US3254466A - Method of erecting a multi-story building structure - Google Patents

Description

June 7, 1966 E. J; voN HEIDENSTAM 3,254,466

METHOD OF ERECTING A MULTI-STORY BUILDING STRUCTURE INVENTOR Erik Johan von Heidensfam ATTORNEYS June 7, 1966 E. J. VON HEIDENSTAM 3,254,456

METHOD OF ERECTING A MULTI-STORY BUILDING STRUCTURE FiledvOO'.. 4;, 1962 2 Sheets-Sheet 2 f77-5 22 26 28 MII lib 28C? 9 INVENTOR E rik Johan von Heidenslom ATTORNEYS United States Patent O METHOD OF ERECTING A MULTI-STORY BUILDING STRUCTURE Erik Johan von Heidenstam, Regeringsgatan 58, Stockholm, Sweden Filed Oct. 4, 1962, Ser. No. 228,437 Claims priority, application Sweden, June 30, 1953, 6,192/ 53 4 Claims. (Cl. 52-745) The present application is a continuation-in-part of my copending application Serial No. 440,223, filed June 29, 1954, and now abandoned. l

This invention relates to improved multi-story, large floor area building structures and to a novel method of erecting such structureswhich represents a substantial improvement over prior art erection techniques, especially the lift-slab method of construction currently in vogue.

In the lift-slab method of construction, as currently practiced, a concrete ground slab is poured at the building site around or under an array of supporting columns, generally I-beams or structural steel, erected on separate foundations prior to casting of the ground slab. Liftslabs, which will form the floors for the upper stories and the upper or roof slab of the building unit under construction are then poured on the ground slab, jacked up the columns into place, and fastened to the columns. Descriptions of this construction technique have been published in the June 1950 issue of Architectural Forum at pages 135-141, in the January 1949 issue of Architectural Record at pages 121-123, and in United States Patents Nos. 2,686,420, issued August 17, 1954, to P. N. Youtz, for Slab Lifting Apparatus, and 2,715,013, issued August 9, 1955, to T. B. Slick, for Apparatus for Erecting a Building.

This method of construction has a serious defect which severely curtails its usefulness. The relatively slender floor and roof supporting columns have insufficient stiffness to resist lateral loads imposed upon the building structure during the erection process by high winds, cyclones, tornadoes, earthquakes, nuclear shock and blast waves, and the like.

Partially erected, lift-slab constructed buildings have on several occasions been seriously damaged or collapsed by mere Wind action, for example. In one striking example of such damage, reported in the Engineering News- Record (April 19, 1956, issue at page 25; May 3, 1956, issue at page 25; and June 14, 1956, issue at page'26), wind action tilted a partially completed eight story building being erected by the lift-slab method seven feet out of plumb.

To improve the lateral stability of Vthe building units during the erection process, various expediente, such as guy Wires, rods, and struts have been employed. Such devices, however, are of only limited utility. First, because of the necessarily substantial length of such devices and 'slab technique is completed. Although the columns are to a certain extent rigidied by their interconnection through the lift-slabs, the exterior walls of the completed building present a much greater area against which latice erally directed forces may act, largely offsetting the lateral load resistance gained by interconnecting the columns through the lift-slabs.

As a result of the problems encountered in providin adequate 'resistance to lateral loads, especially during the erection process, the prior art lift-slab techniques are useful only in erecting buildings of relatively few stories. In May of 1956 the highest building erectedby the liftslab method was a mere 77 feet above ground according to the May 3, 1956, issue of Engineering News-Record at page 25. f

It is a primary object of the present invention to prolvide a novel and improved method of constructing multistory, relatively large oor Iarea building units which retains the advantageous features of the lift-slab technique while eliminating the drawbacks of that method, especially the problem of providing adequate resistance against lateral loads that may be imposed during the erection process and, under certain catastrophic conditions, after completion of the building.

Another primary object of the present invention resides in the provision of novel and improved building structures which have substantially greater resistance to Vlateral forces than buildings constructed by the lift-slab technique.

erect-ing multi-story buildings and building units which have all the advantageous features of the lift-slab method of construction, but which enable the erection of subst-antially higher structures than is possible by the latter method.

And a further primaryobject of the present invention is the provision of building structures of significantly greater height than is possible by employing the liftslab method of construction.

