BACKGROUND OF THE INVENTION
Modern technology has provided for the partial or complete automation of nearly all industry, thereby making available an incredible variety of goods and services even to people of quite modest financial circumstances. A notable exception to this, however, has been the building construction industry and particularly that portion of the industry which is primarily concerned with housing. In many respects, housing is still built in much the same manner as 50 or more years ago, and with the ever-increasing price levels for labor and materials, much of the housing that is currently available is beyond the economic reach of a substantial portion of the population, so that urban decay is now a widespread blight extending throughout the world and resulting not only in entirely inadequate housing but also in numerous social ills as well.
It is now widely recognized that conventional methods of construction of housing, and other types of buildings as well, can no longer suffice, not only because of the high cost of construction with old-fashioned building methods, but also because it is simply impossible to build housing in sufficient quantities by these old-fashioned methods to take care of the surging need for housing. In recent years, a considerable amount of effort has been expended on developing new methods of housing construction which take advantage of the mass production technology that has evolved in most other industries. As a consequence, it is now known that housing structures such as individual homes, so-called "townhouses," and other structures of modest height such as from one to two or three stories in height, can more economically be built in factories using the modular concept, i.e., a concept whereby a portion of such a structure is built as a unit or module in a factory, transported to the site, and then assembled together, with modular units being placed alongside each other and/or above each other in a predetermined configuration. The assignee of the present application has been a leader in this type of construction and has already constructed hundreds of homes built in this way in various places throughout the country.
In many instances, however, the above-mentioned modular housing technology is not fully adequate to meet the pressing needs for housing. Thus, the available technology has quite generally been limited to the construction of buildings of relatively low height. As mentioned above, the method of construction has been to place the factory-built modular units alongside one another and also to stack them on top of each other in a predetermined configuration; however, the overall height of the completed structure must necessarily be rather severely limited since the structure is completed in a rather conventional manner, i.e., by building from the ground up. Thus, the practice is first to place the modules for the ground level in place, and then to stack on top of these the modules for the second floor, and so on, until finally the top unit with its roof is placed in position. However, it will be readily apparent that this method of construction severely limits the height of such a structure because of the considerable difficulty in lifting a module, weighing a number of tons, from ground level to any appreciable height. Quite obviously, mobile cranes have a definite limitation as to how high they can raise a load and also, such cranes, if constructed to be adequate to raise a module to a considerable height, must necessarily be positioned at a substantial distance from the periphery of the foundation which may be impractical. Fixed cranes also have a limitation as to how heavy a load can be lifted, and elevators of adequate load-lifting capacity to lift a module weighing perhaps ten tons or so must be of such size and strength as to be economically prohibitive for use. Of course, if elevators of adequate capacity are used, there still remains the problem of moving the module laterally into its precise position once it has been raised to the required height.
There is, nevertheless, a very considerable need to be able to construct high rise units more quickly and at lower cost than is presently possible. In urban centers, where land is scarce and oftentimes extraordinarily expensive, it is simply not practical to remove existing structures and to replace them with garden-apartment type communities or townhouses having only two or three stories since the population density permitted by such types of construction is entirely too low to be practical. It is of the utmost importance, therefore, that modern technology solve the problem of how to build a high rise building quickly and at low cost. To do this, it is necessary to employ modular construction techniques because of the very great economies which can result from this type of construction. Of course, one of the most outstanding economies is the ability to continue construction irrespective of weather conditions. As is well known, construction delays due to weather result in an economic loss in this country alone of many billions of dollars a year. In addition, by using assembly line techniques in a factory where modules are built, it is possible to have workers specialize on specific tasks so that each is able to accomplish his given task quickly and efficiently. Also, it is possible to avoid or reduce much of the handling of material that is involved since the required material at each stage of the building of a module can readily be positioned adjacent the site where such materials are to be used; pneumatic and electric tools can very conveniently be used because they can so conveniently be connected to a source of electrical or pneumatic power; and adhesives and caulking materials can readily be conveyed from a central supply to appropriate stations at the module building site by pipes and/or tubes. These various economies make possible the construction of a structure much more rapidly than can be accomplished on the building site itself, with a considerable saving in cost.
