JPH1037257A - Underground reservoir and its construction method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an underground water storage tank that is easy to construct and has excellent earthquake resistance and a construction method thereof. SOLUTION: A foundation slab 1 of an underground water reservoir is constructed by cast-in-place concrete, and an L-shaped and rectangular lower end segment 2, an intermediate segment 3 and an upper end respectively installed at a corner portion and a flat portion of the underground water reservoir. The walls of the underground reservoir are constructed by installing the segments 4 while being joined to each other in the circumferential direction and the vertical direction of the underground reservoir, and the rectangular roof panel 5 is joined to the upper end of the wall. It is constructed in the shape of a rectangular box by bridging while constructing the roof of the underground reservoir.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground reservoir for storing water for daily use, fire prevention, or emergency drinking water in parks, estates, condominiums, factories and the like, and a construction method thereof.

[0002]

2. Description of the Related Art In general, underground water for storing living water, fire prevention water, or emergency drinking water is used in parks, housing estates, condominiums, factories, and other premises. So it is installed,
Conventionally, this kind of underground reservoir is mainly constructed of cast-in-place reinforced concrete or precast reinforced concrete.

[0003] However, the former requires a large installation space,
In addition, extra work and cost are required for safety works such as landscaping, and the construction period is unavoidably prolonged. Further, water leaks and the like are apt to occur, and there are many issues to be improved in quality control and construction control.

[0004] On the other hand, in the latter, roots are cut to a predetermined size and depth at an installation site, safety foundations and other safety works are performed, and foundation concrete is poured, and a box culvert is placed on the foundation concrete. It is laid horizontally, and both ends are attached with a reinforced concrete plate and tightened with a PC steel bar to make it an integral structure with the box culvert. Therefore, there is a problem that the installation place needs to be wide and the traffic becomes an obstacle. In addition, there was a problem that it was weak to earthquakes because it was long in the horizontal direction of the plane.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an underground water storage tank which is easy to construct and has excellent earthquake resistance, and a construction method thereof.

[0006]

An underground reservoir according to the present invention is constructed by constructing a foundation slab by cast-in-place concrete, and forming an L-shaped wall which is installed at a corner portion and a flat portion of the underground reservoir. A segment and a rectangular segment are constructed by being installed while being joined to each other in the circumferential direction and the vertical direction of the underground reservoir, and the roof is joined to a rectangular roof panel at the upper end of the wall. It is constructed in a rectangular box shape by being bridged while being constructed.

In addition, a partition is provided therein to divide the inside into a plurality of parts, and a tension member is inserted into the wall in the circumferential direction and / or the vertical direction of the underground reservoir, or both directions to introduce prestress into the wall. And so on.

In the construction method of an underground water reservoir according to the present invention, a plurality of segments are installed on the ground while being joined to each other to construct a wall around the entire periphery thereof, and then the wall is attached to the inner side thereof. Submerging the ground while excavating the ground, then constructing the foundation slab by cast-in-place concrete at the bottom of the wall, and constructing a roof by hanging a roof panel on the wall. Features.

[0009] Further, a partition is provided inside to partition the inside into a plurality, and a tension member is inserted into the wall in the circumferential direction and / or the vertical direction of the underground reservoir to introduce prestress into the wall. And build.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 to 7 show an embodiment of the present invention. In the drawings, reference numeral 1 is constructed to a predetermined thickness by cast-in-place concrete on a root excavated to a predetermined depth, The foundation slabs 2, 3, and 4 constituting the floor of the underground reservoir are erected around the foundation slab 1 so as to form a rectangular box while being joined to each other in the circumferential direction and the vertical direction of the underground reservoir. The lower segment, the middle segment and the upper segment, which constitute the wall of the underground reservoir, are bridged over the upper end of the upper segment 4 assembled in a rectangular box shape. A roof panel constituting a roof portion of the water storage tank, and reference numeral 6 denotes an intake port protruding from the roof panel 5 for flowing water into the underground water storage tank.

Reference numeral 7 denotes a joint between the lower end segments 2, a joint between the intermediate segments 3, a joint between the upper end segments 4, a joint between the lower end segment 2 and the intermediate segment 3, These segments 2, 3, and 4 are attached to the joint between the middle segment 3 and the upper end segment 4 and the joint between the upper end segment 4 and the roof panel 5, respectively. And a joining plate 8 for joining the upper end segment 4 and the roof panel 5, respectively, is screwed to the lower end segment 2, the middle segment 3, the upper end segment 4 and the edge of the roof panel 5, respectively. , Joining bolts for bolting the joining plate 7 to the edges of these segments 2, 3, 4 and the roof panel 5.

