JP5568022B2 - Shaft construction member and shaft structure - Google Patents

Description

  The present invention relates to a shaft construction member for constructing a shaft by being stacked in a vertical direction, and a shaft structure constructed by the shaft construction member.

  Sewers, culverts, electrical / communication cables, etc. buried underground are usually provided with vertical shafts (also called manholes) so that workers who manage them can enter and exit from the ground. ing.

  If water such as rainwater or sewage (hereinafter simply referred to as “water”) that flows into this shaft falls freely in the vertical direction within the shaft and gives a continuous impact to the shaft bottom, damage will occur at the shaft bottom. Occurs. Therefore, recently, a means has been proposed in which a vertical water guide pipe (drop shaft) provided with a spiral guideway having a smooth helicoid surface in a shaft is used to flow down water while swirling along the guideway. .

  However, since the water flowing down while rotating along the spiral guide path is continuously accelerated up to the bottom of the shaft, the flow velocity reached is still high.

  In view of this point, semi-elliptical inclined flat plates are arranged alternately on the left and right sides, and they are connected with triangular or trapezoidal vertical flat plates to form a guide path with a stepped linear bent spiral, thereby freeing water. Developed a vertical conduit that reduces the gradient of acceleration and lowers the flow velocity by combining the falling motion and the spiral falling motion, colliding the free fall energy with the spiral fall energy, and consuming energy from the initial stage of the fall. (For example, refer to Patent Document 1 below).

  That is, the vertical flow guide pipe of the spiral flow method described in Patent Document 1 collides the water flowing down along the inclined plate and the water falling like a waterfall from the middle of the inclined plate to the next inclined plate. The fall energy is attenuated.

JP 2004-339922 A

  However, in the method of colliding the water flowing down along the inclined plate and the water falling from the middle of the inclined plate, it is difficult to set the design flow rate in anticipation of the degree of fall energy to be attenuated. The intended design flow rate may not be able to flow down. If the inflowing water increases while the falling energy is excessively attenuated, the drainage becomes insufficient and water leakage occurs.

  Moreover, when the water flowing down along the inclined plate and the water falling from the middle of the inclined plate collide with each other, the flow of the flowing down water is very disturbed over the entire guide path. Moreover, since a relatively large amount of jumping water is continuously generated, a large amount of air is mixed in the flowing water, and the air is taken to the downstream trunk line together with the water. When a pump station is installed along the downstream trunk line, water containing a large amount of air hinders the normal operation of the pump and causes pump failure. Furthermore, the air entrained in the downstream trunk line moves to another shaft existing in the downstream trunk line, and in many cases, the air stays in the shaft for a long time without being discharged well, thereby increasing the internal pressure in the shaft. If heavy rain occurs when the internal pressure in the shaft is raised, the air is further compressed, and in the worst case, an accident occurs in which the lid that closes the shaft is blown away.

  In addition, when the water continuously flowing along the inclined plate and the water falling from the middle of the inclined plate collide with each other, a low frequency vibration is generated, which causes vibration pollution to the surrounding environment.

  In particular, when jumping water occurs in pipes that flow down sewage, such as sewage pipes, rainwater pipes, confluence pipes, and interception pipes, a large amount of hydrogen sulfide gas is generated along with the jumping water, resulting in early corrosion of the pipe wall. Connected. The early corrosion of the pipe wall not only increases the cost of reconstruction, but also causes the operator to slip. Also, the generation of hydrogen sulfide gas worsens the working environment in the pipe and harms the health of the worker.

  The present invention was developed in order to solve the technical problem, and has a novel structure capable of constructing a shaft that has a small amount of air entrainment and that can suitably lower the arrival flow rate of water that has flowed into the shaft. It is an object to provide a shaft construction member and a shaft structure constructed by the shaft construction member.

  The shaft construction member of the present invention is a shaft construction member for constructing a shaft having a turning channel that is rotated along the inner wall surface and displaced in the vertical direction by being stacked in the vertical direction. The shaft construction member includes a hollow cylindrical body and an inclined plate that is provided along the inner surface of the cylindrical body and forms a part of the rotating flow path. The upper end side connection portion and the lower end side connection portion are each provided with a longitudinal gradient that is gentler than the vertical gradient of the inclined plate, and at least one of the upper end side connection portion and the lower end side connection portion is open to the cylindrical body. When projecting from the end toward the outside and stacked in the vertical direction, the upper end side connection portion is adjacent to the lower end side connection portion existing in the other shaft construction member located at the upper position, The lower end side connection part is further located at the lower level. Adjacent to the upper end side connection portion existing in the mine construction member, the upper surface of the upper end side connection portion and the upper surface of the lower end side connection portion form a continuous deceleration channel at each adjacent location. And

  In the shaft construction member of the present invention, it is preferable that the connecting portion has a longitudinal gradient of 0 ± 5%.

