MASS™

Shear Wall

Single-wythe masonry shear walls.

shear wall screen capture

The shear wall module designs single-wythe concrete block masonry shear walls, which can be designed using a running bond arrangement only.

MASS™ Version 1.1 designs shear walls in accordance with CSA S304.1-04 Clause 7 and Clause 10, and allows the following wall configurations:

  • Unreinforced, ungrouted block masonry walls using hollow, semi-solid or solid units
  • Unreinforced, fully grouted hollow and semi-solid block masonry
  • Reinforced, fully grouted hollow block masonry and semi-solid block masonry
  • Reinforced, partially grouted hollow and semi-solid block masonry

These shear wall configurations can be constructed using a considerable variety of masonry units. For shear walls, MASS™ Version 1.1 supports the following block types: hollow, semi-solid, solid, half-high, half-block, and bond block. The default concrete block sizes available include 10, 15, 20, 25, and 30 cm units. The default block strengths include 15, 20, 25, and 30 MPa. MASS™ Version 1.1 does not support using brick units for shear wall design.

The support conditions available in the shear wall module include: fixed, fixed(R) and free, where fixed(R) specifies that the support condition is fixed in rotation, but not translation. Loadbearing shear walls are typically loaded laterally, parallel to the face of the wall, and are designed to resist in-plane shear. Shear walls also experience axial loading.

This version of the program allows the designer to specify boundary elements on both ends of the shear wall. These boundary elements are traditionally called flanges if they are intersection masonry walls or boundary elements if they intersect masonry columns or pilaster units. Boundary elements can also be composed of other materials such as concrete or steel; however, the software does not allow other materials. Flanges or boundary elements must be fully specified in this version of the program.

Depending on the applied load, the support conditions, and the resistance of the masonry, a shear wall may or may not need to be reinforced. For shear walls that require reinforcement, up to two steel bars per cell can be placed. The program fixes the spacing of the reinforcing bars to the largest allowed by users and reduces this spacing if necessary to achieve a successful design, keeping with CSA S304.1-04: 10.15. The default steel bar sizes available include 10, 15, 20, 25, and 30 mm diameter bars.

The shear wall module performs engineering calculations to design for the axial load and the moment, using the full length of the wall (not a per metre design). This design includes a detailed P-M diagram. In addition, the wall module provides shear design (which may include the addition of bond beams and/or joint reinforcement).