JPH0410555B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" This invention relates to a method of constructing the roof of a petroleum storage tank.

"Prior Art" The requirements imposed on the roof of an oil storage tank are as follows.

() Must have the ability to control rainwater, dust, snowfall, etc.

() It is possible to prevent the release and diffusion of evaporated substances generated from stored materials into the atmosphere.

() It must be lightweight and have limited (some kind of constraint value) vertical rigidity.

() To reduce the load on the bottom plate, which is the most important part of a storage tank, as much as possible.

Conventional roofs implemented under these various requirements are as follows. First, what is shown in FIG. 2 is a conical support type fixed roof tank, which is constructed by supporting a garter 1 with support pillars 2.

The one shown in FIG. 3 is a conical fixed roof tank with a fixed roof that is supported by a pair of raised hands 3.

What is shown in FIG. 4 is a general structure of a type 4 dome roof.

All of these roofing materials are made of steel, which makes them heavy, so for large diameter (40m) structures, it is recommended to install multiple supports, use a large truss roof structure, or strengthen the side walls of the storage tank on the abutment platform. It has become a thing.

``Problems to be Solved by the Invention'' However, with the roof structure described above, during construction and re-erecting, not only does the scaffolding for ground assembly become large-scale, but also a large-sized lifting machine is required.

Furthermore, the reduction in the load applied to the bottom plate is insufficient.

``Means for Solving the Problems'' and ``Operations'' The present invention has been made in view of the above-mentioned circumstances, and its gist is that when constructing the roof of an oil storage tank, the top chord is replaced with a steel beam. , the bottom chord of the cable,
The web material is composed of a steel beam bundle, the steel beams are fixed radially to the central shaft member, the inner end of the cable is attached to the central shaft member, or the outer end is fixed to the tip of the steel beam, and the cable The space frame is movably attached through the lower end of the steel beam bundle, and the space frame is assembled into a flat surface, and by applying tensile force to the cables, compressive force and bending moment are exerted on the steel beam to form a dome shape. A dome made up of curved beams and cables is assembled on the bottom plate of the storage tank, and then tension is introduced into the cables to compress the steel beams beyond a predetermined curvature, and the side walls of the storage tank are The space frame at the bottom of the tank is lifted up, the cable tension is partially released, the steel beam is expanded to a specified curve, and the steel beam is placed on the side wall and fixed. The aim is to reduce the amount of construction materials used during construction and to downsize the lifting equipment.

"Example" This will be explained in detail below based on the drawings.

1 and 5 both show an embodiment of a dome constructed of beams and cables according to the present invention. In the first illustrated example, 5 in the figure is a steel beam that becomes the upper chord of the space frame. As shown in FIG.
is fixed. Reference numeral 7 denotes a cable serving as a lower chord member, and a supporting metal fitting 9 (Fig.
(Fig.), and its inner end 10 is movably inserted into the
As shown in the figure, it is pivotally attached to a mounting part 11 provided on an annular member 6, and its outer end is attached to a steel beam 5 as shown in figure h.
The wedge 1 is movably inserted into the support fitting 12 at the tip of the wedge 1.
It can be fixed at 3.

To make the dome of this example, the steel beams 5, annular member 6, cables 7, and steel bundles 8 are assembled in figures a and d.
Place it on the ground as shown in the diagram and assemble it at that location. Next, support metal fitting 1 at the tip of steel beam 5
When tension is introduced by pulling the cable 7 inserted through the steel beam 2, the cable is tensioned in a straight line as shown in Figure b, and compressive force and bending moment act on the steel beam 5, causing it to curve slightly and rise. When the cable 7 is further pulled, the compressive force and bending moment of the steel beam 5 and the tensile force of the cable 7 are transmitted to the member at the other end via the annular member 6. The result will be a curved surface as shown.

When a predetermined curved surface is reached, the outer end of the cable 7 is wedged 1 into the support fitting 12 of the steel beam 5 as shown in Figure h.
3, and its intermediate portion is fixed to a support fitting 9 at the lower end of the steel bundle 8 to complete the dome.

Since the dome of the present invention is constructed as described above, the upper chord material is subjected to compression and bending.
The bottom chord is subjected to tension, making it the most rational member structure from a mechanical point of view, so it can be designed at low cost.The steel beams are installed radially through an annular member in the center, so it can be used in one span. The dome can be made into a large dome twice the length of the dome, and the structure is simple and has no unnecessary parts, making it extremely easy to construct. Since the construction is carried out close to the ground, it is highly accurate and easy to construct as it does not require temporary materials such as scaffolding.

In addition, in the fifth illustrated example, reference numeral 14 in the figure is a steel beam serving as the upper chord member of the space frame, and as shown in Figure d, the steel beams are arranged radially around the central axis 15 as the central axis member, and each central axis Fixed at 15. Reference numeral 16 denotes a cable serving as a lower chord member, which is movably inserted into a support fitting 18 (figures f and g) at the lower end of a steel beam bundle 17, which serves as a web member, provided at a suitable location in the middle of the steel beam 14; The end portion 19 is fixed to the tip 20 of the steel beam 14 as shown in FIG. It is placed close to the ground so that it is in the above state, that is, the state shown in Figures a and d, and the ground assembly is completed at that position.

Next, when tension is introduced by pulling the cable 16 inserted through the hole 21 of the central shaft 15, the cable is tensioned in a straight line as shown in Figure b, and the steel beam 1
Compressive force and bending moment act on 4, causing it to curve slightly and rise. When the cable 16 is pulled further, it becomes a curved surface as shown in figure c. When the predetermined curved surface is reached, the inner end of the cable 16 is fixed to the hole 21 of the central shaft 15 with a wedge 22 as shown in figure e. The intermediate portion is fixed to a support fitting 18 at the lower end of the steel bundle 17 to complete the curved surface of the dome.

