Patent Publication Number: US-6668508-B2

Title: Shear panel assembly

Description:
FIELD OF THE INVENTION 
     The present invention relates to a shear panel assembly for reducing the risk of damage to buildings as a result of lateral forces applied to the building. 
     BACKGROUND OF THE INVENTION 
     Typical building frame construction includes a frame anchored to the foundation and a roof assembly supported by the frame. The frame typically includes a plurality of vertically oriented studs attached between upper and lower plates. Inner and outer siding materials are attached to the frame. In a typical residential building, framing is accomplished by employing lumber and wood products. 
     Lateral forces applied to the wall, which may occur as a result of high winds or earthquakes, can cause the upper section of the wall to move relative to the lower section. This movement is commonly assumed to be in a direction parallel to and in the plane of the wall. Excess movement of the upper section of the wall relative to the anchored lower section can result in damage to the frame that may be catastrophic. 
     A variety of designs have been developed for resisting lateral forces. One method for providing lateral stiffening includes attaching a sheet material such as oriented strand board (OSB) or plywood to the frame exterior such that it spans across several studs and is attached to the upper and lower plates. A shear force applied to the wall in a direction parallel to and in the plane of the wall is therefore transmitted through the sheet material to a bottom plate and the foundation of the structure, thereby reducing the tendency of the upper portion of the wall to move relative to the lower portion of the wall. To enhance the strength of the shear panel, the bottom plate of the shear panel is typically fastened to the foundation by a plurality of anchor bolts or tiedowns to better resist shear forces. 
     Shear panels that incorporate a face-mounted shear membrane must include a reduced frame member depth in order to fit within the dimensions of common or standard framing elements. The resulting panels can exhibit reduced strength, reduced resistance to lateral forces and a reduced moment of inertia. In addition, shear panels that incorporate a face-mounted shear membrane are prone to warping and torque when lateral force is applied. In particular, the application of repetitive lateral motion, such as that experienced during cyclic shear testing of prefabricated shear panels, reveals that such face-mounted membranes tend to warp and twist, leading to failure of the shear panel. Even shear panels that incorporate the shear membrane in a sandwich structure exhibit failure upon repetitive lateral movement. 
     Also problematic, when such panels do fail, is that they tend to exhibit a brittle failure profile, that is, the panel provides resistance to lateral movement until a failure point is reached, at which point the shear panel fails rapidly and catastrophically, with the loss of a substantial amount of structural integrity. 
     What is needed is a shear panel assembly with improved performance to cyclic shear loading and improved ductility so that the panel will withstand greater cyclic lateral movement, and that upon failure, fail gradually rather than catastrophically. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a shear panel assembly that includes a frame and a panel diaphragm, where the frame comprises an upper horizontal frame member, a first upright, a second upright, and a lower horizontal frame member. The frame includes a panel diaphragm edge receiving member formed on an inner peripheral face of the frame, within a depth of the frame. The panel diaphragm includes a peripheral edge that is connected to the frame at the panel diaphragm edge receiving member. 
     Another form the invention takes includes a shear panel that includes a frame, where the frame comprises an upper horizontal frame member, a first upright that pivotally interconnects a first end of the upper horizontal frame member, a second upright that pivotally interconnects a second end of the upper horizontal frame member, a lower horizontal frame member that pivotally interconnects a lower end of the first upright and a lower end of the second upright, and a panel diaphragm that is connected to the frame. 
     Yet another aspect of the invention includes a shear panel hold-down that comprises a base and at least one pivotable upright engagement tab attached to and extending from the base. 
     Additional objects, advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     The advantages of the present invention will be understood more readily after a consideration of the drawings and the Detailed Description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a representative assembled and installed perspective view of a shear panel assembly according to the present invention. 
     FIG. 2 is a representative assembled front view of a shear panel assembly according to the present invention. 
     FIG. 3 is a representative exploded perspective view of a shear panel assembly according to the present invention. 
