JP2011143930A - Band unit for anchoring underground tank and anchoring structure of underground tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the work load when anchoring an underground tank by reducing the weight of a receiving base on which the tank is placed, and providing an anchoring band having a high tensile strength and a metal piece fitting structure in a fixing structure of the horizontal cylindrical underground tank for storing liquid fuel or the like. <P>SOLUTION: A receiving base includes a structure in which an arc part in contact with the bottom surface of a tank barrel part and leg parts at both ends are formed of FRP (fiber-reinforced plastic) strips, and fastening parts to a floor plate are reinforced with iron sheets. A band unit used to fix the tank on the receiving base includes an iron or FRP adhesive plate having a multi-layered fiber-reinforced layer stuck to a band body and both sides of its ends with an epoxy-based adhesive, a rigid fastening plate for fastening the adhesive plate from both outer sides of the adhesive plate by bolts, and a metal piece connected to or integrated with the adhesive plate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fixing structure for a horizontal cylindrical underground tank used for storing liquid fuel or the like.

  This type of underground tank is fixed on a floor slab installed in the basement with a cradle that supports the lower surface of the trunk in multiple places and a plurality of bands that are stretched in an inverted U shape on the upper surface of the trunk. ing. The cradle is made of concrete or a strip-shaped steel plate. In Patent Document 1 below, leg portions extending obliquely downward are provided at both ends of a receiving plate made of a strip-shaped iron plate formed in an arc shape in accordance with the curvature of the tank body portion, and the leg portions are fixed to the floor slab with anchor bolts. A cradle with a structure is shown.

  The band hung around the upper part of the tank body is made of FRP (fiber reinforced plastic), and is fixed to anchor bolts provided on the floor slab via metal fittings attached to both ends thereof. The band is provided with a connecting portion for connecting portions on both sides thereof at a portion located at the top of the tank. Also in this connection part, it has the structure which attaches metal fittings to the band made from FRP, and connects these metal fittings with a volt | bolt.

  This band has the effect of placing the underground tank on the cradle and preventing the underground tank from rising due to the water pressure of the groundwater. The tension of the band can be adjusted by a bolt at the connection portion at the top of the tank. Since this band functions to prevent the underground tank from rising, a large underground tank is required to have sufficient tensile strength to withstand the large buoyancy.

JP 7-215396 A

  Since the FRP band for fixing the underground tank needs to be connected to an anchor bolt or a tension adjusting bolt, an end of the FRP band is attached to an end of the FRP band. Epoxy adhesive is used to fix the band and metal fittings, but the strength of the bonded part is as low as about 1/2 or less of the band itself, so the strength of the bonded part can be reduced to the required tensile force. In order to make it strong enough to withstand the load, the size of the band and metal fittings must be larger than the required size, which increases the cost and work for fixing the underground tank to the floor slab due to an increase in weight, etc. There was a problem that the burden increased.

  Moreover, since the weight of the steel plate support proposed in Patent Document 1 is heavy, one worker cannot attach it to the floor slab, and two people work to fix the underground tank to the floor slab. There was a problem of requiring a worker.

  The present invention provides a band body and bracket mounting structure having high tensile strength in a band (hereinafter referred to as a “band unit”) having brackets attached to both ends used for fixing an underground tank. The aim is to reduce the cost and weight of the unit, thereby reducing the cost of the band unit and reducing the work burden when fixing the underground tank. Moreover, this invention further improves the workability at the time of fixing an underground tank by further reducing the weight of the steel plate support, which is lighter and easier to work than a concrete support. Is an issue.

  The band unit 2 used for fixing the underground tank of the present invention is made of FRP having a band main body 21 and an iron plate or a multilayer fiber reinforced layer bonded to both sides of the end 21a of the band main body with an epoxy adhesive. Adhesive plates 43, 51, a rigid fastening plate 44 for fastening the adhesive plates 43, 51 on both sides with bolts 45 from the outside, and metal fittings 4 (4a, 4b) connected to or integral with the adhesive plate. It is to have.

  The adhesive plate 43 made of iron plate can be integrated with the metal fitting 4 attached to the end of the band unit 2. For example, one piece 43 of metal fittings made of two iron plates bent into an L shape is attached to each adhesive plate. In addition, a bolt hole may be provided in the other piece 42 so that the anchor bolt 6 and the tension adjusting bolt 7 are inserted.

