bimrocks.com is an accessible  source of information on bimrocks for geological and geotechnical practitioners. The only other site like this one is my original bimrocks site, hosted by Geoengineer.org

The  papers, presentations, dissertations, posters, Short Courses and photographs here are offered by myself and others who have kindly extended their permission. Please contact me if you want to contribute content to this site but note that I only post useful and well-presented material.  Use the resources freely, but please credit  authors! All resources are provided on the condition that they be used for sole use, and for the non-commercial purpose of scientific and engineering research.

What are bimrocks?

  • block-in-matrix rocks
  • mixtures of rocks composed of geotechnically significant blocks within a bonded matrix of finer texture
  • melanges, fault rocks, weathered rocks, etc.
  • geologically, spatially, and mechanically heterogeneous
  • trouble$ome to geotechnical engineers, geologists, contractors and owners

The words geotechnically significant in the above definition of bimrocks mean that there are criteria for scale, strength contrast, proportion and size of blocks. In bimrocks, blocks must have mechanical contrast with the matrix and, at the scale of engineering interest, there must be enough blocks  of a certain size range to contribute to the overall strength of the rock mass.

Isn’t bimrocks just a silly word? No. Bimrocks is a word with little geological connotation- coined with engineers in mind – for the vast range of geological fabrics of hard blocks mixed with weaker matrix. Learn more about the origin of the word bimrocks here.

Aren’t bimrocks rare? No, they are very common and thus there is no excuse for geopractioners to avoid characterizing them. If you are a geotechnical engineer, think “rock/soil mixtures”. Bimrocks  include many complex geological mixture of hard blocks in weaker matrix: fault rocks, weathered rocks, lahars and melanges. Chaotic melanges  are the most difficult bimrocks to characterize. You can learn more about melanges, and the role that one Northern California melange had in my life and research,  here .

So what? Who cares? Bimrocks universally frustrate the economic and accurate characterization, design and construction  of civil  engineering works.  Bimrocks are troublesome to geopractitioners, including geotechnical engineers and geologists. Owners and contractors care a lot, too – they lose money because of the troubles, although their lawyers help resolve the troubles.

How can this site help? My bimrock websites are likely the only sites where you can easily find useful and free information on working with melanges and other bimrocks: papers, presentations, short course literature, etc.

Need information:? The annotated presentation “An Introduction to Bimrocks“ is a useful review on bimrocks. You are not alone in trying to work with geological complexity – see also my most recent contribution: Geopractitioner Approaches to Working With Anti-Social Melanges, a chapter in the book in Special Paper 480: Mélanges: Processes of Formation and Societal Significance, by John Wakabayashi and Yildirim Dilek, published by the Geological Society of America. Wakabayashi and Dilek’s  full-text introduction to the volume is available at the GSA website.

Visit my bimrocks blog for infrequent thoughts, ideas, information  and comments by readers


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