JP2012246682A - Configuration method of excessive gap water drainage structure, excessive gap water drainage structure and filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a configuration method of an excessive gap water drainage structure, capable of configuring the excessive gap water drainage structure without freezing the ground therearound.SOLUTION: First, a bearing hole penetrating through invert concrete 25 is formed. Next, a sheath pipe 67 in a state that a core cutter is inserted thereinto is arranged in a manhole body 7. A lower end of the sheath pipe 67 is inserted into and fixed to a bearing hole 33. Water is poured into the sheath pipe 67 and then, a mounting hole 35 penetrating through a bottom slab block 5 is formed under the bearing hole by a cutter head. After the mounting hole 35 is formed in the bottom slab block 5, the core cutter is pulled out from the sheath pipe 67. Then, a filter 37 is put into the sheath pipe 67 and the filter 37 is press-fitted into the mounting hole 35.

Description

  The present invention provides an excess pore water drainage structure for draining excess pore water generated in the ground around the manhole structure when the ground around the manhole structure is compacted as an earthquake countermeasure or in the event of an earthquake, The present invention relates to a method for constructing an excess pore water drainage structure and a filter suitable for use in the excess pore water drainage structure.

  When the ground vibrates violently due to an earthquake, the ground liquefies, and the manhole structure having a hollow interior and a small specific gravity may be lifted by buoyancy from the liquefied ground. When the manhole structure is lifted, the upper end side of the manhole structure protrudes from the road surface or the like. For example, the vehicle collides with the upper end side of the protruded manhole structure, causing a big accident.

  Such lift of the manhole structure at the time of the earthquake is effective by providing the manhole structure with a drainage structure for draining excess pore water of the ground liquefied by the earthquake as described in Patent Document 1, for example. Can be prevented. The rise of the manhole structure during an earthquake also gives vibration to the ground around the manhole structure as described in, for example, Patent Document 2, and the drainage structure of excess pore water provided in the manhole structure. Therefore, it is also possible to effectively prevent the excess pore water generated by vibrations by draining and compacting the ground around the manhole.

JP 2007-63967 A JP 2009-263871 A

  By the way, in the excess pore water drainage structure of patent documents 1 and patent documents 2, excess pore water generated on the ground around the manhole structure is guided into the manhole structure and is connected to the manhole structure. It is drained by being drained. Therefore, it is a good idea to install a filter that prevents the inflow of earth and sand at the entrance to the manhole structure of excess pore water, but this filter is placed on the side wall of the manhole at the sewage pipe mouth position. Therefore, prior to disposing the filter, it is necessary to take measures to prevent, for example, the surrounding ground from being frozen and the groundwater from entering the manhole structure.

  Then, this invention aims at provision of the excess pore water drainage structure which can be constituted without freezing the surrounding ground, and the construction method of the excess pore water drainage structure which can constitute the excess pore water drainage structure without freezing the surrounding ground To do. Another object of the present invention is to provide a filter suitable for use in an excess pore water drainage structure.

  In order to achieve this object, a method for constructing an excess pore water drainage structure according to the present invention is a method for constructing an excess pore water drainage structure that drains excess pore water generated on the ground around a manhole structure, A first step of making a vertical (for example, vertical or almost vertical) support hole in the bottom of the object from the inner surface (or upper surface) of the bottom to an intermediate position in the vertical direction, and a lower end sealed in the support hole A second step of providing a mantle structure in the manhole structure, and injecting liquid into the mantle structure, so as to extend upward (for example, vertically upward or substantially vertically upward). A third step of applying water pressure to the portion (or lower surface portion), and a vertical direction penetrating from the bottom surface portion of the support hole to the outer surface (lower surface) of the bottom portion by driving a drill inserted in the sheath tube (For example, hanging A fourth step of drilling a mounting hole (or a substantially vertical), and removing the drill from the sheath tube, placing a filter in the sheath tube containing liquid, and mounting the filter in the mounting hole. And a sixth step of removing the sheath tube from the support hole and attaching a drain pipe extending upward to the filter. The bottom of the manhole structure is a portion that is located at the bottom of the manhole structure and does not have fluid permeability. In the present invention, even if a through hole for attaching a filter is formed at the bottom of the manhole structure, groundwater does not flow into the manhole structure from the through hole due to the liquid injected into the sheath tube. Therefore, when the filter is attached, a method of freezing the ground is not necessary in order to prevent the groundwater from flowing into the manhole structure. The drill can be placed in the sheath tube when the sheath tube is provided in the manhole structure. Alternatively, the drill can be placed in the sheath after the sheath is provided in the manhole structure. The liquid can be injected into the sheath after drilling into the sheath. Alternatively, the liquid can be injected into the sheath tube before drilling into the sheath tube. A drain pipe will be arrange | positioned inside a manhole structure.