The joining plate 7 is attached to both the inner and outer sides of the lower end segment 2, the intermediate segment 3 and the upper end segment 4, and the joining bolt 8 is attached to the lower end segment 2, the intermediate segment 3 and the lower end segment 2. The segments are screwed into the inner and outer sides of the upper end segment 4, and each segment is double-joined from both the inner and outer sides by the joining plate 7 and the joining bolt 8 (FIG. 4 (b)). )reference).

The joining of the segments by the joining plate 7 and the joining bolts 8 is performed at a plurality of locations (at least two to three locations in the circumferential direction and the vertical direction) of the underground reservoir according to the scale of the underground reservoir to be constructed. ).

The base slab 1 is laid with split stones 9 on the roots excavated to a predetermined depth, casts discarded concrete 10 on the split rockstones 9, and further reinforced reinforcing steel on the discarded concrete 10. It is constructed by arranging reinforcing bars and placing concrete (see Fig. 5 (b)). At a predetermined position of the base slab 1, a water collecting pit 12 used for cleaning the inside of the reservoir is formed. The water collecting pit 12 is formed so as to be located directly below the water intake 6 of the roof panel 5.

Lower segment 2, middle segment 3
Of the upper end segment 4, the segments installed at the corners of the underground reservoir are all integrally formed in an L-shape corresponding to the shape of the corners of the underground reservoir, and are installed outside the corners. The segments are formed in a rectangular plate shape, and the segments adjacent to each other in the lateral direction are joined at flat portions other than the corner portions. In this way, the corners of the wall are integrally constructed with L-shaped segments, and the joints between the segments are made entirely flat, avoiding corners where stress tends to concentrate, thereby improving earthquake resistance. I can do it.

A tension member (not shown) such as a PC steel wire is continuously inserted in the lower segment 2, the middle segment 3 and the upper segment 4 in the circumferential direction and / or the vertical direction of the underground reservoir or in both directions. As a result, a predetermined amount of prestress is introduced into the wall.

The lower end of the lower end segment 2 is formed to be thick over a certain height in preparation for an upper load and an earthquake load, and the base 2a is subjected to the upper load and the earthquake load.
Has made. The base 2a is formed continuously in the circumferential direction of the reservoir. Furthermore, the lower end segment 2,
Both the middle segment 3 and the upper end segment 4 are formed from precast concrete at the factory.

The lower end segment 2 thus formed
Are erected around the base slab 1, an intermediate segment 3 is erected on the lower end segment 2, and an upper end segment 4 is erected on the intermediate segment 3.

The intermediate segment 3 and the upper end segment 4 are further stacked according to the scale (depth) of the underground reservoir.

In this case, the lower end segment 2, the middle portion segment 3 and the upper end segment 4 are erected so that the joints (joints) of these segments are not continuous in the vertical direction and are staggered. ing.

A plurality of anchor bolts 13 are horizontally protruded from the inside of the base portion 2a of the lower end segment 2,
The anchor bolt 13 is welded to the reinforcing steel bar 11 arranged in the concrete of the foundation slab 1 (see FIG. 5 (b)). The anchor bolt 13 is screwed to and protrudes from an insert nut 14 embedded in the concrete of the lower end segment 2.

A water stop plate 15 made of rubber, plastic, or the like for stopping water at this portion is horizontally interposed at the contact surface between the base portion 2a of the lower end segment 2 and the base slab 1. Before the concrete of the foundation slab 1 is cast, one end of the water stop plate 15 is fitted into a concave groove 16 formed on the inner side of the foundation 2a and may be protruded in advance.

Further, insert nuts 17 are embedded in the edges of the lower end segment 2, the intermediate segment 3, and the upper end segment 4, and the joining bolts 8 are screwed into the insert nuts 17 (FIG. 4 (a)). ), (b)). The insert nut 17 is firmly fixed in the concrete of each segment by an anchor reinforcing bar (not shown).

A recess 18 is provided around the insert nut 17.
Is formed, and the joining plate 7 is attached to the recess 18 so that the joining plate 7 and the joining bolt 8 do not protrude from the surface of the segment.

