- journal_title：Quarterly Journal of Engineering Geology and Hydrogeology
- Contributor：D.A. Gunn ; L.M. Nelder ; P.D. Jackson ; K.J. Northmore ; D.C. Entwisle ; A.E. Milodowski ; D.I. Boardman ; A. Zourmpakis ; C.D. Rogers ; I. Jefferson ; N. Dixon
- Publisher：Geological Society of London
- Date：2006-
- Format：text/html
- Language：en
- Identifier：10.1144/1470-9236/04-045
- journal_abbrev：Quarterly Journal of Engineering Geology and Hydrogeology
- issn：1470-9236
- volume：39
- issue：2
- firstpage：173
- section：Original Article
Metastable loessic brickearth comprises a stiff fabric structure with inter-particle interactions different to those normally associated with clay-sized or silt-sized particle fabrics. Laboratory samples loaded near <em>in situem> moisture contents exhibited little consolidation and relatively high shear wave velocities, which changed in response to sample flooding. <em>In situem> hydro-collapse caused non-monotonic changes in the velocity of shear waves through loessic brickearth that was subjected to simple flooding and to flooding while under additional surface loading. Hydro-collapse <em>in situem> resulted in an overall reduction of up to 50% in the shear wave velocity. A conceptual model of brickearth structure based on SEM images is presented to explain the process of collapse and its effect on shear wave velocity. These indicate a transition from a relatively low-density, high-stiffness fabric to the higher-density, lower-stiffness fabric during structural collapse of the loessic brickearth. The collapse process disrupts clay bridge-bonds that hold individual and aggregated clay-coated silt sized particles in an open packed structure, and which are absent in a more closely packed collapsed structure. These studies provide information for geohazard research and the development of shear wave velocity and other geophysical tools to assess soil collapse potential <em>in situem>.