  The support hole is advantageously larger in diameter than the mounting hole. The mounting hole can be easily formed.

  In the fifth step, if the filter is tightly pushed into the attachment hole and attached in the attachment hole, the arrangement of the filter becomes simple.

  The drain pipe has a drawer portion extending from the filter to the vicinity of the inner peripheral surface of the manhole structure, and a main body portion extending upward along the inner peripheral surface from the tip of the drawer portion, If the process includes a process of embedding the drawer part below the inner surface of the bottom part, the inner shape of the manhole structure after the construction of the excess pore water drainage structure does not become complicated.

  If the step of closing the upper end opening of the support hole with the bottom cover is provided, the shape of the bottom inner surface of the manhole structure becomes flat.

  If the tip end cover that swings in the opening direction by the water pressure of excess pore water to open the tip opening is swingably provided at the tip opening of the drain pipe, the sewage can be grounded with a simple configuration. It is possible to effectively prevent backflow into the inside.

  The filter has a filter body having an inflow hole on the lower surface, and a connection pipe portion provided with a water stop valve extending upward from the filter body, and the filter body is tightly fitted in the mounting hole. By being pushed in, it can be attached in the attachment hole. Here, a sealing member is provided on the outer periphery of the filter body, and the filter body is pushed tightly into the mounting hole so that the sealing member is compressed between the filter body and the mounting hole. Can be configured. The drain pipe is connected to the distal end side of the connection pipe portion. The water stop valve opens and closes the flow channel of the connecting pipe part.

  The bottom surface of the seal member is preferably formed so as to extend outward while being inclined upward. If comprised in this way, even if it enlarges the protrusion amount to the outer side of a sealing member, when pushing a filter main body into an attachment hole, pushing resistance will not become excessive.

  A filtration structure is formed inside the filter main body, and this filtration structure is a filtration net provided at the position of the inflow hole, and a coarse aggregate (for example, mesalite) disposed on the filtration net, It is preferable to have. Large solids are removed with a filter net, and small dirt is removed with coarse aggregate such as mesalite.

  It is preferable that the filter net is made of resin and a punching plate is laid under the filter net. A resin filter mesh can reduce the mesh, but lacks strength. If a punching plate is laid on the lower side, large solids are removed by the punching plate.

  The excess pore water drainage structure of the present invention is an excess pore water drainage structure that drains excess pore water generated on the ground around the manhole structure, and is disposed above and below the inner surface of the bottom of the manhole structure. A first hole in a vertical direction (for example, vertical or substantially vertical) opened to reach a middle position in the direction, and a hole penetrating from a bottom surface portion of the first hole to an outer surface of the bottom portion, A second hole having a smaller diameter than the first hole in the vertical direction (for example, vertical or substantially vertical), a filter press-fitted into the second hole, and an upwardly attached to the filter. And a drain pipe. This excess pore water drainage structure can be easily configured to an existing structure, for example, without freezing the surrounding ground.

  Similarly, the filter includes a filter body having an inlet on the lower surface, a connecting pipe portion provided with a water stop valve extending upward from the filter body, and a seal provided on the outer periphery of the filter body. And a member. The filter body is pressed into the second hole so that the seal member is compressed between the filter body and the second hole. Similarly, the water stop valve opens and closes the flow channel of the connecting pipe portion.

