JP2623220B2 - Pre-stress introduction method of anchor strap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method for introducing a prestress of an anchor strap in a CLNG storage tank or the like.

[0002]

2. Description of the Related Art Conventionally, when a steel double-shelled storage tank is constructed on a stilt-type foundation as shown in FIG. 11, a spacer is inserted at a fixing point on a side plate, and an anchor strap is provided below the foundation plate. A method of introducing a prestress for an anchor strap, which controls the tensile force generated at the time of cooling down by removing the spacer after releasing the pressure and removing the pressure after the water filling pressure test after taking the deflection and finally fixing it, is known.

[0003] In such a method for introducing a pre-stress of an anchor strap, in the case of a raised floor type foundation, it is possible to remove the bending of the anchor strap below the foundation slab, but in the case of a pre-embedded type anchor strap, this technique is introduced. Can not.

On the other hand, in the case of a solid foundation, an anchor strap is preliminarily embedded, and there is a means for removing the bending of the anchor strap by a wedge-shaped jig at the side plate side fixation at the time of a water filling pressure test, and simultaneously fixing the anchor strap by welding. (For example,
(See Japanese Patent Publication No. 58-14960)

[0005] In this case, since the spacer cannot be attached, there is a disadvantage that a greater tensile force is generated in the anchor strap at the time of cooling down than when the spacer is present.

SUMMARY OF THE INVENTION It is an object of the present invention to adjust the distance between an anchor strap and a backing plate during a water-filled pressure test by using an anchor strap to be precedently buried and to use a spacer and a gap piece for construction, and apply the anchor strap to the anchor strap. An object of the present invention is to provide a method capable of easily controlling a load to be applied.

[0007]

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, the structure of the present invention is to bury and fix a base portion in a foundation concrete of an outer tank constituting a ground-type flat-bottom cylindrical storage tank such as a PCLNG storage tank. A T-shaped anchor strap provided with a jack receiving member at the center of the upper end is pressed against the inner tank side plate surface in an empty state, and its mounting position is written on the side plate, and the mounting positions of the backing plates are determined on the left and right sides. A second step of welding and fixing a jacking plate provided with a jack support plate at a mounting position of the backing plate, and holding both the backing plates above the support plate via an insertion gap of the jack supporting plate. A third step of welding the lower side of the plate and slidably interposing the upper left and right sides of the anchor strap between the upper side of the presser plate and the inner tank side plate, and holding an appropriate amount of water in the inner tank; Left and right support in test state A fourth step of fitting the jack support plate into the gap between the jack support plate and the holding plate, and interposing a jack between the jack support plate and the jack receiving member to apply tension to the anchor strap; Insert a spacer for construction of a predetermined thickness in the upper part between the upper left and right sides and the two backing plates, and after interposing a gap piece corresponding to this in the remaining lower gap, only this gap piece to the holding plate The fifth step of welding includes the sixth step of releasing the pressure after the water filling pressure test and removing the construction spacer, jack and jack supporting plate.

[0008]

[Function] Uses two types of spacers for construction and gap pieces, welds the backing plate to the inner tank side plate when empty, and welds the gap piece and the holding plate at the time of water filling pressure test where there is no gap between the inner tank bottom plate and the cooling material By doing so, the anchor strap can be accurately positioned. On the other hand, it is possible to use a hydraulic jack to remove the bending of the anchor strap, thereby improving workability.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an anchor mounting base 3 buried in a foundation concrete 2 of an outer tank 1 constituting a ground-type flat-bottom cylindrical storage tank A such as a PCLNG storage tank.
An anchor box 4 is mounted on the base and fixed by supports 5, 6, and 7. That is, the anchor mounting base 3, the supports 5, 6, 7 and the anchor box 4 are buried when the foundation concrete 2 is cast. Then, as shown in FIG. 2, the support 5 projecting from the surface of the foundation concrete 2 at the time of the construction of the bottom cold insulator 8 is cut off, and the bottom cold insulator 8 is cut.
The inner tank 9 is constructed on the upper part. In the figure, reference numeral 10 denotes a T-shaped anchor strap having a base inserted into and fixed to the anchor box 4 and projecting sides 10a formed on the left and right ends of the upper end.
Is a jack receiving member fixed to the center of the upper end portion of the anchor strap 10 and having a cross shape in front, and 12 is an anchor box 4 for preventing the wobble of the anchor strap 10.
The spacer 13 made of wood or the like inserted in the upper part of the box has a rain action for preventing rainwater from entering the anchor box 4. The bottom cooler 8 is composed of a light bone concrete block 8a, a pearlite concrete block 8b, and a pearlite concrete 8c.

