岩石的抗拉强度远低于其抗压强度，而天然岩石体内部随机分布的孔裂隙等缺陷将显著影响岩石体的强度和破坏特征。因此，研究含偏心裂隙岩石的拉伸强度及破坏特征对岩体工程的稳定性具有重要意义。本文以含裂隙类岩石试样为研究对象，开展了平台巴西劈裂试验、VIC-3D试验及声发射试验。分析了预制裂隙的偏心距和倾角对试样拉伸强度、宏观劈裂破坏特征和微观损伤演化特征的影响规律。基于现有巴西劈裂理论和所得试验结果，建立了含偏心裂隙岩石试样的峰值载荷预测模型。并利用损伤理论，结合COMSOL数值软件再现了试样劈裂破坏过程，研究了裂隙的偏心距、倾角、位置和数量等对其强度和劈裂破坏的影响，揭示了偏心裂隙岩石劈裂破坏机理。获得主要研究结论如下：

(1) 不同偏心距和倾角下试样的荷载-位移曲线变化趋势相似，均具有压密阶段、弹性阶段、裂纹稳定扩展阶段及裂纹非稳定扩展阶段；预制裂隙的存在削弱了试样的强度，且试样的强度受裂隙偏心距及倾角的共同影响；不同偏心距下试样峰值荷载随着倾角的增加呈现不同的变化规律；随着偏心距的增大，试样的峰值荷载呈逐渐增加的趋势。

(2) 当裂隙倾角一定，在偏心距r为0mm、5mm时，试样破坏产生的裂纹主要由预制裂隙尖端向加载端扩展，当偏心距r为10mm时，试样裂纹主要沿加载轴线扩展。而在偏心距一定时，当裂隙倾角α为30°-90°时，试样劈裂破坏过程明显变化，且破坏模式相似；垂直方向劈裂裂纹的产生均是由于拉应力导致的，而水平方向裂纹主要由于压应力导致的；裂隙倾角对试样的声发射特征无明显影响，当偏心距r为0mm即无偏心时，声发射振铃计数呈现集中分布型，当裂隙存在偏心距时，其声发射振铃计数呈现均匀分布型。

(3) 基于试验结果，并结合含平台巴西圆盘完整试样的抗拉强度理论公式，建立了在偏心距一定时，不同裂隙倾角下岩石试样的峰值载荷预测模型。在此基础上，建立了裂隙偏心距和倾角双因素耦合作用下岩石试样的峰值荷载预测模型。并通过与增加的试验结果进行对比，证明了预测模型的正确性与合理性。

(4) 利用损伤理论，借助于COMSOL数值软件建立了含裂隙试样劈裂试验的数值模型，并与试验结果进行对比分析，验证了该数值模型的合理性；当裂隙在水平方向上时，随偏心距增加，裂隙对试样破坏影响越小，而峰值荷载呈递增的变化趋势；当裂隙在加载轴线上，随偏心距增加，裂隙对试样的破坏影响增加，而峰值荷载呈递减趋势。裂隙距离加载轴线越近，对试样破坏影响越显著，其峰值荷载越小；当试样含双裂隙时，裂隙倾角对试样的破坏影响较小，但其峰值荷载随倾角增加呈先减后增的趋势；当双裂隙在水平方向上时，随偏心距增加，对试样破坏影响越小，其峰值荷载却逐渐增加。

The tensile strength of rock is much lower than its compressive strength. However, the random distribution of pore cracks and other defects in natural rock body will significantly affect the strength and failure characteristics of rock body. Therefore, the study of tensile strength and failure characteristics of rock with eccentric fractures is of great significance to the stability of rock mass engineering. In this paper, we carried out platform Brazilian splitting test, VIC-3D test, and acoustic emission test on rocks with cracks. We analyzed the influence of eccentricity and crack dip angle on tensile strength, macroscopic splitting failure characteristics, and microscopic damage evolution characteristics of specimens. Based on the existing Brazilian splitting theory and the obtained test results, the peak load prediction model of rock samples with eccentric cracks was established. Based on the damage theory and COMSOL numerical software, the splitting failure process of specimens was reproduced. The effects of eccentric distance, crack dip angle, position, and number of cracks on the strength and splitting failure are studied, and the splitting failure mechanism of eccentric fractured rock was revealed. The main conclusions are as follows:

(1) The variation trends of load-displacement curves of specimens are similar under different eccentric distance and crack dip angle, with compaction stage, elastic stage, stable crack growth stage, and unstable crack growth stage. The prefabricated cracks weaken the strength of the specimen, and the strength of the specimen is affected by the eccentricity and crack dip angle of the cracks. The peak load of the sample under different eccentric distances shows different variation laws with the increase of crack dip angle. With the increase of the eccentric distance, the peak load of the specimen shows a trend of increasing gradually.

(2) When the crack dip angle is constant and the eccentric distance r is 0 mm and 5 mm, the cracks caused by the failure of the sample mainly propagate from the prefabricated crack tip to the loading end. When the eccentric distance r is 10 mm, the crack propagates along the loading axis. When the eccentric distance is constant and the crack dip angle α is 30° - 90°, the splitting failure process of the sample changes obviously, and the failure mode is similar. Vertical splitting cracks are caused by tensile stress, while horizontal splitting cracks are mainly caused by compressive stress. The crack dip angle has no obvious effect on the acoustic emission characteristics of the sample. When r is 0 mm, i.e. no eccentric distance, the ringing count of acoustic emission presents a concentrated distribution pattern. When the crack has eccentric distance, the acoustic emission ringing count presents uniform distribution.

(3) Based on the test results and combined with the theoretical formula of the tensile strength of the complete Brazilian disc with the platform, we established a peak load prediction model for rock samples with different fracture inclinations when the eccentric distance is constant. On this basis, the peak load prediction model of rock samples is established under the coupling of two factors fracture eccentric distance and crack dip angle. The correctness and rationality of the prediction model are proved by comparing with the additional test results.

(4) Based on the damage theory and COMSOL numerical software, a numerical model for splitting test of specimens with cracks was established, and the numerical results were compared with the test results to verify the rationality of the numerical model. When the crack is in the horizontal direction, as the eccentric distance increases, the effect of the crack on the failure of the specimen is smaller, and the peak load shows an increasing trend. When the crack is on the loading axis, as the eccentric distance increases, the damage of the crack on the specimen increases, while the peak load shows a decreasing trend. The closer the crack is to the loading axis, the more significant the impact on the failure of the specimen, and the smaller the peak load. When the specimen contains double cracks, the crack dip angle of the crack has little effect on the failure mode of the specimen, but the peak load decreases first and then increases with the increase of the crack dip angle. When the double cracks are in the horizontal direction, as the eccentric distance increases, the influence on the failure of the specimen is smaller, but the peak load increases gradually.

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