  In the shaft construction member of the present invention, the corner formed by the upper surface of the lower end side connecting portion and the inner surface of the cylindrical body is filled with a buffer portion having a longitudinal gradient opposite to the longitudinal gradient of the inclined plate. Is preferred.

  The shaft structure according to the present invention is characterized in that a plurality of the shaft construction members according to the present invention are stacked in the vertical direction.

  According to the present invention, the amount of air entrainment is small, and the arrival flow rate of water flowing into the shaft can be suitably reduced.

FIG. 1 is a perspective view showing a shaft construction member of the present invention according to Embodiment 1 in a partially transparent state. FIG. 2: is sectional drawing (a) which shows the shaft construction member of this invention which concerns on Embodiment 1, and top view (b). FIG. 3: is sectional drawing (a) which shows the shaft structure of this invention constructed by piling up the plurality of shaft construction members of this invention which concern on Embodiment 1, and a perspective view which cuts off a cylindrical body partially ( b). FIG. 4 is a perspective view showing a shaft construction member according to the second embodiment in a partially transparent state. FIG. 5 is a cross-sectional view (a) showing a shaft structure of the present invention constructed by stacking a plurality of shaft construction members of the present invention according to Embodiment 2, and a perspective view showing a partially cut-out cylinder. b). FIG. 6 is a perspective view showing the shaft construction member according to the third embodiment in a partially transparent state.

  Hereinafter, although an embodiment of the present invention is described based on a drawing, the present invention is not limited to this embodiment.

<Embodiment 1>
FIG. 1 shows a shaft construction member 1 according to Embodiment 1 of the present invention. The shaft construction member 1 according to the present embodiment is precast concrete formed by curing and hardening after placing concrete on a formwork. The shaft construction member 1 includes a hollow cylinder 2 and an inclined plate 3 provided along the inner surface of the cylinder 2. In addition, in this invention, the raw material which forms the shaft construction member 1 is not specifically limited. The shaft construction member 1 may be formed using, for example, resin or metal. Moreover, the shaft construction member 1 is not necessarily formed integrally. For example, the shaft construction member 1 may be formed by forming the cylindrical body 2 and the inclined plate 3 as separate bodies and combining them. good.

  In the present embodiment, the cylindrical body 2 has a cylindrical shape, that is, a horizontal sectional shape is circular. In the present invention, the shape of the cylindrical body 2 is not particularly limited. As the shape of the cylindrical body 2, in addition to the cylindrical shape, for example, the horizontal cross-sectional shape may be an ellipse, a quadrangle, or a further polygonal shape. The cylinder 2 may be formed as a divided body divided in the vertical direction or the horizontal direction, and the divided bodies may be combined.

  In the present embodiment, the inclined plate 3 is arranged along the inner wall of the cylindrical body 2, and as shown in FIG. 2 (a), has a longitudinal gradient that is inclined from the upper open end to the lower open end of the cylindrical body 2. Have. The longitudinal gradient of the inclined plate 3 is normally set to about 10 to 100% (about 5 to 45 degrees as an inclination angle). In the present embodiment, a longitudinal gradient of 60% (inclination angle of about 30 degrees) was given. The upper surface of the inclined plate 3 is preferably flat from the viewpoint of strength and ease of manufacture, but is not limited to this, and may be, for example, a gentle curved surface. Moreover, in this embodiment, although only the longitudinal gradient is provided to the inclined plate 3, you may provide the synthetic | combination gradient which added the cross gradient. However, in order to maintain a smooth flow of water from the upper end to the lower end of the inclined plate 3, the transverse gradient is preferably kept within 0 ± 5% (inclination angle of about ± 3 degrees).

  An upper end side connecting portion 4H and a lower end side connecting portion 4L to which a gentler vertical gradient than the vertical gradient of the inclined plate 3 is provided are provided at the upper end and the lower end of the inclined plate 3, respectively. The area of each connection part 4H, 4L should just be determined suitably according to a design flow volume etc., and is not specifically limited. Usually, the area of each connection part 4H and 4L is about 5 to 20% with respect to the area of the inclined plate 3, respectively. In the present embodiment, the area of each connecting portion 4H, 4L is set to about 10% with respect to the area of the inclined plate 3.