  In the structure in which the adhesive plate 51 is made of an FRP plate, both pieces of the FRP plate bent in a U-shape are used as the adhesive plate 51, and a metal rod or a metal pipe 49 is inserted into the portion bent in the U-shape. A metal rod or pipe is integrated with the metal fitting 4 or connected to the metal fitting with a hinge structure.

  According to the test conducted by the inventors of the present application, the FRP adhesive plate 51 is made of a glass fiber woven fabric or nonwoven fabric as a reinforcing material, and a glass fiber that is aligned in the direction in which the tension acts as a reinforcing material. It is good to use an FRP plate having a structure in which 7 to 9 layers of roving layers are laminated, and further, an FRP plate having a reinforcing layer containing carbon fiber of 1 to 10% of its volume is high. It is preferable for obtaining the tensile strength.

  In the underground tank fixing structure according to the present invention, together with the band unit 2 having the above structure, an arc portion in contact with the bottom surface of the tank body portion and the leg portions at both ends thereof are formed by FRP strips, to the floor slab. It is preferable to use the cradle 3 having a structure in which the fastening portion is reinforced with the iron plate 32. By using the band unit 2 and the cradle 3 as described above, it is possible to significantly reduce the work load in the work of fixing the underground tank 1 onto the underground floor slab 11, and the fixing work previously performed by two workers. Can be performed by one operator.

  In order to increase the tensile strength at the connection between the band main body and the metal fitting, the first thing to consider is to increase the bonding area. Increasing the width of the band body in order to increase the bonding area is against the problem of reducing the band body and metal fittings. Therefore, in order to increase the bonding area, the longitudinal dimension L of the band body is increased. It is necessary to widen the bonding area. However, when the test was performed with the bonding area widened in this way, the tensile strength of the bonded portion was maximized at a certain length, and when the length was further increased, the strength decreased. In the test using a band having a width of 65 mm, the maximum value was about 200 to 115 KN (kilonewtons) with an adhesive length of 200 mm. The tensile strength of the band body is 200 KN.

  Adhesive plates 43 and 51 made of iron plate or FRP are bonded to both sides of the end of the band body, and a fastening plate made of an iron plate having the same shape as the joining surface is attached to the outer surface of the adhesive plate, and fastening on both sides A test was also conducted on a structure in which the plate was fastened with a bolt penetrating the band main body and the adhesive plate was pressure-bonded to the band main body, but a desired strength could not be obtained. The tensile strengths of the three samples were 151 KN, 152 KN, and 147 KN, respectively, and the average value was 150 KN.

  The present invention has been completed through various trials and errors as described above. Adhesive plates 43 and 51 made of iron plate or FRP are bonded to both ends of the band main body, and a fastening plate 44 attached to the outside thereof. According to the structure in which the adhesive plates 43 and 51 that are fastened with bolts 45 and 45 and bonded to both surfaces of the band main body 21 are crimped to the band main body 21 at the portion protruding outward in the width direction of the band main body 21. The tensile strength comparable to that of the band main body 21 can be imparted to the joint between the adhesive plates 43 and 51, and the band unit can be significantly reduced in cost and workability when fixing the underground tank. it can.

  In addition to the band unit having the above-described structure, the cradle 3 having a structure in which the arc portion in contact with the tank body 1 and the support portions at both ends thereof are made of FRP and the fastening portion with the floor slab is reinforced by the reinforcing iron plate 32 is used. Thus, the workability when fixing the underground tank to the floor slab can be greatly improved, and the number of workers required for fixing the underground tank can be reduced.

The front view which shows the 1st example of the junction part of a band main body and a metal fitting. Side view of the joint of FIG. The front view which shows the 2nd example of the junction part of a band main body and a metal fitting. Side view of the joint of FIG. The front view which shows the principal part of the cradle in the fixed structure of this invention Top view of the fixed part of the cradle Plan view of FIG. Front view showing the whole fixed structure of the underground tank Side view of FIG.

