JP5212976B2 - Drainage structure and straight pipe joint used for drainage structure - Google Patents

Description

  The present invention separates the facility for collecting used water and rain water, etc. inside and below the building, particularly under the bridge girder, and the drainage facility for guiding the water collected by the facility to a sewer pipe or the like. And a straight pipe joint suitable for use in the drainage structure.

  In a building, when facilities that collect used water or rainwater (hereinafter referred to as water collection facilities) are separated from drainage facilities that lead the water collected by the water collection facilities to sewer pipes, etc. Are usually connected by a drain pipe. However, the relative position between the water collection facility and the drainage facility may change due to expansion and contraction of the equipment construction material according to changes in temperature. There are things to do. Therefore, the drain pipe connecting the water collecting facility and the drainage facility provided at a distant position requires a configuration for buffering the relative movement of both facilities.

  As a configuration for buffering the relative movement of the water collection facility and the drainage facility provided at a distant position, for example, a drainage pipe structure of a bridge can be cited. The bridge girder of the bridge expands and contracts in the direction of the bridge axis according to the temperature change, but if this expansion and contraction is restricted, the bridge girder will be damaged due to the force accompanying its deformation, so the expansion and contraction is allowed by the joint structure . For this reason, the bridge girder and the pier will move relative to each other in the bridge, and when the rainwater collected on the road surface on the bridge girder is guided to the drainage system under the pier, the bridge girder side drainage pipe connected to the road surface and the pier side connected to the drainage system A structure for buffering the relative movement of the bridge girder and the pier is necessary at the connection portion with the drain pipe.

  A structure for buffering the relative movement between the bridge girder and the bridge pier has been devised for a long time. As such a structure, for example, an elevated section drainage disclosed in JP-A-57-77703 (Patent Document 1). There is a pipe connection device. In this connection device, a packing made of an elastic material such as rubber is attached to the inner wall of an end portion (connection portion) of the drain pipe in a circumferential direction, and the outer diameter of the drain pipe is slightly larger than that of the drain pipe. A small drainage pipe is inserted. The packing has a curved portion at the center in the width direction, and both side portions of the curved portion are bonded to the inner wall of the outer drain pipe, and are depressed outwardly by the outer peripheral surface of the drain pipe into which the curved portion is inserted. The two drain pipes are connected in a confidential state. Therefore, the seam of the elevated part is completely sealed while sufficiently absorbing vibrations of the elevated part, and overflow of earth and sand water during cleaning can be prevented.

  However, the connection device of Patent Document 1 has a problem that it cannot cope with movement in a direction orthogonal to the drain pipe axis, although the movement in the drain pipe axis is buffered. Therefore, in order to be able to cope with any movement in the direction parallel to or perpendicular to the drain pipe axis, a method of installing a gutter on the upper part of the pier side drain pipe and loosely fitting the bridge girder side drain pipe to this gutter Has been adopted. However, this method has a problem that foreign matter enters from the gap between the bridge girder-side drain pipe and the gutter and the drain pipe is clogged, or the drainage overflows from the gap. Accordingly, means for solving these problems have been devised. As such means, there is a connection structure of a viaduct drainage pipe disclosed in Japanese Patent Laid-Open No. 2003-301413 (Patent Document 2).

  In the connection structure of Patent Document 2, the drainage basin side (drainage facility side) drainage basin fixed to the bridge pier and the drainage upper pipe fixed to the viaduct road floor side are loosely fitted. The cap is covered with a water collecting cap. As the cap, for example, a cap provided with a donut disk-shaped outer end portion having a central hole 7 for loosely draining the upper drain pipe at the center portion and having a small height flange is employed. And according to this connection structure, it has excellent durability against external force due to vibration or bending stress applied to the connection part of the drain pipe fixed to the bridge pier part and the viaduct road surface part respectively, and the fallen leaves Since the entry of other dust and foreign matter is prevented, the drainage function is excellent.

