small diameter pipe. . At least one small-diameter pipe 3 is fixed to a curved pipe usually used by welding as necessary. In addition, it is desirable to cover the tip of the small-diameter pipe 3 of the curved pipe located at the top of the straightening pipe row so that earth and sand do not enter.
[0014]
Next, the strength in the longitudinal direction of the curved pipe roof greatly depends on the strength of the fastening portion because the curved pipe row is formed by sequentially joining a plurality of short curved pipes in the length direction. Fastening in the lengthwise direction of the curved pipe is mainly performed by welding or a shape memory alloy joint. In addition to this, it is preferable to use the curved pipe shown in FIG. 4 in terms of improving the strength of the fastening portion.
[0015]
That is, as shown in FIGS. 4 (a) and 4 (b), the section joints 2a and 2b are protruded at one end (right end in the figure) of the curved pipe body 1 and are recessed at the other end by the same length as the protruding length. deep. Further, as shown in the drawing, the front and rear end portions of the section joints 2a and 2b are formed in the corresponding concave and convex shapes so as to be engaged when they are abutted. The end surfaces of the curved pipes to be fastened are also formed in an uneven shape, and after connecting the end surfaces by welding or shape memory alloy joints, etc., the section joints 2a and 2b of the portion overlapped with the previous curved pipe are inserted. By welding with the mating curved pipe, the connection strength between the pipes can be significantly increased.
[0016]
The section joints 2a and 2b fixed to both side surfaces of the curved pipe main body have the same length and the same curvature as the pipe main body, and D / 2 or more (D: outside of the pipe main body) on the extension of the side surface of the pipe main body. (Diameter) It is desirable to install in a state shifted in the axial direction. Even if the length is shifted by less than D / 2, the protruding length p is short, and sufficient connection strength cannot be obtained by welding, so at least D / 2 is set. The upper limit of the protrusion length p is not particularly defined, but if it protrudes too long, it is troublesome on the work surface and easily deformed, so it is practical to be within 2D.
[0017]
In addition, a small-diameter pipe attached to both sides of the pipe body as necessary has the same length and the same curvature as the pipe body, and D / 2 or more on the extension of the side surface of the pipe body (D: outside of the pipe body) (Diameter) It may be attached in a state shifted in the axial direction, or may be attached with the end faces aligned without protruding at all.
[0018]
【Example】
[Construction conditions]
Curved pipe: 1330 length x 267 outer diameter (mm), curvature (R) = 4000 mm,
・ Section joint:
Male part 50mm solid steel material is welded to the side of the pipe with steel material with 20mm leg.
Female part: Pipe material with an inner diameter of 60mm cut out with a width of 25mm in the longitudinal direction, and fixed to the side of the pipe by welding.
The length of the joint is the same as that of the curved pipe, but is fixed to the side surface of the pipe by being shifted in the axial direction by 300 mm.
・ Curve pipe for straightening:
The above curved pipe, size and R are the same curved pipe, and two 40 mmφ pipes (same length as the curved pipe) having many small holes (5 mm diameter) are welded to both sides of the section joint on the male side.
[0019]
[Construction Procedure]
Six curved pipes are connected to each other in the axial direction to form a first pipe row, and a second pipe row is also connected in a radial direction via a section joint to form a pipe roof. go. Although the three pipe rows were connected in this way, the curved pipe was bent due to the influence of the ground, and it was predicted that it would be difficult to directly connect the fourth pipe row. For this reason, the fourth pipe row was formed with a straightening pipe row at a position about 340 mm away from the joint portion of the third pipe. A predetermined curved pipe roof was constructed by continuously connecting the planned pipe row to the straightening pipe row. The third pipe row was also constructed using a curved pipe with a small diameter pipe attached to one side. Thereafter, cement-based chemicals were injected into the straight pipes and the narrow pipes in the third pipe row to strengthen the soil between the third and fourth rows.
[0020]
[Construction results]
Seven days after the chemical injection, the bottom of the curved roof was excavated and removed to form a space. However, it was confirmed that the portion where the chemical was injected had solidified enough and had strength and strength. It was confirmed that the second pipe row was integrated.
[0021]
【The invention's effect】
According to the construction method according to claim 1 of the present invention described above, even if the curved pipe row has a tendency to bend or zigzag at the time of construction, it can be easily overcome, and a high-strength wide curved pipe roof structure can be obtained. A series of constructions can be completed in a short time as a result of being able to form stably and not having to force the section joints together.
[0022]
Further, Ri by the curve pipe according to the present invention claimed in claim 2, it is possible to firmly connect the curve pipe itself in the axial direction.
[Brief description of the drawings]
FIG. 1 is a construction diagram of a pipe line for explaining a construction method of the present invention.
FIG. 2 is a partially enlarged view of a pipe constituting the straightening pipe row used in the present invention.
FIG. 3 is an enlarged cross-sectional view of a pipe line constructed according to the present invention.
4A is a plan view showing a specific example of a curved pipe according to the present invention, FIG. 4B is a front view, and FIG. 4C is a view taken along line AA in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Curved pipe main body 1A, 1B, 1C Curved pipe row 1D Straightening pipe row 2a, 2b Section joint 3 Small-diameter pipe 4 for chemical injection 4 Small hole 5 Chemical injection location

Claims (2)

  When constructing an arc-shaped connecting wall in the ground by laying a new curved pipe row adjacent to the previously installed curved pipe row by meshing with a section joint, the preceding curved pipe row and the following curved pipe row When the bending by the section joint is inconvenient, the subsequent curve pipe does not mesh with the preceding curve pipe, and the joint is not more than L / 5 to 2L ( L: the length of the curved pipe diameter plus the length of the male and female section joints), and the subsequent curved pipe is laid, and at least the chemical solution is injected from the side of the succeeding curved pipe row to this separated location. A method for constructing a curved roof. The section joint fixed to both sides of the curved pipe body has the same length as the pipe body, and is shifted in the axial direction by D / 2 or more (D: outer diameter of the pipe body) on the extension of the side surface of the pipe body. The curved pipe used in the method according to claim 1, wherein the curved pipe is attached .

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