To fully understand and appreciatethe present invention, an awareness of certain specialized terms employed to describe various aspects of this invention is necessary. These terms Iare as follows:

Building structure: The basic supporting framework of a completed multi-story building or building unit, including generally a plurality of lift-slabs (which form the roof and upper floors of the completed building or building unit) xed to a spatial array of load bearing columns.

Ground slab: A slab, which will normally be of reinforced concrete, forming the base on which the lift-- slabs are cast. It may be cast on the ground or on suitable foot-ings or pilings or may be formed of precast slab sections. It need not be of reinforced or pre-Stressed concrete, but may be made of other suitable materials.

Lift-slab: A slab, normally of reinforced concrete and preferably-pre-str'essed, cast in place on the ground slab and surrounding the load bearing columns and at least a portion of one tower or the position thereof. Lift-slabs, when raised to their final positions, may form the roof of the buildingand, -in all cases, the floors of its upper stories. Lift-slabs may also -be fabricated from materials other than reinforced concrete.

Lateral load: A load acting laterally on a building or building unit, a building structure, a partially erected building sturcture, or building structure components. The most common lateral loads are those imposed by wind loads which impose shear stresses and bending moments on the load bearing columns and set up destructive oscillations in the building structure. Destructive lateral loads may also be imposed by certain catastrophic occurrences as, for example, by the overpressure and suction phases of a nuclear detonation and by earthquakes, which have an effect similar to that produced by wind loads.

Load-bearing column: A vertical, elongated, relatively slender structural member having little resistance to lateral loads, especially if it is of a length'equalling the height of several stories, to which the lift-slabs are fastened. Load-bearing columns may be I-beams or other structural shapes or may be fabricated from reinforced concrete or other materials.

Spatial array: An arrangement of load-bearing columns spaced from each other and from one or more towers. The load-bearing columns support the lift-slabs.

Structure suited for human occupancy: A structure having a hollow interior sufliciently large that it may be ernployed to house elevators or staircases, or heating and air conditioning equipment and other utilities to which human access for service is desirable, or which is of such size that it may be divided into rooms suitable for living quarters. During the erection process a structure suited for human occupancy may house or support mechanism for hoisting men and materials as the building structure rises above the ground.

Tower structure: One or more towers. A tower is a vertical, rigid, lateral load resistant hollow structural member normally of monolithic construction (although it may be constructed in any other manner desired). A tower structure is employed in a building structure to guide the lift-slabs when they are raised and/or locate them in temporary or final locations and to absorb lateral loads imposed upon the building structure during its erection and upon the completed building. The hollow interiors of towers are sized 'to permit human occupancy,

In the novel construction method provided by the present invention, a ground slab, a spatial array of load-bearing columns, and a tower structure are constructed, though not necessarily in this order'. Thereafter, a stack of liftslabs are cast on the ground slab around the load-bearing columns and at least a portion of at least one tower or the position thereof. The lift-slabs are then lifted to predetermined positions and connected to the load-bearing columns.

A number of advantages obtain from this method of construction. The tower structure provides one or more free standing lateral load resistant units to guide and/or locate the lift-slabs as they-are raised into position. At the same time, the tower prevents lateral movement of the lift-slab While they are being raised, while they parked, after they are in place, and after the building is completed, even though the structure is raised a substantially larger number of stories than is possible by the prior liftslab method.

The towers serve an additional useful function. Having a hollow interior with cross sectional dimensions of generous proportions, they are well suited for human occupancy.

Also, as the tower structure absorbs all laterally acting loads, the load-bearing columns need be made only strong enough to withstand the compressive loads exerted by the lift-slabs and the components added to the building structure to complete the building. Consequently, the load-bearing columns need not be over-designed to provide resistance to lateral loads as has sometimes been done in the past.

In my Swedish Patent 125,902, published August 30, 1949, I disclosed a sectional tower structure in which vertical exterior walls are formed around a central vertical shaft extending the height of the completed building. Floor slabs including a number of separate sections separated by internal vertical walls are formed on the base level and then lifted separately to desired levels in the various areas of the building between the shaft and the surrounding walls. The uppermost slab in each building is lifted first to its final position and fixed in place to the walls and then the remainder of the slabs are in descending order, lifted and fixed in place.

United States Patent No. 2,705,359, issued April 5, 1955, to A. B. Strandberg, discloses a separate tower type monolithic building construction with a central spiral stair-well providing access to different floor levels divided into access passages. The floors are formed as part of the monolith in the usual manner of concrete construction prior to the development of lift slabs.