  As described above, if the method for constructing an excess pore water drainage structure of the present invention is used, an excess pore water drainage structure can be easily constructed in an existing manhole structure. Moreover, the excessive pore water drainage structure of this invention can be easily comprised in an existing structure, for example, without freezing the surrounding ground. The filter of the present invention is suitable for use in the method for constructing the excess pore water drainage structure of the present invention and the excess pore water drainage structure of the present invention.

It is a figure which shows the structure of the manhole structure provided with the structure of the manhole structure provided with the excess pore water drainage structure which concerns on this invention, or the configuration method of the excess pore water drainage structure which concerns on this invention. It is a figure which shows the detail of a filter part. It is a flow which shows the construction method of the excess pore water drainage structure. It is a figure which shows a bottom part drilling process, and is a figure explaining formation of a support hole. It is a figure which shows a bottom part drilling process, and is a figure explaining the state which has arrange | positioned the core cutter in a sheath pipe. It is a figure which shows a bottom part drilling process, and is a figure explaining the state which put the water in the sheath pipe. It is a figure which shows a bottom part hole drilling process, and is a figure explaining formation of an attachment hole. It is a figure which shows installation processes, such as a filter, and is a figure explaining attachment to the attachment hole of a filter. It is a figure which shows installation processes, such as a filter, and is a figure explaining the guide groove formed in the inner surface of invert concrete. It is a figure which shows the installation process of a filter etc., and is a figure explaining the state which stored the guide pipe in the guide groove and was closed with the concrete. It is sectional drawing which shows the structure of a filter. It is a figure which shows another attachment aspect of a filter. It is a figure which shows another attachment aspect of a filter.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a manhole structure having an excess pore water drainage structure according to the present invention or a configuration of a manhole structure in which the method for configuring an excess pore water drainage structure according to the present invention is implemented, and FIG. It is a figure which shows the detail of a filter part.

  The manhole structure 1 is configured by placing a bottom slab block 5 on a basic crushed stone 3 and installing a manhole body 7 on the bottom slab block 5. The manhole body 7 is placed on the bottom slab block 5. An annular pipe mounting wall portion 11 to which the sewage pipe 9 is connected, an annular straight wall portion 13 placed on the pipe mounting wall portion 11, a large-diameter lower end opening portion, and a small-diameter upper end opening portion are provided. An annular inclined wall portion 17 placed on the straight wall portion 13 and formed on the straight wall portion 13 so that one circumferential portion 15 rises vertically, and an adjustment ring 19 placed on the inclined wall portion 17; An iron lid receiving frame 21 placed on the adjustment ring 19 and a manhole cover 23 attached to the lid receiving frame 21 are provided. An invert concrete 25 is accommodated in the pipe mounting wall portion 11 so as to be placed on the bottom slab block 5, and the invert concrete 25 is connected to the downstream sewer pipe from the upstream opening 27 connected to the upstream sewer pipe 9. A flow groove 31 having a semicircular cross section is provided so as to extend to the downstream opening 29 connected to the line 9, and the flow groove 31 is formed so as to coincide with the lower half of the upstream opening 27 and the downstream opening 29. Has been.

  The invert concrete 25 has an operation hole 33 having a large diameter (for example, a diameter of about 180 mm) penetrating from the upper surface (inner surface) to the bottom surface (outer surface or outer bottom surface) on one side of the running water groove 31. A mounting hole (second hole) 35 having a small diameter (for example, a diameter of about 130 mm) penetrating from the upper surface to the bottom surface is formed below the operation hole (first hole) 33. A filter 37 is disposed in the operation hole 33 and the attachment hole 35, and the groundwater that passes through the attachment hole 35 and the operation hole 33 and is guided into the manhole body 7 is filtered when passing through the filter 37. The Rukoto. The filter 37 includes a filter main body 39 having an inlet 38 (see FIG. 11) on the lower surface, a connection pipe portion 41 provided so as to protrude upward from the filter main body 39, and flowing water of the connection pipe portion 41. A water stop valve 44 having an operation portion (operation rotating handle) 43 for opening and closing provided in the connection pipe portion 41 so that the passage 42 (see FIG. 11) can be opened and closed, and a filter main body 39 An annular seal ring (seal member) 45 provided on the outer periphery, the filter body 39 is fixed in the mounting hole 35, and the connection pipe portion 41 is positioned in the operation hole 33. It is disposed in the hole 33 and the mounting hole 35. The filter main body 39 is fixed by being pushed into the mounting hole 35 so that the space between the filter body 39 and the mounting hole 35 is sealed by the seal ring 45, and the upper end of the connection pipe portion 41 is at the upper end opening 46 of the operation hole 33. It is located on the lower side.