  In FIGS. 8 and 9 showing the fixing structure of the horizontal cylindrical underground tank 1 to the floor slab 11 installed in the ground, 3 is a cradle having both ends fixed to anchor bolts 6 provided on the floor slab 11, 2 Is a band unit that extends over the trunk of the underground tank 1 in an inverted U shape. The cradle 3 includes an arc portion 3a bent with a curvature equal to the circumference of the trunk of the underground tank 1, leg portions 3b at both ends thereof, and a fixing portion 3c extending horizontally outward from the lower ends of the leg portions. ing. As shown in FIGS. 6 and 7, the fixing portion 3 c is provided with a V-shaped cut 31 from the outside, and the anchor bolt 6 is inserted into the cut 31.

  One band unit 2 is arranged on each of the left and right sides when viewed from the front. Each band unit 2, 2 has metal fittings 4, 4 attached to the lower end and the upper end. The metal fitting 4 at the lower end has a bolt hole through which the anchor bolt 6 is inserted, and is fixed to the floor slab 11 with the anchor bolt 6. The metal fitting 4 at the upper end has a bolt hole through which the tension adjusting bolt 7 is inserted, and the left and right band units 2, 2 are connected by the tension adjusting bolt 7 inserted through the hole.

  1 and 2 are views showing a first example of a connection portion between the band main body 21 of the band unit 2 and the metal fitting 4 (4a). The metal fitting 4a of this first example is composed of two iron plates 41, 41 bent into an L shape, and one of the bent pieces 42, 42 are overlapped and bonded to each other to provide a bolt insertion hole. It has become. The other refracted pieces 43 and 43 are bonded to both surfaces of the end portion with an epoxy adhesive so as to sandwich the end portion 21a of the band main body, and further to the outside, the band main body 21 and the band main body 21 are bonded to this. Fastening plates 44, 44 having dimensions projecting outside the width of the steel plate pieces 43, 43 are attached, and bolts 45 inserted into bolt holes provided in portions projecting outside the width are used to It fastens in the state which piled up the metal plate pieces 43 and 43 of the metal fitting which has comprised the edge part 21a and the adhesive plate.

  The tensile strength of the joint where the metal fitting 4a is attached to the 65mm wide band body with the above structure is 171KN (kilonewton), 168KN, 171KN, and the average value is 168KN for three samples with an adhesive length L = 200mm. Yes, three samples with an adhesion length L = 300 mm were 188 KN, 190 KN, 176 KN, and the average value was 185 KN. In the example shown in the figure, two places in the longitudinal direction of the band are fastened by the fastening plate 44, but a tendency that the tensile strength of the structure in which only one place is fastened is more excellent.

  1 and 2 are connected to both ends of a band main body 21 having a predetermined length to form the left and right band units 2 and 2 shown in FIGS. 8 and 9, and one of the metal fittings 4a is connected to the anchor bolt 6 Is fixed to the floor slab 11, the other is connected by a tension adjusting bolt 7, and the underground tank 1 is fixed to the cradle 3. When buoyancy acts on the underground tank 1 due to the water pressure of the groundwater, the tension acting on the band units 2 and 2 resists the buoyancy and prevents the underground tank from rising.

  3 and 4 are views showing a second example of the connection portion between the band main body 21 of the band unit 2 and the metal fitting 4 (4b). The metal fitting 4b of the second example is provided with a bolt insertion hole in a bottom surface 47 of an iron plate bent in an upward U shape in a side view, and two bent pieces 48 bent upward (leftward in FIGS. 3 and 4). , 48 is a structure in which an iron round bar 49 is stretched between them. The end portion 21a of the band main body and the metal fitting 4b are formed by attaching U-shaped pieces 51 and 51 to both surfaces of the end portion 21a of the band main body with an epoxy resin, and a round bar 49 of the metal fitting at the bent portion. Is connected through the FRP connecting member 50 inserted therethrough.

  That is, the U-shaped pieces 51 and 51 of the FRP connecting member 50 serving as an adhesive plate are bonded to both surfaces of the end portion 21a of the band main body with an epoxy-based adhesive, and further on the outer side, the band main body 21 and Fastening plates 44, 44 having dimensions projecting outside the width of both the pieces 51, 51 of the FRP connecting member adhered thereto are attached, and bolt holes provided in the portions projecting outside the width are provided. The end portion 21a of the band main body and the two pieces 51, 51 of the FRP connecting member serving as an adhesive plate are fastened together with the inserted bolt 45 in an overlapping state. And the round bar 49 of a metal fitting is penetrated by the part bent to the U-shape of the FRP connection member 50, and the FRP connection member 50 and the metal fitting 4b are connected.