     FIG. 4 is a representative front upper corner detail of a shear panel assembly according to the present invention. 
     FIG. 5 is a representative front lower corner detail of a shear panel assembly according to the present invention. 
     FIG. 6 is a representative top sectional view of a shear panel assembly according to the present invention. 
     FIG. 7 is a representative vertical sectional view of a shear panel assembly according to the present invention. 
     FIG. 8 is a representative vertical sectional view of a shear panel assembly according to the present invention. 
     FIG. 9 is a representative assembled front view of a shear panel assembly including two panel diaphragms and an intermittent upright according to the present invention. 
     FIG. 10 is a front view of a shear panel hold-down according to the present invention. 
     FIG. 11 is a first side view of a shear panel hold-down according to the present invention. 
     FIG. 12 is a rear view of a shear panel hold-down according to the present invention. 
     FIG. 13 is a second side view of a shear panel hold-down according to the present invention. 
     FIG. 14 is a front view of a shear panel hold-down according to the present invention. 
     FIG. 15 is a side view of a shear panel hold-down according to the present invention. 
     FIG. 16 is an isometric view of an installation jig according to the present invention. 
     FIG. 17 is a partial front view of a shear panel assembly that includes a telescoping installation jig according to the present invention. 
    
    
     DETAILED DESCRIPTION AND BEST MODE OF THE INVENTION 
     The present invention is directed to a shear panel assembly comprising a frame and a panel diaphragm connected to the frame. The shear panel assembly may include one or more shear panel hold-downs, or incorporate the panel diaphragm within an inner periphery of the frame. The shear panel frame includes first and second uprights, and upper and lower horizontal frame members that interconnect the first and second uprights. The frame interconnections may incorporate pivotal connections. 
     Typically, the panel diaphragm is secured to the first and second uprights and the upper and lower horizontals within the stud depth, i.e. within the depth of the shear panel frame members. The panel diaphragm is secured within the frame, preferably, inserting the peripheral edges of the panel diaphragm into an edge receiving member formed in, attached to or otherwise comprising in part the frame. In one preferred embodiment of the invention, the edge receiving member includes a groove or gap formed on the inner faces of the first and second uprights and the upper and lower horizontals. An edge receiving member may also include any frame configuration which results in a recess or channel, with or without a bottom, such as a gap formed between two sandwiched structural members, the resulting configuration sized and configured to accept a peripheral edge of a panel diaphragm. An edge receiving member may be formed as a result of the assembled configuration of sub-frame members, or in the alternative, it may be formed as a result of a cutting operation, such as sawing or routing, on one or more sub-frame members. In the preferred embodiment of the invention, the edge receiving members are formed in the first and second uprights by sawing or routing a groove on the inner faces of each of the first and second uprights. 
     In one embodiment of the invention, the shear panel assembly may include a center or intermittent upright connected to the upper and lower horizontals. The intermittent upright includes an edge receiving member formed on both side faces for engagement with a side peripheral edge of the panel diaphragm. 
     Placing the shear panel diaphragm within the inner periphery of the shear panel frame results in a shear panel assembly that has the advantage of not decreasing the out-of-plane stud depth. Additionally, a symmetric placement of the panel diaphragm within the depth of the frame promotes ductility and consistency of performance under load. Prying forces are reduced and secondary stresses that may be associated with asymmetrical configurations, such as in those situations wherein sheeting is nailed to the exterior surface of a stud wall, are minimized. 
