INVESTIGATION ON NONLINEAR ELASTIC BEHAVIOUR OF ROCKS BASED ON A TWO-PART HOOKE?S MODEL
LI Lianchong1，2，LIU Huihai2，ZHAO Yu3
(1. School of Civil and Hydraulic Engineering，Dalian University of Technology，Dalian，Liaoning 116024，China；
2. Earth Sciences Division，Lawrence Berkeley National Laboratory，Berkeley 94720，USA；3. College of Civil
Engineering，Chongqing University，Chongqing 400030，China)
Abstract：The nonlinear behavior plays an important role in the stability of rock engineering. As an attempt to more accurately model the elastic response of porous or fractured rocks，a recently developed stress-strain relationship，called two-part Hooke?s model(TPHM)，is incorporated into a coupled reservoir-geomechanical simulator，TOUGH-FLAC3D code. TPHM is based on a macroscopic approximation that the natural strain (volume change divided by rock volume at the current stress state)，rather than the engineering strain(volume change divided by the unstressed rock volume)，should be used in Hooke?s law for accurate modeling of the elastic deformation except when mechanical deformation is very small. We first implement TPHM into a modified Mohr-Coulomb model providing by FLAC3D to demonstrate the numerical algorithm of TPHM in a geomechanical simulator. Then the nonlinear deformation behavior characterized by a shallow sloping stress-strain curve at low stress levels is numerically obtained with rock specimens under loading and unloading processes. Finally，based on the numerical simulation on the deformation of rock mass around an underground tunnel ED-B in Mont Terri laboratory，we show the usefulness of TPHM in light of its applicability to practical problems，and the importance of incorporating more accurate constitutive models for modeling mechanical response for field-scale problems related to rock engineering with unloading process.
李连崇1，2，LIU Huihai2，赵 瑜3. 基于双应变胡克模型的岩石非线性弹性行为分析[J]. 岩石力学与工程学报, 2012, 31(10): 2119-2126.
LI Lianchong1，2，LIU Huihai2，ZHAO Yu3. INVESTIGATION ON NONLINEAR ELASTIC BEHAVIOUR OF ROCKS BASED ON A TWO-PART HOOKE?S MODEL. , 2012, 31(10): 2119-2126.
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2012, Vol. 31 