Next, when the inner tank 9 is empty, the anchor strap 10 is pressed against the inner tank side plate 9a surface to write the anchor strap 10 on the side plate 9a surface (not shown), and the side plate 9a Is determined, and the caul plate 14 is welded to this mounting position. As shown in FIGS. 3 and 4, the mounting position of the backing plate 14 is located below the lower edges of both protruding sides 10a formed on the anchor strap 10 with an interval larger than the thickness of a later-described construction spacer. This is a portion where the upper edge of the backing plate 14 is provided. Further, support plates 15 for supporting and supporting a support plate of a hydraulic jack, which will be described later, are provided at the lower center of the abutment plate 14, respectively. The welding between the backing plate 14 and the side plate 9a is to weld the left and right side edges and the lower edge to the side plate 9a while leaving the upper side of the backing plate 14. Subsequently, as shown in FIGS. 5 and 6, a lower portion of a holding plate 16 having the same vertical axis as the supporting plate 15 is welded to the surfaces of the both contacting plates 14, and a lower end of the holding plate 16 and the supporting plate 15 are welded. An intervening gap 19 of the support plate 18 of the hydraulic jack 17 is formed between the upper end of the anchor strap 1 and the upper end of the anchor strap 1.
0 of the anchor strap 10 between the side plate 9a and the holding plate 16
0a is vertically slidable.

Next, a water filling pressure test is carried out by filling the inner tank 9 with water at a water level of about ２, and as shown in FIGS. The support plate 18 of the hydraulic jack 17 is bridged between the formed intervention gaps 19, and the hydraulic jack 17 is interposed between the support plate 18 and the jack receiving member 11, and the hydraulic jack 17 is operated. Thus, tension is applied to the anchor strap 10 to eliminate the bending of the anchor strap 10. Next, a spacer 21 having a predetermined thickness is inserted above a gap 20 formed between the lower ends of the left and right protruding sides 10a formed on the anchor strap 10 and the corresponding upper side of the backing plate 14, After selectively filling the remaining lower gap with the corresponding gap piece 22, only the gap piece 22 is pressed by the holding plate 16.
To weld. After the water filling pressure test is completed, water is drained to remove the water pressure applied to the inner tank side plate 9a, and then the tension tension of the anchor strap 10 by the hydraulic jack 17 is released, and the construction spacer 2 is removed.
1, the hydraulic jack 17 and the support plate 18 are removed, and the operation is completed.

[0012]

According to the configuration of the present invention as described above, the following effects can be obtained. (A) Since there is no thermal effect because the backing plate is positioned and welded when the inner tank is empty, there are two types of spacers and gap pieces used during the water filling pressure test, and only the gap piece and the holding plate are welded. Thereby, the anchor strap previously embedded in the foundation concrete can be accurately and easily positioned. (B) By using a hydraulic jack, it is possible to easily remove the flexure of the anchor strap and control the load to be applied to the anchor strap, so that the pre-stress force at the time of cooling down is almost uniform for all anchor straps. Can be

[Brief description of the drawings]

FIG. 1 is a side view showing a state in which an anchor strap is buried in outer tank foundation concrete.

FIG. 2 is a side view showing a state where an inner tank is constructed on outer tank foundation concrete.

FIG. 3 is a front view of a main part in a state where a backing plate is welded to a predetermined position of an inner tank side plate.

FIG. 4 is a side view of FIG. 3;

FIG. 5 is a front view of a state in which a holding plate is welded to a backing plate.

FIG. 6 is a side view of FIG. 5;

FIG. 7 is a front view of a state where a hydraulic jack and two types of spacers are set.

FIG. 8 is a side view of FIG. 7;

FIG. 9 is a front view of a state where a hydraulic jack and a spacer are removed.

FIG. 10 is a side view of FIG. 9;

FIG. 11 is a side view showing bending of an anchor strap provided on a conventional raised floor foundation.

[Explanation of symbols]

 A Underground flat bottom cylindrical storage tank 1 Outer tank 2 Basic concrete 3 Anchor mounting base 9 Inner tank 9a Side plate 10 Anchor strap 10a Projecting side 14 Backing plate 15 Support plate 16 Pressing plate 17 Hydraulic jack 18 Support plate 19 Intervention gap 20 Gap 21 Construction Spacer 22 gap piece

Claims (1)

(57) [Claims] 1. A T-shaped anchor strap having a base buried and fixed in the foundation concrete of an outer tank constituting a ground-type flat-bottom cylindrical storage tank such as a PCLNG storage tank, and a jack receiving material is provided at a center of an upper end thereof. A first step of pressing against the inner tank side plate surface in the liquid state, writing the mounting position on the side plate, and determining the mounting position of the pressing plate on the left and right sides, the jack supporting plate was provided at the mounting position of the pressing plate. A second step of welding and fixing the caul plate, the lower side of the presser plate being welded to the both caul plates via the insertion gap of the jack support plate above the support plate, and between the upper side of the presser plate and the inner tank side plate. A third step of slidably interposing the upper left and right sides of the anchor strap in the inner tank. An appropriate amount of water is contained in the inner tank, and the jack support is provided in the gap between the left and right support plates and the holding plate in the water filling pressure test state. Bridge the mating board A fourth step of interposing a jack between the jack supporting plate and the jack receiving member to apply tension to the anchor strap, and performing a predetermined thickness work on an upper portion between the upper right and left sides of the anchor strap and the both backing plates. A fifth step of inserting a spacer corresponding to this into the remaining lower gap and inserting only this gap piece into the holding plate, releasing the pressure after the water filling pressure test, and removing the pressure 6. A method for introducing prestress into an anchor strap, comprising: a sixth step of removing a spacer, a jack and a jack support plate.