     The combination of an edge receiving member located on the first and second uprights along a centerline of the inner faces of the first and second uprights and the panel diaphragm secured to the first and second uprights within an edge receiving member by cross nailing may improve shear panel performance. When a lateral force is applied to the shear panel, the first and second uprights are alternately placed in compression and tension. Forces are transferred through the panel diaphragm through the cross nailed edges to the first and second uprights. Cross nailing the side peripheral edges at the centerline of the first and second uprights within a groove results in improved strength at nailed connections and a reduced tendency to pull through, a condition wherein the head of the nail pulls through a secured component. The centerline location and attachment of the panel diaphragm to the first and second uprights results in an ability to use common outside or nominal dimensions for the frame members. This configuration results in optimal performance for the structural member and an increased moment of inertia compared to designs employing frame members having reduced dimensions. In addition, the centerline location and attachment of the panel diaphragm to the first and second uprights results in reduced probability of failure due to out-of-plane buckling forces. 
     The shear panel assembly may incorporate pivotal interconnections between the uprights and upper and lower horizontal frame members. Even shear panel assemblies that incorporate face-mounted shear panel diaphragms exhibit advantageous properties when they also incorporate pivotal connections. Such shear panel assemblies resist brittle failure, as even when the conventional fasteners securing the shear panel frame and shear panel diaphragm are stressed to failure, such shear panel assemblies retain ductility, and tend to flex in response to lateral stress, rather than fail catastrophically. 
     Shear panel assemblies that include symmetric placement of the panel diaphragm with the inner periphery of the shear panel frame, as well as pivotally interconnected frame members, exhibit substantially increased resistance to lateral stress and angular displacement without catastrophic failure. 
     The pair of upright frame members and the upper and lower horizontals may be formed of solid or engineered wood products. “Engineered wood products” as used herein refers generally to wood products formed of wood fibers of various configurations, bonded by adhesives and cured or treated to form a dimensional member. Engineered wood products may include, but are not limited to, oriented strand board (OSB), oriented strand lumber (OSL), laminated strand lumber (LSL), laminated veneer lumber (LVL), glued laminated timber (Glu-Lam), and parallel strand lumber (PSL). Advantages found in the use of engineered wood products include dimensional stability, uniformity of material and a greater predictability and repeatability of performance. For example, a laminated strand lumber (LSL) sold by TrusJoist® under the trademark TimberStrand® may be employed for the frame components. This material selection results in a significant advantage particularly to the extent that members formed of laminated strand material are essentially free of growth irregularities or structural deformation associated with twisting and the like. Additionally, the selection of LSL permits relatively higher nailing density patterns or clusters in critical areas, for instance along the panel diaphragm edges and the panel diaphragm centerline top edge. The panel diaphragm is formed, preferably, from oriented strand board (OSB) or other suitable sheet material. 
     The shear panel assembly typically includes a shear panel hold-down. The hold-down includes a base having at least one upright frame member engagement tab attached and extending from the base for attachment to an upright frame member. The base is typically configured to be attached to a lower horizontal frame member. 
     In one embodiment, the upright frame member engagement tab is attached to the base along a line substantially bisecting the width of the base and lying on a plane parallel to the plane of the shear panel. This embodiment of the shear panel hold-down allows attachment to an upright frame member along a vertical line in the plane of the panel diaphragm. In another embodiment, the hold-down includes two upright engagement tabs spaced appropriately to either accommodate an upright frame member between the tabs, or to fit into slots cut into the upright frame member. The upright frame member engagement tab may be formed of weldable steels or other alloys or in the alternative may be cast from iron or other alloys. 
     The base of the hold-down may be a tubular base that is formed of a section of standard dimensional steel tubing having a rectangular or square cross-section. In the alternative, the base may be cast from iron or other alloys. Instead of being formed from steel tubing, the base may be substantially U-shaped in cross-section. 
     In one embodiment, the upright frame member engagement tab is pivotally attached to the base so as to permit angular movement between the tubular base and an attached upright frame member to which the engagement tab is attached. 
     Referring now to FIGS. 1 through 3, shear panel assembly  10  includes shear panel  11  and hold-down  40 . Shear panel  11  includes panel diaphragm  12  that is secured within frame  13 . FIG. 1 shows shear panel  11  installed at a corner of framed wall section W employing anchor bolts  47  cast in foundation F and threadedly engaging hold-down  40 . 
