JP6466773B2 - How to install stabilization pipes for embankment - Google Patents

Description

  The present invention relates to a method for installing a horizontal pipe for embedding embedding used for stabilization of embankment.

  In Japan, slope failures due to earthquakes and heavy rains occur frequently, and embankment conservation is an urgent issue.

  In order to prevent collapse of the embankment slope, drainage of embankment is effective for groundwater level in the embankment by appropriate drainage measures.

  When the drainage pipe is directly placed on the embankment, it may cause clogging of the soil particles into the slits of the pipe, so-called clogging, or the outflow phenomenon of the soil particles into the pipe, and the groundwater level over a long period of time. Due to repeated saturation and unsaturation of the embankment due to fluctuations in the soil, there is a concern that the accumulation of fine particles around the slit will progress and the drainage performance will decline.

  Conventionally, pipe installation intervals have been empirically engineered to be about 1 m, and specific design methods such as optimal installation intervals and installation arrangements have not been established.

  The current buried pipe design standards dealing with embankments under high embankments include road earthwork carpart construction guidelines 1 (hereinafter referred to as road earthwork guidelines) and the Ministry of Agriculture and Water land improvement project plan design standards design “pipeline” 2 (hereinafter referred to as agriculture water). Both of them are designed based on the Marston-Spangler theory.

  However, since this theory is constructed based on many unreasonable assumptions, it has been pointed out that earth pressure and pipe deformation calculated by this theory are quite different from the actual ones.

  Furthermore, in the road earthwork guidelines, the bending moment generated in the pipe body and the deflection rate of the pipe are calculated by the Marston-Spangler theory, and it is buried under the embankment so that these do not exceed the resistance bending moment and allowable deflection rate of the pipe. The maximum cover height of culverts is specified as 20 m for rigid box culverts and concrete pipes, and 30 m, 7 m and 10 m for flexible corrugated metal culverts, rigid vinyl chloride pipes and reinforced plastic composite pipes, respectively. However, if the cover is higher than that, it only states that it is necessary to make a rational design with detailed examination, and no specific design method is shown.

  On the other hand, the agricultural water standard does not indicate the limit soil cover height to which the Marston-Spangler theory can be applied for rigid pipes, but for flexible pipes, the soil cover height of 15 m is the application limit of the MS theory.

  However, the design method for the overburden height exceeding this is not shown. In this way, all of the current design standards dealing with burying under high embankments are constructed based on the Marston-Spangler theory that does not reflect the actual situation, and concrete design methods for cases where the embankment height exceeds 15 m or 30 m Not shown.

  For example, we investigated the deformation behavior of HIPE (High Density Polyethylene) pipe, which has been used frequently in recent years as a drain pipe buried under high embankment, and the effect of countermeasure work to prevent excessive deformation, HDPE having creep behavior In order to prevent drain ring packing, the vertical deflection rate δ at the time of embankment construction should be 15% or less for short-term service and 10% or less for long-term service for 50 years.

As an attempt to make an earthquake-resistant structure using a pipe body made of a rigid body such as iron, there is the following patent document, which uses a pipe body made of a rigid body such as iron.
JP 2006-188940 A

  In this patent document 1, as shown in FIG. 17, the drainage pipe 2 has many holes 4 penetrating in the longitudinal direction. The holes 4 are formed in a long hole shape and are arranged in a staggered pattern in the circumferential direction. Furthermore, the drainage pipe 2 has a closed portion in which one end is crushed flat and closed in a substantially sharp shape. In the figure, 9 indicates the ground by embankment, and 8 indicates an inclined surface.

  As is also the case with Patent Document 1, in construction in a narrow space, it is necessary to perform construction by connecting a short small-diameter thin-walled steel pipe by welding or the like.

  Usually, a welded connection of a thin-walled steel pipe requires a skilled engineer, and there are problems such as a limited construction environment.

  Therefore, development of convenient technology that can easily connect steel pipes at the site is strongly desired.

  The purpose of the present invention is to eliminate the inconveniences of the conventional example, and by placing it on the embankment, by demonstrating the reinforced soil function, it is also possible to improve the embankment's resistance to vibrations due to overloading and traffic loads, rainfall and earthquakes. An object of the present invention is to provide a method for installing a stabilizing pipe for embankment that has a rigidity that can be contributed and is convenient to be directly connected to the embankment when it is directly placed on the embankment.