  A guide pipe (drawer portion) 47 having a bent portion is connected to the connection pipe portion 41, and the guide pipe 47 extends from the connection pipe portion 41 to the inner peripheral surface of the pipe mounting wall portion 11 or near the inner peripheral surface, or The end portion 49 of the guide pipe 47 is bent toward the outer peripheral surface of the invert concrete 25 or near the outer peripheral surface and rises along the inner peripheral surface of the pipe mounting wall portion 11. The other portion of the guide pipe 47 is located in the invert concrete 25. A guide pipe (main body part) 51 is connected to the distal end portion 49 of the guide pipe 47, and the guide pipe 51 extends vertically upward along the inner peripheral surface of the pipe mounting wall portion 11 and the inner peripheral surface of the straight wall portion 13. Thus, the upper end of the guide pipe 51 is located above the groundwater level. The upper end portion of the guide pipe 51 is bent so as to face the horizontal direction, and the tip opening 53 of the guide pipe 51 is a drainage lid (tip portion lid body) attached to the guide pipe 51 via a hinge 55 so as to be swingable. The drainage lid 57 is rocked by the increase of the water pressure in the guide pipe 51 to open the tip opening 53 of the guide pipe 51. Even if the water pressure in the guide pipe 51 is lowered, the drain lid 57 is configured to be held in the open position. To return the drain lid 57 to the closed position, the drain lid 57 is rotated in the closing direction. There is a need. As the hinge 55, a pair of brackets provided on the guide pipe 51 and having a structure in which a support pin provided on the drain lid 57 is rotatably supported can be employed.

  An upper end opening 46 of the operation hole 33 of the invert concrete 25 is closed with a fitting lid (bottom lid) 59 so as to be openable, and the fitting lid 59 forms an upper surface of the invert concrete 25.

In the manhole structure 1 having such a configuration, the filter 37 disposed in the mounting hole 35 and the operation hole 33, the guide pipe 47 connected to the filter 37, and the guide connected to the guide pipe 47. The pipe 51 and the excess pore water drainage structure 61 constitute an excess pore water drainage structure 61. Even if the ground around the manhole structure 1 vibrates due to the earthquake and excessive pore water is generated in the ground, Passing through the basic crushed stone 3 having the above, passing through the filter 37, ascending in the induction pipe 51 in the filtered state, opening the drainage lid 57, discharging the water into the manhole body 7, and flowing into the sewer pipe 9. (See arrow). Therefore, since excess pore water is drained from the ground around the manhole structure 1, liquefaction of the ground is prevented. In addition, for example, when the manhole structure 1 itself is vibrated and the ground around the manhole structure 1 is vibrated and compacted, excess pore water generated by the vibration of the ground is drained in the same manner as in the earthquake. Therefore, effective compaction of the ground is achieved and liquefaction of the ground during an earthquake is prevented.

  FIG. 3 is a flow showing a method of configuring the excess pore water drainage structure 61.

  The method of constructing the excess pore water drainage structure 61 is a method of constructing the excess pore water drainage structure 61 in the existing manhole structure 1. First, a necessary space is secured on the road surface around the existing manhole structure 1. , Install a work zone or arrange security guards (security equipment process A). Next, deposits and deposits in the manhole body 7 are removed by spraying high-pressure water (manhole cleaning step B). And the support hole (operation hole) 33 and the attachment hole 35 are opened in the invert concrete 25 and the bottom block 5 of the manhole structure 1 (bottom part drilling process C). Finally, the filter 37 and the induction pipe 51 are installed (filter installation process D). When the excess pore water drainage structure 61 is completed, the manhole body 7 is vibrated using a vibrator to compact the surrounding ground (vibration process E), and then into the ground from the peripheral wall of the manhole body 7 An injection material (for example, mortar) is injected to close the void in the surrounding ground (gap filling step F), and the countermeasure for lifting the manhole structure 1 or the manhole body 7 is completed.

