Construction of a lift shaft or stair core

Abstract

Abstract A method of forming a lift shaft or similar in a multi-storey building is disclosed. The method includes the casting the shaft in segments (typically in the order of 800mm deep) and then assembling the segments atop each other to form the shaft. The segments have vertical passages which align to form channels in which rebar can be inserted to tie the structure together. 2021107156 25 2021 Aug

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Invention title: “CONSTRUCTION OF A LIF SHAF OR STAIR CORE” Applicant: IAVILAER PTY LTD Associated provisional applications: Provisional application number 2020904112 filed 10 November 2020 The following statement is a full description of the invention, including the best method of performing it known to me: “CONSTRUCTION OF A LIFT SHAFT OR STAIR CORE” Field of the Invention

[0001] The present invention relates to the construction of lift shafts, stair cores and similar inter-storey structures in multi-storey buildings. Background to the Invention

[0002] In “mid-rise” (typically two to eight storey) construction there must be means to travel between storeys. Typically, this is done via lifts (elevators) or stairs. In both cases, a four-walled structure is required which extends through multiple building storeys. For convenience, the following description will refer to lift shafts, although it is equally applicable to stair cores.

[0003] In mid-rise construction there are three methods which are commonly used to form lift shafts. The first is to lay load bearing masonry blocks in a traditional manner, then add reinforcement, and core-fill. The second is to use precast panels. The third method is to cast in situ by pouring concrete within a formwork system which includes reinforcing. The latter can include systems where the formwork forms an outer skin on the finished lift shaft, or formwork arranged to be removed to leave a concrete wall.

[0004] There are difficulties involved with each of these methods. Block walls are slow to erect, and require skilled tradespeople. Precast panels are heavy, and require a large crane on-site. Poured concrete in finished formwork systems provide little ability to verify reinforcement and concrete condition. Removable formwork is both expensive and labour-intensive.

[0005] The present invention seeks to propose an alternative system for the construction of lift shafts, stair cores and the like. Summary of the Invention

[0006] According to one aspect of the present invention there is provided a method of constructing an inter-storey structure within a multi-storey building, the method including the steps of: pre-forming shaft segments, each shaft segment being rectangular in cross section: locating a first shaft segment at a required location within the multi- storey building; and sequentially mounting additional shaft segments atop the first shaft segment to form the inter-storey structure.

[0007] The term ‘shaft segment’ will be understood to refer to segments of lift shafts, stair cores and other similar inter-storey structures.

[0008] It will be appreciated that although the shaft segments have been described as being rectangular in cross section, this includes segments which have gaps in one wall, for instance to form openings into the inter-storey structure.

[0009] It is preferred that each shaft segment has at least one vertical passage extending within a wall of the shaft segment. The passage is preferably formed by a tube cast within a wall of the shaft segment, the tube extending vertically. These passages can be aligned to form a vertically extending channel through the inter-storey structure.

[0010] The method includes the further step of locating reinforcing rods within the vertically extending channel(s) of the inter-storey structure. The vertically extending channel(s) can then be filled with a curable substance such as a grout.

[0011] It is preferred that the reinforcing rods are longer than the vertically extending channels. In a preferred embodiment, the reinforcing rods extend through the first shaft segment and into aligned holes beneath the first shaft segment. In the preferred embodiment the reinforcing rods also extend above the top of the inter-storey structure, providing a ‘tie point’ for a higher structure (which may be a further inter-storey structure).

[0012] It will be appreciated that each shaft segment has four corners which are cast into position, thus providing structural integrity. This is in contrast to the use of pre-cast panels, in which the corners must be joined by a weld plate.

[0013] It is anticipated that each shaft segment is likely to have a height in the order of 800mm. Brief Description of the Drawings

[0014] It will be convenient to further describe the invention with reference to preferred embodiments of the present invention. Other embodiments are possible, and consequently the particularity of the following discussion is not to be understood as superseding the generality of the preceding description of the invention. In the drawings:

[0015] Figure 1 is a plan view of a lift shaft constructed in accordance with prior art techniques;

[0016] Figure 2 is a front view of the lift shaft of Figure 1;

[0017] Figure 3 is a plan view of a lift shaft in accordance with the present invention:

[0018] Figure 4 is a front view of the lift shaft of Figure 3, showing hidden elements:

[0019] Figure 5 is a schematic perspective of the lift shaft of Figure 3; and

[0020] Figure 6 is a schematic exploded view of the lift shaft of Figure 3. Detailed Description of Preferred Embodiments

[0021] Referring to the Figures, Figures 1 and 2 show a lift shaft 10 having a rear wall 12, two side walls 14 and a front wall 16. The front wall 16 includes an opening 18 to serve as a doorway. The lift shaft 10 has been constructed in a single piece, using concrete poured into framework as known in the prior art.