     As shown in FIGS. 2 and 3, shear panel assembly  10  includes shear panel  11  and hold-down  40  including anchor bolt  47 . Shear panel  11  includes panel diaphragm  12  that is secured within frame  13 . Frame  13  includes first upright  20 , second upright  21  and upper horizontal frame member  24  and lower horizontal frame member  27  interconnecting first upright  20  and second upright  21 . 
     Referring to FIG. 3, frame  13  is configured having an edge receiving member formed on the inner periphery of frame  13 . More particularly, first upright  20  and second upright  21  are formed having groove  31 A, shown in FIG. 3, and groove  31  B, shown in FIG.  6 . In addition, the structure resulting from the assembly of first upper horizontal element  25  and second upper horizontal element  26  and first lower horizontal element  28 , second lower horizontal element  29  provides an edge receiving member in the form of a gap between these parts as further described below. 
     Upper horizontal  24  as shown comprises a composite construction having first upper horizontal element  25  and second upper horizontal element  26 . In the embodiment of the invention shown, first upright  20  and second upright  21  are formed having milled upper ends forming tongues  51  and  52 . Similarly, first upper horizontal element  25  and second upper horizontal element  26  are formed having milled ends such that first upright  20 , second upright  21 , first upper horizontal element  25  and second upper horizontal element  26  may be joined employing a lap joint. As seen in FIG. 6, upon assembly, first upper horizontal element  25  and second upper horizontal element  26  provide an edge receiving member, groove  31 C along an inner face of upper horizontal  24  between first upper horizontal element  25  and second upper horizontal element  26 . 
     Lower horizontal  27  also includes a composite construction having first lower horizontal element  28 , second lower horizontal element  29  and sill plate  30 . First lower horizontal element  28  and second lower horizontal element  29  are connected to sill plate  30  in such a manner that the resulting assembly provides an edge receiving member, groove  31  D, (shown in FIG.  8 ), along an inner face of lower horizontal  27  between first lower horizontal element  28 , second lower horizontal element  29  upon assembly. 
     Panel diaphragm  12  includes a continuous peripheral edge shown as top peripheral edge  14 A, bottom peripheral edge  14 B, first side peripheral edge  14 C and second side peripheral edge  14 D. Panel diaphragm  12  also include includes first upper cope  15 A, second upper cope  15 B, first lower cope  16 A and second lower cope  16 B. As shown in FIGS. 2 and 3 panel diaphragm  12  is secured within frame  13  employing several distinct nailing patterns. Side peripheral nails  39 A secure first side peripheral edge  14 C and second side peripheral edge  14 D in groove  31 A, shown in FIG. 3, and groove  31 B, shown in FIG. 6 respectively. Upper nails  39 C secure top peripheral edge  14 A between first upper horizontal element  25  and second upper horizontal element  26 . Upper nails  39 C are located in a concentration about a centerline of panel diaphragm  12  that promotes ductility in the assembly as further discussed below. Lower nails  39 D secure bottom peripheral edge  14 B between first lower horizontal element  28  and second lower horizontal element  29 . Lower nails  39 D are dispersed broadly across the width of bottom peripheral edge  14 B in a manner that promotes rigidity in the connection of bottom peripheral edge  14 B between first lower horizontal element  28  and second lower horizontal element  29 . In each case, side peripheral nails  39 A, upper corner nails  39 B, upper nails  39 C and lower nails  39 D are all driven in a cross nailing pattern. 
     FIGS. 2 and 3 show first upright  20  having first upright engagement tab slot  22  and second upright engagement tab slot  23 , (shown in FIG.  3 ). 
