U.S. patent application number 09/880883 was filed with the patent office on 2002-04-25 for shear wall panel.
Invention is credited to Leung, Thomas.
Application Number | 20020046514 09/880883 |
Document ID | / |
Family ID | 27171060 |
Filed Date | 2002-04-25 |
United States Patent
Application |
20020046514 |
Kind Code |
A1 |
Leung, Thomas |
April 25, 2002 |
Shear wall panel
Abstract
A shear wall panel for a building has a rectangular frame of
vertical and horizontal members. Inside of the rectangular frame,
at least four diagonal members are joined at their ends to create a
multi-segmented assembly having at least three vertices and first
and second ends and possibly forming a polygon, one of the at least
three vertices secured to each of the vertical and an upper
horizontal members, the first and second ends secured to a lower
horizontal member. The members are preferably of wood and connected
together with toothed plates. The panel is shear connected to a
foundation or laterally stabilized wall or floor below the shear
wall panel, possibly by a bolt between the foundation or laterally
stabilized wall or floor below the shear wall panel and the
intersections between the vertical members and the diagonal
members. Upper strap connectors attach the upper horizontal member
to a roof, floor or wall of the building. The upper strap
connectors comprises metal straps, a first portion of which have
teeth bent out of the metal strap, a second portion of which have
holes for nailing through the metal strap into the roof, floor or
wall of the building.
Inventors: |
Leung, Thomas; (Vancouver,
CA) |
Correspondence
Address: |
Scott Pundsack
Bereskin & Parr
Box 401
Toronto
ON
CA
|
Family ID: |
27171060 |
Appl. No.: |
09/880883 |
Filed: |
June 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09880883 |
Jun 15, 2001 |
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PCT/CA00/01221 |
Oct 13, 2000 |
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PCT/CA00/01221 |
Oct 13, 2000 |
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09419934 |
Oct 18, 1999 |
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60283339 |
Apr 13, 2001 |
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Current U.S.
Class: |
52/167.3 ;
52/293.3; 52/481.1; 52/693; 52/712 |
Current CPC
Class: |
E04B 2001/2696 20130101;
E04B 2001/3583 20130101; E04C 2/386 20130101; E04B 1/10 20130101;
E04B 2001/2684 20130101 |
Class at
Publication: |
52/167.3 ;
52/293.3; 52/481.1; 52/693; 52/712 |
International
Class: |
E04B 002/70; E04H
009/02; E04H 009/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 1999 |
CA |
2,285,890 |
Claims
I claim:
1. A shear wall panel for a building comprising, (I) outer
rectangle members comprising, a) a pair of spaced apart vertical
members having upper ends and lower ends; b) an upper horizontal
member extending between and secured to the upper ends of the
vertical members; and, c) a lower horizontal member extending
between and secured to the lower ends of the vertical members
wherein the outer rectangle members form an outer rectangle; and,
(II) inner polygon members comprising, d) at least four continuous
diagonal members secured together end to end to form an inner
polygon having at least a first, a second, a third and a fourth
vertex, wherein (e) the inner polygon is located inside of the
outer rectangle; (f) the ends of the diagonal members of the first
vertex are secured to one of the vertical members; (g) the ends of
the diagonal members of the second vertex are secured to the upper
horizontal member; (h) the ends of the diagonal members of the
third vertex and are secured to the other vertical member; (i) the
ends of the diagonal members of the fourth vertex are secured to
the lower horizontal member; (j) when more than four continuous
diagonal members are present, any remaining ends of the continuous
diagonal members are secured to a first end of an extender member
wherein the extender member has a second end secured to at least
one outer rectangle members at a corner of the outer rectangle;
and, (k) vertically oriented connectors connected to the vertical
members and adapted to each be secured to a rod extending upwards
from a foundation or laterally stabilized wall or floor of the
building below the shear wall panel near each of the vertical
members wherein the vertically oriented connectors are located
adjacent to the first and third vertices.
2. The shear wall panel of claim 1 wherein the ends of the diagonal
members of the first, second, third and fourth vertices are secured
to one of the horizontal or vertical members at about the midpoint
of the one of the horizontal or vertical members.
3. The shear wall panel of claim 1 wherein the vertically oriented
connectors are wedge shaped blocks located above the first and
third vertices.
