Hold-down Database

The program includes a database of standard hold-downs, which you can edit using a database editor incorporated in Shearwalls to update hold-down properties or add new hold-downs

Database File

The Database folder of the WoodWorks installation contains a file called Holddowns.mdb, which is a Microsoft Access database of hold-downs used by the Shearwalls program. Shearwalls now includes an editor to modify the database, but it is also possible to modify the file directly via Microsoft Access.

Database Structure

The database consists of two tables, a Hold-down table that contains the properties of the hold-down that are relevant to Shearwalls design, and a Displacement table which contains hold-down capacities and displacements corresponding to each combination of minimum stud width and depth. The record in the displacement table contains a reference ID to the hold-down that uses that displacement record.

Hold-down Table

The hold-down table contains the following data:

• Name
• Horizontal fastener type ( bolts or nails)
• Number of horizontal fasteners (per bracket or strap)
• Horizontal fastener diameter
• Whether published elongation and fastener slippage are combined into one displacement
• Whether published elongation includes the anchor bolt, or it is for the bracket/strap only
• Whether it includes an anchor bolt
• Anchor bolt diameter
• The maximum anchor bolt length for which the published elongation applies
• Whether for this hold-down, we use displacement at maximum capacity for deflection analysis
• Whether the hold-down includes a shrinkage compensation device
• Whether the hold-down is to be used as the default hold-down for new projects in Shearwalls

Displacement Table

The hold-down displacement table is needed for hold-downs for which the entire assembly displacement is published.

For those hold-downs for which only the bracket or strap elongation is published, then only one displacement record is needed, corresponding to the elongation of the bracket or strap. The displacement of anchor bolt and horizontal fasteners is calculated separately by Shearwalls using the information in the Hold-down table.