     FIG. 4 is a front view upper corner detail of a shear panel assembly  10  showing second upper corner joint  34  formed where pin  37 B hingedly interconnects upper horizontal  24  and second upright  21 . Panel diaphragm  12  is shown with top peripheral edge  14 A fastened to upper horizontal  24  with upper nails  39 C. Second cope  1   5 B promotes ductility of shear panel assembly  10  by permitting panel diaphragm  12  to pivot about centerline nail cluster  55  with greater displacement. 
     FIG. 5 is a front view lower corner detail of a shear panel assembly  10  showing second lower corner joint  36  formed where lower horizontal  27  and second upright  21  are joined by hold-down  40 . Panel diaphragm  12  is shown with lower peripheral edge  14 B fastened to lower horizontal  27  with lower nails  39 D with space  53  observed between lower peripheral edge  14 B and sill plate  30 . First lower horizontal element  28  is attached to the upper face of sill plate  30 . Second upright  21  is pivotally connected to hold-down  40 . As shown, upright frame member engagement tab  42  is pivotally connected to tubular base  41  by pin  44 . Upright frame member engagement tab  42  inserts into second upright engagement tab slot  23  and is pinned with lower corner connectors  38  which extend through a cooperating aperture  43 . Second lower cope  16 B, space  53  and the pivotable connection of the upright frame members to their respective hold-downs, all promote ductility of shear panel assembly  10  by permitting panel diaphragm  12  to pivot with greater displacement. 
     FIG. 6 is a top view sectional of a shear panel assembly  10  showing first upper corner joint  33  and second upper corner joint  34  formed where pins  37 A and  37 B hingedly interconnect upper horizontal  24  to first upright  20  and second upright  21 . First upright  20  and second upright  21  are formed having groove  31 A and groove  31 B respectively. Panel diaphragm  12  is shown with top peripheral edge  14 A fastened to first upper horizontal element  25  and second horizontal element  26  upper nails  39 C. Centerline nail cluster  55  is shown extending laterally from centerline C of shear panel assembly  10 . Centerline nail cluster  55  exhibits a cross nailing pattern. Copes  15 A and  15 B permit panel diaphragm  12  to pivot about centerline nail cluster  55  with greater displacement. The configuration of shear panel  11  as shown in FIG. 6 results in an assembly having a depth D. As shown, panel diaphragm  12  is secured symmetrically within a depth D of shear panel  11 . 
     FIG. 7 is a vertical sectional detail showing second side peripheral edge  14 D of panel diaphragm  12  inserted within groove  31 B of second upright  21 . Second side peripheral edge  14 D of panel diaphragm  12  fits snugly within the root of groove  31 B. Nails  39  are depicted in a cross nailing pattern providing a double shear connection. 
     FIG. 8 is a top view sectional of a shear panel assembly  10  showing first lower corner joint  35  and the second lower corner joint  36 . First lower horizontal element  28  and second lower horizontal element  29  are connected to sill plate  30 , (shown in FIG.  3 ). The relative configurations of first lower horizontal element  28   20  and second lower horizontal element  29  provide an edge receiving aperture or gap along an inner face of lower horizontal  27  into which bottom peripheral edge  14 B fits. Bottom peripheral edge  14 B is sandwiched between first lower horizontal element  28  and second lower horizontal element  29  and cross nailed with lower nails  39 D. Upright frame member engagement tab  42  of hold-down  40  is shown inserted within first upright engagement tab slot  22  and lower corner connector  38  is inserted through connector aperture  43 . An upright frame member engagement tab is shown similarly inserted within second upright engagement tab slot  23  with a lower corner connector  38  inserted through a corresponding connector aperture  43 . 
     Employing cross nailing as shown in FIG.  8  and throughout, particularly at FIGS. 3,  6  and  7 , results in a double shear connection with substantially improved shear strength along the nailed joints. 