  In the present embodiment, the upper end side connection portion 4H is projected from the upper open end of the cylindrical body 2 toward the outside (upper portion). In the present invention, the lower end side connection portion 4L may protrude from the lower open end of the cylindrical body 2 toward the outside (lower portion). Further, each of the connecting portions 4H and 4L may be protruded from the open end of the cylindrical body 2 to the outside.

  The longitudinal gradient of each connecting portion 4H, 4L is not particularly limited as long as it is gentler than the longitudinal gradient of the inclined plate 3. Usually, it is preferable that the upper surface of each of the connection portions 4H and 4L is substantially horizontal as 0 ± 5% (preferably 0 ± 2% (inclination angle is about ± 1 degree)). Similar to the inclined plate 3, the upper surfaces of the connecting portions 4H and 4L are preferably flat, but the present invention is not limited to this, and a gentle curved surface is also possible. In the present embodiment, the gradient of each of the connecting portions 4H and 4L may be a combined gradient that includes a transverse gradient. In addition, it is preferable to keep the transverse gradient of each connection part 4H and 4L within 0 ± 5% (preferably within 0 ± 2%) similarly to the inclined plate 3.

  In the present embodiment, since the transverse gradient of each connecting portion 4H, 4L together with the inclined plate 3 is set to 0% (Level), as shown in FIG. 2B, each connecting portion 4H, 4L The corner (gradient change point) formed by the upper surface of the inclined plate 3 and the upper surface of the inclined plate 3 intersects the vertical gradient of the inclined plate perpendicularly. When a curved surface or a transverse gradient is given to the inclined plate 3 or each connecting portion, the change point of the gradient intersects with the vertical gradient of the inclined plate in a state shifted from the vertical depending on the degree of the curved surface or the transverse gradient. To do. It is preferable to provide a longitudinal curve by chamfering or filling the change point of the gradient.

  The inclined plate 3 and the connecting portions 4H and 4L occupy half of the opening area of the cylindrical body 2 when the inside of the cylindrical body 2 is projected in parallel from the upper open end to the lower open end. In the present embodiment, the inclined plate 3 and the connecting portions 4H and 4L are arranged so as to occupy half of the opening area of the cylindrical body 2 in order to give the flat inclined plate 3 as large an area as possible and a gentle inclination angle. However, the ratio of the inclined plate 3 and the connecting portions 4H and 4L to the opening area of the cylindrical body 2 can be designed by changing as appropriate. In the present embodiment, the inclined plate 3 and the connecting portions 4H and 4L are supported only by the inner wall of the cylindrical body 2. However, the support strength can be increased by further supporting the inclined plate 3 and supporting members such as ribs and columns. preferable.

  As shown to Fig.3 (a), the vertical shaft construction member 1 constructs the vertical shaft (the vertical shaft structure of the present invention) 10 by being stacked in the vertical direction. As shown in FIG. 3 (b), when stacking the shaft construction member 1, the upper end side connection portion 4 </ b> H in the lower shaft construction member 1 and the lower end side in the shaft construction member 1 located in the upper position. The connecting portion 4L is adjacent to each other, and the deceleration channel 7 in which the upper surface of the upper end side connecting portion 4H and the upper surface of the lower end side connecting portion 4L are continuous is formed at each adjacent portion. At this time, the upper end side connection portion 4H that protrudes from the upper open end of the cylindrical body 2 toward the outside (upper portion) enters the shaft construction member 1 side located at the upper position by the protruding height, and is therefore adjacent. The step generated between the upper surface of the upper end side connection portion 4H and the upper surface of the lower end side connection portion 4L is reduced. In the present embodiment, the protruding height of the upper end side connection portion 4H is set so that the upper surface of the upper end side connection portion 4H constituting the deceleration flow path 7 and the upper surface of the lower end side connection portion 4L are flat surfaces. ing.

  When the plurality of shaft construction members 1 are stacked in the vertical direction in this way, a whirling passage that is displaced in the vertical direction while rotating around the inner wall surface is formed in the shaft 10. This whirling channel is a channel in which the upper surface of the inclined plate 3 and the deceleration channel 7 are alternately connected.

  The water that has flowed into the shaft 10 flows down while turning in the shaft 10 along the turning channel. As shown by arrows in FIGS. 3A and 3B, the water flowing down while rotating along the rotating flow path accelerates while converting the potential energy into kinetic energy in each inclined plate 3. Thereafter, the water that reaches the deceleration channel 7 collides with the inner wall of the shaft 10, moves along the inner wall of the shaft 10 while expanding the almost horizontal deceleration channel 7, and consumes kinetic energy. Then slow down. Thereafter, the water decelerated by consuming kinetic energy flows down along the inclined plate 3 positioned at the lower stage. By repeating this, the arrival flow rate of water is preferably lowered.

