OA19021A - Self-supporting three-dimensional prestressed structure, method and device for its construction - Google Patents

Abstract

This invention relates to a self-supporting threedimensional prestressed structure, as well as a method and a device for erecting same, to be employed in the construction of residential and nonresidential buildings. The structure is constructed of vertical form-defining flexible rodlike members (1) stressed during the construction of the structure, as well as horizontal flexible rodlike members (2) each forming a closed curve. The horizontal members (2) are also stressed during construction and welded or rigidly affixed by other means to the vertical formdefining members (1). Instead of horizontal circular members (2) the structure can be constructed completely or to some extent using a spiral member, also stressed during the construction of the structure that is rigidly affixed to the vertical form-defining flexible members (1).

Description

Application of the invention

This invention relates to a self-supporting three-dimensional prestressed structure, as well as a method and a device for erectîng same, to be employed in the construction of residential and nonresidentîal buildings and specifically cîvic and production halls, greenhouses, temples, swimming pools and other similar three-dimensional premises.

Background and existing technologies

A well-known and widely-used method for the construction of three-dimensional structures comprises the assembly of preformed éléments to form the intended threedimensional structure with the required shape. The most common materials for building a structure of this type and by this method are preformed métal profiles.

The structure erected by this method is not prestressed, and requires considérable expenditure of materials.

Another method used in practice for erectîng self-supporting structures comprises the présélection of a site where to construct the intended structure, followed by leveling and laying a foundation. Part of an inflatable membrane with the required shape and size is then placed symmetrically in relation to a predetermined géométrie center and secured airtightly to the foundation. The membrane is înflated to the required shape by injecting compressed air between its lower edge and the foundation. Polyuréthane foam material is then sprayed against the under surface of the înflated form. After the foam becomes rigid it is strengthened by the attachment of reinforcing rods. The structure can then be pressure sprayed with concrète (shotcrete)m, if necessary.

The self-supporting three-dimensional structure is thus constructed of an inflated membrane sprayed against the under surface with polyuréthane foam and reinforced by regularly spaced members attached to one another in sequence.

This method relies on the use of an inflatable membrane or part thereof, which is costly and in most cases not reusable. The method is also restricted to the construction of concrète structures.

Description of the invention

It is an object of this invention to create a self-supporting three-dimensional prestressed structure with improved tensile strength and stability, and with low expenditure of materials.

Another object of this invention is to provide a method based on improved technology for construction of self-supporting three-dimensional prestressed structures.

A further object of this invention is to create a device for implementing the method for construction of self-supporting three-dimensional prestressed structures.

These objects are achieved by means of a self-supporting three-dimensional prestressed structure comprising regularly spaced members attached to one another in sequence to form a three-dimensional building or part thereof.

According to this invention the self-supporting three-dimensional prestressed structure comprises vertical form-defining flexible rodlike members stressed during the construction of the structure, as well as horizontally and/or spirally positioned flexible rodlike members also stressed during construction, each forming a closed curve. The horizontal closed-curve members are rigidly joined to the vertical formdefining members.

Both the vertical and the horizontal closed-curve flexible rodlike members are made of métal.

The device for construction of self-supporting three-dimensional prestressed structures comprises a number of symmetrically and radially posîtioned telescopic arms each hinged to a circle posîtioned at the center of the device. At the tip of each telescopic arm there is a guide block holding a corresponding vertical rodlike member.

According to one possible embodiment, the guide block comprises two parallel plates (cheeks) fixed to the telescopic arms, whereas between said cheeks are installed in sequence grooved rollers. The opening between the rollers is at least equal to the cross-sectional diameter of the vertical rodlike member to be held between them.

The method for construction of self-supporting three-dimensional prestressed structures requires the sélection of a géométrie center for the intended structure. According to the invention the method also comprises the following operations in the below-stated sequence:

- positioning and affixing of the central circle of the device at the géométrie center of the structure;

- configuration ofthe telescopic arms ofthe device for construction of self-supporting three-dimensional prestressed structures to conform to its intended shape and size;

- insertion of one end of each vertical rodlike member through a guiding block on the respective telescopic arm and into a prepared socket in the foundation;

- the next stage is the incrémental upward movement of each telescopic arm along the respective flexible vertical rodlike member, either in sequence or simultaneously, thus stressing the flexible vertical member;

- after each incrémental upward step of ail telescopic arms, the achieved élévation is flxed by attachment of horizontal flexible rodlike members around the circumference of the structure to form a contour;

- the device is removed after the self-supporting three-dimensional prestressed structure has been completed.