     FIGS. 9 depicts an alternate embodiment of the invention shown generally as shear panel assembly  110  which may be employed in situations requiring a wider shear panel installation. Shear panel assembly  110  includes shear panel  111  and hold-down  40  including anchor bolt  47 . Shear panel  111  includes panel diaphragms  112  and  113  that are secured within frame  115 . Frame  115  includes first upright  120 , second upright  121  and intermittent upright  122 . First upright  120 , second upright  121  and intermittent upright  122  hingedly interconnect with upper horizontal  124  and lower horizontal  127 . Intermittent upright  122  is formed having a groove on each of the two opposing side faces, one groove being configured to receive a peripheral edge of panel diaphragm  112  and the opposing groove being configured to receive a peripheral edge of panel diaphragm  113 . 
     A particular embodiment of the shear panel hold-down of the invention is shown in FIGS. 10-13. The hold-down incorporates a tubular base  41  to which upright frame member engagement tab  42  is attached. Upright frame member engagement tab  42  extends from the tubular base  41  along a line V substantially bisecting the width of tubular base  41 . Upright frame member engagement tab  42  lies on a plane perpendicular to a longitudinal axis L of the tubular base. Upright frame member engagement tab  42  extends through side wall  48  of tubular base  41  and is pivotally attached to tubular base  41  by pin  44  that is attached also to tubular base  41 . Upright frame member engagement tab  42  includes a plurality of connector apertures  43 . Hold-down  40  also includes first ear  45  and second ear  46  for attachment to lower horizontal  27 . Second ear  46 , as shown attached across the open end of tubular base  41 , serves to stiffen tubular base  41 . Anchor bolt  47  is provided to secure hold-down  40  to a foundation as shown in FIG.  1 . 
     A preferred embodiment of the shear panel hold-down of the invention is shown in FIGS. 14-15. Hold-down  140  incorporates a base bracket  141  to which upright frame member engagement tabs  142  are attached. The upright frame member engagement tabs are pivotally connected to base bracket  141  by a clevis pin  144 . Clevis pin  144  provides a pivotable connection between base bracket  141  and upright frame member engagement tabs  142 , and therefore the upright frame member of the shear panel assembly. As discussed above, the pivotable connection in the shear panel assembly of the invention provide resiliency in response to applied stresses. However, in order to confer the desired degree of stiffness in the assembled shear panel, the clevis pin should snugly fit into the base bracket and upright frame member. Installation of the clevis pin may therefore be facilitated by incorporating a rounded or tapered tip  148  on the clevis pin, as shown in FIG.  15 . The tip or nose is typically prepared from a polymeric material, and is preferably nylon that is 20% glass filled. 
     The upright engagement tabs  142  include a plurality of apertures  143  for attaching the upright frame member using a plurality of fasteners. Similarly, the base bracket includes a plurality of apertures  150  for attaching a lower horizontal frame member using a plurality of fasteners. Base bracket  141  further includes slots for adjustably securing the hold-down to an anchor bolt  147 . In one aspect of the invention, the base bracket includes one or more apertures that serve as inspection ports for examining the connection to the anchor bolt. 
     Although a variety of anchor bolts and fasteners are suitable for securing a hold-down to a foundation, as shown for the hold-down of FIGS. 14-15 anchor bolt  147  is a U-shaped anchor bolt having two threaded ends that are each engaged by a fastener that is a complementarily threaded nut. The hold-down of FIGS. 14-15 further includes a washer plate  152  interposed between the base bracket and the anchor bolt fasteners. The washer plate provides the shear panel assembly with improved resistance to ‘twisting’ or ‘prying’ forces. 
     Referring to FIG. 3, to assemble, first side peripheral edge  14 C and second side peripheral edge  14 D of panel diaphragm  12  are inserted within grooves  31 A and  31  B, as seen in FIG. 6, of first upright  20  and second upright  21  respectively. Each of the first upper corner joint  33  and the second upper corner joint  34  are assembled by fitting tongue  51  of first upright  20  and tongue  52  of second upright  21  with the milled ends of first upper horizontal element  25  and second upper horizontal element  26  and pinning the joints using pins  37 A and  37 B. Upon assembly, the relative configurations of first upper horizontal element  25  and second upper horizontal element  26  provide an edge receiving aperture or gap along an inner face of upper horizontal  24  into which top peripheral edge  14 A fits. 