  The tensile strength of the joint part in the above structure between the band main body 21 having a width of 65 mm and the FRP adhesive plates 51 and 51 is 182 KN (kilonewton), 185 KN, and 208 KN for three samples having an adhesive length L = 200 mm. The average value was 192KN, and the three samples having the adhesion length L = 300 mm were 175KN, 193KN, and 190KN, and the average value was 186KN. The first one of the three samples with an adhesive length L = 200 mm and the three samples with L = 300 mm have a structure in which two bands in the longitudinal direction are fastened with fastening plates 44. The latter two of the three samples of = 200 mm have a structure in which only one place is fastened by the fastening plate 44.

  3 and 4 are connected to both ends of a band main body 21 having a predetermined length to form the left and right band units 2 and 2 shown in FIGS. 8 and 9, and one of the metal fittings 4b is connected to the anchor bolt 6 Is fixed to the floor slab 11, the other is connected by a tension adjusting bolt 7, and the underground tank 1 is fixed to the cradle 3.

  FIG. 5 is a front view showing a main part of a cradle suitable for use with the band units 2 and 2 having the above structure. FIG. 8 shows the front of the cradle and FIG. The cradle 3 includes an arc portion 3a that supports the bottom surface of the cylindrical portion of the underground tank 1 to be fixed, a leg portion 3b that extends obliquely outward and downward from both sides thereof, and a fixing portion 3c that extends horizontally outward from the lower end of the leg portion. And an integral structure. The arc portion 3a is formed into an arc shape having a curvature equal to the circumference of the trunk portion of the underground tank 1 to be fixed. The arc part 3a and the leg part 3b are band-shaped members only of FRP.

As shown in FIG. 6, the fixing portion 3 c is provided with a V-shaped cut 31 from the outside, and the anchor bolt 6 is inserted into the cut portion to be fixed on the floor slab 11. A reinforcing iron plate 32 is embedded in the portion where the cut 31 of the fixing portion 3c is provided.
By using the structure of the cradle 3 as described above, the weight can be significantly reduced without impairing the strength required for the cradle, and the work for fixing the cradle 3 on the floor slab 11 can be performed by one worker. It becomes possible to do in.

DESCRIPTION OF SYMBOLS 1 Underground tank 2 Band unit 3 Base 3a Arc part 3b Leg part 4 (4a, 4b) Metal fitting 6 Anchor bolt 7 Tension adjustment bolt 11 Floor slab 21 Band main body 32 Reinforcement iron plate 43 Adhesive plate 44 Fastening plate 45 Fastening bolt 50 Made of FRP Connection member 51 Adhesive plate

Claims (3)

  In a band unit for fixing an underground tank comprising a band main body (21) and a metal fitting (4) attached to the end (21a) of the band main body, both sides of the end (21a) of the band main body (21) An adhesive plate (43, 51) made of an iron plate or a multilayered fiber reinforced layer bonded with an epoxy-based adhesive, and a bolt (45) positioned on the outer side in the width direction of the double-sided adhesive plate A band unit for fixing an underground tank, comprising: a rigid fastening plate (44) to be tightened by a clamp and a metal fitting (4) connected to or integrally with the adhesive plate.   The adhesive plate (43) made of an iron plate and the metal fitting (4a) composed of two iron plates (41) bent into an L shape, each of the bent pieces being used as the adhesive plate. The band unit for fixing an underground tank according to claim 1, wherein a bolt hole through which an anchor bolt (6) or a tension adjusting bolt (7) is inserted is provided in the other piece (42) which is bonded in a stacked manner.   A band unit (2) according to claim 1 or 2, and an arcuate portion (3a) that contacts the bottom surface of the underground tank body, and is made of FRP with a reinforcing iron plate embedded in a fixed portion (3c) to the floor slab. An underground tank (1) mounted on the cradle (3) fixed to a floor slab (11) provided in the basement with anchor bolts (6). Is fixed to the floor slab with the anchor bolts and fastened with the two band units connected to each other with the tension adjusting bolts (7).

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