According to the method, openings of a given shape are made in the structure by first making frames with the required dimensions and shape, and then affixing them at the required positions. The bordering sections of the structure are affixed to the frames permanently, and then the excess parts of the structure enclosed in the frames are eut away.

The self-supporting three-dimensional prestressed structure thus erected is then sheathed in reinforcing mesh, plastered over and finished in an appropriate building material, such as cernent, clay, adhesive mix.

The advantages of the invention are found in the improved speed of construction of the structure, the decreased expenditure of materials and the lower cost, as well as the capability to erect structures of various shapes.

Another major advantage of the self-supporting three-dimensional prestressed structure is the improved tensile strength.

Description of the drawings

A possible embodiment of the invention is illustrated by the drawings, whereas:

FIG. I is an axonometric view of a self-supporting three-dimensional prestressed structure shaped as a hemisphere;

FIG. 2 shows a device for construction of self-supporting three-dimensional prestressed structures;

FIG. 3 is an axonometric view of a guiding block fitting of the device for erecting the structure;

FIG. 4 shows the start of construction of a self-supporting three-dimensional prestressed structure;

FIG 5 shows a bent vertical rodlike member attached to a telescopic arm of the device;

FIG. 6 shows a bent vertical rodlike member held in a guiding block fitting;

FIGS. 7 and 8 show consecutive stages of construction of a self-supporting threedimensional prestressed structure;

FIG 8 shows a finished and covered self-supporting three-dimensional prestressed structure.

An example embodiment of the invention

An example of the construction of a self-supporting three-dimensional prestressed structure is shown in FIG. I. The example shows a self-supporting three-dimensional prestressed structure shaped as a hemisphere. The structure is constructed of vertical form-defining flexible rodlike members ( l ) stressed during the construction of the structure, as well as horizontally positioned flexible rodlike members (2) each formîng a circular contour. The horizontal members which are also stressed are welded or rigidly joined by other means to the vertical form-defining rodlike members (l).

The horizontal circular contours are parallel to each other.

The device for construction of self-supporting three-dimensional prestressed structures is shown as (3) on FIG. I.

Instead of horizontal circular members (2) the structure can be constructed completely or to some extent using a spiral member, also stressed during the construction of the structure that is rigîdly affixed to the vertical form-defining flexible members (l).

The device (3) for the construction of the self-supporting three-dimensional prestressed structure and the implémentation or the method comprises a number of symmetrically and radially positioned telescopic arms (4) each hinged to a circle (5) positioned at the center of the device FIG. 2. At the tip of each telescopic arm (4) there is a guide block fixing (6) FIG. 3. In this embodiment the guide block (6) comprises two parallel plates or cheeks (7) fixed to the telescopic arm (4), whereas between said cheeks (7) are installed in sequence grooved rollers (8). The opening between the rollers (8) is at least equal to the cross-sectional diameter of the vertical rodlike member (!) to be held between them.

By varying the lengths of the telescopic arms (4) it is possible to configure threedimensional prestressed structures with different shapes.

The method for construction of self-supporting three-dimensional prestressed structures, which also explains the operatîng principle of the device, comprises the following operations in the sequence below:

1. A site and of a géométrie center for the structure are selected. If the structure wîll be shaped as part of a sphere, such as a hemisphere (FIG. 4), the radius of the structure is also determined;

2. The site is leveled undemeath the selected géométrie center and a foundation is laid;

3. The material for the structure’s framework is selected and prepared. Commonly used materials are flexible members (l), made for instance of wood, plastic or composite with rodlike or pipe profile;

4. The raster for the structure is determined, namely the number of the vertical and horizontal members for the intended structure with hemispherîcal (or more complex) shape. The thickness of the material and the raster are determined based on the intended purpose of the structure and the type of the material;

5. The device for construction of self-supportîng three-dimensional prestressed structures (3) is then placed on the foundation and fixed to same;

The number of the telescopic arms (4) of the device corresponds to the number of the vertical rodlike members of the intended structure. When building a hemisphere, the length of the telescopic arms (4) is a constant number equal to the radius of the structure. When building more complex shapes, the length of each telescopic arm (4) can vary in each stage of the construction process, in order to achieve the intended complex three-dimensional shape.

6. The vertical rodlike members (l) are placed at regular intervals along the circumference of the intended structure, and then they are fed through the guiding blocks (6) of the telescopic arms (4). For better stability, the rodlike members (!) can be anchored into prepared sockets undemeath the guiding blocks (6). The sockets can be prepared from sections of métal pipe with inside diameter greater than the diameter of the selected material that are driven into the foundation. If a concrète foundation is laid under the outside perimeter of the structure, the vertical flexible members can be affixed directly into the concrète.