  However, the connection structure disclosed in Patent Document 2 still leaves problems due to the shape of the catchment basin. In other words, when a catchment basin is used, the opening area must be increased in order to cope with the movement in the direction perpendicular to the drain pipe axis, and when the opening area is increased, There is a problem that problems such as mud accumulation are likely to occur, and maintenance is troublesome. Therefore, it is preferable not to use a catchment for the structure for buffering the relative movement of the bridge girder and the pier.

Means for buffering the relative movement between the bridge girder and the pier without using a catchment have also been devised previously. As such means, for example, an elevated drainage pipe disclosed in Japanese Utility Model Publication No. 56-168688. There are connection devices. In this connection device, a drainage pipe having flexibility, a so-called bellows-like flexible pipe is used, and the drainage pipe itself is deformed in accordance with the movement of the bridge girder, so that the drainage pipe on the road floor side is not used. And can connect the pier side drain pipe
JP-A-57-77703 JP 2003-301413 A Japanese Utility Model Publication No. 56-168688

  However, in the drainage structure using the flexible pipe, when a sudden change in the pipe internal pressure due to the increase in the internal flow velocity of the drain pipe occurs, there is a problem that the external pressure is applied to the flexible pipe and the flow becomes worse. Therefore, it is necessary to increase the pipe diameter in order to ensure a sufficient flow rate. In addition, when the external pressure becomes extremely large, the flow does not stop worsening and the flexible pipe is damaged by the so-called water hammer phenomenon (a phenomenon in which positive pressure and negative pressure are alternately repeated inside the drain pipe). There was also.

  Therefore, the present invention provides a drainage structure that can alleviate a sudden change in the pressure in the flexible pipe when the flexible pipe is used to buffer the relative movement of the water collecting equipment and the drainage equipment provided at remote locations, An object is to provide a straight pipe joint suitable for use in a drainage structure.

  In the drainage structure according to the present invention, the thin tube and the thick tube are fixed in a state where one end of the thin tube is inserted into the thick tube coaxially arranged with the thin tube, and the inner surface of the thick tube and the outer surface of the thin tube are fixed. A straight pipe joint having a gap communicating with the inside of the thick pipe is provided. The straight pipe joint is arranged with the narrow pipe vertically upward, a flexible pipe is connected to the end of the thick pipe where the thin pipe is not inserted, and the gap is open to the atmosphere. In the present invention, the flexible tube is a flexible tube that can be freely expanded and contracted. For example, a tube having an annular protrusion provided on the outer periphery of the tube wall at equal intervals in the axial direction, or an outer periphery of the tube wall. What provided the protrusion which draws a spiral is suitable. However, there is no restriction | limiting in the shape, As long as it has the flexibility which buffers sufficiently the relative movement of the connected water collection equipment and drainage equipment, the pipe material of other shapes may be sufficient.

  In the straight pipe joint according to the present invention, the thin tube and the thick tube are fixed in a state where one end of the thin tube is inserted into the thick tube coaxially arranged with the thin tube, and the inner surface of the thick tube and the outer surface of the thin tube Are communicated with the inside of the thick pipe.

  In the present invention, a thick tube means that the diameter of the end into which the thin tube is inserted is larger than that of the thin tube with respect to the thin tube into which one end is inserted, and the diameter is larger than that of the thin tube over the entire length. There is no need. The diameter of the end portion of the thick tube to which the flexible tube is connected may be smaller than the diameter of the end portion into which the thin tube is inserted.

  Moreover, in this invention, the cross-sectional shape of a thick tube, a thin tube, and a flexible tube may be a square.

