Design and Construction of Mat Foundations
Abstract
Mat foundations commonly support all types of structures. Flat mats from 2 to 8 ft in thickness often containing two-way steel reinforcement top and bottom usually support multistory or heavy structures. Mats less than 1 ft thick often constructed with steel reinforced ribs or stiffening crossbeams usually support light one or two story structures. Many of these mats have been designed and constructed for supporting permanent military facilities, particularly in heavy/shrinking and compressible soil. Some of these mats have experienced significant differential movement leading to cracking in the structure and have required costly remedial work. Attempts to reduce such maintenance expenses of some structures have lead to substantially increased design and construction costs for mat foundations. This report provides information on serviceability of structures, guidelines for evaluation of soil, and some structure input parameters for design analysis and guidelines for design and construction of ribbed mat foundations in expansive soils. Methods have been developed for evaluation of effective soil elastic moduli and stiffness of structures. New concepts are proposed for determining some soil input parameters for design in expansive soils such as the depth of the active zone for heave and edge moisture variation distance. Several case history studies of ribbed and flat mat foundations have been investigated to assist determination of suitable procedures for calculating deformation behavior of mat foundations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1989
- Accession Number
- ADA216450
Entities
People
- Lawrence D. Johnson