4. A shear wall panel for a building comprising, (I) outer
rectangle members comprising, a) a pair of spaced apart vertical
members having upper ends and lower ends; b) an upper horizontal
member extending between and secured to the upper ends of the
vertical members; and, c) a lower horizontal member extending
between and secured to the lower ends of the vertical members
wherein the outer rectangle members form an outer rectangle; and,
(II) inner polygon members comprising, d) at least four continuous
diagonal members secured together end to end to form an inner
polygon having at least a first, a second, a third and a fourth
vertex, wherein (e) the inner polygon is located inside of the
outer rectangle; (f) the ends of the diagonal members of the first
vertex are secured to one of the vertical members; (g) the ends of
the diagonal members of the second vertex are secured to the upper
horizontal member; (h) the ends of the diagonal members of the
third vertex are secured to the other vertical member; (i) the ends
of the diagonal members of the fourth vertex are secured to the
lower horizontal member; (j) when more than four continuous
diagonal members are present, any remaining ends of the continuous
diagonal members are secured to a first end of an extender member
wherein the extender member has a second end secured to at least
one outer rectangle members at a corner of the outer rectangle;
and, (k) rods connected to a foundation or laterally stabilized
wall or floor of the building below the shear wall panel extend
vertically through the shear wall panel near the vertical members
and are secured to the shear wall panel near the top of the shear
wall panel or to a solid structure adjacent and above the top of
the shear wall panel.
5. The shear wall panel of claim 4 wherein the ends of the diagonal
members of the first, second, third and fourth vertices are secured
to one of the horizontal or vertical members at about the midpoint
of the one of the horizontal or vertical members.
6. A shear wall panel for a building comprising, (I) outer
rectangle members comprising, a) a pair of spaced apart vertical
members having upper ends and lower ends; b) an upper horizontal
member extending between and secured to the upper ends of the
vertical members; and, c) a lower horizontal member extending
between and secured to the lower ends of the vertical members
wherein the outer rectangle members form an outer rectangle; and,
(II) inner polygon members comprising, d) four continuous diagonal
members secured together end to end to form an inner polygon having
at least a first, a second, a third and a fourth vertex, wherein
(e) the inner polygon is located inside of the outer rectangle; (f)
the ends of the diagonal members of the first vertex are secured to
one of the vertical members; (g) the ends of the diagonal members
of the second vertex are secured to the upper horizontal member;
(h) the ends of the diagonal members of the third vertex and are
secured to the other vertical member; (i) the ends of the diagonal
members of the fourth vertex are secured to the lower horizontal
member; and, (j) vertically oriented connectors connected to the
vertical members and adapted to each be secured to a rod extending
upwards from a foundation or laterally stabilized wall or floor of
the building below the shear wall panel near each of the vertical
members wherein the vertically oriented connectors are located
adjacent to the first and third vertices.
7. The shear wall panel of claim 4 wherein the ends of the diagonal
members of the first, second, third and fourth vertices are secured
to one of the horizontal or vertical members at about the midpoint
of the one of the horizontal or vertical members.
8. The shear wall panel of claim 4 wherein the vertically oriented
connectors are wedge shaped blocks located above the first and
third vertices.
9. A shear wall panel for a building comprising, (1) outer
rectangle members comprising, a) a pair of spaced apart vertical
members having upper ends and lower ends; b) an upper horizontal
member extending between and secured to the upper ends of the
vertical members; and, c) a lower horizontal member extending
between and secured to the lower ends of the vertical members
wherein the outer rectangle members form an outer rectangle; and,
(II) inner polygon members comprising, d) four continuous diagonal
members secured together end to end to form an inner polygon having
at least a first, a second, a third and a fourth vertex, wherein
(e) the inner polygon is located inside of the outer rectangle; (f)
the ends of the diagonal members of the first vertex are secured to
one of the vertical members; (g) the ends of the diagonal members
of the second vertex are secured to the upper horizontal member;
(h) the ends of the diagonal members of the third vertex are
secured to the other vertical member; (i) the ends of the diagonal
members of the fourth vertex are secured to the lower horizontal
member; (j) rods connected to a foundation or laterally stabilized
wall or floor of the building below the shear wall panel extend
vertically through the shear wall panel near the vertical members
and are secured to the shear wall panel near the top of the shear
wall panel or to a solid structure adjacent and above the top of
the shear wall panel.
10. The shear wall panel of claim 7 wherein the ends of the
diagonal members of the first, second, third and fourth vertices
are secured to one of the horizontal or vertical members at about
the midpoint of the one of the horizontal or vertical members.
11. A method of making a shear wall for a building for resisting
earthquake induced loads, comprising the steps of: (i) providing a
shear wall panel according to claim 1 adapted to resist earthquake
loads; (ii) placing the shear wall panel onto a foundation or
laterally stabilized wall or floor of the building; and, (iii)
bolting the vertical members of the shear wall panel to the
foundation or laterally stabilized wall or floor with bolts adapted
to resist uplift of the vertical members created in an
earthquake.