  Since the water flowing down along the whirling channel collides with the inner wall of the shaft 10 and changes its direction, some turbulence occurs in the deceleration channel 7. However, this turbulence of the flow is relatively gentle except when the flow rate is high, such as during heavy rain, that is, when the flow rate is small to medium. Further, in the inclined plate 3, the flow disturbance is hardly generated. Furthermore, almost no jumping occurs except at high flow rates. Since almost no water jump occurs in the swirling flow path, generation of hydrogen sulfide gas and generation of vibration pollution are suppressed. Also, air entrainment to the downstream trunk line is reduced.

  In particular, in the present embodiment, the protrusion height of the upper end side connection portion 4H is set so that the upper surface of the upper end side connection portion 4H constituting the deceleration channel 7 and the upper surface of the lower end side connection portion 4L are flat surfaces. Therefore, the water is smoothly transferred from the lower end side connection portion 4L to the adjacent upper end side connection portion 4H, and the occurrence of water jump is further reduced in the deceleration flow path 7.

  In Table 1 below, air entrainment when sewage flows down under the same conditions for each of the vertical water conduit described in Patent Document 1 and the shaft 10 constructed by the shaft construction member 1 according to this embodiment. The result of comparing the amount, noise, occurrence of jump water, generation amount of sulfide gas, and flow down.

  By the way, in this invention, when forming the deceleration flow path 7 by making the upper surface of the upper end side connection part 4H and the upper surface of the lower end side connection part 4L continuous, the upper surface of the upper end side connection part 4H as in this embodiment. And the upper surface of the lower end side connection portion 4L are most preferably flat, but there is a slight difference between the upper surface of the adjacent upper end side connection portion 4H and the upper surface of the lower end side connection portion 4L. There may be a difference in level.

  As the steps that can occur in the deceleration flow path 7, there are two steps: a step where the upper surface of the lower end side connection portion 4L is at a high position and a step where the upper surface of the upper end side connection portion 4H is at a high position. Among these, when the level | step difference which the upper surface of the upper end side connection part 4H becomes a high position has arisen, the level | step difference concerned becomes a barrier, and the water which flows through the deceleration flow path 7 consumes much kinetic energy in order to get over the level | step difference. This makes it possible to further reduce the water arrival flow rate. In addition, since the smooth flow of water may be inhibited when the level difference is too large, it is usually preferable that the level difference is 5 cm or less, preferably 3 cm or less. Moreover, it is preferable that the step is filled with mortar or the like so as to be a gentle step to give a gentle inclined surface.

<Embodiment 2>
FIG. 4 shows a shaft construction member 1 according to the second embodiment of the present invention. The difference from the shaft construction member 1 according to the first embodiment is that the corner formed by the upper surface of the lower end side connection portion 4L and the inner surface of the cylinder 2 has a longitudinal gradient opposite to the longitudinal gradient of the inclined plate 3. It is to be filled with the buffer part 5 having

  Here, when the corner portion formed by the upper surface of the lower end side connection portion 4L and the inner surface of the cylindrical body 2 is filled with the buffer portion 5, the area of the upper surface of each connection portion 4H, 4L should remain about 50 to 80%. Is preferred. In the present embodiment, the corner portions are filled with the buffer portion 5 so that the area of the upper surface of each connection portion 4H, 4L remains about 70%.

  Further, the vertical gradient of the buffer portion 5 is not particularly limited as long as the gradient is opposite to the vertical gradient of the inclined plate 3. Usually, it is preferable to set it to about 40 to 160% (inclination angle of about 20 to 60 degrees). In the present embodiment, the vertical gradient of the buffer portion 5 is set to 100% (45 degrees as an inclination angle). In addition, the inclined surface of the buffer part 5 may be flat or curved. Moreover, the inclined surface of the buffer part 5 is good also as a synthetic | combination gradient which added the transverse gradient.

  In the present embodiment, the auxiliary buffer portion 51 is provided at the corner portion formed by the upper surface of the upper end side connection portion 4H and the extension line of the inner surface of the cylindrical body 2. The auxiliary buffer 51 is arranged adjacent to the buffer 5 when the shaft 10 is constructed, and complements the buffer 5.

  As shown in FIGS. 5 (a) and 5 (b), the shaft construction member 1 is constructed in the same manner as in the first embodiment to construct a shaft 10 by being stacked in the vertical direction. In the constructed shaft 10, a swirl passage that is displaced along the inner wall surface and that is displaced in the vertical direction is formed.