A further advantage of the building construction method of this invention resides in the ability to increase the size of the building conveniently and in a relatively short time as compared to conventional building methods. Thus, the jacking structures can again be inserted in place between the already positioned fixed supporting structures, and the existing building can then be raised to permit the insertion of further modules in exactly the same way as previously described.
SUMMARY OF THE INVENTION
It is a principal object of this invention to provide a method for constructing a building formed of modular units, which method permits of rapid and economical construction of the building. In effect, the building is constructed in a manner which is the reverse of that normally employed in that the top story is constructed first and then raised by an amount substantially equal to the height of a module. The second topmost story is then inserted and fastened to the top story, and the two top stories are then raised another level so as to permit insertion into the building of the modules which make up the third story from the top, and with this procedure occurring repeatedly until the building is completed.
The construction method of this invention employs modules which are formed in part of reinforced concrete, and in part of structural steel members which are readily capable of absorbing both the dead load and the live loads which will ultimately be imposed upon the structure. The modules are placed upon a series of supporting structures which may be positioned below ground level. Alternate ones of the supporting structures are permanently fixed in place and form the supports for the building when it is completed. Between each pair of such permanent supporting structures is positioned a second type of supporting structure which may be temporarily placed and removed when the building is completed and is provided, moreover, with a jacking means which is capable of raising a substantial load.
After the supporting structures are all in place, i.e., both the permanent supports and the temporary supports having the jacking means, a row of modules is placed on the supports and secured to each other as by bolting. When this is done, the temporary supporting structures have their jacking means operated so as to raise the entire top story of the building by substantially the height of a single story. When this is accomplished, the spaces now appearing immediately above the permanent supporting structures are filled by inserting a module in each such position, and when all of these open spaces have thus been filled with modules, the jacking means associated with the temporary supporting structures are all lowered, thereby providing additional spaces in which further modules can be placed. There is then provided a second row of modules which will eventually comprise the second topmost story of the building. The modules of this row are now all secured together by suitable bolts passing through the structural supporting members. Following this step, the jacking means is again raised to thereby raise the two top stories of the building by substantially the height of a single story, and it will be readily apparent that this again provides empty spaces, one above each of the permanent supporting means into which additional modules can now be inserted. The above-described procedure is carried out repeatedly until the desired building height is achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
In describing the invention, reference will be made to the accompanying drawings in which:
FIG. 1 is a perspective view showing in particular a single module of the present invention and showing also a portion of a second module placed atop the first module;
FIGS. 2A-2F comprise a series of diagrammatic representations illustrating the manner in which a building formed of a plurality of modules of the type shown in FIG. 1 is erected to any desired height.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates in perspective view a typical module of the kind which is intended to be used in the construction of a building in accordance with the method of this invention. The module is formed in part of an outer framework which comprises a plurality of structural members, preferably of steel to provide the desired strength. Preferably, I-beams and channel beams of adequate dimensions to support the predetermined load are provided for this outer framework.
The framework for the module comprises along the short end 5 of the module, two vertically disposed I-beams 6 and 7 whose height is at least equal to the overall height of the module. Although the opposite end of the module is not shown in FIG. 1, it is to be understood that the module is symmetrically constructed and that therefore two additional I-beams corresponding to the beams 6 and 7 are provided exteriorly of the module at the remote end as well. Secured to the bottom end of the two I-beams 6 and 7 is a channel-shaped structural member 8 which is preferably secured to the I-beams 6 and 7 by bolts (not shown). A similar channel-shaped member 17 is secured to the columnar I-beams at the remote end of the module. Interconnecting the I-beams 6 and 7 and channel beam 8 with the corresponding parts at the remote end of the module are a pair of I-beams 15 and 16 which extend along the bottom of the module, and each such bottom I-beam 15 or 16 is secured to the respective column I-beam 7 or 6 and to channel beam 8 by angle plates (not shown) and bolts (not shown).
Secured to the top surfaces of the channel beams 8 and 17 and to transversely extending I-beams 15 and 16 is a floor 25 which is preferably formed of steel-reinforced concrete. The floor may be finished with a suitable covering material such as carpeting or vinyl sheet material or the like (not shown). The interior of the module is divided by various wall partitions 21 and 22, and the module may also be provided with floor cabinets 24 and wall cabinets 23 for a kitchen module.