  According to the drainage structure of the present invention, since the gap between the inner surface of the large pipe and the outer surface of the thin pipe in the straight pipe joint is open to the atmosphere, the outside air flows out through this gap when the pressure in the flexible pipe changes. The pressure in the flexible tube will return to the same level as the atmosphere. Therefore, the rapid change in the pressure in the flexible pipe is alleviated, and the flow is not deteriorated or the water hammer is not damaged due to the pressure change. In addition, since the flow becomes smooth, the load on the drainage pipe in the entire drainage path including the drainage structure can be reduced and the life can be extended, and the flow path area can be reduced, that is, the pipe diameter can be reduced. There is an advantage that the entire piping system can be reduced in size and materials can be saved. In addition, the straight pipe joint is arranged so that the thin pipe arranged coaxially and relatively fixed to the thick pipe is arranged on the upper side in the vertical direction, so that foreign matter can accumulate without interfering with the flow in the drain pipe. There is no overflow from the drainage. In addition, the gap between the inner surface of the thick tube and the outer surface of the thin tube is for the purpose of ventilation, so there is no need to buffer the relative movement of the water collection facility and the drainage facility, so there is freedom in shape and foreign matter is mixed in It can be made into a size and shape that is difficult to nest by wild birds.

  The drainage structure according to the present invention is particularly suitable as a drainage structure in the case where the rainwater collected on the road surface on the bridge girder is led to drainage equipment under the pier under the bridge girder. In the conventional drainage structure, when the flow deteriorates, there is a problem that rainwater overflows in a facility called a drainage basin that collects rainwater on the road surface. However, by using this drainage structure, rainwater flows smoothly through the drainage pipe, so that it is possible to prevent rainwater from overflowing from the drainage basin. In addition, when the bridge girder has a box girder structure, this drainage structure may be built in the box girder, in which case work from the outside becomes unnecessary, and there is no need to use a scaffold or an aerial work vehicle. There is also an advantage that economic maintenance is possible.

  However, the drainage structure according to the present invention can be suitably used not only under the bridge under the bridge but also inside or below other buildings. In addition, since the clearance of the straight pipe joint opens toward the upper side in the vertical direction, the open-air arrangement is not so preferable.

  The straight pipe joint according to the present invention has a structure in which the thick pipe and the thin pipe arranged coaxially are relatively fixed, and the gap between the inner surface of the thick pipe and the outer surface of the thin pipe communicates with the inside of the thick pipe. It is suitable for the drainage structure according to the present invention.

  In the present invention, there is no limitation on the cross-sectional shape of the thick tube, the thin tube, and the drain tube, but it is preferably a square shape, and in that case, the cross-sectional shape can be matched with the drain tube arranged in the girder. Therefore, there are advantages that the flow is smooth, that the processing of the cross-section changing portion can be omitted, that the drainage pipe is shaped in consideration of the landscape, and that it can be stored in a limited space. However, even if the cross-sectional shape is a circle (round tube), the same effect can be obtained in terms of alleviating a rapid change in the pressure in the flexible tube.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view showing an overview of a drainage structure according to the present invention. FIG. 2 shows a straight pipe joint according to the present invention, wherein (a) is a front view, (b) is a right side view, (c) is a plan view, and (d) is a bottom view. In FIG. 2, the rear view is the same as the front view, and the left side view is the same as the right side view.

  The drainage structure shown in FIG. 1 is applied when the rainwater collected on the road surface 12 on the bridge girder 11 is guided to the drainage equipment under the bridge pier under the bridge girder. The road surface 12 has a slope that decreases from the center in the width direction toward the side, and rainwater that falls on the road 12 flows to the side and is collected by a drainage basin 13 provided on the side. The bottom portion of the drainage basin 13 communicates with a drainage pipe 14 penetrating the bridge girder 11 in the vertical direction.