At the joint of the lower end segment 2, the intermediate segment 3 and the upper end segment 4, a seal member 19 is attached to the outside and the inside on both sides thereof in a double or triple manner on one side. Filler 20 for sealing is filled between 19 and 19, so that the water-stopping treatment and the waterproof treatment of the joint between the segments are surely performed (FIG. 5).
(a)).

The seal member 19 is formed of a woven fabric made of chemical fibers such as glass fiber and carbon fiber, and is adhered to the surface thereof while applying an adhesive resin such as an epoxy resin. The filler 20 is made of, for example, urethane resin.

A semicircular, triangular or trapezoidal concave groove 21 is formed at a predetermined depth on the joint surface between the segments.
If the groove 21 is filled with the filler 22 for sealing, the filler 22 is pressed into the groove 21 by the segments, so that the joint 22 between the segments can be reliably filled with the filler 22 and the segments can be filled. Waterproofing and waterproofing of the joint can be reliably performed (see FIG. 5 (a)).

Further, the inner surfaces of the base slab 1, the lower end segment 2, the intermediate segment 3 and the upper end segment 4 are waterproofed by applying paint such as epoxy resin over the entire surface.

When used in the treatment, drainage, and storage of hot springs in food and chemical factories, etc., the base slab 1 and the inside of each segment are placed so as not to adversely affect the concrete in the segment. A sheet (not shown) made of an elastic material such as rubber is stuck.

The roof panel 5 is formed into a rectangular plate from precast concrete at a factory. Adjacent roof panels 5 are joined by joining plates 7 and joining bolts 8 in the same manner as joining segments. Also, the upper end segment 4 and the roof panel 5
A water-stop packing (not shown) is interposed in the joint surface between the segments, and the same water-stopping treatment as in the joint between the segments is performed.

The water intake port 6 is factory-formed into a cylindrical shape by precast concrete, and is attached to the roof panel 5 by bolting or the like.

FIGS. 6 (a) and 6 (b) show another method for joining the adjacent segments, the roof panels and the upper end segment 4 and the roof panel 5, and show a concave portion in the joint surface between the adjacent segments. 23 are provided, bonding metal fittings 24 are attached to the concave parts 23 so as to face each other, and the bonding metal fittings 24 are bonded to each other with bonding bolts 25.
The segments and the upper end segment 4 and the roof panel 5 are joined to each other.

FIGS. 7 (a) and 7 (b) show an underground reservoir in which a vertical partition 26 is provided in the underground reservoir to divide the interior into two chambers. The lower end segment 2, the middle portion segment 3 and the upper end segment 4 to which both ends of the vertical partition 26 are joined are connected to a joint 27 for joining the vertical partition 26.
And is formed into a substantially T-shaped cross section.

Embodiment 2 of the Invention Next, the construction method of the underground reservoir according to the present invention will be described. (1) First, on the ground, the lower end segment 2, the middle portion segment 3, and the upper end segment 4 are assembled into a rectangular box shape to underground reservoir. Build the wall.

In addition, a waterproofing treatment is performed on the joint portion of each segment and a waterproof treatment is performed on the inside and outside of each segment. Furthermore, a tension member is inserted into the wall in the circumferential direction, the vertical direction, or both directions to introduce a predetermined large prestress into the wall.

(2) Next, while excavating the ground inside the wall constructed in a rectangular box shape, the wall is gradually submerged in the ground (by the so-called “open well method”).

In this case, it is necessary to consider the friction between the segment and the surrounding ground.
Is formed slightly larger (about 2 to 20 cm) over a height H of about 10 to 100 cm from the lower end (FIG. 1).
(a), (b)), the friction between the surrounding ground and the wall can be reduced,
The wall can be settled relatively smoothly. In this case, the outer diameter of the lower end segment 2 and the height from the lower end are set to optimal values based on the soil properties of the surrounding ground.

For example, when the surrounding ground is clayey, the outer diameter is small and the height is high. When the surrounding ground is clayey, the outer diameter is large and the height is low.

(3) Next, when the wall can be submerged to a predetermined depth, the root cut bottom is leveled, the split stone 9 is laid thereon, the discarded concrete 10 is poured, and the reinforcing steel 11 is placed thereon.
And constructing the foundation slab 1 by casting concrete. Before pouring concrete, a water stop plate 15 is attached to the inside of the lower segment.