It should be noted that when one module is stacked atop the other, the vertical column I-beams 6 and 7 are vertically aligned with each other. Since each columnar I-beam 6 or 7 has a length at least equal to the overall height of the module (and is preferably equal in length to the height of the module), the beams 6 and 7 of the respectively stacked modules abut each other so that the weight of each unit or module is supported by the aligned I-beams 6 and 7 of the stacked modules through the successive modules. The ceiling of each module may comprise sheetrock material or the like 18 and need not be designed to support any portion of the load of the modules stacked above since all of the floor load of the higher module is borne by the transversely extending I-beams 16' and 16 and carried thereby to the I-beams 6 and 7 at each end of the module.
FIGS. 2A-2F illustrate the manner in which a multistory building may be erected quickly and inexpensively, according to the invention, using the modules shown in FIG. 1.
In FIG. 2A, the foundation for the building is shown at 15, and it will be apparent to one skilled in the art that such foundation may be below grade level although of course it is entirely possible to construct a building with the foundation 15 at grade level. In any event, a first step in the method of erecting a building is to place on the foundation 15 a plurality of structural supporting units 10 which are spaced so as to underlie alternate ones of the modules to be coupled together to form the top story of the building. The supporting structures 10, which are shown only diagrammatically in FIGS. 2A-2F, are formed of structural steel members which, it will be understood are suitably cross braced and supported so that they will each be capable of supporting and raising a number of modules equal to twice the number of floors to be included in the completed building or structure.
Each supporting structure 10 is provided with a jacking means diagrammatically illustrated as 12 in FIG. 2B and having a capability of selectively raising a load vertically by an amount at least equal to the overall height of a module. Although only two vertical lifting columns are shown in FIG. 2B, it should be understood that the device 10, 12 is preferably constructed as a rectangular parallelepiped having vertical supporting members at each corner and also a jacking means at each corner.
Between each pair of the temporary supporting structures 10, each including a jacking means 12, there is provided a permanent supporting structure 11. Each such supporting 11 is rigidly secured to the foundation 15 so as to form a permanent part of the building when complete. Each supporting structure 11 is also suitably cross braced and of sufficient strength as to be able to support a dead load corresponding to the weight of a number of modules equal to twice the number of stories in the completed building, and also whatever live load may be placed on the floor of the module, wind loading, etc.
When all of the supporting structures 10 and 11 are in place, as shown in FIG. 2A, the next step is to position on top of each of the supporting structures a series of modules 13 and 14. Although these modules may all be substantially identical in exterior configuration and structural details, although possibly differing in interior partition arrangement, plumbing, wiring, etc., they have been designated in FIGS. 2A-2B by different reference characters 13 and 14 dependent only upon whether the module is supported upon a jacking supporting structure 10 or upon a fixed supporting structure 11.
Once the various modules 13, 14 are in place on the supporting structures 10, 11 as in FIG. 2A, the modules are all coupled together by suitable bolts passing through adjoining structural supporting members. When this has been completed, the jacking means associated with each of the temporary supporting structures 10 is raised, and the operation of the various jacking means 12 is suitably synchronized, as is known in the art, to ensure that the row of modules is raised uniformly and in a level fashion by an amount substantially equaling the overall height of a single module, with the result that the structure under assembly then has the general appearance shown in FIG. 2B.
Thereafter, there is inserted in each of the blank spaces extending above a respective one of the permanent supporting structures 11 an additional module 14 as shown in FIG. 2C. When all of these modules are inserted in the alternate spaces, the various jacking means 12 associated with the temporary supporting structures 10 then are all lowered as shown in FIG. 2D, the topmost row of interconnected modules now being all supported on the supporting structures 11 through the intervening modules 14. It will be apparent that this now provides additional gaps which permits the insertion of modules 13 to fill these gaps so that finally a row of adjoining modules 13, 14 is provided which comprises all of the modules required for the second-from-the-top story of the building which will then have the general appearance shown in FIG. 2E.
When this is done, the next step is to operatively couple together all of the modules of this second-from-the-top story of the building so that raising of the jacking means 12 associated with the temporary supporting structures 10 will permit raising of the two top stories as an integral unit, thereby again providing voids alternately spaced and respectively positioned above the permanent supporting structures 11 which may be inserted for the third-from-the-top story of the building. The above-described procedure is repeated as many times as is required until the building is of the desired height. When this is accomplished, the temporary supporting structures 10 and associated jacking means 12 may all be removed so as to permit them to be used in the assembly of another building.