  The lower end portion of the drain pipe 14 protrudes from the underside, and the flexible pipe 5 is connected to the lower end portion via the straight pipe joint 4. As described in detail in FIG. 2, the straight pipe joint 4 fixes the thin pipe 1 and the thick pipe 2 in a state where one end of the thin pipe 1 is inserted into the thick pipe 2 arranged coaxially with the thin pipe 1. It is a thing. Bolts and nuts are used to fix the narrow tube 1 and the thick tube 2, and both ends of the bolts spanning the opposing surfaces of the thin tube 1 and the thick tube 2 are fastened with nuts to the thin tube 1 and the thick tube 2, respectively. The gap 3 between the inner surface of the thick tube 2 and the outer surface of the thin tube 1 communicates with the inside of the thick tube 2 without being blocked. The thin tube 1 is arranged on the upper side in the vertical direction, the flexible tube 5 is connected to the end 2a of the thick tube 2 where the thin tube 1 is not inserted, and the gap 3 is opened to the atmosphere. Moreover, the diameter of the end 2a to which the flexible tube 5 of the thick tube 2 is connected is smaller than the diameter at the end 2b to which the thin tube 1 is inserted. In addition, although the drain pipe 14 and the material of the thin pipe 1 and the large pipe 2 of a straight pipe joint should just have sufficient durability, a hard vinyl chloride is suitable, for example. The straight pipe joint 4 may be any size as long as it fits the drain pipe 14. For example, the drain pipe 14 is widely used in a highway bridge or the like, and has a long side length of 250 mm and a short side length. When a rectangular tube having a rectangular cross section of 150 mm in length (hereinafter referred to as “250 × 150”) is used, the dimensions of the end 2a where the thin tube 1 of the thick tube 2 is not inserted and the thin tube 1 is 210 × 110, the inner diameter is 200 × 100, and the end of the thick tube 2 into which the thin tube 1 is inserted is preferably an outer dimension 250 × 150 and an inner diameter 238 × 138. In this case, the opening efficiency of the gap 3 (the area of the gap 3 with respect to the opening area of the end where the narrow tube 1 is inserted) is about 30%.

  The flexible pipe 5 is provided with a plurality of annular ridges arranged at equal intervals in the axial direction on the outer periphery of the pipe wall, and the pipe wall between the annular ridges is thin, and the extension of the bridge girder 11 is provided. It has the flexibility to follow. The material of the flexible tube 5 may be any material as long as it has sufficient durability and flexibility. For example, ethylene propylene rubber (EPDM) is suitable.

  A rigid drain pipe 15 is connected to the lower end of the flexible pipe 5. The drain pipe 15 is fixed to the pier 17 via a fixing tool 16. The fixing tool 16 is composed of a grip portion that is opened and closed by cutting a ring member and a support portion that extends from the cut portion of the ring member (not shown), and the drain pipe 15 is gripped by the grip portion. In this state, the end of the support portion is fixed to the surface of the pier with bolts. The drain pipe 15 is preferably made of, for example, hard vinyl chloride, like the drain pipe 14. The material of the fixing tool 16 is preferably a metal having corrosion resistance. For example, a material having a hot dip galvanizing specification of SS400 is suitable.

  According to this drainage structure, the flexible pipe 5 can buffer the relative movement of the bridge girder 11 and the pier 17. Since the gap 3 of the straight pipe joint 4 is open to the atmosphere, when the pressure in the flexible pipe 5 changes, outside air flows in and out through the gap 3, and the pressure in the flexible pipe 5 is the same as the atmosphere. Return to the level. Therefore, the rapid change in the pressure in the flexible pipe 5 is alleviated, and the flow is not deteriorated due to the pressure change, and the water hammer is not damaged.

  Further, since the flow becomes smooth, the flow is not deteriorated even if the flow path area is reduced, that is, the pipe diameter is reduced. Therefore, the diameter of the end of the thick pipe 2 to which the flexible pipe 5 is connected is made smaller than the diameter of the end to which the thin pipe 1 is inserted, and the pipe system on the lower side (downstream side) than the straight pipe joint 1 is used. Miniaturization and material saving are attempted.

  The cross-sectional shape of the thin tube 1, the thick tube 2, and the flexible tube 5 is a square. Therefore, since the cross-sectional shape can be matched with the drain pipe arranged in the girder, the flow becomes smooth, the processing of the cross-section change part can be omitted, the drain pipe shape considering the landscape, limited There are advantages such as being able to be stored in a space. However, even if the cross-sectional shape is a circle (round tube), the same effect can be obtained in terms of alleviating a rapid change in the pressure in the flexible tube.