In order to achieve the above object, the present invention provides a method in which a thin steel pipe is connected to the embankment horizontally or inclined at 0 to 5 °. The thin-walled steel pipe is inserted into the existing thin-walled steel pipe with a new thin-walled steel pipe set in the propulsion machine. Place the thin-walled steel pipe to be connected to the steel pipe so that it will butt, apply a two-component acrylic adhesive to the outside of the thin-walled steel pipe and the inside of the sheath, and slide the thin-walled steel pipe into the sheath. The gist is to bond and press fit into the ground as a predetermined length.

  According to the first aspect of the present invention, the thin-walled steel pipe has a function of lowering the water level in the embankment by embedding it as a drainage pipe, and exerts a reinforced soil function to prevent vibration, rain and earthquake due to an overload or traffic load. It can also contribute to improving the proof stress of embankments.

  In addition, by using a sheath pipe, it can be easily connected on site, unlike a mechanical joint using a screw or welding, and the connection part has a bending strength and compression equal to or higher than the main part. It can have a tensile strength.

  In addition, it is to be constructed on embankment, and even if there are vegetation and buildings (adjacent structures) around it and a large work space cannot be secured, it can be done if a relatively narrow work space is secured, and there is no welding work, etc. There is no risk of environmental pollution.

The two-component mixed acrylic adhesive is optimal for use in the present invention as a structural adhesive developed exclusively for genus bonding as a two-component room temperature curable adhesive.

In addition to this, small diameter thin steel pipes are press-fitted by a propulsion machine with an excavation head at the tip, and can be easily and quickly press-fitted without frictional resistance, and thin-walled steel pipes can also be easily joined via a sheath Can be done.

The gist of the present invention described in claim 2 is that the adhesive has an adhesive thickness of 1 mm or less and the sheath tube has a length of 200 mm or more.

According to the second aspect of the present invention, the thinner the bonding thickness (clearance) is, the easier it is to bond the steel pipe and the sheath pipe, and the higher thickness can be obtained more uniformly than the thicker one. Higher strength can be obtained with longer length.

  As described above, the method for installing the stabilization pipe of the embankment according to the present invention is to place the embankment on the embankment and demonstrate the function of reinforcing soil, so that the resistance of the embankment to vibrations due to overloading and traffic loads, rainfall and earthquakes. In addition to having the rigidity that can contribute to the improvement of the structure, it is convenient because it can be easily connected on site when it is directly placed on the embankment.

  Hereinafter, embodiments of the present invention will be described in detail. In the present invention, as shown in FIG. 12, the thin steel pipe 3 is connected and placed on the embankment 1 horizontally or at an inclination of 0 to 5 °. The connection between the thin steel pipes 3 is as shown in FIG. The thin steel pipes 3 are arranged so as to face each other, the adhesive is applied to the outside of the thin steel pipe 3 and the inside of the sheath pipe 24, the height of the thin steel pipe 3 and the sheath pipe 24 is adjusted, and the thin steel pipe 3 is slid. It is glued in a form that fits into a sheath and is pressed into the ground as a predetermined length.

  The thin steel pipe 3 has a length of 550 to 1100 mm, an outer diameter of 76.3 mm, an inner diameter of 67.9 mm, and a plate thickness of 4.2 mm.

  The sheath tube 24 has a length of 210 mm, an outer diameter of 89.1 mm, an inner diameter of 80.7 or 78.1 mm, and a plate thickness of 4.2 or 5.5 mm.

  As the adhesive, a two-component mixed acrylic adhesive uses a structural adhesive developed exclusively for metal bonding as a two-component room temperature curable adhesive.

  Main agent A is an acrylic monomer, elastomer, polymerization initiator, main agent B is an acrylic monomer, elastomer, and polymerization accelerator. Since it is a two-component main agent, the performance does not deteriorate even if the blending ratio fluctuates, and the acrylic monomer is washed with interfacial oil. Therefore, the oil surface adhesion is good, and the acrylic monomer contains a polar group and contributes to adhesion such as hydrogen bonding. The cured product has a sea-island structure that exhibits toughness.

As an example, “Metal Rock” (registered trademark) Y600 series manufactured by Cemedine Co., Ltd. is suitable for the adhesive, and the properties are shown in Table 1 below.

  The adhesive thickness is preferably 1 mm or less, and the sheath tube is preferably 200 mm or more in length.

  In addition, as shown in FIGS. 4 to 12, the placement on the embankment 1 at the site is performed by providing a pointed excavation head 12 having a fishtail at the tip of the thin steel tube 3 that becomes the tip tube 3 a, and the propulsion machine 14. To do.