12. A method of attaching the top of a wooden shear wall panel to a
roof, floor or wall of the building above the shear wall panel
comprising the steps of, a) providing at least two tensile strap
connectors wherein the tensile strap connectors are metal straps
having a first portion and a second portion, the first portion
having teeth whose width is substantially parallel to a line
dividing the first portion from the second portion, the second
portion having holes without teeth; (b) pounding first portions of
the tensile strap connectors into the top corners of the shear wall
panel such that the second portions of the tensile strap connectors
extends upwards from the shear wall panel; (c) driving fasteners
through the holes of the second portion of the tensile strap
connectors and into the roof, floor or wall of the building above
the shear wall panel.
13. The method of claim 10 further comprising, (a) providing one or
more shear strap connectors wherein the shear strap connectors are
metal straps having a first portion and a second portion, the first
portion having teeth whose width is substantially perpendicular to
a line dividing the first portion from the second portion, the
second portion having holes without teeth; (b) pounding first
portions of the one or more shear strap connectors into the top of
the shear wall panel between the tensile strap connectors such that
the second portions of the one or more tensile strap connectors
extends upwards from the shear wall panel; (c) driving fasteners
through the holes of the second portions of the one or more shear
strap connectors and into the roof, floor or wall of the building
above the shear wall panel.
Description
[0001] This is a continuation-in-part of PCT Application No.
PCT/CA00/01221 filed by Thomas Leung on Oct. 13, 2000; a
continuation-in-part of U.S. patent application Ser. No. 09/419,934
filed by Thomas Leung on Oct. 18, 1999; and, a non-provisional of
U.S. provisional application filed by Thomas Leung on or about Apr.
13, 2001 entitled "Shear Wall Panel". All of the applications
mentioned above are incorporated herein by this reference to
them.
FIELD OF THE INVENTION
[0002] This invention relates to shear walls and, more
particularly, to a prefabricated shear wall panel for use in frame
construction.
BACKGROUND OF THE INVENTION
[0003] Shear walls or shear wall panels are used to resist lateral
forces in a structure created, for example, by wind loads applied
to the side of a structure or earthquakes. Conventional shear walls
typically fall into three categories: (a) braced frames, (b) moment
frames and (c) frames with structural sheathing.
[0004] In braced frames, a stud wall has braces which extend
diagonally from the a rim joist or plate at the top of the wall to
a rim joist, plate or foundation at the bottom of the wall. The
braces cross one or more of the studs and therefore requires cuts
in the studs to let the bracing into the wall or finish materials
which can accommodate the protruding bracing member. In order to
avoid cutting the studs significantly or to minimize how far the
brace protrudes from the wall, the braces are typically made of a
steel strip or rod or a thin wooden board. Since the bracing member
is longer than the wall studs, the slenderness of the bracing
member limits its compressive strength and so the bracing members
are installed in pairs slanting in opposite directions to provide a
tensile member to resist lateral forces in either direction. In
addition to these shortcomings, the braces typically occupy
significant lengths of the walls which are then unavailable for
windows.
[0005] In moment frames, various corners between studs and plates
or joists are reinforced, typically with triangular steel plates or
wooden knees. With the corners reinforced, lateral movement is
resisted by moment in the studs which must bend before one of their
ends can be displaced laterally while remaining vertical. This
method may be suitable for timber frame or large I-beam structures
in which the studs have large cross sections, but is inefficient
when applied to light framing using "2 by" lumber or light metal
channels. In these applications, the studs have limited moment
resistance and large numbers of stud to plate or joist connections
must be reinforced.
[0006] In frames with structural sheathing, plywood or oriented
strand board are nailed to the studs and any sills, headers etc.
used to frame openings. The sheathing panels are resistant to
lateral deformation. When properly attached to the wall, the
sheathing panels transfer this resistance to the wall primarily as
a shear force around the perimeter of the sheathing panel. To
resist this shear force, a concentrated nailing pattern is required
around the perimeter of the sheathing panel. Any openings for
windows require more intensive nailing and yet still weaken the
panel such that some building codes deem sections of the wall with
openings to have no lateral resistance. The process is time
consuming and heavily dependant on quality workmanship. Further, in
recent years it has been discovered that the tightly nailed
sheathing panels in combination with an interior vapour barrier
trap moisture within the wall which often leads to fungus growth
and premature failure of the wall.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a shear
wall panel. Various embodiments of the present invention are
suitable for light framing, particularly in wood. Various
embodiments of the present invention provide such a shear wall
panel that does not require structural sheathing or interior
vertical studs, that is suitable for pre-assembly in a factory, or
presents reduced interference with placing windows in the
structure.
[0008] The invention is directed at a shear wall panel for a
building comprising,
[0009] a) a pair of spaced apart vertical members having upper ends
and lower ends;
[0010] b) an upper horizontal member extending between and secured
to the upper ends of the vertical members;
[0011] c) a lower horizontal member extending between and secured
to the lower ends of the vertical members;
[0012] d) at least four diagonal members joined end to end in a
multi-segmented assembly having at least three vertices between a
first end and a second end,
[0013] wherein the multi-segmented assembly is located inside of
the members in a), b) and c) above; one of the at least three
vertices is secured to each of the members in a) and b) above; and,
the first end and second ends are secured to the lower horizontal
member.