There is no recognition in these patents, which exemplify the prior art, that such tower-like structures or buildings may be used as lateral load resistant structural elements in a substantially larger building unit to. prevent lateral movement of the latter during the erection process and after the building unit is completed.

From the foregoing it will be apparent that another object of the present invention resides in the provision of a building structure and in the method of erecting a building structure in which a tower suiciently rigid to withstand lateral loads imposed on the structure and having a hollow interior suiiciently large for human occupancy is employed.

Another object of the present invention resides in the provision of an improved building construction for reducing the number and size of load bearing columns required.

Yet another and extremely important object of the present invention is the provision of novel building structures when can be erected at a substantially lower cost than is possible by currently employed construction techniques such as the lift-slab method.

Other objects and further novel features of the present invention will become more fully apparent from the appended claims andas the ensuing detailed description and discussion proceeds in conjunction with the accompany ing drawings in which:

FIGURE l is a schematic elevation, partially in section, of a portion of a building structure erected by the novel technique provided by the present invention;

FIGURE 2 is a generally schematic elevation of the building of FIGURE l as it appears during the initial stages of the erection process and illustrates, in particular, the manner in which the lift-slabs, which -will form the floors of the upper stories and the roof of the building structure, are constructed;

FIGURE 3 is a plan view of the building structure of FIGURES 1 and 2;

FIGURE 4 is a generally schematic elevation, similar to FIGURE 2, showing a method of erecting a building structure at a later stage of the erection process with a number of the lift-slabs raised to their final positions in the building structure;

FIGURE 5 is a horizontal section through a hollow, rectangular tower and shows a lift-slab and an arrangement of rollers provided to facilitate upward movement of the lift-slabs relative to the towerwhile wind is blowing; and

FIGURE 6 is a view similar to FIGURE 5 of a U-sectioned tower and an arrangement of runners which may be employed to facilitate upward movement of the liftslabs relative to the towers.

Referring now to the drawing, in which exemplary structure is shown, FIGURE 1 illustrates a building structure 20 constructed in accordance with the principles of and pursuant to the novel construction techniques provided by the present invention. Building structure 20, which is erected on a foundation indicated generally by reference character 22, consists of a plurality of lift-slabs 24a-f supported in vertically spaced relationship to form the upper lioors and the roof of building 20 by columns 26 (only one of which is shown) and prevented from moving laterally by a tower structure such as tower 2S.

The first step in erecting multi-story building structure 20 is the preparation of foundation 22, the details of which comprise no part of the present invention. Foundation 22 may take any one of several well known forms. For example, it may consist merely of the soil of the building site graded, compacted, and stabilized. Or, as further or reinforced con- Y 28 are then constructed on foundation 22 in any desired sequence. For the purpose of explaining the present invention, it will be assumed that ground slab 30 is first constructed and that load-bearing columns 26 and tower 28 are then erected on the slab in that sequence.

The details of ground slab 3 0, also, form no part of the present invention. Perhaps most commonly, ground slab 30 will be fabricated from reinforced concrete poured in situ. A suitable alternative, by way of example, is precast concrete slab sections.

A spatial array of load-bearing columns 26, which will generally be of prefabricated construction, is then erected on ground slab 30. The number and relative location of load-bearing columns 26, the material from which they are fabricated, and the manner in which they are supported at their lower end will vary Widely from building to building. Preferably, load-bearing columns 26 are so spaced that the weight of lift-slabs 24a-f and other structural components, such as exterior walls, added to building structure 20 to complete the building will be distributed among the several columns. Suitable materials from which load-bearing columns 26 may be fabricated include reinforced concrete and structural shapes such as I-beams and H-beams. be unitary members, but perhaps more commonly will be fabricated from a number of lengths united in an appropriate manner.

It is one of the important features of the present invention that load-bearing columns 26 need to be made only strong enough to withstand the compressive load of lift-slabs 24:11 and the building components (not shown) and the live load supported on the slabs since all necessary resistance to lateral forces or loads is provided by the tower structure. By thuspermitting the use of substantially smaller and also fewer load-bearing columns, the method of construction provided by the present invention effects a substantial savings in the cost of the loadbearing columns.

Towers 28 (see also FIGURE 3) are then erected. In the exemplary building structure shown in FIGURES 1-3, a tower structure formed of two towers 28 is employed. The necessary number of towers, however, will vary from building to building as will their location relative Y to the exterior walls of the building. For some buildings,

a single tower may suice; for others, a larger number of towers may be required. If a single tower is employed, it must be constructed to withstandl torsional stresses developed by eccentrically acting lateral loads.

