Abstract:
The invention concerns the method of constructing and assembling the component structural elements for stadiums and the like structures, in which method the elements are assembled in overlying layers over the foundation for the structure, with hinged connections between the elements, and lifting certain of these elements, permits gravity to cause the other elements to rotate downward where the lower ends are placed on the supportive foundation, and they are secured to provide a rigid structure.

Description:
BACKGROUND 
     The construction of stadiums is one of the oldest of building arts, and they have been constructed by many methods: including cast in place concrete, brick and masonry, stone, precast concrete, cast iron, and steel. Of special interest is the stadium constructed for the Solano College, California, utilizing the teaching of Johnson U.S. Pat. No. 3,494,092, in which supportive elements were cast extending outward from the deck, and modules so formed were assembled to form alternate modules for the stadium, and then later modules with deck only were placed alternately to complete the structure. The method, at the date in 1971, proved to be the fastest and most economical in competitive bid. The method had the basic disadvantage of requiring transportation of the elements and being limited in the size that could be cast, which made it practical only for small stadiums. Other precast concrete methods have been relatively complex, and quite difficult to bring into proper alignment, to avoid warped and twisted elements, and to make water tight. In addition the structural suitability of the completed structure was difficult to attain. 
     The present invention bases itself on avoiding these problems and on the current experiences of the inventor in constructing various projects around the world with folding methods. 
     DESCRIPTION OF THE INVENTION 
     The basic concept begins with constructing a foundation slab for the entire stadium, and overlying this, constructing a series of modules, each module with an inner end positioned on the inner perimeter of the planned stadium, two sides extending perpendicular to this perimeter and an outer end located parallel to the inner end at the horizontal developed distance from the inner end; and girders are constructed along each of the edges of each module, and the inner ends of the girders are hingeably connected to the inner perimeter of the foundation, and supportive elements are fabricated between the girders, and hingeably connected to the outer portion of said girder lengths, and lifting the outer portion of the girders causes the supportive element to rotate downward to a position where the lower end of the rotated element is supported on the foundation, and it is secured to form a rigid structure. The present invention discloses methods of constructing the girders and the underlying supportive elements to produce the desired slopes for stadiums and the means of preassembling the required structural parts. There is disclosed a new and novel arrangement for constructing &#34;wishbone&#34; columns, and the method of constructing discontinuous decks for stepped stadiums. In addition, there is disclosed the arrangement for forming the modules to form segmentally curved stadiums. 
     Thus, an entire stadium may be precast in a preassembled position for a stadium of any shape, in which all the parts are prefit together, and lifting the modules one by one, brings them into alignment with the adjacent module, where adjacent decks may be secured together, and the vertical supportive elements secured to the foundation to complete a total structure. In addition, the method provides a great deal of freedom for the designer so that extremely handsome stadiums are possible and economical. It has been estimated that this method can save up to 25% of the structural cost for a comparable size stadium and save up to 30% in construction time. Other advantages will become apparent from the drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1, shows the foundation slab; the underlying girders and supportive elements; a completed module ready to lift; and two modules erected. 
     FIG. 2, and FIG. 3, show detail of a section of girder and pivot connection. 
     FIGS. 4, 5, and 6, show the arrangement for discontinuous deck in plan and section for a tiered stadium. 
     FIG. 7. shows the plan arrangement of modules around a curve. 
     FIG. 8. shows the detail for placing a gutter between adjacent modules. 
    
    
     DETAIL DESCRIPTION OF THE DRAWINGS 
     Referring to FIG. 1, the foundation slab 1, and an extension of a casting bed 2, is shown. The casting bed is required to provide for the developed length of the module in the flat. This casting bed may be developed as a walkway around the finished stadium if desired. 
     In module B, the side girders 3, are shown defining edges of the module, with supportive elements 4,5,6,7, cast between, and the supportive element 8 extending outward beyond the inner perimeter of the stadium foundation. Pivot connections 9, hingeably attach the girders to the supportive elements. The girders are divided by hinged joint 15 into an inner and outer portion. 
     Module C, is shown with a slab 11, cast over the underlying girders 3, and supportive element 4. In the preferred practice, this slab and the underlying girders would be cast monolithic. A series of planks 12 are cast overlying slab 11. Each of these planks is hingeably connected to slab 11, at the upper edge of the plank. A front wall 13, for the module, is shown in cast position with hinges at the inner edge. Hole 14 represents one of the possible design elements for the wall, which could be modeled or prefinished as desired while in the flat. 