[0014] The lower horizontal member is shear connected to a
foundation or laterally stabilized wall or floor below the shear
wall panel. The shear connection may include vertically oriented
connectors connected to the lower ends of the vertical members to
resist upward tensile forces on the vertical members. In an
embodiment, these vertically oriented connectors are wooden thrust
blocks, preferably oriented so that the grain of the wood is
vertical with a hole through the thrust blocks to accept a rod
extending upwards from the foundation or a laterally stabilized
wall or floor of the building below the shear wall panel.
Alternatively or additionally, the shear wall panel may be
connected to a foundation or laterally stabilized wall or floor of
the building below the shear wall panel by tensile rods connected
to a foundation or laterally stabilized wall or floor of the
building below the shear wall panel. The tensile rods extend
vertically through the shear wall panel near the vertical members
and are secured to the shear wall panel near the top of the shear
wall panel or near a solid structure adjacent the top of the shear
wall panel.
[0015] Upper connectors transfer shear and tensile forces from a
roof, floor or wall of the building above the upper horizontal
member to the shear panel. In an embodiment, the upper shear
connectors comprise metal straps, a first portion of which have
teeth bent out of the metal strap, a second portion of which have
holes for nailing through the metal strap into the roof, floor or
wall of the building. Tensile metal straps have teeth whose width
is parallel to a line dividing the first portion of the metal strap
from the second portion of the metal strap. Shear metal straps have
teeth whose width is perpendicular to a line dividing the first
portion of the metal strap from the second portion of the metal
strap.
[0016] The invention is further directed at a shear wall panel as
described above having wooden members attached to each other with
toothed plates pounded through the members. The upper horizontal
member preferably has a notch or extends beyond a vertical member
so that the shear wall panel may be connected to the upper plates
or upper horizontal members of adjacent wall panels.
[0017] The invention is further directed at a metal strap for
connecting substantially abutting wooden members comprising, (a) a
first portion of the metal strap having teeth bent out of the metal
strap; and, (b) a second portion of the metal strap having holes
for nailing through the metal strap. An embodiment has teeth whose
width is parallel to a line dividing the first portion of the metal
strap from the second portion of the metal strap. Another
embodiment has teeth whose width is perpendicular to a line
dividing the first portion of the metal strap from the second
portion of the metal strap.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Embodiments of the present invention will be described with
reference to the following drawings:
[0019] FIG. 1 is a perspective view of a shear wall panel according
to an embodiment of the invention.
[0020] FIG. 2 is a perspective view of a portion of the shear wall
panel of FIG. 1, the portion including a vertically oriented
connecter according to an embodiment of the invention.
[0021] FIG. 3 is a perspective view of a shear wall panel according
to another embodiment of the invention.
[0022] FIG. 4 is a perspective view of a shear wall panel according
to another embodiment of the invention.
[0023] FIG. 5 is a perspective view of another embodiment of the
invention showing metal plate connectors.
[0024] FIG. 6 is a perspective view of a shear connector according
to an embodiment of the invention.
[0025] FIG. 7 is a perspective view of a tensile connector
according to an embodiment of the invention.
[0026] FIG. 8 is a perspective view of shear wall panels according
to an embodiment of the invention in use in a first and second
floor of a building.
[0027] FIG. 9 is a perspective view of the shear wall panel of FIG.
1 with alternative vertically oriented connectors.
[0028] FIG. 10 is a perspective view of the shear wall panels of
FIG. 8 with alternative vertically oriented connectors.
[0029] FIG. 11 is an elevation view of a shear wall panel according
to another embodiment of the invention.
[0030] FIG. 12 is a perspective view of a shear wall panel
according to another embodiment of the invention.
[0031] FIG. 13 is a perspective view of multiple shear wall panels
according to an embodiment of the invention in use in a first floor
of a building.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] Referring now to FIG. 1, a shear wall panel 10 for a
building is shown. The shear wall panel 10 has a pair of spaced
apart vertical members 12 having upper ends 14 and lower ends 16.
An upper horizontal member 18 extends between and is secured to the
upper ends 14 of the vertical members 12. A lower horizontal member
20 extends between and is secured to the lower ends 16 of the
vertical members 12. Four diagonal members 22 are joined end to end
to create a multi-segmented assembly 24 inside of the rectangle
formed by the vertical members 12, upper horizontal member 18 and
lower horizontal member 20. The multi-segmented assembly 24 has
three vertices 26, each attached to one of the vertical members 12
or the upper horizontal member 18, preferably at their midpoint.
