JP2013108276A - Curved propulsion method and gland used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a propulsion pipe in a rearmost part from being cracked even in the case where a propulsion pipe of a short pipe length is used in sharply curved propulsion.SOLUTION: A tubular propulsion pipe 10 are connected successively while interposing cushion materials 20 between propulsion pipe end faces in upper and lower portions of its end face and extruded in a propulsion pipe axis direction by a back-pushing jack 14. When performing curved propulsion by changing a horizontal direction between propulsion pipes neighboring to each other with the cushion material portion between upper and lower propulsion pipe end faces as a fulcrum, on a front end face of a gland 12 interposed between the back-pushing jack 14 and a propulsion pipe in a rearmost part, propulsion pipe pressurizing protrusions 31 are provided at upper and lower positions corresponding to the cushion material 20 between propulsion pipe end faces, and a rear end face of the gland 12 is extruded by the back-pushing jack 14.

Description

  The present invention relates to a propulsion method for extruding a cylindrical concrete propulsion pipe connected to a rear end portion, and relates to a curve propulsion method suitable for the construction of a sharp curve pipe having a small curvature radius, and a press ring used in the method. .

  Generally, in the propulsion method, a leading excavator is installed at the tip of a propulsion pipe manufactured at a factory, and the ground is excavated by the leading excavator, and the propulsion pipe is sequentially added to the rear end side to push it forward. This is a construction method in which a pipe rod constructed by connecting a number of propulsion pipes in the axial direction is constructed in the ground by being pushed out by a jack.

  In recent years, the curve construction to bend in the horizontal direction has increased, and there is a demand for a sharp curve construction in which the radius of curvature of the curved portion is 10 times or less of the pipe diameter.

  Curve construction in the conventional propulsion method uses a propulsion pipe having a small length with respect to the diameter, and as shown in FIG. 5, the propulsion pipe end faces at the upper and lower portions of the joint end faces of the axially adjacent propulsion pipes 1 and 1 A curved pipe rod is constructed by interposing an intermediate cushion material 2 and changing the angle in the axial direction between the propelling pipes in the horizontal direction with the cushioning material 2 between the propulsion pipe end faces as a fulcrum.

  Further, in the propulsion method, the pusher wheel 3 is joined to the rear end surface of the propulsion pipe 1 connected to the rearmost part, and is propelled by the main push jack 4 through the pusher wheel 3. As shown in FIG. 6, the positional relationship in the week direction between the main push jacks 4, 4 and the propulsion pipe end face cushion members 2, 2 is such that the propulsion pipe end face cushion members 2, 2 are bent in the horizontal direction. The jacks 4 and 4 are the left and right portions of the rear end surface of the propulsion tube 1 because of the necessity of workability, whereas the jacks 4 and 4 are located at the upper and lower portions of the front end surface of the rearmost propulsion tube 1 because they need to be used as supporting points. .

  For this reason, a steel ring having a highly rigid structure is used for the pusher wheel 3, whereby the pressing force by the main pushing jack 4 is dispersed on the front surface of the rear end face of the propulsion pipe 1 (for example, Patent Documents 1 and 2). , 3).

JP 7-229389 A JP 2004-19299 A JP 2008-111241 A

  In the curve construction in the conventional propulsion method described above, a short straight propulsion pipe is used, and the curved portion of the pipe rod is formed by gradually changing the axial direction of the propulsion pipes adjacent to each other in the horizontal direction. However, in order to take a large change in the axial direction, the cushioning material between the propulsion pipe end faces is interposed only at the upper and lower positions of the adjacent propulsion pipes, and the propulsive force is transmitted only through the cushioning material between the propulsion pipe end faces. .

  In addition, the press ring to be interposed between the main push jack and the propulsion pipe uses a ring with a high rigidity made of steel, and by this push ring, the pressure of the main push jack acts on the pipe wall evenly, The damage to the propulsion pipe is eliminated.

  If cracks or the like occur during propulsion, damage to the propulsion pipe is eliminated and cracks can be prevented by using the push wheels in layers or by increasing the rigidity of the push wheels.

  However, in the recent sharp curve propulsion construction, there are many cases where cracks occur during propulsion near the main push jack of the propulsion pipe, and in this case, it is often impossible to solve even if the push wheels are stacked or the rigidity is increased. There was a problem.

  The reason for this is that in the case of a sharply curved propulsion pipe, there are many cases in which the pipe length is short compared to the pipe diameter in order to increase the number of joints, and in order to improve the curve workability, the cushioning material between the end faces of the propelling pipe is walled. The cause is thought to be that there are many cases where the adhesive is applied only to the top and bottom of the tube rather than to the entire surface of the thickness.

