Environmental Engineering Reference
In-Depth Information
Chapter 6
Soil Collapse due to Water Infiltration
6.1. Introduction
This chapter is devoted to the behavior of soils that are prone to collapse when
infiltrated by water, with special attention paid to loess deposits. Typical examples
are given on loess from Northern France. Loess is a silty Aeolian sediment,
transported in periglacial conditions and deposited in cold steppe environments near
the margins of main quaternary ice-sheets, mainly around 50°N in the Northern
hemisphere. Some deposits also exist in South America.
According to Dudley [DUD 70], the soil collapse depends on:
- soil mineralogy, with active clays and large clay fractions decreasing the
magnitude of collapse;
- grain size distribution and shape, with higher collapse in poorly graded soils
with irregular angular shapes;
- natural water content with larger collapse for drier soils;
- initial porosity with larger collapse for loose soils;
- shape and dimension of the pores;
- bounding agents;
- nature and concentration of dissolved ions.