     First lower horizontal element  28  and second lower horizontal element  29  are connected to sill plate  30 . Upon assembly, the relative configurations of first lower horizontal element  28  and second lower horizontal element  29  provide an edge receiving aperture or gap along an inner face of lower horizontal  27  into which bottom peripheral edge  14 B fits. Each of the first lower corner joint  35  and the second lower corner joint  36  are assembled by inserting an upright frame member engagement tab  42  of a hold-down  40  into first upright engagement tab slot  22  or second upright engagement tab slot  23 . First ear  45  and second ear  46  extend over the outer faces of lower horizontal  27 . Lower corner connectors  38  are inserted at first lower corner joint  35  and second lower corner joint  36  respectively extending through a corresponding connector aperture  43 . 
     In the preferred embodiment of the invention, nailing of the top peripheral edge  14 A of panel diaphragm  12  to first upper horizontal element  25  and second upper horizontal element  26  is concentrated towards the centerline of panel diaphragm  12 . Centerline nail cluster  55  of upper nails  39 C provides initial stiffness and resistance against a shear force applied to shear panel assembly  10  as centerline nail cluster  55  creates moment connections at small displacements. As greater displacement of shear panel assembly  10  occurs, upper corner nails  39 B yield gradually and pins  37 A and  37 B act like a hinge promoting ductility of shear panel assembly  10  while maintaining structural integrity. In one preferred embodiment of the invention, first upright  20  and second upright  21  each pivotally attach at a hold-down  40  as previously described and shown in FIG.  5 . 
     Installation of a preassembled shear panel typically requires the placement of multiple anchoring devices, typically anchor bolts, in a poured foundation. Placement of the anchor bolts is typically facilitated by the use of an installation jig, typically supplied with the shear panel, that holds the anchor bolts in a predetermined and appropriate spacing and orientation while the foundation is being poured. After the foundation is set, the installation jig is removed and the shear panel assembly is installed. 
     A typical installation jig  160  shown in FIG.  16 . During use, projections  162  are inserted into the clevis pin holes of the base brackets to provide appropriate spacing and orientation between the base brackets. In one aspect of the invention, the installation jig is composed of a polymeric material, such as polypropylene or a copolymer of polypropylene. Installation jigs of the type shown in FIG. 16 facilitate the installation of base brackets for shear panels that have a predefined spacing. 
     Variations may exist between individual shear panel assemblies due to manufacturing differences, inconsistent or unpredictable swelling of wood products, or other factors, with the result that a single premanufactured installation jig is unable to accurately place the anchor bolts for every shear panel. In this case, an adjustable, or telescoping, installation jig is used to accurately place the anchor bolts in the foundation. FIG. 17 shows a telescoping installation jig  170  attached to a preassembled shear panel  175 . Jug  170  is first adjusted to match the spacing between clevis pin holes  172  of the upright engagement tabs  174  of the shear panel assembly, my manipulating a telescoping connection  176 . As shown in FIG. 17, jig  170  exhibits a shallow U-shaped profile. This nonlinear conformation is necessary in order to simultaneously attach to both clevis pin holes  172  on the preassembled shear panel. After jig  170  is set at the appropriate length, telescoping portion  176  is fixed in place by tightening one or more set screws or some other appropriate locking mechanism. After the length of the jig is fixed, the jig is removed from shear panel assembly  175 , the base brackets and anchor bolts are mounted to the installation jig, and the anchor bolts are installed in the foundation. The use of telescoping installation jig  170  permits the anchor bolts to be installed to fit a particular shear panel assembly with precision. 
     Although the present invention has been shown and described with reference to the foregoing operational principles and preferred embodiments, it will be apparent to those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. The present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.