  4 to 7 are views showing the bottom hole drilling presentation A (first process to fourth process).

  In the bottom hole drilling step A, first, it is determined in which position of the invert concrete 25 the support hole 33 is provided. The position where the support hole 33 is provided is, for example, a position where the sheath tube can be vertically set so as not to hit the upper end opening of the inclined wall portion 19 from the position. When the position for providing the support hole 33 is determined, the hole drilling machine 63 is installed in the manhole body 7, the predetermined position is drilled, and the support hole 33 penetrating the invert concrete 25 is formed (FIG. 4). When the support hole 33 is formed, the hole drilling machine 63 is removed, and the sheath tube 67 with the core cutter 65 inserted therein is disposed in the manhole body 7. The sheath pipe 67 is configured by, for example, vertically stacking a plurality of pipe members having an outer diameter of about 180 mm substantially equal to the diameter of the support hole 33 and an inner diameter of about 160 mm, and the lowermost pipe member (steel pipe) is The uppermost tube member protrudes from the upper end opening of the manhole body 7 by being inserted into the support hole 33 and fixed. A space between the lowermost tube member and the support hole 33 is sealed. The core cutter 65 is formed by connecting an extension rod 71 to a cutter head 69 having an outer diameter of about 130 mm, and the extension rod 71 is configured by connecting a plurality of rod members vertically or in the length direction. The uppermost rod member extends upward from the uppermost tube member. In order to arrange the core cutter 65 in the sheath pipe 67, for example, when the lowermost pipe member is fixed in the support hole 33, the cutter head 69 is inserted into the pipe member, and the rod member is inserted into the cutter head 69. It is possible to adopt a method in which one rod is connected, and thereafter the rod members are connected corresponding to the piled tube members. And if the sheath pipe 67 which has the core cutter 65 can be arrange | positioned, the upper end part of the extension rod 71 of the core cutter 65 will be connected to the cutter drive part 73 arrange | positioned on the ground (FIG. 5). Next, water W is put into the sheath tube 67. Water W is injected into the sheath pipe 67 until the water surface becomes higher than the groundwater level so that groundwater flows when the mounting hole 33 is opened in the bottom block 5 and soil and sand do not enter the mounting hole 33. (FIG. 6). When the water W is put into the sheath tube 67, the cutter driving unit 73 is operated, and the attachment hole 35 penetrating the bottom block 5 is formed below the support hole 35 by the cutter head 69 (FIG. 7). The cutter head 69 has a smaller diameter than the sheath tube 67.

  8 to 10 are views showing a filter installation step D (fifth step and sixth step).

  When the attachment hole 35 is formed in the bottom block 5, the cutter driving unit 73 is removed from the extension rod 71, and the extension rod 71 is pulled out from the sheath tube 67 together with the cutter head 69. Then, the filter 37 is connected to the extension rod 71 instead of the cutter head 69, and the extension rod 71 is inserted into the sheath tube 67 from the filter 37 side. At this time, the water stop valve 44 of the filter 37 is kept closed. The extension rod 71 and the filter 37 are connected by using an appropriate filter press-fit joint. And the filter 37 is pushed with the extension rod 71, and the filter main body 39 is press-fit in the attachment hole 35 so that the outer peripheral seal ring 45 may be crushed and deformed (FIG. 8). When the filter 37 is fixed in the mounting hole 35, the inner surface (surface) of the invert concrete 25 is shaved from the support hole 33 to the outer peripheral surface along the pulling direction of the guide pipe 47 to form a guide groove 75 ( FIG. 9). Then, one end portion of the guide pipe 47 is connected to the connection pipe portion 41 of the filter 37, the guide pipe 47 passes through the guide groove 75 and reaches the outer periphery of the invert concrete 25, and the tip end portion of the guide pipe 41 is inverted concrete 25. Alternatively, the guide pipe 47 is disposed so as to protrude upward from the guide groove 75. When the guide pipe 47 is disposed in the guide groove 75, the guide groove 75 is closed by pouring concrete into the guide groove 75 (FIG. 10). Then, the guide pipe 51 is connected to the tip of the guide pipe 47 protruding upward from the invert concrete 25, and a finger or a rotation tool is inserted into the operation hole 33 to rotate the operation part 43, and the water stop valve 44 The water supply state or the open state is set, and the support hole (operation hole) 33 is closed with a removable fitting lid 59.

