Simple Ribbed Mat Foundation Design

Although mat foundations are more difficult and more costly to design than individual spread footings they can be used effectively.

Simple ribbed mat foundation design. This document provides guidance for the design and construction of conventionally reinforced ribbed mat slab rrms foundation systems. Rigid frame mat this type of mat is used when columns carry extremely heavy loads. Suspended slabs can include flat two way waffle and ribbed framing systems. In such design basement walls act as ribs or deep beam.

In this mat pedestals are provided at the base of the columns. The foundation is created by placing a series of single use plastic forms set directly on grade to create a grid of ribs and then monolithically pouring a post tensioned rebar or fiber reinforced concrete. For a successful design the layout of mat foundation should be carried out with due consideration of both settlements and bearing capacity. Fig 4 shows a typical rigid frame mat.

When the depth of beam exceeds 90 cm in simple beam and slab mat a rigid frame mat is referred. It is used where the supporting soil has low bearing capacity. Post tensioning may be included in both slabs and beams to balance a percentage of the self weight. A raft foundation also called a mat foundation is essentially a continuous slab resting on the soil that extends over the entire f.

Reinforced ribbed mat slabs 1. A waffle slab foundation also called a ribbed slab foundation is an above ground type of foundation used to provide load bearing capacity in expansive rocky or hydro collapsible soils. Mat raft foundation design in staad pro. For example the flat slab analogy which has been very successfully used in many cases has also led to structural failures in many other cases due to lack of understanding of the basics.

A mat foundation also may be used to resist hydrostatic pressures or to bridge over small soft spots in the soil provided the mat is adequately reinforced. The bearing capacity increased by combining all individual footings in to one mat since bearing capacity is proportional to width and depth of foundations. Academia edu is a platform for academics to share research papers. Slabs or foundations can be of any shape and can include edges shaped with circular and spline curves.