     Modules D and E are shown erected with the girders elevated to a compound slope, and the supportive elements 4, and 5 rotated to the vertical and supportive position. Walls 6,7, and 8 have rotated down to form a rigid box element to provide lateral support for the deck 11, which is hingeably secured thereto. Seats 12, have been pivoted up to level position, and there secured. Wall 13, has been rotated up to a vertical position. 
     Module E is shown erected and connected to Module D, and the elements 4 of each module working together to provide structural support around the perimeter of the stadium. The horizontal decks that would be part of the completed stadium, have been omitted for clarity of the illustration. In addition, the thickness of the slab has been exaggerated for clarity. The shape of the element 4, at the top end is arbitrary and may be shaped to the designer&#39;s fancy. In addition, the lower configuration, which for element 4, is shown nested together in module B, may be modified as long as the structural integrity is maintained. 
     In FIG. 2, girders 3, are shown cast together with slab 11, and a pivot connection 9, providing the hinged connection to 5. Steps 12 are shown in elevation. 
     FIG. 3, shows the cross section and shows the division of the girder to provide the changing slope. It should be noted that this permits the approximation of the ideal curve for viewing angles for a stadium or amphitheater, which is here very easy to accomplish. The filler block 17, varies according to the steepness of the slope and is locked into position by the back edge of the next ahead tread. The actual seats would be applied later and would be of traditional type, wood, metal, plastic, or aluminum. If desired, heating pipes could pass thru void 18, or the voids could be used for passing warm air, which would give great comfort to a stadium theater. Hinges 16, secure the treads to the slab. In addition, a waterproof membrane, may be applied to the surface 19, and the embedded hinged element to provide a waterproof deck and protection from the weather. 
     FIG. 6 shows the plan arrangement of a discontinuous slab or girder arrangement. Side girders 20 are pivotally connected to the supportive element 21, by pivot 22. Pivot 22 may comprise a continuous tube thru which a post tensioned cable may be threaded to tie the entire stadium together. Item 23 shows a next supportive element with a pivot 24 connecting the supportive element to one portion of the girder, and a pivot 25, connecting the supportive element to the other portion of the side girder. The action of this arrangement is seen in FIG. 4, where the rotation of the supportive element serves to elevate a portion of the deck to a higher position, thus forming an upper tier. By selecting the length of 21, and 23, and 27, the specific slopes of the decks can be determined for the best viewing angle. In the preferred method of erecting the module, the inner end of the module would first be erected and walls 27,28,38 rotated to vertical, and secured to the foundation. The back portion of the stadium would then be elevated and ends 31, and 32, of the supportive elements brought into supportive position and secured to the foundation. 
     FIG. 8, shows one means of securing adjacent modules together with bolts threaded thru pivot tubes provided thru the girders 3. These tubes could be in position during the casting over a common core, so alignment is assured. 
     FIG. 8 also shows one form of gutter 45, which could be inserted between the sides of the girders. An expansive material 46, or a resilient material in the space, could complete the seal. Surface 48 would be covered with a waterproof membrane. 
     FIG. 7. shows two modules in the horizontal projected position, 36 and 37, with the gap 38, between them in this position. When the modules are elevated, the gap 38 would be eliminated and they could come together as 36A, and 37A. Since the sides of 38 are straight for each slope of the deck, and the width of the deck at the change of slope is mathematically determinable, there is no problem in forming a perfect fit. 
     IN CONCLUSION 
     From the above description, the invention has been disclosed to be a very simple method for achieving dramatic results in a new and novel way. In this disclosure, the use of concrete has been emphasized as the preferred material. However, the same general geometric configurations are attainable in steel and wood, and the invention should be considered applicable to the other materials, to the degree that they may comply with fire codes, earthquake codes and the like. 
     Details of specific hardware have been disclosed in other patents and patent applications of the present inventor, or are in his library as trade secrets. 
     In summary, it is believed that a new and novel method is disclosed for the construction of stadiums and the like, in a more efficient, economical, faster, better way, than any method known to the inventor. The fact that stadiums are currently being constructed by the old systems by the industry would make it seem that the subject material is not obvious to the practicioners of the art.