  FIG. 11 is a cross-sectional view showing the structure of the filter 37.

  The filter body 39 of the filter 37 is a vinyl chloride tubular body 77 having a short opening at both upper and lower ends, and a vinyl chloride annular body disposed at the upper end of the tubular body 77 and having a fixing hole 79 formed in the center. A reinforcing plate 81, a vinyl chloride cap 85 that is placed on the upper side of the cylindrical body 77 so as to cover the annular reinforcing plate 81, and has a communication hole 83 that is larger than the fixing hole 79 at the center, and a cylindrical shape An annular vinyl chloride water collecting part 87 attached to the lower side of the body 77 and an annular water expansion positioned and fitted between the cap 85 and the water collecting part 87 on the outer periphery of the cylindrical body 77 A rubber seal ring 45, and a water collecting portion 87 is formed integrally with an upper ring portion 89 fitted to the lower side of the cylindrical body 77 and a lower end of the upper ring portion 89, While reducing the diameter on the lower side of the cylindrical body 77 It has a water collecting ring portion 91 extending towards the. In the water collection ring portion 91, for example, water collection slits 93 extending from the lower end to the upper portion are formed at equal intervals in the circumferential direction. The water collection ring portion 91 of the water collection portion 87 and the lower end opening of the cylindrical body 77 constitute an inflow port 38. The seal ring 45 has three annular lip portions 95 protruding on the outer peripheral side on the upper side, and the bottom surface 97 of each annular lip portion 95 extends outward or expands in diameter while being inclined upward. . In the drawing, reference numeral 99 denotes a stopper ring fitted on the outer periphery of the cap 85, and the outer diameter of the stopper ring 99 is larger than the inner diameter of the mounting hole 35. The filter 37 is pushed into the mounting hole 35 until the stopper ring 99 comes into contact with the inner surface or the upper surface of the bottom plate 5.

  An annular fixing surface 101 is formed on the inside of the upper end of the water collection ring portion 91 of the water collection portion 87 so as to protrude inward, and overlapped with the SUS punching plate 103 and the upper surface of the punching plate 103. A polypropylene resin net 105 is disposed at the inflow port 38 with the outer peripheral portion sandwiched between the fixed surface 101 and the lower end of the cylindrical body 77. The resin net 105 has a mesh pitch of 1.8 mm × 1.8 mm, and the punching plate 103 is formed with a hole diameter of 5 mm and an aperture ratio of 50% or more.

  The connection pipe part 41 includes a cylindrical main body part 107, a cylindrical communication part 109 fitted to the lower inner periphery of the main body part 107, and a nut 111 screwed to the outer periphery of the upper end part of the main body part 107. And have. The lower end of the main body 107 is located in the communication hole 83 of the cap 85 and abuts the periphery of the fixing hole 79 of the reinforcing plate 81, and the lower end of the communication part 109 protruding below the main body 107 is the reinforcing plate. 81 is fixed to the reinforcing plate 81 through a fixing hole 79. A resin net 113 similar to the polypropylene resin net 105 is covered on the lower end opening of the communication part 109 protruding downward from the reinforcing plate 81. The connection pipe portion 41 is provided with a water stop ball valve (water stop valve) 115. The water stop ball valve 115 includes a ball 117 disposed in the water flow path 42 above the connecting portion 109, and An operation handle 121 that rotates the ball 117 so that the through-flow path 119 of the ball 117 is aligned with the flowing water channel 42 or blocks the flowing water channel 42 with the ball 117 is provided. FIG. 11 shows a case where the through flow path 119 of the ball 117 and the water flow path 42 coincide with each other and the water stop ball valve 115 is in an open state.

