<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:creator>D.A. Lockner</dc:creator>
  <dc:date>1998</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;A semiempirical constitutive law is presented for the brittle deformation of intact Westerly granite. The law can be extended to larger displacements, dominated by localized deformation, by including a displacement-weakening break-down region terminating in a frictional sliding regime often described by a rate- and state-dependent constitutive law. The intact deformation law, based on an Arrhenius type rate equation, relates inelastic strain rate to confining pressure&amp;nbsp;&lt;/span&gt;&lt;i&gt;P&lt;sub&gt;c&lt;/sub&gt;&lt;/i&gt;&lt;span&gt;, differential stress σ&lt;/span&gt;&lt;sub&gt;Δ&lt;/sub&gt;&lt;span&gt;, inelastic strain ε&lt;/span&gt;&lt;sub&gt;&lt;i&gt;i&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and temperature&amp;nbsp;&lt;/span&gt;&lt;i&gt;T&lt;/i&gt;&lt;span&gt;. The basic form of the law for deformation prior to fault nucleation is&amp;nbsp;&lt;/span&gt;&lt;img class="section_image" src="https://agupubs.onlinelibrary.wiley.com/cms/asset/7605b92c-b201-4a82-9234-688e34be2a61/jgrb11305-math-0001.gif" alt="urn:x-wiley:01480227:media:jgrb11305:jgrb11305-math-0001" data-mce-src="https://agupubs.onlinelibrary.wiley.com/cms/asset/7605b92c-b201-4a82-9234-688e34be2a61/jgrb11305-math-0001.gif"&gt;&lt;span&gt;&amp;nbsp;where σ&lt;/span&gt;&lt;sub&gt;o&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and ε&lt;/span&gt;&lt;sub&gt;o&lt;/sub&gt;&lt;span&gt;&amp;nbsp;are normalization constants (dependent on confining pressure),&amp;nbsp;&lt;/span&gt;&lt;i&gt;a&lt;/i&gt;&lt;span&gt;&amp;nbsp;is rate sensitivity of stress, and α is a shape parameter. At room temperature, eight experimentally determined coefficients are needed to fully describe the stress-strain-strain rate response for Westerly granite from initial loading to failure. Temperature dependence requires apparent activation energy (&lt;/span&gt;&lt;i&gt;E&lt;/i&gt;&lt;span&gt;* ∼ 90 kJ/mol) and one additional experimentally determined coefficient. The similarity between the prefailure constitutive law for intact rock and the rate- and state-dependent friction laws for frictional sliding on fracture surfaces suggests a close connection between these brittle phenomena.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1029/97JB03211</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Geophysical Union</dc:publisher>
  <dc:title>A generalized law for brittle deformation of Westerly granite</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>