Towers 28 are preferably of monolithic construction, formed in situ, and may advantageously be fabricated from reinforced concrete. They may have a rectangular, circular, or other desired cross-sectional configuration. Towers 28 may be constructed by the slip-form technique in which, as applied to the present invention, appropriate forms are erected at the locations of towers 28 on ground slab 30. Suitable reinforcing is placed in the forms which are then lled with concrete. After the concrete has set, the slip-forms are elevated and the process is repeated until, section by section, the towers reach the desired height. This permits towers 28 to be raised at substantially the same height as the lift-slabs, as shown in FIGURE 4. The slip-form method of constructing concrete structures, which forms no part of the present invention, is described in United States Patent No. 1,435,448, issued November 14, 1922, to C. H. McGregor, for Form for Use in Erecting Tapered Concrete Chimneys, for example. Towers 28. may also be constructed by other known techniques and this invention is intended to cover towers so constructed.

The completed towers 28 will typically have external horizontal dimensions on the order Iof feet by 15 feet and will extend the height of building structure 20. Be-

The load-bearing columns may,

` their pre-determined elevated positions.

cause they are relatively massive structures, each of the towers 2-8 may be provided with its own separate and independent foundation 32 (shown in dotted lines in FIG- URE 1) which may be formed in any of the various ways discussed above in conjunction with foundation 22.

It is the primary function of towers 28 to prevent the movement of lift-slabs 24a-f by laterally acting loads while lift-slabs 24a-f are being raised, after they reach their final positions, and after the building structure and the building itself are completed. The tower structure will, in most cases, provide a resistance to laterally imposed loads, both static and dynamic, which greatly exceeds the total load resisting capacity of columns 26.

Towers 28 serve an additional useful function. Because of their relatively large cross-sectional dimensions, the hollow interiors 34 of the towers are suitable for human occupation. vFor example, staircases, elevators, and utilities such as heating and air conditioning systems may be located in the hollow interiors 34 of the towers 28. As a further example, the hollow interiors 34 of towers 28 may be made into rooms suitable for living quarters by installing iloors at various levels in the towers. Such floors will, in addition, increase the stiffness of the tower,

adding to its capability to withstand lateral loads. Finally, towers 28 may be utilized to house or support hoists for men 'and materials as building structure 20 is raised above ground level.

After construction of ground slab 30, a plurality of lift-slabs-in the illustrated exemplary embodiment liftslabs 24a-f-are cast in situ on ground slab 30 so that the lift-slabs surround the positions of bearing columns 26 and the position of at least a portion of at least one tower 28. The technique -of casting a plurality or stack of lift-slabs is in itself well-known and its details form no part of the present invention. A detailed description of this technique is found in United States Patent No. 2,720,017, issued October 1l, 1955, to P. N. Youtz, for Methed of Erecting Buildings.

After the lift-slabs 24a-f have been poured and the concrete has set and cured, thelift-slabs are raised to Apparatus for raising lift-slabs is well known and forms no part of the present invention. Two forms of apparatus which are suitable are those shown in United States Patent No. 2,686,420, issued August 17, 1954, to P. N. Youtz, for Slab Lifting apparatus, and in United States No. 2,715,- 013, issued August 9, 1955, to T. B. Slick, for Apparatus for Erecting a Building.

A preferred method of raising lift-slabs 24a-f, when erecting a building of substantial height, is shown in FIG- URE 4. One or more of the lift-slabs lare raised a substantial distance above the ground and then parked by temporarily connecting them to load bearing columns 26 in their nal positions and/or slightly below the upper ends of towers 28. In FIGURE 4, for example, the three lower slabs 24a-c have been parked at their final positions and the three uppermost slabs 24d-f have been parked near the upper ends of towers`28. The lower lif slabs 24a-c Imay then' be permanently connected to loadbearing columns 26 and towers 28.

Towers 28 lmay then be extended upwardly until they reach the level indicated by reference'character 3S in FIGURE 4. The uppermost lift-slab 241 will then be lifted in one `ope-ration to its final position (indicated by in dotted lines and identified by reference character 36a and temporarily fastened to load-bearing columns 26. The remaining lift-slabs 24a-e are then raised upwardly toward lift-slab 241, one at a time with towers 28 guiding their upward movement. After being raised they, like lift-slab 241, are temporarily fastened to load-bearing columns 26. At the completion of the lifting sequence, slab 24a will be at the position identified by reference character 36a.