The multi-segmented assembly 24 also has first and second ends 27
attached to the lower horizontal member 20. In the embodiment shown
in FIG. 1, the first and second ends 27 are joined to each other so
that the multi-segmented assembly 24 is a polygon. In such cases,
the first and second ends 27 are preferably joined to the lower
horizontal member 20 at its midpoint. The multi-segmented assembly,
with the assistance of the vertical members 12, upper horizontal
member 18 and lower horizontal member 20, preferably supports shear
and vertical forces against the shear wall panel 10 substantially
without the assistance of structural cladding or sheathing or
continuous interior vertical studs. Studs may be added to support
sheathing or other structures, and insulation and sheathing will be
added to finish the wall, but these components are not relied on to
assist in withstanding loads against the shear wall panel.
[0033] The shear wall panel 10 is adapted for use in a light timber
frame. The vertical members 12, upper horizontal member 18, lower
horizontal member 20 and diagonal members 22 (collectively referred
to as members 28) are preferably made of wood. More preferably the
members 28 are made of wood of the same width as studs in other
parts of the light frame so that the shear wall panel 10 will be of
the same width as the remainder of the wall. Further preferably,
the members 28 are made of "2 by" nominal dimensional lumber which
is usually more economical than using custom sized or larger
dimension lumber. The "2 by" lumber may be doubled or tripled as
required to withstand the design forces on the shear wall panel 10.
For example, in shear wall panels 10 of up to 8 feet in width, the
members 28 are typically made of doubled "2 by" lumber.
[0034] Although the members 28 may be nailed together, they are
preferably connected with metal toothed plates 30 pressed or
pounded through the members 28 wherever an end of one member 28 is
adjacent another member 28. As in conventional stud framing, the
upper horizontal member 18 and lower horizontal 20 extend to cover
the overlap rather the vertical members 12. It is preferred if the
members 28 directly abut each other, but the toothed plates 30
advantageously allow for small spaces between members 28 to be
joined together such that moderately imprecise joinery can be
tolerated. The shear wall panel 10 is manufactured by cutting and
placing the members 28 on a table or work surface, positioned as
described above, and then pounding or pressing the toothed plates
30 into the members 28 in the places described above and shown in
the Figures. The configuration of the shear wall panel 10 allows
all of the metal plates 30 to be pressed or pounded from outside
the perimeter of the shear wall panel 10 avoiding the need to
create sub-assemblies or alternate between cutting and placing
operations and pressing or pounding operations.
[0035] Referring still to FIG. 1, the shear wall panel 10 is shown
attached to the foundation 32 of a building. The shear wall panel
10 may also be placed on top of a floor deck on top of the
foundation 32 with suitable modifications to the description below.
When a lateral force F, as produced by an earthquake or high wind
such as a tornado or hurricane for example, is applied to the shear
wall panel 10, it is resisted internally by compression stresses c
and tensile stresses t and externally by reaction force R exerted
by the foundation 32. Depending on the direction of lateral force
F, either of the vertical members 12 can be placed in tension and
tend to lift away from the foundation 32. To counteract this
tendency, vertically oriented connections 34 adjacent the
intersections between the lower horizontal member 20 and the lower
ends 16 of the vertical members 12 connect the vertical members 12
to the foundation 32. Referring to FIGS. 1 or 2, the vertically
oriented connection 34 is made of an anchor bolt 36 cast in the
foundation 32 which passes through the lower horizontal member 20
and a vertically oriented connector 38, both of which have holes or
spaces to admit the anchor bolt 36. A washer 42 is placed over the
anchor bolt 36 followed by a nut 40 which is threaded onto the
anchor bolt 36 to complete the connection to the foundation 32.
[0036] The vertically oriented connector 38 may be a thrust block
made of wood preferably oriented so that the grain of the wood is
substantially vertical to take advantage of the increased
compressive strength of the wood parallel to the grain. Such a
vertically oriented connector 38 is attached by a metal plate 30 to
the lower end 16 of the vertical member 12. Preferably, the metal
plate 30 covers substantially all of the thrust block to confine
the thrust blocks deformation and increase its compressive
strength. Further preferably, the same metal plate 30 also attaches
to the lower horizontal member 20 to provide a secure connection
between the vertical member 12 and the lower horizontal member
20.
[0037] Vertically oriented connector 38 made of wood as shown in
FIGS. 1 and 2 are easily and inexpensively included in the shear
wall panel 10 during manufacture. The thrust blocks shown in FIGS.
1 and 2 in particular are made of two blocks of "2 by" material
with a space between them to accept the anchor bolts 36 thus
avoiding the need to drill a hole through the thrust blocks while
allowing the anchor bolt 36 to be near the vertical members 12 for
low eccentricity. In narrow shear wall panels 10 (typically less
than eight feet wide) under some loads, however, a wooden
vertically oriented connector 38 may need to be larger than shown
and have a plurality of holes for a plurality of anchor bolts 36 to
provide sufficient strength. In these cases, suitable commercially
available vertically oriented connectors 38 are preferred.
