Title: Concrete Q&A: Designing Beams in Mat Foundation and more

Author(s):

Publication: Concrete International

Volume: 41

Issue: 8

Appears on pages(s): 71-72

Keywords:

DOI:

Date: 8/1/2019

Abstract:
Section 18.13.3.3 of ACI 318-141 states: “Grade beams and beams that are part of a mat foundation subjected to flexure from columns that are part of the seismic-force-resisting system shall be in accordance with 18.6.” Section 18.6 applies to “beams of special moment frames that form part of the seismic-forceresisting system and are proportioned primarily to resist flexure and shear.” Because a mat foundation is a flexural member, does this clause mean that a solid mat needs to be detailed like a special moment frame? In other words, what are “beams that are part of a mat foundation”? For coupled shear walls in Seismic Design Category (SDC) B or C, are the link beams to be designed as ordinary moment frame beams or intermediate moment frame beams? What is a recommended spacing for contraction joints in concrete walls in buildings?