  A performance test of the drainage structure according to the present invention was performed using an actual viaduct. The performance test was conducted on the P14 up line near the P15 up line of the Uchimaki viaduct on the second Tomei Expressway under construction. The results of the performance test are shown in Table 1. Moreover, the conditions of each test are shown below.

"Example 1"
An EPDM flexible pipe was connected through a straight pipe joint to a drain pipe that passed through the box girder and protruded under the girder. Furthermore, the drainage route was constructed by connecting the lower side of the flexible pipe to the drainage pipe fixed to the pier. Then, the waste water path, water in an amount exceeding the design flow rate (0.0332m ³ / s) slightly (0.0446m ³ / sec) was poured into the drainage pipe from the water bath and observe the state of the flexible tube. FIG. 3 shows an overview of the drainage structure of the first embodiment. In FIG. 3, substantially the same parts as the drainage structure shown in FIGS. 1 and 2 are denoted by the same reference numerals. As shown in FIG. 3, the end girder 11 in which this drainage structure is adopted has a box-type structure, and an overhanging portion 11a extends in a horizontal direction from a box-type portion 11b located at the center. And the road surface 12 is formed in the upper surface of this overhang | projection part 11a and the box-shaped part 11b, and the drainage basin 13 is provided in the side part of the road surface 12. FIG. A drain pipe 14 communicates with the bottom of the drainage basin 13, and the drain pipe 14 is drawn into the box-shaped part 11b through the lower side of the overhang part 11a. And it penetrates the bottom wall of the box-shaped part 11b and extends under the girder. The drain pipe 14 employs a round pipe at the lower side of the overhanging portion 11a and the inside of the box-type part 11b, and a square pipe is adopted at a portion penetrating the bottom of the box-type part 11b. A joint for converting the cross-sectional shape is used at the connecting portion of the pipe. A rectangular tube having a rectangular cross section having an outer dimension of 250 × 150 is used, and a straight pipe joint 4 connected thereto has an end 2a and a narrow tube in which the thin tube 1 of the thick tube 2 is not inserted. 1 has an outer dimension of 210 × 110 and an inner diameter of 200 × 100, and the end of the thick tube 2 into which the thin tube 1 is inserted has an outer dimension of 250 × 150 and an inner diameter of 238 × 138 (opening ratio of the gap 3). 30%). The flexible pipe 5 and the drain pipe 15 on the downstream side of the straight pipe joint 4 are also of a rectangular cross-sectional shape, and are fixed at a position that does not protrude from the side surface of the pier 17 inside the groove 17 a provided in the pier 17. Yes. In addition, the fixing tool 16 similar to the Example shown in the said FIG.1 and FIG.2 is used for fixation with respect to the bridge girder 11 and the bridge pier 17 of the drain pipes 14 and 15. FIG.
"Example 2"
A larger amount (0.0957 m ³ / sec) of water than in Example 1 was poured into the drain pipe from the water tank in the same drainage path as in Example 1, and the state of the flexible pipe was observed.

“Comparative Example 1”
An amount of water (0.0462 m ³ / second) slightly exceeding the design flow rate was poured into the drainage pipe from the water tank into the drainage path obtained by removing the straight pipe joint from the drainage path of Example 1, and the state of the flexible pipe was observed.
“Comparative Example 2”
A larger amount (0.0990 m ³ / sec) of water than Comparative Example 1 was poured into the drain pipe from the water tank in the same drainage path as Comparative Example 1, and the state of the flexible pipe was observed.

“Comparative Example 3”
In the drainage path in which the position of the straight pipe joint in the drainage path of Example 1 was changed from the upstream side to the downstream side of the flexible pipe, an amount (0.0446 m ³ / sec) of water slightly exceeding the design flow rate from the water tank into the drain pipe The state of the flexible tube was observed.
“Comparative Example 4”
A larger amount (0.0941 m ³ / sec) of water than Comparative Example 3 was poured into the drainage pipe from the water tank in the same drainage path as that of Comparative Example 3, and the state of the flexible pipe was observed.

