本文選題：節(jié)理巖體　切入點：宏細觀缺陷　出處：《長安大學》2014年博士論文　論文類型：學位論文

【摘要】：巖體是一種既不但含有節(jié)理、裂隙等宏觀缺陷而且同時又含有微裂紋、微孔洞等細觀缺陷的天然損傷地質(zhì)材料，針對目前巖體損傷本構(gòu)模型研究中大都僅考慮其中一類缺陷的不足，提出了在巖體力學特性分析中應(yīng)同時綜合考慮宏細觀缺陷及其影響效應(yīng)的觀點，并在試驗研究與理論分析的基礎(chǔ)上建立了相應(yīng)的巖體損傷本構(gòu)模型。為此，論文主要進行了以下幾方面的研究工作： （1）通過MTS（material teting system）單軸壓縮試驗及SHPB（split HopkinsonPressure Bar）試驗對巖體進行了靜、動態(tài)壓縮試驗，分別研究了宏觀缺陷（節(jié)理）和細觀缺陷（微裂紋）對巖體力學特性及破壞模式的影響規(guī)律，結(jié)果表明兩類缺陷對巖體力學特性均有顯著影響，不容忽視。 （2）基于損傷力學觀點，把微裂紋對巖體的損傷作為標量來考慮，采用基于weibull分布的細觀統(tǒng)計損傷模型作為不含宏觀節(jié)理的巖石損傷本構(gòu)模型，而后在此基礎(chǔ)上通過引入二階損傷張量來描述節(jié)理對巖體的宏觀損傷，由此建立了相應(yīng)的巖體損傷本構(gòu)模型，該模型很好地考慮了宏細觀兩類缺陷的共同影響。最后利用該模型對節(jié)理巖體的力學特性進行了計算，初步驗證了該模型的合理性。 （3）基于巖體結(jié)構(gòu)力學觀點，建立了基于變形元件的巖體損傷本構(gòu)模型，把巖塊視為服從weibull分布的損傷統(tǒng)計本構(gòu)模型的彈性元件，而把節(jié)理面作為閉合變形元件，并考慮試件沿節(jié)理滑移對強度和變形影響。算例表明該模型能較好地反映試件強度隨節(jié)理傾角及節(jié)理條數(shù)的變化規(guī)律，初步說明了該模型的合理性。 （4）利用所建立的損傷本構(gòu)模型對直立層狀及順傾層狀巖質(zhì)邊坡的失穩(wěn)破壞與單節(jié)理巖體的強度問題進行了計算分析，認為當考慮了巖體內(nèi)部同時存在的宏、細觀缺陷后，，所得出的結(jié)果也將更符合工程實際。
[Abstract]:Rock mass is a kind of natural damaged geological material which not only contains macroscopic defects such as joints and fissures, but also contains microcracks, microvoids and other meso-defects at the same time. In view of the deficiency that only one kind of defects is considered in the present study of damage constitutive model of rock mass, the viewpoint that macro and mesoscopic defects and their influence effects should be considered in the analysis of rock mass mechanical properties is put forward. Based on the experimental study and theoretical analysis, the corresponding damage constitutive model of rock mass is established. 1) static and dynamic compression tests of rock mass were carried out by MTS(material teting system uniaxial compression test and SHPB(split HopkinsonPressure Bar-test. The effects of macroscopic defects (joints) and meso-defects (micro-cracks) on the mechanical properties and failure modes of rock mass were studied respectively. The results show that the two kinds of defects have significant influence on the mechanical properties of rock mass and can not be ignored. (2) based on the viewpoint of damage mechanics, the damage of rock mass caused by microcracks is considered as a scalar, and the meso-statistical damage model based on weibull distribution is used as the constitutive model of rock damage without macroscopic joints. Then, by introducing second-order damage Zhang Liang to describe the macroscopic damage to rock mass, the corresponding damage constitutive model of rock mass is established. The model takes into account the mutual influence of macro and meso defects. Finally, the model is used to calculate the mechanical properties of jointed rock mass, and the rationality of the model is preliminarily verified. Based on the viewpoint of structural mechanics of rock mass, the damage constitutive model of rock mass based on deformation element is established. The rock block is regarded as the elastic element of the statistical constitutive model of damage from weibull distribution, and the joint surface is regarded as the closed deformation element. The effect of slip along joints on strength and deformation is considered. The model can reflect the variation of strength with the joint inclination and the number of joints, and the rationality of the model is preliminarily explained. 4) the damage constitutive model is used to calculate and analyze the instability and strength of vertical and downdip bedded rock slopes. It is considered that the macro- and meso-defects in rock mass are taken into account when the failure of vertical bedded rock slopes and the strength of single-joint rock masses are taken into account. The results will also be more in line with the actual engineering.
【學位授予單位】：長安大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TU45

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