System and method for increasing the shear strength of a framed structure

Abstract

Reinforcing system for retrofitting wall to increase the ductility and resistance to shear forces of a gypsum board wall to a level comparable to plywood-sheathed wall. Fiber-reinforced polymer panel is attached to substantially cover surface of gypsum board to protect it against rupture in earthquake. Reinforcement is enhanced by fiber anchors installed along base of wall and door frames. Connector strips tie together frame members to prevent separation from wall.

1 . A system for reinforcing a framed structure, the structure including: a plurality of framing members including: at least one pair of vertical support members in parallel spaced-apart relation, one horizontal top connecting member connecting the top portions of the vertical support members, at least one horizontal bottom connecting member connecting the bottom portions of the vertical support members and wall sheathing attached over the framing members; said system including:
 at least one connector strip of resin-impregnated textile, said strip adapted to connect a top connecting member to a bottom connecting member; said strip including:
 a first end attached to the top connecting member; 
 a second end attached to the bottom connecting member; 
 an inner face disposed toward the wall sheathing; 
 an exposed face disposed away from the wall sheathing; and 
 a middle portion between said first and second ends; and 
   ductile attachment means attaching each said end to one connecting member.   
     
     
         2 . The system of  claim 1 , further including:
 at least one anchor plate, said anchor plate attached between one said strip end and one connecting member; said ductile attachment means further attaching said anchor plate with said strip end and said connecting member.   
     
     
         3 . The system of  claim 1 , said at least one connector strip comprising:
 a pair of connector strips attached to the top and bottom connecting members such that said pair of connector strips form an “X” shape on the wall sheathing.   
     
     
         4 . The system of  claim 3 , said pair of strips attached such that the longitudinal axis of one said strip is disposed at a angle in the range of 70-110 degrees to the longitudinal axis of the other said strip. 
     
     
         5 . A method for reinforcing a framed structure that includes framing members, including a first vertical support member and a second vertical support member in parallel spaced-apart relation, one horizontal top connecting member connecting the top portions of the vertical support members, and at least one horizontal bottom connecting member connecting the bottom portions of the vertical support members; the method including the steps of:
 providing a first strip of material having: a first end, a second end, and a middle portion therebetween and with a length approximating the distance between the junction of the first support member with the top connecting member and the junction of the second support member with the bottom connecting member;   attaching the first end of the first strip to the junction of the first support member with the top connecting member using ductile attachment means;   attaching the second end of the first strip to the junction of the second support member with the bottom connecting member using ductile attachment means;   providing a second strip of material having: a first end, a second end, and a middle portion therebetween and with a length approximating the distance between the junction of the second support member with the top connecting member and the junction of the first support member with the top connecting member;   attaching the first end of the second strip to the junction of the second support member with the top connecting member using ductile attachment means; and   attaching the second end of the second strip to the junction of the first support member with the bottom connecting member using ductile attachment means such that the middle portion of the second strip overlies the middle portion of the first strip.   
     
     
         6 . The method of  claim 5 , wherein the ends of the strips of material are attached to junctions of framing members such that the longitudinal axes of the attached first and second strips form an angle of 70 to 110 degrees. 
     
     
         7 . The method of  claim 5 , wherein each step of attaching an end of a strip to a junction using ductile attachment means comprises the step of creating a fiber anchor, further including the sub-steps of:
 creating a borehole that passes through the end of the strip and into a framing member;   inserting a length of roving through the end of the strip and into the framing member such that a free end protrudes from the end of the strip;   backfilling the borehole with adhesive to capture the roving; and   attaching the free end of roving to the end of the strip with adhesive.   
     
     
         8 . The method of  claim 7 , wherein each step of attaching an end of a strip to a junction comprises the step of creating a plurality of fiber anchors by repeating the sub-steps of  claims 7  a plurality of times.