As shown in Table 1, the occurrence of the water hammer phenomenon was not confirmed in Example 1 and Example 2, and it was confirmed that a stable drainage function was exhibited with respect to continuous water flow for 30 seconds. On the other hand, in Comparative Example 1 in which no straight pipe joint was provided, it was confirmed that the water hammer phenomenon occurred even when the amount of water was slightly higher than the design flow rate. From this result, it has been confirmed that the drainage structure according to the present invention has an effect of mitigating a sudden change in the pressure in the flexible pipe. In Example 2, although no water hammer phenomenon occurred, water leakage was confirmed. Since this leakage is also confirmed in Comparative Example 4, which has a comparable amount of water, it is surmised that this leakage is the limiting amount of water in this piping system itself, such as the connection state.

Moreover, when the position of the straight pipe joint in the drainage structure of Example 1 and Example 2 is disposed on the downstream side of the flexible pipe, first, in Comparative Example 3 where the amount of water is slightly higher than the design water amount, It was confirmed that the water hammer phenomenon did not occur as in 1. However, in Comparative Example 4 in which the amount of water was increased, water did not flow in the vertical pipe fixed to the pier, but water stayed in the flexible pipe located on the upstream side, and the flexible pipe swelled. The shape of the expanded flexible tube was not restored even after the water disappeared, and after that it could not be used continuously thereafter. As a result, in order to effectively utilize the drainage structure according to the present invention, it was confirmed that the position of the straight pipe joint needs to be on the upstream side of the flexible pipe.

  The drainage structure and straight pipe joint according to the present invention are particularly suitable for application to the bridge under the bridge as shown in the above specific example, but there is no limitation on its use, and the inside or the bottom of other buildings. It is also possible to apply to.

1 is a front view showing an overview of an embodiment of a drainage structure according to the present invention. The Example of the straight pipe joint which concerns on this invention is shown, (a) is a front view, (b) is a right view, (c) is a top view, (d) is a bottom view. It is a front view which shows the general view of Example 1 in the performance test of the drainage structure which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Narrow pipe 2 Thick pipe 2a End part 3 Crevice 4 Straight pipe joint 5 Flexible pipe 11 Bridge girder 11a Overhang part 11b Box-type part 12 Road surface 13 Drainage basin 14, 15 Drainage pipe 16 Fixing tool 17 Pier 17a Groove

Claims (6)

  The thin tube (1) and the thick tube (2) are fixed in a state where one end of the thin tube (1) is inserted into the thick tube (2) arranged coaxially with the thin tube (1). The gap (3) between the inner surface of (2) and the outer surface of the thin tube (1) has a straight pipe joint (4) communicating with the inside of the thick pipe (2), and the straight pipe joint (4) The flexible tube (5) is connected to the end portion (2a) of the thick tube (2) where the thin tube (1) is not inserted, and the gap ( 3) A drainage structure characterized by being open to the atmosphere. The diameter of the end (2a) of the thick pipe (2) to which the flexible pipe (5) is connected is smaller than the diameter of the end (2b) to which the thin pipe (1) is inserted. Item 10. The drainage structure according to Item 1.   The drainage structure according to claim 1 or 2, wherein the thin pipe (1), the thick pipe (2), and the flexible pipe (5) have square cross-sections. The thin tube (1) and the thick tube (2) are fixed in a state where one end of the thin tube (1) is inserted into the thick tube (2) arranged coaxially with the thin tube (1). A straight pipe joint in which the gap (3) between the inner surface of (2) and the outer surface of the thin tube (1) is open to the atmosphere and communicates with the inside of the thick tube (2). The diameter of the end (2a) of the thick tube (2) where the thin tube (1) is not inserted is smaller than the diameter of the end (2b) where the thin tube (1) is inserted. The straight pipe joint described in 1. The straight pipe joint according to claim 4 or 5, wherein a cross-sectional shape of the thick pipe and the thin pipe is a square.

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