[0038] Additional foundation connections 44 are made of anchor
bolts 36 cast in the foundation 32 which pass through the lower
horizontal member 20 and are held in place by a nut 40 and washer
42. Where the shear wall panel 10 is attached to a floor attached
to the foundation 32, the vertically oriented connections 34 and
foundation connections 44 pass through the floor. In combination,
the foundation connections 44, and vertically oriented connections
34 shear connect the shear wall panel 10, meaning that they
transmit the reaction force R to the shear wall panel 10 and resist
the tensile forces on the members 28 connected to the lower
horizontal member 20. For the purposes of calculations, however, it
is assumed that the vertically oriented connections 34 resist all
of the tensile forces on the vertical members 12. Where the
multi-segmented assembly 24 is a polygon, tensile forces on one
diagonal member 22 are counteracted by adjoining diagonal members
22. In these cases, special vertically oriented connections 34 are
typically not required where the diagonal members 22 attach to the
lower horizontal member 20.
[0039] Depending on the exterior and interior wall coverings or
fixtures, nailers 46 may be nailed into the shear wall panel 10 as
required. Similarly, if a window is required in the shear wall
panel 10, headers 48 and sills 50 can be nailed inside the shear
wall panel 10. If these requirements are known early enough, the
nailers 46, upper sills 48 and lower sills 50 can also be attached
with metal plates when the shear wall panel 10 is assembled. In
shear wall panels 10 of sufficient width, the open space in the
centre of the shear wall panel 10 provides considerable
architectural freedom for placing windows within a shear wall.
[0040] Despite the large opening in its centre, the shear wall
panel 10 is surprisingly effective in supporting vertical loads on
the wall. Vertical load is first supported by the upper horizontal
member 18 and transferred to the vertical members 12 and to the
vertex 26 of multi-segmented assembly 24 abutting the upper
horizontal member 18. The upper diagonal members 22 further
transmit vertical load to the lower portions of the vertical
members 12. The lower diagonal members 22 counteract the lateral
component of the force transferred by the upper diagonal members 22
so that the vertical members 12 are not bent laterally. Because the
multi-segmented assembly 24 can support a vertical load, a large
opening is provided without the need to design the upper horizontal
member 18 as a conventional header.
[0041] Referring now to FIGS. 3, 4 and 12, alternate embodiments of
the shear wall panel 10 are shown which provide even greater space
for a window opening and, in the case of FIG. 4, for a door
opening. In these Figures, the multi-segmented assembly 24 is
formed of additional diagonal members 22 creating additional
vertices 26. These additional vertices 26 are connected by
extenders 52 to corners formed by the intersection of the vertical
members 12 with either the upper horizontal member 18 or the lower
horizontal member 20. In other respects, the shear wall panels in
FIGS. 3, 4 and 12 are similar to the shear wall panel 10 in FIG. 1
although the distribution of internal forces differs slightly. In
FIG. 4, an additional difference is that the first and second ends
27 of the multi-segmented assembly 24 are not joined to each other
to make a polygon. In this case, shear forces on the shear wall
panel 10 creates an upwards force at one of the first or second
ends 27 that is not resisted by the other. To counter the upwards
force, foundation connections 44 are placed adjacent the first and
second ends 27. Depending on the load, however, additional
vertically oriented connections 34 may be required in place of the
foundation connections 44. To install a very large window, a shear
wall panel can be used which repeats the structure of the upper
half of FIG. 3 as the lower half of the shear wall panel as shown
in FIG. 12. In this case, the two lowest diagonal members 22 of
FIG. 3 are each replaced by two diagonal members 22 connected by
extenders 52 at the newly created vertices to corners between the
vertical members 12 and the lower horizontal member 20.
[0042] Referring now to FIG. 5, a shear wall panel 10 is shown
attached to a superior structure 54 above it. The superior
structure 54 could be, for example, a roof, a header over a large
opening such as a garage door or the wall or floor of a second
story. In a high wind, such as a tornado or hurricane, or during an
earthquake, for example, the superior structure 54 may be subject
to a lateral force applied above the upper horizontal member 18.
Accordingly, moment and shear forces will be created between the
superior structure 54 and the upper horizontal member 18 of the
shear wall panel 10. In other cases, such as where the superior
structure 54 is a header over a large opening, similar moment and
shear forces are created when a lateral force is applied anywhere
to the structure. These forces are resisted by attaching the
superior structure 54 and the upper horizontal member 18 together,
preferably with strap connectors 56.