  In view of such a conventional problem, the present invention is a curve propulsion for preventing cracks from occurring at the rearmost propulsion pipe even in the case of using a propulsion pipe having a short pipe length in the above-described sharp curve propulsion construction. It is made for the purpose of providing a construction method and a press ring used in the construction method.

  In order to solve the conventional problems as described above and achieve the intended object, the invention according to claim 1 is characterized in that a cylindrical propelling pipe is provided, and a propulsion pipe end face cushion material is provided at the upper and lower portions of the end face. The propulsion pipe at the rearmost part is pushed in the axial direction of the propulsion pipe by a main push jack via a ring-shaped pusher wheel joined to the rear end face of the propulsion pipe, and the end faces of the upper and lower propulsion pipes are connected. In the curve propulsion method in which the horizontal direction between the mutually adjacent propulsion pipes is changed with the cushion member portion as a fulcrum, the curve pushing method is arranged between the main push jack and the rearmost propulsion pipe. Protruding parts for pressing the propulsion pipe are provided at the upper and lower positions corresponding to the cushioning material between the propulsion pipe end faces on the front end face of the push ring to be interposed, and the rear end face of the push ring is pushed out by the main push jack, The driving force from the push jack is to be promoted by tell propulsion tube through the protrusion.

  According to a second aspect of the present invention, in addition to the structure of the first aspect, at least the front end surface of the projection of the push ring is configured by a cushion member between the end surfaces of the propelling pipes.

  The invention according to claim 3 is characterized in that the cylindrical propulsion pipe is sequentially connected to the upper and lower portions of the end face with a cushion member between the end faces of the propulsion pipe, and the rearmost propulsion pipe is connected to the rear of the propulsion pipe. Pushing in the direction of the propelling pipe axis by a push jack through a ring-shaped pusher joined to the end face, and the horizontal direction between the adjoining propelling pipes with the upper and lower propelling pipe end face cushions as fulcrums In the pusher wheel used in the curve propulsion method that is propelled by changing the curve, a pusher body part having a ring shape substantially the same diameter as the end face of the propelling pipe, and a front end face of the pusher wheel body part are projected. And a pair of propelling projections for pushing the propelling tube, the projecting projection for pushing the propelling tube is provided at a position corresponding to the cushioning member between the propelling tube end surfaces, and the projection from the rear end surface of the presser wheel main body portion. Extrusion with push jack But it lies in the to be transmitted through the propulsion tube extrusion projection.

  According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, at least the front end surface of the projection of the push ring is configured with a cushion member between the end surfaces of the propelling pipe.

  In the present invention, the cylindrical propulsion pipe is sequentially connected to the upper and lower portions of the end face with a cushion member between the end faces of the propulsion pipe, and pushed out in the axial direction of the propulsion pipe by the main push jack, and the upper and lower propulsion pipes In the curve propulsion method in which the cushioning portion between the end faces is used as a fulcrum to change the horizontal direction between the adjacent propulsion pipes, the curve is propelled. Between the former push jack and the rearmost propulsion pipe Protrusion pipe pressurization projections are provided on the front end face of the interstitial push wheel at the upper and lower positions corresponding to the cushioning material between the propulsion pipe end faces, and the rear end face of the pusher wheel is pushed out by the main push jack so that the end face of the propulsion pipe Even when the intermediate cushioning material and the pressing position where the thrust is applied by the main push jack are shifted from each other in the direction of the propulsion pipe, they are added to the rear end face of the rearmost propulsion pipe. Since the generated pressure is concentrated on the rear end surface corresponding to the position of the cushioning material between the end surfaces of the propulsion pipe, the shear stress generated in the propulsion tube is reduced, and the maximum stress leading to crack generation can be increased, resulting in cracks. This makes it possible to promote a sharp song without causing any problems.

  Further, in the present invention, the projecting portion of the push wheel is configured such that at least the front end surface thereof is composed of a cushion material similar to the cushion material between the end surfaces of the propulsion tube, so that the rear end surface of the concrete propulsion tube is uneven. However, the end face and the projection are in point contact with each other, stress concentration on the end face is prevented, and cracking can be prevented.

It is a fragmentary longitudinal cross-section which shows the outline of the propulsion pipe extrusion part of the last part in the curve propulsion method which concerns on this invention. It is a disassembled perspective view which shows the positional relationship of a cushioning material between a pushing pipe end surface same as the above, a press ring, and a former | pressing jack. FIG. 2 shows a pressurized state of the propelling tube main body in the test example, where (a) shows case 1, (b) shows case 2, and (c) shows case 3. It is a graph which shows the crack load in cases 1-3 shown in FIG. It is a partial longitudinal cross-sectional view which shows the sharp curve construction state in the conventional propulsion construction method. It is explanatory drawing which shows the arrangement | positioning relationship of the circumferential direction of a former pushing jack same as the above, and the cushion material between propulsion pipe end surfaces.

