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Abstract In order to study the influence of water saturation on mechanical properties and energy mechanism of karst limestone，uniaxial and pseudo-triaxial compression tests are carried out under natural and saturated states by rock mechanics test equipment RMT–150B. The testing results of mechanical properties indicate that saturation has a significant effect on the strength and deformation characteristics of karst limestone；and the regression relationship between peak strength and confining pressure can be expressed by Coulomb strength criterion in principal stress. Similar softening coefficient and their reduction rate decrease with the increased confining pressure. From the perspective of energy，the energy features and energy mechanism in the process of rock failure are studied by tests；and then some conclusions are drawn as fellows：the total absorbed energy U，releasable strain energy before peak stress and their increasing rates with axial strain under saturated condition are less than corresponding values of natural specimen. The release rate of after peak stress declines under two states with confining pressure，especially the release rate of for saturated specimen is larger in general. Each strain energy at peak stress increases linearly with the confining pressure；and the intrinsic reason for destroyed style difference is that the difference of dissipated energy under two states varies with confining pressure. Real-time evolution process of karst limestone specimen can be divided into different stages. As for dissipated energy，it differs slightly in compression and elastic deformation stage under two states；but in yield phase，dissipated energy of saturated rock increases faster.
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Received: 01 April 2013
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2014, Vol. 33 
