en Research Paper Research Paper <font size="1" face="Times-Italic"><font size="1" face="Times-Italic"><p align="left">In this paper shear behavior of two calcareous sands having different physical properties are</p><p align="left">investigated using drained and undrained triaxial tests. The investigated sands are obtained from two different</p><p align="left">zones located in Persian Gulf, Kish Island and Tonbak region. Analysis based on energy aspects show that</p><p align="left">friction angle in these soils, having crushable particles, is formed of three components: substantial internal</p><p align="left">friction angle, dilation and particle breakage angle. Dilation component is available in the two investigated</p><p align="left">sand. Particle breakage component is a function of grains hardness, structure and geometry shape. Particles</p><p align="left">breakage decreases the volume of sample during drained tests and creates positive pore water pressure during</p><p align="left">undrained tests. Two investigated sands show different amount of dilation and particle breakage under similar</p><p align="left">conditions. Simultaneous dilation and particles crushing and different amount of them result in different shear</p><p align="left">behavior of the two studied sands. Energy aspects are used to determine the effect of particle crushing on the</p><p align="left">shear strength. There is a suitable compatibility between relative breakage of grains and consumed energy</p><p align="left">ratio for particle breakage.</p></font></font> calcareous soil, triaxial test, dilation, particle breakage, energy 108 119 http://ijce.iust.ac.ir/browse.php?a_code=A-10-668-56&slc_lang=en&sid=1 Mahmoud Hassanlourad 180031947532846006007 180031947532846006007 No Hosein Salehzadeh 180031947532846006008 180031947532846006008 Yes Habib Shahnazari 180031947532846006009 180031947532846006009 No