Typically, a shelter is needed to give protection against rain for, e. g., the spectators'stand of different kinds of outdoors sport arenas, whereby the shelter is formed by a long and lip-like horizontal overhang roof mounted on a vertically erected support structure. Due to adverse weather conditions such as the weight of snow accumulated on the overhang portion of the shelter and wind load directed thereon, the stresses imposed on the shelter structure may become very high, thus needing the support constructions of the shelter to have a good strength and deformation performance.

In many of the prior-art shelters, the horizontal main support structures of the overhang portions are comprised of different kinds of steel, reinforced concrete or gluelam wood principal rafters spaced at a distance from each other. Generally, the spacing of the principal rafter members of the overhang portion is the same as the spacing of vertical support members such as pillars supporting the rear portion of the shelter. Resultingly, the cross-sectional dimensions of the horizontal main support members particularly in long overhang portions must be made large if no other separate support struc- tures such as pillars are used for supporting the front edge of the overhang portion. However, a separate support structure of the front edge of the overhang portion forms

a visual obstacle in, e. g., observers'stands preventing the observers from seeing freely to the site of action and from moving unobstructedly over the stand area. The large dimensions increase the weight of the support structures, which means that also the foundations of the shelter must be made sturdy, which again is a factor increasing the erection costs of the shelter.

Furthermore, structures having large dimensions are visually massive, which makes them difficult to adapt to their surroundings.

The use of plain or reinforced concrete as a building material is hampered by the steadily increasing ecologi- cal demands concerning such issues as materials recycl- ing. Moreover, a great number of support structures of conventional shelters made from prestressed concrete have been found to suffer from carbonization of concrete as well as other damage caused by freezing and corrosion that deteriorate the strength properties of the structure and give rise to extra costs of repair.

It is an object of the present invention to provide an entirely novel type of shelter capable of reducing the above-described problems of prior-art structures.

The goal of the invention is achieved by means of making the beams of the horizontal principal rafters from laminated veneer lumber material fabricated by lamination glueing from veneers of different sizes. Advantageously, the laminated veneer beams are made with a boxed cross section and the shape of their cross section is varied at different points of the beam according to the stress

level at the given point. The horizontal rafter beams of the overhang portion of the shelter are pitched denser than the spacing of the vertical main support pillars of the shelter, whereby the horizontal rafter beams can have a slim cross section. The horizontal rafter beams are supported at their rear ends by two separate vertical support structures of the shelter, one of the structures being located exactly at the rear end of the rafter beams and the other in a relatively close proximity to the rear end. The vertical support structures may comprise, e. g., two rows of support pillars aligned parallel to the longitudinal direction of the shelter. To above the overhang portion can be adapted the support structures made from steel, for instance, that bear both upward and downward directed vertical forces, whereupon the forces are further transmitted along the vertical support struc- tures down to the foundations of the shelter.

More specifically, the shelter according to the invention is characterized by what is stated in the characterizing part of claim 1.

The invention provides significant benefits.

There is no need for supporting the front edge of overhang portion of shelter by means of separate pillars that are visually obstructing because the overhang portion can be made very lightweight thanks to the good strength properties of the laminated veneer lumber used in the main support structures. A shelter according to the invention also features low loads on the vertical support structures of the overhang portion and shelter

foundations, thus allowing these elements to have small dimensions, which is a factor contributing to reduced shelter erection costs. Furthermore, a shelter according to the invention has visually lightweighted and streamlined outlook that readily is in a good balance with its surroundings.

Wood is also used as the shelter lining material, thus rendering the shelter good acoustic qualities. For instance, the excellent sound absorption of wood gives the shelter a short reverberation time. The structure of the shelter can be made modular, whereby a single basic construction of the shelter can be readily adapted to erect shelters of different lengths and breadths without a need to redesign the basic construction. In addition to new building projects, the shelter according to the invention is very easy to adapt to cover existing spectators'stands of an uncovered construction, since the vertical support structures of the shelter are located close the rear portion of the shelter thus allowing their erection in most cases behind the uncovered stand without any need for dismantling the stand structures.

The invention is next examined by way of making reference to the appended drawings, in which FIG. 1 shows a cross section of a shelter according to the invention; FIG. 2 shows the shelter construction of FIG. 1 in a view taken from above the overhang portion;

FIG. 3 shows the shelter construction of FIG. 1 in a view taken from below the overhang portion; FIG. 4 shows a cross section of another shelter construc- tion according to the invention; and FIG. 5 shows the frame of the shelter construction of FIG. 4 in a 3D view.

Now referring to FIGS. 1,2 and 3, the embodiment shown therein is a shelter according to the invention adapted to cover a spectators'stand, whereby the horizontal main support structure of the overhang portion of the shelter is formed by substantially horizontal rafter beams 1 spaced at a distance from each other. The material of the rafter beams 1 is laminated veneer lumber. The rafter beams 1 have a boxed cross section, and the shape of their cross section at different points of a rafter beam 1 is varied as required to meet the stress level imposed on each given point. The front part of the vertical main support structure of the shelter is comprised of essentially vertical front pillars 7 aligned in a row running parallel to the longitudinal direction of the shelter. The number of the front pillars 7 is at least two. Respectively, the rear part of the vertical main support structure of the shelter is comprised of essentially vertical rear pillars 8 aligned in a row running parallel to the longitudinal direction of the shelter, whereby the number of the rear pillars 8 is also at least two and they are aligned parallel to the respective front pillars 7 in the breadth direction of

the shelter.

