# consol1 - 53:030 Class Notes C.C Swan University of Iowa...

This preview shows pages 1–4. Sign up to view the full content.

Period #15: Soil Compressibility and Consolidation (I) A. Motivation and Overview Our objective is now to understand how soils compress or consolidate with time after loads are placed on them. This a question of great importance when designing: a) foundations for all types of structures; b) landfills;or c) virtually anyother system that rests on soil. In studying the consolidation of soils there are two basic issues to be addressed: 1) Once a load is applied, how much settlement will occur? and 2) On what time scale will the settlement occur? A historic example of relevance is the Tower of Pisa. In this case, the builders did not understand either: how to compute soil settlements under structural loading; or how to compute the time scale on which settlements would occur. Consequently, over a time scale of centuries, the soil beneath this famous structure has developed very significant consolidation settlements. If unchecked, the structure would ultimately topple over. 1 53:030 Class Notes; C.C. Swan, University of Iowa

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
B. Magnitude of Settlement/Consolidation in Soils Consider the following block diagram for a soil: For simplicity in treating the compression of soils, it isssumed that: a) the soil grains themselves are rigid and incompressible; and b) the change in volume of a soil is due to a re-arrangement of the soil grains, leading to a reduction of void volume. For most soils, these assumptions are quite valid. 2 53:030 Class Notes; C.C. Swan, University of Iowa Voids Solids V v or H v V s or H s V s + V v = V V v = eV s (1+e)V s = V V s = V/(1+e) H s + H v = H H v = eH s (1+e)H s = H H s = H/(1+e)
53:030 Class Notes; C.C. Swan, University of Iowa When a soil is subjected to compressive stresses, there will be a reduction of volume. Most of the volume reduction comes from a reduction in void volume, as shown below. General Case

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 11

consol1 - 53:030 Class Notes C.C Swan University of Iowa...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online