[0043] Referring to FIGS. 5, 6 and 7, the strap connectors 56 are
made of metal straps having a first portion 58 with teeth 60 bent
out of the metal strap and a second portion 62 with holes 64 for
nailing through the metal strap into the roof, floor or wall of the
building. In FIG. 7, a tensile metal strap 66 is shown, having
teeth 60 whose width is parallel to a line dividing the first
portion 58 of the strap connector 56 from the second portion 62 of
the strap connector 56. As shown in FIG. 5, the first portion 58 of
the tensile metal strap 66 is attached to the upper ends 14 of the
vertical members 12 and the second portion 62 of the tensile metal
strap 66 extends upwards from the shear wall panel 10 to be nailed
to the superior structure 54. In FIG. 6, a shear metal strap 68 is
shown having teeth 60 whose width is perpendicular to a line
dividing the first portion 58 of the strap connector 56 from the
second portion 62 of the strap connector 56. The first portion 58
of the shear metal strap 68 is attached to the upper horizontal
member 18 and the second portion 62 of the shear metal strap 68
extends upwards from the shear wall panel 10 to be nailed to the
superior structure 54.
[0044] Now referring to FIG. 8, a shear wall panel 10 on a first
floor is attached to a second floor 70 of a superior structure 54.
An upper floor shear wall panel 110 is located above the shear wall
panel 10 below, preferably such that their vertical members 12 are
directly one above the other. The tensile metal straps 66 are not
used, but rather second floor vertically oriented connectors 134
are used. The second floor vertically oriented connectors 134 are
analogous to the vertically oriented connections 34 except that the
foundation bolt 36 is replaced by a through bolt 136 threaded on
both ends to receive nuts 40 and upper thrust blocks 138 are
provided in the upper corners of the shear wall panel 10. The lower
horizontal member 20 of the upper floor shear wall panel 110 is
shear connected to the laterally stabilized floor wall or floor
below by the second floor vertically oriented connectors 134 and by
shear metal straps 68. The first portion 58 of the shear metal
straps 68 is attached to the lower horizontal member 20 and their
second portion 62 extends downwards from the upper floor shear wall
panel 110 to be nailed to the second floor 70 or the shear wall
panel 10 below. In this way, shear wall panels 10 can be provided
for multistorey buildings efficiently at least up to 4 stories
high. Where the foundation 32 is wood or separated from the shear
wall panel 10 by a wooden floor deck, shear metal straps 68 (shown
in dashed lines) may be used with or in place of foundation
connections 44.
[0045] To connect the shear wall panel 10 to an adjoining wall
panel, the upper-most board of the upper horizontal member 18 may
be extended beyond the vertical members 12. This extended board
laps over the top plate of an adjacent wall panel forming part of a
conventional double top plate. Alternatively, as shown in FIG. 8,
the entire upper horizontal member 18 may be extended beyond the
vertical members 12 in which case the studs of an adjacent wall
panel are attached directly to the extended upper horizontal member
18. Further alternatively, as shown in FIG. 13, the shear wall
panel 10A can also be integrated with one or more other wall panels
610 (which may or may not be a shear wall panel 10B) by placing one
or more plates 600 over the upper horizontal member 18 of the shear
wall panel 10 and extending the one or more plates 600 to the other
panels 610. This involves more material than the methods above but
avoids the need for extended upper horizontal members 18 which may
be an advantage if the shear wall panels 10 are assembled off
site.
[0046] Referring now to FIGS. 5, 9 and 10, a tensile rod connection
100 is shown (in dashed lines in FIG. 5) between a shear wall panel
10, 110 and a foundation 32 (FIGS. 1 and 5) or laterally stabilized
wall 10 or floor 70 (FIG. 8) of a building below the shear wall
panel. This alternative connection may be used in addition to or in
place of the previously described vertically oriented connections
34, 134. As for the vertically oriented connections 34, 134,
foundation connections 44 and shear metal straps 68 may be used in
addition to the tensile rod connection 100 but are generally
assumed not to resist any tensile forces on the vertical members
12.
[0047] The tensile rod connection 100 comprises a tensile rod 102,
typically made of steel and threaded at least at its ends. The
tensile rods 102 extend vertically through the shear wall panel 10,
110 near the vertical members 12. The tensile rods 102 are secured
near the top of the shear wall panel 10, 110 or near a solid
structure adjacent the top of the shear wall panel 10, 110 such as
a superior structure 54 (FIG. 5), floor 70 or upper floor shear
wall panel 110 (FIG. 8). The tensile rods 102 are secured to the
foundation 32 (FIGS. 1 and 5) or a laterally stabilized wall 10 or
floor 70 (FIG. 8) of a building below the shear wall panel,
preferably by threaded couplers 104 connected to anchor bolts 36 in
a foundation 32 or to a threaded rod 102 from a lower floor of the
building which is in turn connected to the foundation 32. The
tensile rods 102 are preferably secured to the shear wall panel 10,
110 by nuts 106 screwed down over washers 108 to put the tensile
rods 102 slightly in tension. The nuts 106 preferably abut (a) the
top of the upper horizontal member 18 of a shear wall panel 10 (as
in FIG. 1) where no significant shear or moment forces are expected
between a superior structure 54 and the upper horizontal member 18,
(b) the top of the superior structure 54 (as in FIG. 5) where
significant shear or moment forces are expected between a superior
structure 54 and the upper horizontal member 18 and (c) the top of
the lower horizontal member 20 of an upper floor shear wall panel
110 (as in FIG. 8) when there is one. Vertically oriented
connectors 38 are described earlier are preferably used below each
nut 106 or below upper horizontal members 18 where a nut will be
used above the upper horizontal members.