  Next, the best mode for carrying out the present invention will be described based on examples shown in the drawings.

  FIG. 1 shows a construction state of the curve propulsion method according to the present invention. In the figure, reference numeral 10 denotes a propulsion pipe in a curved construction portion, and 11 denotes a pipe rod connecting the propulsion pipes 10, 10.

  A push wheel 12 is brought into contact with the rear end surface of the propulsion pipe 10 at the rearmost portion, and the rear surface thereof is pushed out in the propulsion direction by a number of struts 13, 13. I have to. The main push jack 14 supports the rear end side on a reaction force receiver 18 built in the shaft.

  Although not shown in the drawing, a leading excavator is installed in the most advanced portion of the propulsion pipe 10, and a pipe rod 11 formed by the propulsion pipe 10 is pushed out into a space excavated by the leading excavator. Yes.

  A joint portion between the propulsion tubes 10 and 10 is configured as shown in FIG. That is, a cylindrical collar 15 protrudes from the outer periphery of the rear end of the concrete propulsion pipe body 10a of each propulsion pipe 10, and the collar of the propulsion pipe 10 on the front side protrudes from the front end of the propulsion pipe main body 10a. The insertion part 16 inserted in 15 is formed.

  A clearance is provided between the inner peripheral surface of the collar 15 and the outer periphery of the insertion portion 16, and a water stop packing 17 is inserted therein, thereby stopping water inside and outside the pipe tub at the joint portion. In addition, this clearance is set to a size that allows an angular change in the axial direction of both propulsion pipes 10 and 10.

  Between the front end surface of the insertion portion 16 and the propulsion tube main body portion 10 a in the collar 15, a cushion member 20 between the propulsion tube end surfaces is interposed. As shown in FIG. 2, the propulsion pipe end-face cushion material 20 is installed in a pair of upper and lower parts of a part obtained by dividing the end face into four equal parts by a radial line, for example. It is stuck on either end face.

  The allowable range of curvature in curve construction is determined by the thickness of the cushion member 20 between the end surfaces of the propelling pipe as shown in FIG. That is, in the case of curve construction using a propulsion pipe having a certain outer diameter, the angle between the front and rear propulsion pipes 10 and 10 in the center line direction is different with the cushion members 20 and 20 between the upper and lower propulsion pipe end faces as fulcrums. In this case, the limit of the contact between the end surfaces of the propulsion pipes on the inner diameter side of the curve is determined by the thickness of the cushion member 20 between the end surfaces of the propulsion pipes.

  The push wheel 12 is inserted into the collar 15 and is in contact with the end surface of the propulsion tube main body 10a. The pusher wheel 12 includes a ring-shaped pusher wheel main body 30 and propulsion pipe pressurizing protrusions 31, 31 that protrude integrally with the front surface thereof.

  The projections 31, 31 are portions of the front end surface of the presser wheel main body 30 that are divided into four equal parts with the radial line as a boundary in the same manner as the above-described cushioning member 20, 20 between the end surfaces of the propelling pipe. It protrudes from a pair of upper and lower parts.

  A cushion material 32 similar to the cushion material 20 between the propulsion pipe end surfaces is attached to the front end surfaces of the protrusions 31 and 31. The cushion material 32 has a hardness that prevents point pressure due to unevenness of the rear end surface of the propulsion tube main body 10a and does not cause tensile stress to act on the propulsion tube 10 when it is compressed. That is, by compressing in the thickness direction, deformation in a direction perpendicular to the compression direction occurs, and it is preferable that the deformation does not affect the end face of the propelling tube as a tensile force.

  As described above, the protrusion is provided with the steel protrusion 31 on the presser wheel body 30 and the cushion material 32 is attached to the tip of the protrusion 31. Also good.

  The projecting portion 31 and the above-described propulsion pipe end face cushion material 20 have end faces that are the same in shape, and are disposed at upper and lower positions corresponding to each other in the direction of the propulsion pipe axis.

  In this embodiment, both ends of the protrusion 31 and the propulsion pipe end face cushion material 20 are oriented along the radial line of the propulsion pipe 10, and the whole has a fan-like shape. The other ends may be parallel to each other in the vertical direction.