  The cylindrical body 77 of the filter main body 39 is filled with mesalite 123 between the lower resin net 105 and the upper resin film 113.

  A split ring 125 is disposed at the upper end of the main body 107. The split ring 125 has a tapered outer peripheral surface 127, and the tapered outer peripheral surface 127 is pressed by the inner peripheral surface 129 of the nut 111 to be tightened to reduce the diameter, and is provided on the inner periphery of the split ring 125. The engaged teeth 131 are configured to move inward. Accordingly, the nut 111 is loosened, and the guide pipe 47 is inserted through the main body 107 through the nut 111, and then, when the nut 111 is tightened, the engaging teeth 131 engage with the guide pipe 47, and the guide The pipe 47 is prevented from coming off (state shown in FIG. 11). In the figure, 133 is a packing that seals between the guide pipe 47 and the main body 107, and 135 is a sliding ring that is disposed between the packing 133 and the nut 111.

  12 to 13 are views showing another attachment mode of the filter 37.

  If the support hole is formed perpendicularly to the invert concrete, the support hole needs to be inclined rather than vertical when the sheath pipe 67 hits the upper end opening of the inclined wall portion 19. If the support hole is formed to be inclined, the sheath pipe 67 provided in the support hole is also inclined, and the upper end side of the sheath pipe 67 can be protruded from the manhole opening without trouble. In FIG. 12, when the support hole 137 (33) is formed to be inclined with respect to the vertical direction from the inner surface of the inverted concrete 25 (when it is formed to extend upward while being inclined to the opposite side across the running water groove 31). In FIG. 13, when the support hole 139 (33) is formed to be inclined with respect to the vertical direction from the flow channel 143 (31) side of the inverted concrete 141 (on the opposite side across the center in the width direction of the flow channel 143). In the case of being formed so as to extend upward while being inclined). In FIG. 13, the diameter of the flowing water groove 143 is considerably large. Here, after the filter 37 is fixed in the mounting hole 145 (35), the guide groove 147 (75) is formed, and the guide pipe 149 (47) is connected to the filter 37, the water stop ball valve 115 is opened. Then, the support hole 139 and the guide groove 147 are filled with concrete. Therefore, a water stop ball valve 151 similar to the water stop ball valve 115 is provided on the distal end side of the guide pipe 149 in preparation for the case where it is necessary to close the flow path of excess pore water. In FIG. 12, the guide pipe 153 is embedded in the guide groove. However, as in the case of FIG. 1, the support hole 137 is only closed with a lid. The cutter head 69 of the core cutter 65 is attached to the connecting rod portion (the rod portion that protrudes short from the cutter head 69) so that it can freely swing or through a universal joint. The mounting holes 155 (35) and 145 are opened by swinging in an almost vertical inclined state. Therefore, the inclination of the mounting holes 155 and 145 from the vertical direction is smaller than the inclination of the support holes 137 and 139 from the vertical direction. Further, in place of the fitting lid 59, a lid having a lid receiving frame 157 and a lid 159 fitted into the lid receiving frame 157 is disposed at the upper end opening of the support hole 137, and the upper end opening of the supporting hole 137 is opened. Can be opened and closed.

  In addition, although it is based on attaching | subjecting the same code | symbol basically to the thing of the same structure as what is shown in FIG. 1, or a substantially the same structure, a different code | symbol is attached | subjected about what has a shape etc. slightly different. 12 and 13 can be understood more clearly by referring to the description of the corresponding part in FIG. The code | symbol of a corresponding part is basically described in the parenthesis.

  The construction method of the excess pore water drainage structure, the filter, and the excess pore water drainage structure of the present invention can be applied to a manhole structure that may float due to liquefaction of the ground when an earthquake occurs.