  The propulsion device 14 has a chuck device and a rotation drive device 15 for the thin steel pipe 3, and is inserted into the thin steel tube 3 in which the rod 5 rotated by the chuck device and the rotation drive device 15 is set to rotate the excavation head 12. As shown in FIG. 4, the first thin-walled steel pipe 3 (tip tube 3a) and the rod 5 are connected to the excavation head 12 as shown in FIG. 4, and the excavation head 12 and the meat steel pipe 3 (tip tube) are connected as shown in FIG. 3a) is set.

  As shown in FIG. 6, excavation is performed by the excavation head 12, and the chuck device and the rotary drive device 15 are pushed out and propelled.

  As shown in FIG. 7, the screw of the rod 5 is removed, the chuck device and the rotary drive device 15 are retracted, and the adapter pipe 6 and the rod 5 are set.

  As shown in FIG. 8, the adapter pipe 6 is used for propulsion, the adapter pipe 6 and the rod 5 are removed as shown in FIG. 9, and the second thin steel pipe 3 is set as shown in FIG.

  At this time, an adhesive is applied to the thin-walled steel pipe 3 to be added to the outside of the tip and the inside of the sheath pipe 24, and the thin-walled steel pipe 3 with the sheath pipe 24 is slid to fit into the existing thin-walled steel pipe 3 into the sheath pipe 24. The thin steel pipes 3 are connected by bonding. An adhesive is also applied to the outside of the rear end of the existing thin steel pipe 3.

  As shown in FIG. 11, the second thin steel pipe 3 is propelled.

  Thereafter, the steps from FIG. 9 to FIG. 10 are repeated to connect the third and subsequent thin steel pipes 3.

  When the chuck device and the rotation drive device 15 are moved back and forth with a hydraulic jack or the like in this way and the thin steel pipe 3 is rotationally press-fitted by one piece, the chuck device and the rotation drive device 15 are retracted, and a new thin steel tube 3 Pieces are set, connected to the rear end, and sequentially pushed.

  In the present invention, the thin-walled steel pipes 3 are connected to each other by fitting a sheath pipe 24 made of a steel pipe to the outer peripheral surface of the joints of the thin-walled steel pipes 3 and 3 and bonding and fixing them with an adhesive. The deformation performance and strength against bending, compression, and tension were verified, and it was confirmed by tests whether or not the same performance as that of the main part of the thin-walled steel pipe was possessed.

  The test is to conduct a bending test of small-diameter thin-walled steel pipes that have been bonded together, to grasp the bending strength and mechanical behavior, and to verify the safety against the embankment pressure that acts during service.

  In the bending test, the thin steel pipe 3 was bonded using the selected adhesive. The joining method arrange | positions so that the thin steel pipes 3 may be faced | matched, and covered the sheath pipe | tube 24 to the junction part, and joined. The bonding method is shown in FIG.

  The bonding method was performed by adjusting the height of the thin steel pipe 3 and the sheath pipe 24 with the pedestal 7, sliding the thin steel pipe 3 from both sides, and fitting into the sheath pipe 24.

The adhesive is applied to the outside of the thin-walled steel pipe 3 and the inside of the sheath pipe 24. The adhesive used for bonding the thin-walled steel pipe 3 is a two-component mixed acrylic adhesive manufactured by Cemedine. Table 2 below shows the physical properties of the adhesive.

A schematic diagram of the bending test is shown in FIG. A four-point bending test was performed so that the same bending stress acts on the joint. The dimensions of the test specimen are shown in Table 3 below.

  In FIG. 2, reference numeral 7 denotes a pedestal, 10 denotes a roller, 11 denotes a jig, a load A, and B between the equal bending section fulcrums B.

  The test specimens used the adhesive thickness (clearance) and sheath tube length as parameters. The measurement items in this test were strain and displacement, and measurement was performed by attaching a strain gauge to the steel pipe and the sheath. The measurement points of the displacement meter were 5 points, both fulcrum portions, 1/4 and 3/4 positions with respect to the total length of the test body, and the center of the test body.

The test results are shown in Table 4 below.

  Except for the case where the adhesive thickness is large and the sheath length is short, the strength (maximum load) is greater than that of the thin steel tube 3 alone.

  The load-displacement curve in each test case is shown in FIG. As shown in the circle in the figure, in this test, abnormal noise was generated several times during loading, and an increase in displacement and a decrease in load were observed.

  The stress distribution at the time of peeling of the adhesive surface and the load-strain curve at the center of the specimen are shown in FIGS. FIG. 13 is a diagram showing the stress distribution during peeling when the adhesive thickness is 0.9 mm, FIG. 14 is a diagram showing a load-strain curve, and FIG. 15 is the stress distribution during peeling when the adhesive thickness is 2.2 mm. FIG. 16 is a diagram showing a load-strain curve.