The laminated veneer lumber used as the material of the rafter beams 1 is made from rotary-cut veneer of coniferous wood into a weather-resistant beam and board material. Spruce or pine logs employed as raw material in laminated veneer lumber manufacture are first debarked and soaked in hot water. Next, the logs are trimmed into shorter logs of 1.6 m or 1.9 m length typical and then turned into about 3.2 mm thick veneer. The veneer is cut into sheets and dried to a moisture content less than 5 per cent, whereupon the veneer sheets are transferred onto a glueing line to be subsequently beveled at their edges for a width of about 3 cm. Next, the sheets are transferred to the glueing and laying steps. The glue is, e. g., a thermosetting phenolic resin. The veneer sheets are laid to form a continuous laminated board having a width of 1.8 m typical. Depending on the application, the thickness of the laminated board may typically vary in the range of 27-75 mm. Subsequently, the laminated veneer blank is transferred to a prepressing step, followed by the actual pressing step that takes place at about 140 °C temperature. Finally, the laminated veneer boards are trimmed and rip-sawn in their longitudinal direction into beams, pillars or boards of desired dimensions. By its qualities, laminated veneer lumber is strong, dimensionally stable, lightweight and nonwarping. The technical qualities of laminated veneer lumber make it possible to design structures having a narrow-breadth cross-section combined with a high waist dimension and a long span. Laminated veneer lumber is typially used as a construction material of, e. g., public buildings, large

halls, structural members in the building industry and residential houses. Laminated veneer lumber is finding an increasing number of applications in multi-story wood buildings and renovations.

The front pillars 7 and the rear pillars 8, which are aligned parallel to each other in the breadth direction of the shelter, are connected at their upper parts to an overlying principal rafter beam 1. Into the rectangular area formed between the front pillars 7 and the rear pillars 8, under the overhang portion, there is arranged a stiffening lattice structure comprising a horizontal stiffening structure 13 adapted between two adjacent front pillars 7, a horizontal stiffening structure 14 adapted between two adjacent rear pillars 8, and stiffen- ing structures 15 adapted between each pair of adjacent front pillar 7 and rear pillar 8. Additionally, a lattice portion 16 of the stiffening lattice structure is spanned between the corners of the rectangle formed between adja- cent front pillars 7 and rear pillars 8. Those principal rafters 1 that are not connected to any one of the front pillars 7 and rear pillars 8, are connected to the stiffening structures 13,14 of the lattice structure that are aligned in the longitudinal direction of the shelter. To every third one of the adjacent front pillars 7, there is placed a stiffening brace 17 having its first end connected to the lower part of the front pillar 7 and the second end connected to the upper end of the adjacent rear pillar 8.

Above the overhang portion of the shelter, at each one of the front pillars 7, there is placed an essentially

vertical support column 9 having its lower part connected to a horizontal principal rafter beam 1. To the upper part of each support column 9 is connected the first end of a front strut 10 and of a rear strut 11 having their second ends connected to the same horizontal principal rafter beam 1 as the support column 9. The second end of the rear strut 11 is connected to the rear end of the rafter beam 1 and the second end of the front strut 10 is connected to the portion of the rafter beam 1 remaining between the front end of the rafter beam and the connec- tion of the support column 9 to the rafter beam. Addi- tionally, the support columns 9 are connected to each other at their upper ends by means of struts 18 running longitudinally at the top of the shelter.

To the upper part of each support column 9 with the ex- ception of the most distal ones, there are also attached the first ends of three tensioning bars 12, of which the central bar is connected by its one end to the same hori- zontal rafter beam 1 as the support column 9 to which all the tensioning bars 12 are connected. The lateral tensioning bars 12 connected to the same support column 9 are connected by their second ends to rafter beams 1 that are located adjacent to said support column 9, which means that in a top view the lateral tensioning bars 12 are spanned as a letter V. Obviously, the most distal support columns 9 have only two tensioning bars 12 connected thereto.

To the upper surface of the principal rafter beams 1 of the overhang portion are connected purlins 3 running in the longitudinal direction of the shelter and having

boards 2, advantageously made from laminated veneer lumber, attached thereto as the roof decking by means of screws, for instance. The roof decking may also be made from boards and the like material.

As strength-improving elements, the decking boards 2 stiffen horizontally the overhang portion of the shelter, in addition to preventing lateral or torsional buckling of the laminated veneer lumber rafter beams 1.