1 Manhole structure 5 Bottom plate block (bottom)
25, 141 Invert concrete (bottom)
33, 137, 139 Support hole 35, 145, 155 Mounting hole 37 Filter 47, 149, 153 Guide pipe (drain pipe)
51 Induction pipe (drain pipe)
71 sheath tube W water

Claims (13)

A method of constructing an excess pore water drainage structure that drains excess pore water generated in the ground around the manhole structure,
A first step of making a vertical support hole in the bottom of the manhole structure from the inner surface of the bottom to the middle in the vertical direction;
A second step in which a lower end is inserted into the support hole in a sealing manner and extends upward, and the manhole structure is provided with a second step;
A third step of injecting liquid into the sheath tube and applying water pressure to the bottom surface of the support hole;
A fourth step of driving a drill placed in the sheath tube to open a mounting hole in the vertical direction penetrating from the bottom surface of the support hole to the outer surface of the bottom;
A fifth step of removing the drill from the sheath tube, placing a filter in the sheath tube containing liquid, and mounting the filter in the mounting hole;
A sixth step of removing the sheath pipe from the support hole and attaching a drain pipe extending upward to the filter; and a method for constructing an excess pore water drainage structure.   2. The method for constructing an excessive pore water drainage structure according to claim 1, wherein the support hole has a larger diameter than the mounting hole.   3. The method for constructing an excessive pore water drainage structure according to claim 1, wherein, in the fifth step, the filter is attached into the attachment hole by being pushed firmly into the attachment hole. The drain pipe has a drawer portion extending from the filter to the vicinity of the inner peripheral surface of the manhole structure, and a main body portion extending upward from the tip of the drawer portion along the inner peripheral surface. ,
The method of configuring an excess pore water drainage structure according to claim 1, 2 or 3, wherein the sixth step includes a step of embedding the drawer portion below the inner surface of the bottom portion. .   5. The method for constructing an excessive pore water drainage structure according to claim 1, further comprising a step of closing an upper end opening of the support hole so as to be openable by a bottom lid.   The tip opening of the drainage pipe is provided with a tip end lid that swings in the opening direction by the water pressure of excess pore water and opens the tip opening so as to be swingable. Item 6. A method of constructing an excess pore water drainage structure according to Item 1, 2, 3, 4 or 5. The filter includes a filter main body having an inflow hole on a lower surface, and a connection pipe portion provided with a water stop valve extending upward from the filter main body, and the filter main body is disposed in the mounting hole. By being pushed tightly, it is installed in the mounting hole,
The said drainage pipe is connected to the front end side of the said connection pipe part, The structure method of the excess pore water drainage structure of Claim 1, 2, 3, 4, 5 or 6 characterized by the above-mentioned.   A seal member is provided on the outer periphery of the filter body, and the filter body is pushed tightly into the mounting hole so that the seal member is compressed between the filter body and the mounting hole. The method for constructing an excess pore water drainage structure according to claim 7.   9. The method of constructing an excess pore water drainage structure according to claim 8, wherein the bottom surface of the seal member is formed to extend outward while being inclined upward.   The excess filter according to claim 7, 8 or 9, wherein a filter net is provided in the inflow hole position inside the filter body, and a coarse aggregate is disposed on the filter net. A method of constructing the pore water drainage structure.   The method for constructing an excessive pore water drainage structure according to claim 10, wherein the filter net is made of resin, and a punching plate is laid under the filter net. Excess pore water drainage structure that drains excess pore water generated in the ground around the manhole structure,
A first hole in the vertical direction opened at the bottom of the manhole structure so as to reach an intermediate position in the vertical direction from the inner surface of the bottom;
A second hole in the vertical direction having a smaller diameter than the first hole, which is formed so as to penetrate from the bottom surface of the first hole to the outer surface of the bottom;
A filter press-fitted into the second hole;
An excess pore water drainage structure comprising an upwardly extending drain pipe attached to the filter. A filter used for the excess pore water drainage structure according to claim 12,
A filter body having an inlet on the lower surface, a connecting pipe portion provided with a water stop valve extending upward from the filter body, and a seal member provided on the outer periphery of the filter body,
The filter body is configured to be press fit into the second hole such that the seal member is compressed between the filter body and the second hole; Feature filter.

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