Geotechnical and geological engineering with melanges, fault rocks and other bimrocks

Dr. Edmund Medley
Medellín Colombia, 18 to 22 September 2017


The Research Group about Geotechnics, the research subdivision on Block in Matrix Soil (Bims) of the Department of Civil Engineering is pleased to have Doctor Edmud Medley's visit at the National University of Colombia (in Medellín headquarters) in order for him facilitate a course on Block in Matrix Rocks (Bimrocks).

Our surroundings is characterized by an inter-mountain valley called the Aburrá Valley, close to the Antioquian Batholith inside the central range of the Northern part of the Andes, in a geographical latitude of only six degrees northern to the Equator central line of the Earth.

This region is a mountainous place, with hard metamorphic but weathered rock masses in a tropical rainy region, with high tectonic compressive activities in the past and at present, with medium to low level earthquakes and with a rail and road network trying to communicate a conurbation with around four millions of individuals.

All these conditions together are not common in South America (not even common in Ecuador or Venezuela, our neighbors); we are only comparable to some regions in some islands of northern Oceania and some other islands at the south east of Asia (e.g. Papua New Guinea and Malaysia).

For this special situation we need to be aware, because we have to develop our knowledge in order to face and mitigate the problems of the coming years related to engineering geology, geotechnics, geological risk management and environmental engineering.

One of the problems in this context and in this region is undoubtedly the nowadays geomaterial called BiMSoil, an acronym of the word Blocks in Matrix Soils a counterpart material to the geomaterial called BiMRocks meaning Blocks in Matrix Rocks.

Bimsoils and Bimrocks (now grouped as BiMs, i.e. Blocks in Matrices) have been studied in the past under a variety of specific differentiable names, for example: heterogeneous materials, chaotic materials, compound materials, crushed breccias, crushed conglomerades, alluvions, colluvions, among other material names. The geotechnical definition BIMs give us today a single name that groups heterogeneous geomaterials, this name is giving us the possibility to unify a particular theoretical frame.

As the history will tell us, the term bimrock first emerged when geologists started to pay attention to the geotechnical behavior of melanges in the western coast of the United States. Also Bimrocks have been studied in the southern Europe.

The first attempts to develop a new knowledge on the mechanical behavior of these materials emerged from bimrocks; but, a theoretical frame about the mechanical behavior for bimrocks or bimsoils is not ready.

This week, we will have the honor to hear the lectures of one of those engineers who worked intensively in order to understand the mechanical behavior of bimrocks. I have the pleasure to present Doctor Edmund Medley who has accepted our invitation.

Doctor Medley is a Geological Engineer (PE) whose alma matter is the University of British Columbia. He has a master of science in Geotechnical Engineering and a PhD both from the University of California at Berkeley. He is a member of the Association of Environmental and Engineering Geologists, American Geophysical Union and the American Society of Civil Engineers among others memberships. He has worked as a consultant for more than thirty years in different states in the United States (e.g. California, Nevada, Hawaii) and countries as the United Kingdom, Canada, Iran, Taiwan, Guam and Papua New Guinea. We has been a professor and researcher at the University of California at Berkley in the United States and at the Royal School of Mines, Imperial College of London and the University of Cambridge in the United Kingdom. He was lecturer of plenty of courses, sessions, distinguished lectures in universities around the world.

This week, the audience will debate with Doctor Medley our concepts on Bims in a wide context. Thank you Doctor Medley for being here this week with us. Your are very welcome here in Medellin and the audience is now under your control.

Prof. Ludger O. Suarez-Burgoa
Universidad Nacional de Colombia
Medellin, September 18, 2017.


In proceedings

  1. Medley, E., Lindquist, E.S., 1995. The engineering significance of the scale-independence of some Franciscan melanges in California, USA. In: J.J.K. Daemen and R.A. Schultz (eds.), Proceedings of the 35th Rock Mechanics U.S. Symposium, Nevada (June): 907-914.
  2. Medley, E.W., Zekkos, D., 2011, Geopractitioner approaches to working with antisocial mélanges, in Wakabayashi, J., and Dilek, Y., eds., Mélanges: Processes of Formation and Societal Significance: Geological Society of America Special Paper 480, p. 261–277, doi:10.1130/2011.2480(13).
  3. Roadfier, J.W., Forrest, M.P. , Lindquist, E.S., 2009. Evaluation of shear strength of melange foundations at Calavera's Dam. Proceedings of 29th US Society for Dams, Annual Meeting and Conference: Managing our Water Retention Systems, Nashville, Tennessee (April): 15.
  4. Medley, E., 1997. Uncertainty in estimates of block volumetric proportions in melange bimrocks. In: P.G. Marinos and G.C. Koukis and G.C. Tsiambaos and G.C. Stournaras (eds.), Proceedings of the International Symposium on Engineering Geology and the Environment, Athens, Greece(June): 267-272.

In periodicals

  1. A. Kalender, H. Sonmez, E. Mendeley, A.C. Tukusluoglu, K.E. Kasapoglu, 2014. An approach to predicting the overall strengths of unwelded bimrocks and bimsoils. Engineering Geology, Vol.183: 65-79.


  1. E.W. Medley, 1994 (Jul). The engineering characterization of melanges and similar block-in-matrix rocks (Bimrocks). University of California, Berkeley, CA. Ph.D. Thesis.
  2. E.W. Medley, 1994 (Jul). Corrections of The engineering characterization of melanges and similar block-in-matrix rocks (Bimrocks). University of California, Berkeley, CA. Ph.D. Thesis.
  3. E.S. Lindquist, 1994 (Apr). The strength and deformation properties of melange. University of California, Berkeley, CA. Ph.D. Thesis.