Having described the method of the present invention for constructing a building, several additional advantages, over and above those previously described, will now become apparent. For one thing, it is immediately evident that neither cranes nor elevators are needed to erect a building since, if the foundation 15 is below grade level and with the tops of the various supporting structures 10 and 11 at grade level, each module 13 or 14 may readily be moved into position atop either one of the supporting structures 10 or 11 without having to raise it above ground level. Also, the coupling together of the various modules, the interconnection of electrical cables, gas conduits, and other utilities, exterior panelling, and all other details required to accomplish the completion of a given story of the building may be carried out substantially at ground level and there is no need to provide scaffolding or cranes, nor is there the danger of having workmen carry out their labors at substantial distances above ground level. Labor time is also reduced because of the elimination of the need for workers to travel long distances through the building to their place of work.
FIGS. 2A-2F show the construction of a building having a depth (i.e., in a direction perpendicular to the plane of the sheet) of only a single module. However, if the building has a depth of more than one module, each additional row is provided with alternately spaced supporting structures 10 and 11 in the same way as shown in FIGS. 2A-2F. Also, under such circumstances, the several rows of modules are all preferably interconnected and the various jacking means 12 for the two or more rows are preferably operated concurrently so that each complete story is raised together as an integral unit. This makes possible the interconnection and completion of all modules substantially at ground level which is, of course, advantageous.
We are aware of a prior art system of building erection which discloses the concept of constructing a building one story at a time, the highest story first, and then raising the building by jacks by a height equal to the height of a single story. However, in this prior art system, the building is not constructed of modules but is instead made by casting reinforced concrete supporting structures for each individual story of the building, with the reinforced concrete having to cure about two weeks for each story before that story can be jacked up to permit work to commence on the next lower story. Also, in such prior art method, the plurality of jacking means are spaced adjacent to each other in the central core of the building which provides the principal support for the structure. The jacks are raised in unison but only by the amount of the jack stroke, and when the building has been raised this amount, each individual jack in turn is lowered so as to permit a spacer block to be inserted. This spacer block must be constructed to close tolerances with a permissible variation in block height of only plus or minus 0.1 millimeters. It is apparent that such blocks cannot be made at low cost and moreover, the requirement that each jack be lowered individually and a block inserted to take up the space, means that the building lifting operation must occur very slowly and in fact, the jacking operation to lift the building by the height of one story requires 2 or 3 days. It will be apparent that the method of the present invention will permit a far greater speed in building erection, only about 4 to 6 hours being required to raise the building by an amount equal to the height of one story.
It has been described above that, according to the preferred method of practicing the invention, only alternately spaced supporting structures are provided with a jacking means. According to a variation of this method coming within the scope of this invention, each of the supporting structures designated as 10 and 11 in FIGS. 2A-2F is of this same type and each has a jacking means associated therewith. To raise the building, all of the jacking means are then operated together and, after such operation, the jacking means of alternately spaced supporting structures are lowered so that the system then has the general arrangement shown in FIG. 2B. According to this modification, each jacking means must still have the capacity to support a load corresponding to the weight of a number of modules equal to twice the number of floors in the building. However, one advantage of this modification is that, by using twice the number of jacking means as in the previously described principal method, each jacking means need have only one-half of the load-raising capacity. This advantage may become of substantial importance with increasing height of the completed building.
According to another variation of the invention, fewer jacking means are used than in the principal embodiment where a jacking means is used for each alternately spaced module. Thus, it may be possible in some instances to provide jacking means only for each third module in a row of modules and to use fixed supporting structures for the remaining intervening modules. This form of the invention has several disadvantages, however, particularly the requirement that each jacking means must then be capable of supporting and raising the weight of three modules. Another disadvantage is that then there is a considerable cantilever effect resulting from the fact that two successively spaced modules, together with all the additional modules stacked thereon, are unsupported. Thus, although this variation of the invention does require less jacking means, it is believed to be of considerably less benefit than the principal form and the first-mentioned variation thereof described above.