If necessary, a permeable material or a permeable mat (not shown) is laid on the discarded concrete to make the structure permeable.

(4) Next, the roof panel 5 is laid over the upper end of the wall (the upper end of the upper end segment 4) to construct the roof, and the water intake 6 is attached to the roof. Finally, the surrounding area is backfilled and the rolling is sufficiently performed to complete the construction.

[0042]

The underground reservoir according to the present invention has the above-described structure, and particularly has an L-shaped segment and a rectangular segment whose walls are respectively installed at the corner portion and the flat portion of the underground reservoir. Are constructed by joining them together in the circumferential direction and the vertical direction of the underground reservoir, so that the corners where stress is easily concentrated are integrally constructed from L-shaped segments, and the joints are formed at the corners. No, and on the wall the underground reservoir in the circumferential direction or up and down direction,
Alternatively, a prestress is introduced into the wall by inserting a tension member in both directions, and a partition is provided inside the wall, so that there is an effect that the seismic resistance is extremely excellent.

Further, the wall portion is installed while joining an L-shaped segment and a rectangular segment which are respectively installed at a corner portion and a flat portion of the underground reservoir, in a circumferential direction and a vertical direction of the underground reservoir. The roof portion is constructed by joining a rectangular roof panel to the upper end portion of the wall portion while being connected to the upper end portion of the wall portion.

Further, a sealing material is applied to the joint portion between the segments at the inner side and the outer side thereof while applying an adhesive resin in a double or triple manner, and a sealing filler is provided at the joint portion. And further, a groove is provided continuously in the circumferential direction of the segment at the joint surface between the segments, and the groove is filled with a filler for sealing, and the base slab and the segment installed at the lowermost stage are also filled. Since the water stop plate is interposed in the abutment surface, the joint between the segments and the joint between the segment and the base slab can be reliably waterproofed and waterproofed. Has the effect of reliably preventing such problems.

Further, since the upper surface of the base slab, the inner surface of the wall portion and the inner surface of the roof portion are covered with a sheet material, there is no fear that the stored material will adversely affect the concrete, so that various materials are not limited to domestic water. There is an effect that can be stored.

In the construction method of the underground reservoir according to the present invention, the underground reservoir wall is first constructed on the ground by installing a plurality of segments, and then the wall is excavated by the inner ground. While gradually sinking into the ground, then building the foundation slab at the bottom of the wall, and installing the roof panel on the wall to build the roof, so assembling and segmenting the segments This has the effect that the joints between the two can be reliably waterproofed and stopped.

Further, since the wall is sunk into the ground while excavating the inside of the wall, there is an effect that the amount of earthwork can be reduced and the labor can be saved.

[Brief description of the drawings]

FIG. 1 (a) is a front view of an underground reservoir, and FIG. 1 (b) is a side view thereof.

2A is a plan view of an underground reservoir, and FIG. 2B is a cross-sectional view thereof.

FIGS. 3A and 3B are longitudinal sectional views of an underground reservoir.

4 (a) is a plan view showing a joint between segments and a joint between roof panels, and FIG. 4 (b) is a longitudinal sectional view thereof.

5 (a) is a longitudinal sectional view showing joints between segments and joints between roof panels, and FIG. 5 (b) is an enlarged longitudinal sectional view showing a joint between a lower end segment and a foundation slab.

6A is a plan view showing a joint between segments and a joint between roof panels, and FIG. 6B is a longitudinal sectional view thereof.

7 (a) and 7 (b) are longitudinal sectional views of an underground water storage tank having a vertical partition.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Foundation slab, 2 ... lower end segment, 3 ... middle segment, 4 ... upper end segment, 5 ... roof panel, 6
… Inlet, 7… Joint plate, 8… Joint bolt, 9… Split stone, 10… Discarded concrete, 11… Reinforcing steel bar, 12… Water collecting pit, 13… Anchor bolt, 14… Insert nut, 15… Water stop plate , 16 ... concave groove, 17 ... insert nut,
18 ... recess, 19 ... sealing material, 20 ... filler, 21 ... concave groove, 22
... filler, 23 ... recess, 24 ... joint fitting, 25 ... joint bolt,
26 ... vertical partition, 27 ... joint part.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Eiichi Nakao 1-12-2 Sakaecho, Fuchu-shi, Tokyo