7. The next stage is the upward movement of the guiding blocks (6) of the telescopic arms (4) along the corresponding vertical rodlike members (l) FIGS. 5 and 6. The movement of each guiding block (6) along the corresponding flexible rodlike member (l) stresses it and forces is to form a circular arc.

The upward movement of ail guiding blocks (6) along the vertical rodlike members (!) can be either sequential or sîmultaneous.

8. A horizontal circular member (2) is placed and affixed (welded) around the bent vertical rodlike members ( 1 ).

9. The upward movement of each telescopic arm (4) (at incréments determined by the selected raster) is sequentîally altemated with the attachment of a horizontal flexible rodlike member (2) (circular in the case of a hemisphere or with more complex closed-contour shape for a structure with a more complex shape) - FIGS 7 and 8. The horizontal flexible rodlike members (2) are affixed rigîdly to each vertical rodlike member (1) by means of a fittîng or by welding. When each horizontal flexible rodlike member (2) is fully attached it fixes ail vertical rodlike members (1) and equalizes their tension.

10. When the entire structure is complété the device (3) is in the configuration “ail arms in a vertical bundle” FIG. 1. At this point the constructed three-dimensional structure is fully self-supported, and ail forces/vectors acting on the structure are in equilibrium. At this stage the device (3) can be removed from the structure and be ready for reuse.

11. If the design requires the making of openings in the structure (doors, Windows, etc.), the frames with the required dimensions and strength are made fïrst, and then affixed at the required positions. The bordering sections of the structure are affixed/welded regularly to the frames, and only then the excess parts of the structure enclosed in the frames are eut away. Any cutting of unframed sections of the stressed structure would cause the abrupt release of the tension with catastrophic results.

12. The complété structure can be covered in waterproofing or other material, or in concrète, and it can be used for civic and production halls, residential buildings, greenhouses, temples, swimming pools and other structures FIG. 9.

Claims (7)

1. A self-supporting three-dimensional prestressed structure comprising of regularly spaced members attached to one another in sequence to form a threedimensional building or part thereof. Said self-supporting three-dimensional prestressed structure comprising vertical form-defining flexible rodlike members (1) stressed during the construction of the structure, as well as horizontally and/or spirally positioned flexible rodlike members (2) also stressed during construction, each forming a closed curve and rigîdly affixed to the vertical form-defining members (1).

2. The self-supporting three-dimensional prestressed structure of claim 1 in which the flexible rodlike members ( 1 and 2) are made of métal.

3· A device for construction of self-supporting three-dimensional prestressed structures comprising a number of symmetrically and radially positioned telescopic arms (4) each hinged to a circle (5) positioned at the center of the device, whereas at the tip of each telescopic arm (4) there is a guide block holding a corresponding vertical rodlike member ( 1 ).

4. The device for construction of self-supporting three-dimensional prestressed structures of claim 3 in which the guide block comprises two parallel plates (cheeks) (7) fixed to the telescopic arms (4), whereas between said cheeks (7) are installed in sequence grooved rollers (8), with the opening between the two rollers (8) being at least equal to the cross-sectional diameter of the vertical rodlike member to be held between them (1).

5. A method for construction of self-supporting three-dimensional prestressed structures comprising the following operations in the below-stated sequence:

- sélection of a géométrie center for the intended structure;

- positioning and affîxîng of the central circle (5) of the device at the géométrie center of the structure;

- configuration of the telescopic arms (4) of the device for construction of selfsupporting three-dimensional prestressed structures to conform to its intended size and shape;

- insertion of one end of each vertical rodlike member (l) through a guidîng block (6) on the respective telescopic arm (4) and into a prepared socket in the foundation;

- next is the incrémental upward movement of each telescopic arm (4) along the respective flexible vertical rodlike member (l), either in sequence or simultaneously, thus stressing the flexible vertical member (l );

- following each incrémental upward step of ail telescopic arms (4), the achieved élévation is fixed by means of attachment of horizontal flexible rodlike members (2) around the flexible vertical rodlike members ( I ) to form a contour;

- the device (3) for construction of self-supporting three-dimensional prestressed structures is removed after the structure has been completed.

6. The method for construction of self-supporting three-dimensional prestressed structures of claim 5 in which openings of any shape in the structure are made by first making frames with the required dimensions and shape, and then affixing them at the required positions. The bordering sections of the structure are then affixed regularly to the frames, and then the excess parts of the structure enclosed in the frames are eut away.

7. The method for construction of self-supporting three-dimensional prestressed structures of claim 5 in which the self-supporting three-dimensional prestressed structure thus erected is then sheathed in reinforcing mesh, plastered over and finished in an appropriate building material, such as cernent, clay, adhesîve mix.