  Solid lines and dotted lines indicate theoretical values. The solid line indicates that the thin steel pipe 3 and the sheath pipe 24 are completely bonded by the adhesive, and is assumed to be a complete synthetic cross section, whereas the dotted line indicates that the thin steel pipe 3 and the sheath pipe 24 are not bonded, Only the sheath 24 is considered an effective cross section.

  In these graphs, the closer the experimental value is to the solid line, the more the thin-walled steel pipe 3 and the sheath 24 are bonded, and the closer to the dotted line, the less the bonding is.

  From this graph, it can be seen that the thicker the adhesive thickness, the more the parts that are not bonded, while the thinner the adhesive thickness, the more firmly bonded.

  This is considered to be because the thinner the bonding thickness (clearance), the easier it was to bond the steel pipe and the sheath, and the higher the thickness, the higher the strength.

  As a study of safety during operation, the earth pressure at the embankment depth of 20 m was calculated with reference to the design method 2 of the buried pipe, and it was 33.3 MPa. Compared with the bending stress of the load at the time of the first abnormal noise generation in each test case, the strength was about 5 times even in the case where the strength is the smallest, indicating that it has sufficient safety. .

  When the strength was compared using the length of the sheath tube 24 and the adhesive thickness as parameters, the thinner the sheath thickness and the longer the sheath tube 24, the higher the strength.

  Therefore, it is desirable that the adhesive has a thickness of 1 mm or less and the sheath tube has a length of 200 mm or more.

  In addition, based on the design method of buried pipe, the earth pressure acting on the steel pipe at the embankment depth of 20m is calculated, and in each test case, even the smallest case is about A strength of about 5 times was obtained.

It is explanatory drawing which shows adhesion | attachment of the thin steel pipe of the installation method of the stabilization pipe of the embankment of this invention. It is a schematic diagram of the bending test of the thin-walled steel pipe which carried out the adhesive joining of the installation method of the stabilization pipe of the embankment of this invention. It is a figure which shows the load-displacement curve in a test. It is a side view which shows the 1st process of thin steel pipe embedding with a propulsion machine. It is a side view which shows the 2nd process of thin steel pipe embedding with a propulsion machine. It is a side view which shows the 3rd process of thin-walled steel pipe embedding with a propulsion machine. It is a side view which shows the 4th process of thin-walled steel pipe embedding with a propulsion machine. It is a side view which shows the 5th process of thin-walled steel pipe embedding with a propulsion machine. It is a side view which shows the 6th process of thin steel pipe embedding with a propulsion machine. It is a side view which shows the 7th process of thin-walled steel pipe embedding with a propulsion machine. It is a side view which shows the 8th process of thin-walled steel pipe embedding with a propulsion machine. It is explanatory drawing which shows the outline | summary of the installation method of the stabilization pipe of the embankment of this invention. It is a figure which shows the stress distribution at the time of peeling in the case of the adhesive thickness of 0.9 mm of an adhesive agent. It is a figure which shows the load-strain curve in case the adhesion thickness of an adhesive agent is 0.9 mm. It is a figure which shows the stress distribution at the time of peeling in the case of the adhesive thickness of 2.2 mm of an adhesive agent. It is a figure which shows the load-strain curve in case the adhesion thickness of an adhesive agent is 2.2 mm. It is a schematic sectional drawing of the principal part which shows a prior art example.

DESCRIPTION OF SYMBOLS 1 ... Filling 2 ... Drainage pipe 2a ... Pipe main body 3 ... Thin-walled steel pipe 3a ... End pipe 4 ... Hole 5 ... Rod 6 ... Adapter pipe 7 ... Base 8 ... Inclined surface
9 ... Ground 10 ... Roller 11 ... Jig 12 ... Drilling head
DESCRIPTION OF SYMBOLS 14 ... Propulsion machine 15 ... Chuck apparatus and rotation drive device 24 ... Sheath pipe

Claims (2)

When connecting a thin steel pipe and placing it on the embankment horizontally or at an inclination of 0 to 5 °, the thin steel pipe is pressed into the ground by placing a drilling head at the tip of the thin steel pipe and propelled by a propulsion machine. The thin-walled steel pipe is joined with a thin-walled steel pipe that is to be connected to the previously-embedded thin-walled steel pipe. Place the two-component mixed acrylic adhesive on the outside of the thin steel pipe and the inside of the sheath pipe, and slide the thin steel pipe so that it fits into the sheath pipe. A method of installing a stabilization pipe for embankments characterized by being pressed into Adhesive Adhesive thickness 1mm or less, the sheath tube installation method of stabilizing the pipe of claim 1 Symbol placement of fill in length and more than 200 mm.

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