[0048] Referring now to FIG. 11, another shear wall panel 510 is
shown. The shear wall panel 510 is similar to the preceding panels,
and may similarly be used in assemblies of pluralities of panels as
described above. The members 28 are made of doubled "2 by" nominal
dimensional lumber, the width depending on the anticipated loading,
although other materials might also be used. The members 28 are
preferably connected with metal toothed plates 30 pressed or
pounded into the members 28 wherever an end of one member 28 is
adjacent another member 28. The shear wall panel 510 is
manufactured as has been described above.
[0049] The shear wall panel 510 is shown attached to the foundation
32 of a building or a laterally stabilized floor or wall below. The
shear wall panel 510 may also be placed on top of a floor deck on
top of the foundation 32 with suitable modifications to the
description below. The shear wall panel 510 is connected to the
foundation 32 so as to resist a lateral force applied to the shear
wall panel 510 with vertically oriented connections 34 which
connect the vertical members 12 to the foundation 32. The
vertically oriented connection 34 is made of an anchor bolt 36 cast
in the foundation 32 which passes through the lower horizontal
member 20 and is connected to a tensile rod connection 100. The
tensile rod connection is as described in FIG. 9 except that the
tensile rod 102 extends vertically through the shear wall panel 510
only to vertically oriented connectors 38 adjacent the vertexes 26
adjacent the vertical members 12 as shown in FIG. 11. To attach a
second story or roof deck above the shear wall panel 510 of FIG.
11, more connectors 104 would be attached above the vertically
oriented connector 538 so that more tensile rods 102 can extend
upwards to the roof deck or to the vertically oriented connectors
of an upper floor shear wall panel 10, 110, 510. The tensile rods
102 are preferably secured to the shear wall panel 510 by nuts 106
screwed down over washers 108 to put the tensile rods 102 slightly
in tension. The washers 108 abut a vertically oriented connector
538 adjacent the intersections between the vertical members 12 and
the diagonals 22. The inventor has observed that this location for
the vertically oriented connector 538 provides a good degree of
ductile elongation of the bolt 36 in earthquake loads and avoids
stress cause by the eccentricity of the bolt 36 on the horizontal
members 18, 20.
[0050] The vertically oriented connector 538 may be a wedge-shaped
thrust block made of wood preferably oriented so that the grain of
the wood is substantially vertical to take advantage of the
increased compressive strength of the wood parallel to the grain.
The vertically oriented connector 538 is attached by a metal plate
30 which preferably covers substantially all of the thrust block.
The vertically oriented connector 38 may be made of two blocks of
"2 by" material as described above or by drilling a hole in a solid
block of wood. Commercial available (typically metal) vertically
oriented connectors 538 might also be used at the same location.
Additional foundation connections 44 may be used as described above
if required, although they typically are not in a 4 foot wide panel
as shown in FIG. 11.
[0051] The shear wall panel 510 may be attached to a superior
structure 54 above it as described in FIG. 5, for example, with
strap connectors as described in FIGS. 5-7. The shear wall panel
510 may also be attached to a shear wall panel 510 on a second
floor in a manner analogous to that shown in FIG. 8 but with the
vertically oriented connectors 38 attached to structure below each
shear wall panel 510 being located as shown in FIG. 11. The shear
wall panel 510 may be connected to adjoining wall panels 510 as
described for other panels above. The vertically oriented connector
34 shown in FIG. 11 may be used in other embodiments of the shear
wall panel, for example the embodiments of FIGS. 3, 4, 5 and 12, as
shown, for example, in FIG. 12.
[0052] It is to be understood that what has been described are
preferred embodiments of the invention. The invention, however, may
be altered and applied to alternative embodiments within the spirit
of the invention as described above, and the scope of the claims
set out below. In particular, the embodiments described above are
suitable for use in light timber framing. It will be apparent to
those skilled in the art, however, that the some aspects of the
invention may be applied to other structural systems, particularly
light gauge metal, engineered steel and timber framing.
* * * * *