岩体结构面强度的Mohr-Coulomb破坏判据与Barton破坏判据的试验对比

TEST COMPARISON BETWEEN MOHR-COULOMB' S AND BARTON'S CRITERIA OF FAILURE FOR STRUCTURE PLANE IN ROCK MASS

岩体结构面强度是工程岩体稳定性设计中的重要参数,目前工程上常用的两个强度判据,即Mohr-Coulomb准则和Barton准则有各自适用条件。本文在对七组具不同岩性、不同粗糙度及起伏度红层样品进行试验的基础上,探讨了在试验过程中所揭示的强度周期性变化现象,同时基于两准则试验数据,分析了它们之间的区别,获得一些重要结论.即JRC、JCS越大,两准则差别越大;在低法向应力下两准则较接近,在高法向应力时,MC准则偏于危险。

The shear strength of structure plane in rock mass is an important parameter for design and construction in engineering rock masses. The classical Mohr-Coulomb' s and Barton' s criteria of failure,which are used to engineering rock masses mechanics,have itself assuming conditions respectively. Based on seven groups of structure plane specimens of lateritic material with different rock components and different roughness, the paper discusses the cyclic change phenomena of shear strength of structure planes in shearing test process ,and analyses the difference between Mohr-Coulomb' s and Barton' s criteria from the test data. An interst-ing and important result is obtained. That is the difference between MC' s and B' s criteria increases with increase of joint roughness coefficient and joint wall compressive strength. Also, the difference decreases with decrease of the normal stress.