BACKGROUND

Many structures are built upon frames coupled to foundations. The vertical posts of these frames often include angle brackets or “feet” that extend outwardly from sidewalls of the posts along the foundation and define a fastener opening. To couple the post to the foundation, a bolt or other fastener is fastened through the fastener opening and into the foundation.

However, this type of connection is known to be brittle. During seismic activity, the structure is subjected to cycles of compression and tension which can cause these brittle connections to fail. This failure of the frame-foundation connection could cause the failure of the structure. Thus, a need exists for a system and a method for connecting a post to a foundation that are not brittle to withstand seismic forces.

SUMMARY

Various implementations include a system for coupling a post to a foundation. The system includes a foundation, a rod, and a post. The foundation has a top surface. The rod has a first rod end and a second rod end opposite and spaced apart from the first rod end. The first rod end is spaced apart from the top surface of the foundation and the second rod end is coupled to the foundation. The post has at least one side wall that at least partially defines an inner cavity and an inner tube disposed within the inner cavity and coupled to the at least one side wall. The at least one side wall has a bottom end. The inner tube has a first tube end and a second tube end opposite and spaced apart from the first tube end. The second tube end is closer than the first tube end to the bottom end of the post. A portion of the rod is disposable within the inner tube such that the first rod end is axially spaced apart from the first tube end. The first rod end is couplable to the first tube end.

In some implementations, the rod includes a threaded portion extending from the first rod end toward the second rod end. The first rod end is coupled to the first tube end by coupling a nut to the threaded portion of the rod.

In some implementations, at least one of the at least one side wall defines a side wall opening. The side wall opening is radially adjacent the first tube end such that the first tube end is accessible through the side wall opening.

In some implementations, the at least one side wall of the post includes a first side wall, a second side wall, a third side wall, and a fourth side wall.

In some implementations, each of the at least two side walls define a side wall opening. The side wall openings are radially adjacent the first tube end such that the first tube end is accessible through the side wall openings.

In some implementations, the post has a square cross-section in a plane parallel to the bottom end of the at least one side wall. The post has a width measured from opposing side walls. The inner tube has a length measured from the first tube end to the second tube end. The length of the tube is at least 1.5 times the width of the post.

In some implementations, the post further includes a bottom wall coupled to the bottom end of the post. The bottom wall defines a bottom wall opening. The second tube end is coupled to the bottom wall, and the portion of the rod that is disposable within the inner tube is extendable through the bottom wall opening.

In some implementations, the system further includes at least one shim that is disposable between the bottom end of the at least one side wall of the post and the top surface of the foundation.

In some implementations, the top surface of the foundation defines a foundation opening. The second rod end is disposed within the foundation opening and coupled to the foundation by grout disposed in the foundation opening.

In some implementations, the inner tube has a length measured from the first tube end to the second tube end. The length of the tube is from 6 to 18 inches.

Various other implementations include a method of coupling a post to a foundation. The method includes coupling a rod to a foundation, disposing the rod within an inner tube of a post, and coupling the first rod end to the first tube end. The rod has a first rod end and a second rod end opposite and spaced apart from the first rod end. The first rod end is spaced apart from the top surface of the foundation and the second rod end is coupled to the foundation. The post has at least one side wall that least partially defines an inner cavity and the inner tube disposed within the inner cavity and coupled to the at least one side wall. The at least one side wall has a bottom end. The inner tube has a first tube end and a second tube end opposite and spaced apart from the first tube end. The second tube end is closer than the first tube end to the bottom end of the post. The first rod end is axially spaced apart from the first tube end.

In some implementations, the rod includes a threaded portion extending from the first rod end toward the second rod end. Coupling the first rod end to the first tube end includes coupling a nut to the threaded portion of the rod.

In some implementations, at least one of the at least one side wall defines a side wall opening. The side wall opening is radially adjacent the first tube end such that the first tube end is accessible through the side wall opening.

In some implementations, the at least one side wall of the post includes a first side wall, a second side wall, a third side wall, and a fourth side wall.

In some implementations, each of the at least two side walls define a side wall opening. The side wall openings are radially adjacent the first tube end such that the first tube end is accessible through the side wall openings.

In some implementations, the post has a square cross-section in a plane parallel to the bottom end of the at least one side wall. The post has a width measured from opposing side walls. The inner tube has a length measured from the first tube end to the second tube end. The length of the tube is at least 1.5 times the width of the post.

In some implementations, the post further includes a bottom wall coupled to the bottom end of the post. The bottom wall defines a bottom wall opening. The second tube end is coupled to the bottom wall. The method further includes disposing the rod through the inner tube and the bottom wall opening.

In some implementations, the method further includes disposing at least one shim between the bottom end of the at least one side wall of the post and the top surface of the foundation.

In some implementations, the top surface of the foundation defines a foundation opening. Coupling the rod to the foundation includes disposing the second rod end in the foundation opening and surrounding the second rod end and a portion of the rod between the top surface and second rod end with grout.

In some implementations, the inner tube has a length measured from the first tube end to the second tube end. The length of the tube is from 6 to 18 inches.