[0022] Figures 3 to 5 show a lift shaft 20 formed in accordance with the present invention. The lift shaft 20 has a rear wall 22, two side walls 24, and a front wall 26. The front wall 26 includes an opening 28 to serve as a doorway.

[0023] The lift shaft 20 is formed of four segments: a first segment 30, a second segment 32, a third segment 34 and a fourth segment 36.

[0024] The first segment 30 is rectangular in cross section, having a height of about 800mm. The first segment 30 has a rear wall 22, two side walls 24 perpendicular to the rear wall 22, and a front wall 26 parallel to the rear wall 22. The front wall 26 has a first portion 38 spaced from a second portion 40 by an opening 28.

[0025] The second segment 32 is the same size and shape as the first segment 30.

[0026] The third segment 34 is similar to the first and second segments 30, 32, except its front wall 26 extends from one side wall 24 to the other side wall 24, with an opening 28 extending only about half-way up the height of the front wall 26.

[0027] The fourth segment 36 is similar again, but with a complete front wall 26 having no opening.

[0028] Each segment 30, 32, 34, 36 has two vertical passages 42 formed in its front wall 26, in the first portion 38. The vertical passages 42 are formed by tubes cast with the front wall 26. The vertical passages 42 of each segment 30, 32, 34, 36 are aligned so as to form vertical channels 44 which extend through the lift shaft 20.

[0029] The lift shaft 20 is constructed by first locating the first segment 30 in its required position within a building. The building includes apertures (not shown) arranged to align with the vertical tubes 42 of the first segment 30.

[0030] The second segment 32 can then be lowered into position atop the first segment 30, with the opening 28 and the tubes 42 of the second segment 32 aligning with the opening 28 and the tubes 42 of the first segment 30.

[0031] Similarly, the third segment 34 and the fourth segment 36 can be lowered into position to complete the lift shaft 20.

[0032] The segments 30, 32, 34, 36 are ‘tied’ together by the use of reinforcing rods 46 such as 20mm rebar. A rod 46 is inserted within each channel 44, extending into the aligned aperture in the building. The rod 46 is long enough to protrude from the top of the channel 44. The channels 44 can then be filled with grout.

[0033] The protruding portions of the rod 46 can be used to provide a ‘starter’ bar for another section of the shaft.

[0034] It will be appreciated that the weight of each segment 30, 32, 34 36 is sufficiently small to be able to be lifted by a self-erecting crane as commonly used on mid-rise building sites.

[0035] It will be further appreciated that the corners of the lift shaft 20 are cast as such, rather than requiring panels to be bolted together.

[0036] Although the invention has been described with the use of two channels 44 and corresponding rods 46, it will be appreciated that in use a plurality of channels 44 spaced around the periphery of the lift shaft 20 are likely to be employed.

[0037] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

Claims

Claims 1. A method of constructing an inter-storey structure within a multi-storey building, the method including the steps of: pre-forming shaft segments, each shaft segment being rectangular in cross section: locating a first shaft segment at a required location within the multi- storey building; and sequentially mounting additional shaft segments atop the first shaft segment to form the inter-storey structure.

2. A method of constructing an inter-storey structure as claimed in claim 1, wherein each shaft segment has at least vertical passage extending within a wall of the shaft segment.

3. A method of constructing an inter-storey structure as claimed in claim 2, wherein each passage is formed by a tube cast within a wall of the shaft segment, the tube extending vertically.

4. A method of constructing an inter-storey structure as claimed in claim 2 of claim 3, wherein the passages are aligned to form a vertically extending channel through the inter-storey structure. 5 A method of constructing an inter-storey structure as claimed in claim 4, wherein the method includes the further step of locating reinforcing rods within the vertically extending channel(s) of the inter-storey structure.

6. A method of constructing an inter-storey structure as claimed in claim 5, wherein the method includes the further step of filling the vertically extending channel(s) with a curable substance. / . A method of constructing an inter-storey structure as claimed in claim 5 or claim 6, wherein the reinforcing rods are longer than the vertically extending channels.

8. A method of constructing an inter-storey structure as claimed in claim 7, wherein the reinforcing rods extend through the first shaft segment and into aligned holes beneath the first shaft segment.

9. A method of constructing an inter-storey structure as claimed in claim 7 or claim 8, wherein the reinforcing rods extend above the top of the inter- storey structure.

10. A method of constructing an inter-storey structure as claimed in any preceding claim, wherein each shaft segment has a height in the order of 800mm. IAVILAER PTY LTD By its Patent Attorneys ARMOUR IP P2391AU01

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