In this way, by providing the push ring 12 with the protrusions 31 and 31 at positions corresponding to the axial direction with the cushion members 20 and 20 between the propulsion pipe end faces, and propelling by the main push jacks 14 and 14 through the push ring 12, Even if the circumferential positions of the main pushing jack 14 and the cushion member 20 between the end surfaces of the propelling pipes do not correspond, the pushing force by the main pushing jacks 14 and 14 is transmitted through the projections 31 and 31 of the push wheels. As a result, the rearmost propulsion pipe 10 is applied to the pressing position of the protrusion 31 and the reaction force from the propulsion pipe end-face cushion material 20. The position coincides with the axial direction, and only the axial compressive force acts on the ring-shaped tube wall of the propulsion tube 10, and the elastic force is small or non-actual. A state in which a crack hardly occurs in 10.
Test example

  As shown in FIG. 3, the pressure test at the time of pushing out the propelling pipe for cases 1 to 3 was performed.

  As shown in FIG. 3 (a), the case 1 uses a concrete cylindrical sample 35 corresponding to the propulsion tube main body 10a, and the sample 35 does not correspond to the propulsion tube end face cushion materials 20, 20. The position was pressurized between the protrusions 31 and 31 of the press wheel 12.

  In the case 2, as shown in (b), the sample 35 was pressurized between the propulsion pipe end face cushion members 20 and 20 and the projections 31 and 31 at positions corresponding to the cushion members 20 and 20.

  In the case 3, as shown in FIG. 2C, the pressure was applied only between the presser wheel main body 30 having no protrusions and the cushioning members 20, 20 between the propulsion pipe end faces.

  The sample 35 used had an inner diameter of 350 mm, a tube thickness of 50 mm, and three types of tube lengths of 100 mm, 200 mm, and 300 mm.

As a result of performing the pressure test of the above cases 1 to 3 on these propulsion pipes, the relationship between the loads at which cracks occurred was as shown in Table 1. The results are shown graphically in FIG.
Table 1

  In case 1, cracks occurred with a considerably small load. This is considered that bending stress like the simple bending test of a beam generate | occur | produces in the axial direction of a pipe body.

  In case 2, the load for generating cracks was significantly larger than in case 1. This is considered to be because compressive stress mainly acts on the concrete because the loading point on the tube wall coincides with the axial direction of the propulsion tube.

  Case 3 is a case where the rigidity of the press wheel is high and a uniform compressive force acts on the concrete, but in reality, only a crack load equivalent to that of case 1 was obtained.

  From this result, even if the push ring of the sharp curve propulsion pipe has a high rigidity and applies a uniform compressive stress to the concrete as in the case 3, the sharp curve construction in which the cushion material is interposed only in the upper and lower portions. It was found that Case 2 was the best.

DESCRIPTION OF SYMBOLS 10 Propulsion pipe 10a Propulsion pipe main-body part 11 Pipe rod 12 Push ring 13 Strut 14 Former push jack 15 Color
16 Insertion part 17 Water-stop packing 18 Reaction force receiving 20 Propulsion pipe end face cushion material 30 Push ring main body part 31 Projection part 32 Cushion material

Claims (4)

The cylindrical propulsion pipe is sequentially connected to the upper and lower portions of the end face with a cushion member between the end faces of the propulsion pipe, and the rearmost propulsion pipe is connected to the rear end face of the propulsion pipe via a ring-shaped push ring. In addition to pushing in the axial direction of the propelling pipe by the former push jack, the curve is propelled by changing the horizontal direction between the adjoining propelling pipes with the upper and lower propelling pipe end face cushions as fulcrums. In the curve propulsion method,
Protrusion for pressing the propulsion pipe is provided on the front end face of the press ring interposed between the main push jack and the rearmost propulsion pipe at a vertical position corresponding to the cushion member between the end faces of the propulsion pipe. A curve propulsion method characterized in that an end surface is pushed out by the main pushing jack, and propulsive force from the main pushing jack is transmitted to the propelling pipe through the projection.   2. The curve propulsion method according to claim 1, wherein at least a front end surface of the protrusion portion of the push ring is configured with a cushion member between the end surfaces of the propulsion pipe. The cylindrical propulsion pipe is sequentially connected to the upper and lower portions of the end face with a cushion member between the end faces of the propulsion pipe, and the rearmost propulsion pipe is connected to the rear end face of the propulsion pipe via a ring-shaped push ring. In addition to pushing in the axial direction of the propelling pipe by the former push jack, the curve is propelled by changing the horizontal direction between the adjoining propelling pipes with the upper and lower propelling pipe end face cushions as fulcrums. In the press wheel used for the curve propulsion method,
A press ring main body portion having a ring shape having substantially the same diameter as the end surface of the propulsion tube, and a pair of propelling portions for pressing the propulsion tube projecting from the front end surface of the press ring main body portion, are integrated.
The projection for pushing out the propelling tube is provided at a position corresponding to the cushion member between the end surfaces of the propelling tube. Curve propulsion method pusher designed to be transmitted.   The push ring for the curve propulsion method according to claim 3, wherein at least a front end surface of the protrusion portion of the press ring includes a cushion member between the end surfaces of the propulsion pipe.

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