This stepwise process is then repeated, lift-slab 24f being raised above the position identified by reference character 36b and fastened in place. Then the remaining lift-slabs are raised upwardly toward lift-slab 247 and temporarily fastened to load-bearing columns 26. When this process of raising the lift-slabs is completed, liftslabs 24a-f will be in the positions identified by reference characters 36o-f, respectively.

As each lift-slab 24a-yc arrives at its final location, it is permanently connected to the load-bearing columns 26 and, if desired, to towers 28. A number of devices have been developed for inter-connecting the lift-slabs and the load-bearing columns and these, in themselves, form no part of the present invention. One typical and satisfactory device of this type is discussed in an article appearing in the June 1950 issue of Architectural Forum at pages 13S-141 (see especially page 138). Any locating means such as wedges (not shown) may be driven between the exterior walls of towers 28 and the lift-slabs to accurately locate the lift-slabs relative to the towers before the final connections are made.

Turning now to FIGURE 1, when lift-slabs 24 are fabricated a substantial clearance (greatly exaggerated in FIGURE 1) is provided betwen the exterior surfaces of towers 28 and the adjacent edges of the apertures 38 in the lift-slabs. Norm-ally, this will suffice to prevent binding between the lift-slabs and the towers as the lift-slabs are raised into position. However, it may in some circumstances be desirable to provide additional facilities for preventing the lift-slabs from binding against the towers as they are raised into place, especially when the wind is blowing. One arrangement which may be employed for this purpose is illustrated in a generally diagrammatic manner in FIGURE 5.

As is shown in FIGURE 5,roller-supporting brackets 40 are fixed in pairs to the wall surfaces 42 defining the aperture 38 in lift-slab 24 through which tower 28 extends. kRollers 44 are rotatably mounted between each pair of brackets 40 on axles 46. As is shown in FIG- URE 4, rollers 44 are preferably employed in pairs at each corner of tower 28 with one of the rollers in each pair riding on one of the two adjoining tower surfaces. Vertically aligned rails 48 may be embedded in the vertical walls 50 of towers 28 to support rollers 44 although, in some circumstances, it may be found desirable to omit rails 48 and allow rollers 44 to bear directly on the exterior surfaces of the tower walls. In other cases it may be deemed desirable to employ springs or hydraulic devices (not shown) to absorb shock loads imposed on rollers 44 by heavy gusts or the like as lift-slab 24 is raised.

FIGURE 6 shows an alternative arrangement for facilitating the movement of the lift-slabs relative to the towers. In this alternative arrangement, runners 52 are fixed to opposing side walls 50' of tower 28 which, as illustrated in this figure, has a hat-like cross-sectional configuration. As lift-slab 24 is raised, it is guided in its vertical movement by runners 52. As with the roller arrangement described above, springs or hydraulic devices (not shown) may be employed to absorb shock imposed on lift-slab 24 as it is raised.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the t appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. The method of erecting on a supporting base a multistory building having concrete slab flooring secured to spaced load-bearing columns and embodying a free-standing lateral load resisting tower structure means, which comprises:

(a) preparing in any desired order:

(i) a tower structure means comprising at least one separate free-standing tower, each said separate free-standing tower thereof having a relatively large cross-sectional area providing a high resistance to laterally applied forces:

(ii) a plurality of load-bearing columns each having a cross-sectional area substantially less than each said separate free-standing tower crosssectional area and relatively low resistance to laterally -applied forces, said load-bearing Columns being spaced from each said separate free-standing tower: and

(iii) a base:

(b) after said base is prepared, forming a plurality of lift-slabs on said base in stacked relationship, each surrounding a plurality of said columns and extending at least partially around each said separate freestanding tower in close proximity to each said tower so that a lateral force applied to said lift-slabs will move Said slabs into Contact with each said tower and be absorbed by said tower structure means;

(c) thereafter raising said slabs by applying vertical force thereto; and

(d) fastening said slabs in predetermined positions vertically along said columns while utilizing said tower structure means to resist forces tending to move said slabs transversely of said columns and tower structure means.

2. The method as set forth in claim 1 in which said tower structure means comprises a plurality of relatively spaced towers.

3. The method as set forth in claim 1 in which said tower structure means comprises the lprimary resistance to lateral movement of said slabs with respect to said columns in the erected building.

