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| Improved Sarma method for stability analysis of jointed rock slopes |
| DENG Dongping，PENG Yihang，WANG Yimin |
| (College of Civil Engineering，Central South University，Changsha，Hunan 410075，China) |
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Abstract In the stability analysis of jointed rock slopes，the traditional Sarma method still has the following deficiencies：(1) The direction of the shear force between joint blocks is unreasonably defined. (2) The tensile cracking between joint blocks and their bottom surfaces(i.e.，the slip surface) is ineffectively treated. (3) The requirement that the direction of the shear force on the sliding bottom surface of joint block is consistent with the overall sliding trend of the slope can not be reliably guaranteed. Therefore，the analysis model of the traditional Sarma method cannot fully satisfy the principle of rationality for force analysis. Hence，the following improvements are made on the basis of the traditional Sarma method as：(1) The relation-equation for determining the direction of the shear force between joint blocks under the trend of relative motion is constructed. (2) The technique of tensile strength cut-off is introduced to reliably estimate the tensile strength of rock joints under the linear Mohr-Coulomb strength criterion. (3) The calculation mechanism is established for allowing the tensile cracking between joint blocks. (4) The treatment approach of increasing factor of safety between joint blocks and degrading with the use of cracks on both sides of joint blocks are proposed to reasonably solve the problem of the bottom surface of joint blocks being cracked. (5) The virtual crack at the side of the reverse sliding blocks is set to effectively deal with the case of the reverse of shear force on the bottom surface of slumping joint block. Thereby，the improved Sarma method for stability analysis of jointed rock slope is proposed. Through the comparison and analysis on some existing examples，the reliability and effectiveness of the present method are verified. Thereafter，the influence of relevant new parameters in the Improved Sarma method on the stability of jointed rock slope is further discussed in detail.
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2023, Vol. 42 