Claims (16)

[Claims] 1. A base slab at a root excavated at a predetermined depth and serving as a floor of an underground reservoir, and a plurality of base slabs surrounding the foundation slab and constituting a wall of the underground reservoir. In the underground reservoir constructed in a rectangular box shape having a plurality of segments and a plurality of roof panels at the upper end of the wall portion and constituting a roof of the underground reservoir, The slab is constructed by cast-in-place concrete, and the wall portion is formed on the corner portion and the flat portion of the underground reservoir with an L-shaped segment and a rectangular segment, respectively, in the circumferential direction and the vertical direction of the underground reservoir. The underground water storage tank is constructed by being installed while being joined to each other, and the roof is constructed by joining a rectangular roof panel to the upper end of the wall while being joined to each other. 2. The underground reservoir according to claim 1, wherein a partition is provided in the underground reservoir to divide the interior into a plurality. 3. A prestress is introduced into the wall by inserting a tendon into the wall in a circumferential direction and / or a vertical direction of the underground reservoir or in both directions. The underground reservoir described in item 2. 4. A base portion is provided at a lower end portion of a lowermost segment constituting a wall portion.
Item 4. The underground reservoir according to item 2, paragraph 2 or 3. 5. A plurality of layers of a sealing material applied to the joint between the segments constituting the wall and the joint between the roof panels constituting the roof by applying an adhesive resin to the inside and outside thereof. The underground water storage tank according to any one of claims 1, 2, 3 and 4, wherein the underwater storage tank is attached to the base and the joint is filled with a sealing filler. 6. The underground base according to claim 5, wherein a groove is provided in a joint surface between the segments and a joint between the roof panels, and the groove is filled with a sealing filler. It seems to store water. 7. A water blocking plate is interposed between contact surfaces of a foundation slab and a segment installed at the lowest stage, wherein the water blocking plate is interposed. Item 7. The underground reservoir according to item 5, 5 or 6. 8. The first, second, third, fourth and fifth features of the present invention, wherein the upper surface of the base slab, the inner surfaces of the walls and the roof are covered with a sheet material. Item 7. The underground reservoir according to item 6, 6 or 7. 9. A foundation slab at a root excavated to a predetermined depth and serving as a floor of an underground reservoir, and a plurality of base slabs surrounding the foundation slab and constituting a wall of the underground reservoir. In the construction method of the underground reservoir comprising a plurality of segments and a plurality of roof panels forming the roof of the underground reservoir at the upper end of the wall portion, the segment is installed on the ground. Constructing the wall of the underground reservoir over its entire circumference, then submerging the wall into the ground while excavating the ground inside it, and then building the foundation slab at the bottom of the wall; And a method of constructing an underground reservoir by installing a roof panel on the wall. 10. The construction method of an underground reservoir according to claim 9, wherein a partition is provided in the underground reservoir to divide the interior into a plurality. 11. A prestress is introduced into the wall by inserting a tendon into the wall in the circumferential direction and / or the vertical direction of the underground reservoir or in both directions.
Item 10. The method for constructing an underground reservoir according to item 10 or 10. 12. The ninth aspect, wherein a base portion is provided at a lower end portion of the lowermost segment constituting the wall portion.
The construction method of an underground reservoir according to paragraph 10, paragraph 10 or paragraph 11. 13. A plurality of layers formed by applying an adhesive resin to a joint between the segments constituting the wall and a joint between the roof panels constituting the roof at the inner and outer sides thereof while applying an adhesive resin. 10. The bonding part is filled with a filler for sealing.
Item 10. The method for constructing an underground reservoir according to Item 10, Item 11, or Item 12. 14. The underground water storage tank according to claim 13, wherein a groove is provided in a joint surface between the segments and a joint between the roof panels, and the groove is filled with a sealing filler. Construction method. 15. A water blocking plate is interposed at a contact surface between a foundation slab and a segment installed at the lowest stage, wherein the water blocking plate is interposed. First
Item 15. The method for constructing an underground reservoir according to item 3 or 14. 16. The method according to claim 9, wherein the upper surface of the base slab, the inner surface of the wall and the inner surface of the roof are covered with a sheet material. First
Item 14. The method for constructing an underground reservoir according to item 4 or 15.