4. The method of erecting a multi-story building comprising:

(a) preparing a supporting base;

(b) constructing a tower structure means comprising A at least one separate free-standing tower having external surfaces, each said separate free-standing tower thereof having a vertically extending axis and a relatively large horizontal cross-sectional area providing a high resistance to laterally :applied forces and an interior space of sufficient size to accommodate human occupancy,

(c) constructing a plurality of load-bearing columns each having a cross-sectional yarea substantially less than each said separate free-standing tower crosssectional area;

(d) forming a plurality of lift-slabs on said base in stacked relationship, each of said slabs having side walls defining through passages, said side walls surrounding a plurality |of said columns and extending at least partially around the exterior surfaces of at least one tower;

(e) providing bearing means extending between the exterior surface of each said separate free-standing tower and said side walls of said lift-slabs for enabling said lift-slabs to be moved substantially parallel to the vertical extending axis of said tower and enabling said tower structure means to prevent any 9 substantial movement between said lift-slabs and said tower structure means in a directionv transversely of said vertically extending axis o-f each said tower; (f) thereafter raising said'lift-slabs by `applying vertical forces thereto; and (g) fastening said slabs in predetermined positions vertically along saidcolumns while utilizing said tower structure means to resist forces tending to move said slabs laterally of said columns and `said tower structure means.

References Cited by the Examiner UNITED STATES PATENTS 15 7/ 1913 Peltzer 52--745 10 2,168,725 8/ 1939 Whelan 52--220 2,686,420 8/ 1954 Youtz 52-126 2,705,359 4/ 1955 Strandberg 264--32 2,715,013 8/1955 Slick 52-745 X FOREIGN PATENTS 966,887 3/ 1950 France. 566,120 12/ 1944 Great Britain.

OTHER REFERENCES Architectural Forum, NALAS, January 1951, page 80. Architectural Record, NA1.A66, December 1950, back A of pages 11 and 12.

Claims (1)

1. THE METHOD OF ERECTING ON A SUPPORTING BASE A MULTISTORY BUILDING HAVING CONCRETE SLAB FLOORING SECURED TO SPACED LOAD-BEARING COLUMNS AND EMBODYING A FREE-STANDING LATERAL LOAD RESISTING TOWARD STRUCTURE MEANS, WHICH COMPRISES: (A) PREPARING IN ANY DESIRED ORDER; (I) A TOWER STRUCTURE MEANS COMPRISING AT LEAST ONE SEPARATE FREE-STANDING TOWER, EACH SAID SEPARATE FREE-STANDING TOWER THEREOF HAVING A RELATIVELY LARGE CROSS-SECTIONAL AREA PROVIDING A HIGH RESISTANCE TO LATERALLY APPLIED FORCES; (II) A PLURALITY OF LOAD-BEARING COLUMNS EACH HAVING A CROSS-SECTIONAL AREA SUBSTANTIALLY LESS THAN EACH SAID SEPARATE FREE-STANDING TOWER CROSSSECTIONAL AREA AND RELATIVELY LOW RESISTANCE TO LATERALLY APPLIED FORCES, SAID LOAD-BEARING COLUMNS BEING SPACED FROM EACH AID SEPARATE FREE-STANDING TOWER: AND (III) A BASE: (B) AFTER SAID BASE IS PREPARED, FORMING A PLURALITY OF LIFT-SLABS ON SAID BASE IN STACKED RELATIONSHIP, EACH SURROUNDING A PLURALITY OF SAID COLUMNS AND EXTENDING AT LEAST PARTIALLY AROUND EACH SAID SEPARATE FREESTANDING TOWER IN CLOSED PROXIMITY TO EACH SAID TOWER SO THAT A LATERAL FORCE APPLIED TO SAID LIFT-SLABS WILL MOVE SAID SLABS INTO CONTACT WITH EACH SAID TOWER AND BE ASBORBED BY SAID TOWAR STRUCTURE MEANS; (C) THEREAFTER RAISING SAID SLABS BY APPLYING VERTICAL FORCE THERETO; AND (D) FASTENING SAID SLABS IN PREDETERMINED POSITIONS VERTICALLY ALONG AND COLUMNS WHILE UTILIZING SAID TOWER STRUCTURE MEANS TO RESIST FORCES TENDING TO MOVE SAID SLABS TRANSVERSELY OF SAID COLUMNS AND TOWER STRUCTURE MEANS.

Images