  The water that has flowed into the shaft 10 flows down while turning around the shaft 10 along the upper surface of the turning channel. As shown by arrows in FIGS. 5A and 5B, the water flowing down while rotating along the upper surface of the rotating flow path accelerates while converting potential energy into kinetic energy in each inclined plate 3. However, the deceleration channel 7 consumes kinetic energy and decelerates.

  In the first embodiment, the water reaching the deceleration flow path 7 changes its vector by directly colliding with the inner wall of the shaft 2, but in this embodiment, the water reaching the deceleration flow path 7 is an inclined plate. The vector is changed while climbing the inclined surface of the buffer portion 5 having an inclination opposite to 3. Since the kinetic energy of water is further consumed when climbing the inclined surface of the buffer part 5, the flow velocity of water can be further reduced. Moreover, since water does not directly collide with the inner wall of the shaft 10, the occurrence of jumping water can be further reduced. Furthermore, erosion of the inner wall of the shaft 10 caused by water collision can be suppressed.

  In addition, in this embodiment, although the buffer part 5 (and auxiliary buffer part 51) is formed integrally with the shaft construction member 1, it is attached after being formed as a separate body from the shaft construction member 1. May be. Further, when the shaft 10 is constructed, it may be provided by filling the corners with mortar or the like.

<Embodiment 3>
FIG. 6 shows a shaft construction member 1 according to the third embodiment of the present invention. The difference from the shaft construction member 1 according to the first embodiment is that the staircase 6 is arranged along the end side (free end) on the center side of the cylindrical body 2 in the inclined plate 3.

  This staircase 6 is used as a scaffold when an operator such as the maintenance work of the shaft 10 needs to enter the shaft 10. In the shaft 10 constructed by the shaft construction member 1 of the present invention, the inflowed water flows down while turning along the inner wall of the shaft 10, and since there is little occurrence of water jump, the stairs 6 gets wet and becomes slippery. Is preferably prevented.

  In the shaft construction member 1 of the present invention, a ladder may be provided instead of the stairs 6, or a handrail may be provided together with the stairs 6. Moreover, since there is very little jumping water, it is also possible to attach a lighting installation.

  Furthermore, in the shaft construction member 1 of the present invention, a notch may be appropriately provided at the free end of the inclined plate 3. When this notch is provided, when the shaft 10 is constructed, it becomes a blow-through communicating with the inside of the shaft 10 in the vertical direction, and the air that has entered the shaft 10 can be more suitably discharged.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used as a shaft provided in a sewer, a culvert, an electric / communication cable or the like buried in the ground.

DESCRIPTION OF SYMBOLS 1 Member for shaft construction 2 Cylindrical body 3 Inclined plate 4H Upper end side connection part 4L Lower end side connection part 5 Buffer part 6 Stairway 7 Deceleration flow path 10 Shaft (vertical structure)

Claims (4)

A shaft construction member for constructing a shaft having a revolving channel that is displaced in the vertical direction while circling along the inner wall surface by being stacked in the vertical direction,
This shaft construction member is
A hollow cylinder,
An inclined plate that is provided along the inner surface of the cylindrical body and forms a part of the revolving channel;
Comprising
At the upper end and the lower end of the inclined plate, an upper end side connecting portion and a lower end side connecting portion each provided with a gentle vertical gradient than the vertical gradient of the inclined plate are provided, respectively.
And at least one of the upper end side connecting portion and the lower end side connecting portion is projected outward from the open end of the cylindrical body,
When stacked vertically,
The upper end side connection part is adjacent to a lower end side connection part existing in another member for constructing a vertical shaft located at an upper position,
On the other hand, the lower end side connection portion is adjacent to the upper end side connection portion existing in yet another shaft construction member located in the lower part,
A shaft construction member characterized in that, in each adjacent portion, the upper surface of the upper end side connection portion and the upper surface of the lower end side connection portion form a continuous deceleration channel. In the shaft construction member according to claim 1,
A shaft construction member in which the connecting portion has a vertical gradient of 0 ± 5%. In the shaft construction member according to any one of claims 1 and 2,
A shaft construction member in which a corner portion formed by the upper surface of the lower end connection portion and the inner surface of the cylindrical body is filled with a buffer portion having a gradient opposite to the longitudinal gradient of the inclined plate.   A shaft structure in which a plurality of shaft construction members according to any one of claims 1 to 3 are stacked in a vertical direction.

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