Additionally, the underside edges of the rafter beams 1 have attached thereto struts 4 running in the longitudinal direction of the shelter and made from, e. g. laminated veneer lumber, whereby the struts that serve to prevent lateral or torsional buckling of the rafter beams 1. To bear downward acting loads, the rafter beams 1 are supported from above by the tensioning bars 12 located above the shelter and by the front struts 10. To bear upward acting loads such as wind-imposed uplift load, respectively, the rafter beams 1 are supported by the front struts 10. The stresses imposed on the tensioning bars 12 and the front struts 10 are transmitted further downward along the support columns 9 to the front support pillars 7 and obliquely backward via the rear struts 11 further to the rear support pillars 8. Horizontally act- ing loads imposed on the rear struts 11 and other related structures are transmitted via the stiffening lattice structure along the stiffening brace 17, which is located at every third space between the adjacent front pillars 7, further to the structures underlying the front pillars 7 and the rear pillars 8.

In the embodiment illustrated in the drawings, those

three principal rafter beams 1 that are located between each pair of adjacent front pillars 7 are not supported by the front struts 10 and the rear struts 11. Hence, the principal rafter beams 1 are connected to an intermediate purlin 6 aligned to run longitudinally at the second ends of the front struts 10, whereby the intermediate purlin serves to transmit the load imposed on the principal rafter beams 1 further to the main support structures of the shelter. Additionally, aligned at the connection points of the tensioning bars 12 to the principal rafter beams 1, there is connected to the principal rafter beams 1 an intermediate purlin 5 running in the longitudinal direction of the shelter and serving to receive forces that are imposed perpendicular to the longitudinal direction of the principal rafter beams 1 by the tensioning bars 12 acting in the V-shaped configuration.

Water drainage from the shelter roof is arranged to take place at the rear of the shelter, and the roofing material is laid on the roof decking boards 2. The waterproofing of the piping feedthroughs in the struc- tures is secured using, e. g., overlapping flange seals.

The rear and front walls of the shelter may be clad with proper materials selected appropriately to suit the use of the shelter or match the same architecturally with the surroundings.

In the shelter according to the invention, the front pil- lars 7 and the rear pillars 8, the intermediate purlins 6, the tensioning bars 12, the stiffening braces 17, the front struts 10 and the rear struts 11, the support

columns 9, the longitudinal struts 18 and parts 13-16 of the stiffening lattice structure are advantageously made from steel.

In the embodiment shown in FIGS. 1,2 and 3, the princi- pal rafter beams are about 220 mm wide and about 300 mm high at their front tips reaching about 900 mm at the highest point of the beam. The mutual spacing between the adjacent rafter beams 1 is made smaller than that of the adjacent front pillars 7 and rear pillars 8 in the longi- tudinal direction of the shelter, e. g., so that the spacing ratio is 1: 4 as shown for the embodiment illus- trated in the drawings. The mutual spacing between the adjacent front pillars 7 and rear pillars 8, respective- ly, is advantageously about 7200 mm, whereby the adjacent rafter beams 1 can be advantageously spaced at 1800 mm distance from each other, thus allowing laminated veneer boards 2 of 1800 mm standard width to be readily attached to the top surface of the overhang front part of the shelter. Furthermore, these dimensions make it easy to extend the length of the shelter by adding such modular shelter sections of 7200 mm lateral width to the end of the shelter. The distance between the front pillars 7 and the rear pillars 8 is dictated by such design factors as the length of the principal rafter beams 1 and the exter- nal forces imposed on the overhang portion of the shelter. As a guideline dimensioning example, the distance between a front pillar 7 and a rear pillar 8 connected to an about 24 m long rafter beam can be about 6 m, whereby the overhang front portion of the rafter beam 1 is about 18 m long.

The embodiment illustrated in FIGS. 4 and 5 is slightly different from that described above by way of having located, in the longitudinal direction of the shelter, in the intervals between the adjacent front pillars 7 and the rear pillars 8, only one rafter beam 1 that is con- nected to the longitudinal support members 13,14 of the shelter. Hence, the stiffening lattice structures 16 and the longitudinal struts 17 may be omitted from the inter- pillar interval between the front pillars 7 and the rear pillars 8. The rear pillars 8 are made bifurcated. To the connection point of each rear pillar 8 to the respective rafter beam 1, there is connected a first end of an oblique brace 19 having its center point connected to the respective front pillar 7 and its second end to a support column 20 of the shelter. Advantageously, the oblique brace 19 is made from laminated veneer lumber.

In addition to those described above, the invention may be implemented in alternative embodiments.

Besides serving to cover spectators'stands, the shelter according to the invention may be adapted to a plurality of different locations including cargo/passenger termi- nals and loading/storage buildings. When required, e. g., to satisfy the visual aspects, the overhang portion of the shelter may be designed to have a curved top or underside shape. When necessary, the rafter beam 1 of a boxed cross section can be replaced by a solid-core beam in, e. g., long shelters when the strength properties of a hollow-core beam fail to meet the specifications. It is also possible that smaller shelters having, e. g., a short overhang portion may be designed so that the front struts

10 and the intermediate purlins 6 can be omitted. Partic- ularly in such shelters of a short overhang portion, the front pillars 7 and the rear pillars 8, the intermediate purlins 6, the tensioning bars 12, the stiffening braces 14, the front struts 10 and the rear struts 11, the support columns 9, the longitudinal struts 18 and parts 13-16 of the stiffening lattice structure that generally are advantageously made from steel may be replaced by respective members made from a laminated veneer lumber.