软-硬自然节理的改进JRC-JCS剪切强度公式  

Improved JRC-JCS shear strength formula for soft-hard natural joints

作　　者：宋磊博 江权[2] 李元辉[1] 杨成祥[1] 刘畅[2] 杨冰[2] 李邵军[2] SONG Lei-bo JIANG Quan LI Yuan-hui YANG Cheng-xiang LIU Chang YANG Bing LI Shao-jun(Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines, Northeastern University, Shenyang, Liaoning 110819, China State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, China)

机构地区：[1]东北大学深部金属矿山安全开采教育部重点实验室,辽宁沈阳110819 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《岩土力学》2017年第10期2789-2798,共10页Rock and Soil Mechanics

基　　金：国家重点研发计划(No.2016YFC0600707;No.2016YFC0801605);国家自然科学基金资助(No.41372315)~~

摘　　要：借助三维白光扫描技术和3D打印技术,浇筑了若干块含相同自然节理面、上下盘壁面强度不同的吻合软-硬节理混凝土试块,并对其进行了不同常法向应力下的剪切试验。试验表明,试件的剪胀程度随着节理壁面强度系数λ_(σc)值的增大而增大,剪切强度随着λ_(σc)值的增大而减小。同时,研究表明,对于软-硬节理,在剪切过程中,软-硬节理两侧都发生了破坏,节理的等效壁面强度JCS_(等效)受壁面强度系数λ_(σc)的影响,相对于硬节理侧,较软节理侧对等效壁面强度JCS_(等效)的贡献更大,并且这种趋势随壁面强度系数λ_(σc)的增大而增强,这也是JRC-JCS(节理粗糙系数-节理壁面强度)强度公式预测软-硬节理强度时具有一定局限性的原因。根据以上分析,以较软节理侧的壁面强度JCS软为基准,建立了关于壁面强度系数λ_(σc)的修正关系函数f(λ_(σc))来确定软-硬节理的等效壁面强度JCS_(等效),进而提出了考虑软-硬节理不同壁面强度组合类型的修正JRC-JCS剪切强度公式,该新公式是对现有的JRC-JCS强度公式的完善。With the help of 3D scanning technology and 3D printing technology, several specimens with the same natural joint but different joint wall compressive strengths were first made, and shearing tests under different constant normal stresses were conducted on them. The direct shear test results show that the strength characteristics on both sides of soft-hard joints affect the shear expansion and shear strength, that is, with the increase of wall strength coefficient 2%, the shear dilatation increases but the shear strength decreases. Moreover, the study also indicates that the damages in the joints surfaces occur on both sides of the soft-hard joints during the shearing process, and the equivalent joint wall strength JCSeq is affected by the wall strength coefficient λ_（σc）. Compared with the hard joint side, the equivalent wall strength JCSeq is improved to a greater extent by the soft joint side, and the trend is strengthened with the increase of the wall strength coefficient λ_（σc）. That is why JRC-JCS strength formula has some limitations in predicting the strength of soft-hard joints. Based on the above analysis, JCSson is the basis for establishing the modified relational functionf（ λ_（σc） ） of soft-hard joints equivalent wall strength JCSeq with respect to wall strength coefficientλ_（σc）. And an improved JRC-JCS shear strength formula considering different wall compressive strength combination types of soft-bard joints is proposed, which is the complement of current JRC-JCS strenh formula.

关 键 词：软-硬节理 节理壁面强度JCS 剪切强度公式 节理面的破坏特征 

分 类 号：TU45[建筑科学—岩土工程]