There is also the method shown in FIG. 6 as a method of introducing tension into the cable.

That is, in the illustrated space frame,
In the figure, 22 is an annular member, 23 is a horizontal drum mounted on the annular member 22, 24 is a drive unit for the drum 23,
25 is a steel beam as a top chord arranged radially around the annular member 22; 26 is a steel bundle serving as a web material provided at a suitable position in the middle of the steel beam 25;
27 is a steel bundle 25 fixed to the tip of the steel beam 25
Cables are shown wound around a drum 22 via a sheave 28 attached to the shaft at the lower end, and a predetermined tension is introduced into the cable 27 by controlling the driving rotation of the drum 22.

Figures 7a to 7c show the construction procedure of the present invention.

That is, the space frame 29 configured as described above is assembled on top of the storage tank bottom plate 30, and tension is introduced into the cables to reduce the steel beam to a predetermined curvature or more (as shown by the horizontally opposed arrow).
9', and around this dome 29' is a storage tank side wall 3.
1, then lift it up using appropriate means (indicated by the upward arrow), partially release the tension on the cable, and make the steel beam a predetermined degree of curvature to achieve the predetermined dome diameter (indicated by the horizontal separation arrow). The peripheral end of the dome 29' is placed on the side wall 31 and further fixed to complete the process.

The relationship between the diameter changes seen from the plane and the longitudinal section of the space frame 29 during the above process is as shown in FIGS. 8 and 9.

As a lift-up means, in Fig. 7, a
As shown in the figure, a support beam 32 may be temporarily installed on the side wall, and a guide ball 33 is erected using this and raised using a climbing jack, etc. As shown in figure b, it is raised by injecting water 35 through a float 34. It may also be raised using air 36 support.

In the case of the space frame 29, the roof surface material is attached by attaching a membrane material or fixing an iron or aluminum plate at one end when assembling the ground, and fixing it at the other end.

Since the construction will be carried out by assembling the ground and lifting it up, there will be no need for large-scale erection scaffolding or lifting equipment.

"Effects of the Invention" As described above, according to the present invention, it is possible to reduce the weight of the roof of an oil storage tank, reduce the amount of temporary materials used during construction, and downsize the lifting machine.

[Brief explanation of drawings]

Figures 1a to 1h show one embodiment of the dome according to the present invention, and figures a to c are explanatory views of only one span seen from the front. Fig. c shows the state in which the steel beam is slightly curved by pulling the dome. Fig. d shows the same state as Fig. a. The right half is a plan view, and the left half is a bottom view showing the cable and steel beam bundle. , Figure e is an enlarged cutaway front view of the left half of the annular member, Figure f is an enlarged side view showing the attachment of the support fittings, Figure G is the same front view, Figure h is an enlarged front view showing the tip of the steel beam, Figures 2 to 4
The figure is an explanatory diagram of the roof of a conventional large-scale oil storage tank, Figures a to h show other embodiments of the dome of the present invention, and a to c are explanatory diagrams of only one span seen from the front. Figure a shows the state when the ground assembly is completed, figure b shows the state where the steel beam is slightly curved by pulling the cable, figure c shows the state when the dome curved surface is completed, figure d shows the same state as figure a, and the right half shows the state. Plan view, left half is a bottom view showing the cable and steel frame bundle, e figure is an enlarged cut-away front view of the central axis, f figure is an enlarged side view showing the attachment of the support fittings, g figure is also a front view, h figure is the steel frame An enlarged front view showing the tip of the beam, FIG. 6 is a space frame half-section showing another means of introducing tension into the cable, FIGS. 7 a to c are explanatory diagrams of the lift-up construction procedure of the present invention, and FIG. FIG. 9 is an explanatory diagram of the relationship between the diameter changes of the space frame during the lift-up process of the present invention. 1... Garter, 2... Pillar, 3... Gassho, 4
... Dome roof, 5 ... Steel beam, 6 ... Annular member, 7 ... Cable, 8 ... Steel bundle, 9 ... Supporting metal fittings, 10 ... Inner end, 11 ... Mounting part, 12 ...
...Supporting metal fittings, 13...Wedge, 14...Steel beam, 15
... Central axis, 16 ... Cable, 17 ... Steel frame bundle, 18 ... Supporting metal fittings, 19 ... Outer end, 20 ...
... Tip, 21 ... Hole, 22 ... Annular member, 23 ...
...Horizontal drum, 24...Drum drive section, 25...
Steel beam, 26... Steel bundle, 27... Cable, 2
8...Sheave, 29...Space frame, 2
9'...Dome, 30...Storage tank bottom plate, 31...Storage tank side wall, 32...Corbel beam, 33...Guide ball, 34...Float, 35...Water, 36...
Air.

Claims (1)

[Claims] 1 The upper chord member is a steel beam, the lower chord member is a cable, and the web member is a steel bundle.The steel beam is fixed radially to the central shaft member, and the inner end of the cable is attached to the central shaft member, or the outer end of the cable is attached to the central shaft member. The space frame is fixed to the tip of the steel beam, the middle part is movably attached through the bottom end of the steel beam, the space frame is assembled into a flat plate, and the steel beam is fixed by introducing tensile force into the cable. The dome, which is made up of beams and cables that are curved into a dome shape by applying compressive force and bending moment, is assembled on the bottom plate of the storage tank, and then tension is introduced into the cables to bend the steel beams to a predetermined curvature or more. After the storage tank side wall is built and the space frame at the bottom of the tank is lifted up, the cable tension is partially released and the steel beam is expanded to a predetermined curve and placed on the side wall. A construction method for the roof of an oil storage tank, characterized in that the roof is mounted and fixed.