高等巖石力學(xué)第78章

第7章巖體(rockmass)7.1變形特性(deformability)7.2強(qiáng)度(strength)代入M-C準(zhǔn)則第8章巖體分級(jí)(rockmassclassification)8.1巖體分類(RMR)系統(tǒng)(rockmassratingsystem)完整巖石的單軸抗壓強(qiáng)度(theuniaxialcompressivestrengthoftheintactrock);巖石質(zhì)量指標(biāo)(RQD);非連續(xù)面間距(Discontinuityspacing);非連續(xù)面情況(Conditionofdiscontinuitysurfaces);地下水條件(Groundwaterconditions);與工程結(jié)構(gòu)相關(guān)的非連續(xù)面方向(Orientationofdiscontinuitiesrelativetotheengineeredstructure).8.2Q系統(tǒng)(Q-system)巖石質(zhì)量指標(biāo)(RQD);非連續(xù)面組數(shù)(numberofdiscontinuitysets);最不利非連續(xù)面粗糙度(roughnessofthe‘mostunfavourable’discontinuity);最弱非連續(xù)面蝕變或填充程度(degreeofalterationorfillingalongtheweakestdiscontinuity);裂隙水(waterinflow);地應(yīng)力情況(stresscondition).RQD=rockqualitydesignation;Jn=jointsetnumber(relatedtothenumberofdiscontinuitysets);Jr=jointroughnessnumber(relatedtotheroughnessofthediscontinuitysurfaces);Ja=jointalterationnumber(relatedtothedegreeofalterationorweatheringofthediscontinuitysurfaces);Jw=jointwaterreductionnumber(relatestopressuresandinflowratesofwaterwithinthediscontinuities),andSRF=stressreductionfactor(relatedtothepresenceofshearzones,stressconcentrationsandsqueezingandswellingrocks)RQD/Jn與巖體幾何結(jié)構(gòu)相關(guān)；Jr/Ja與巖塊間的剪切強(qiáng)度相關(guān)；Jw/SRF是一個(gè)“環(huán)境因子”(environmentalfactor),它綜合水壓力和流動(dòng)速率、剪應(yīng)力區(qū)的存在、巖體擠壓和膨脹，以及原位應(yīng)力狀態(tài)等各方面的影響。8.3巖體分級(jí)系統(tǒng)的應(yīng)用RMR系統(tǒng)的評(píng)分值范圍是0~100，Q系統(tǒng)評(píng)分值范圍是0.001~1000，根據(jù)分級(jí)評(píng)分值可對(duì)巖體進(jìn)行描述。兩種分級(jí)法都是從估計(jì)隧道開(kāi)挖所需支護(hù)的土木工程中來(lái)的，用于別的工程要慎重。以下兩圖為例說(shuō)明兩種方法定量評(píng)價(jià)巖體，估算隧道的“自穩(wěn)時(shí)間”和支護(hù)需求。Romana（1985）通過(guò)考慮以下因素對(duì)RMR值進(jìn)行調(diào)整，將分級(jí)系統(tǒng)推廣應(yīng)用到邊坡工程。F1與邊坡和非連續(xù)面走向之間的平行度有關(guān)；F2與發(fā)生平面破壞的非連續(xù)面的傾角有關(guān)；F3與對(duì)比非連續(xù)面傾角和邊坡傾角有關(guān)；F4與開(kāi)挖方式有關(guān)。8.4分級(jí)系統(tǒng)與巖體特性的關(guān)聯(lián)

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