CAJ | 학술논문

首先分别采用传统加载程序和新加载程序，对利用簇平行黏结模型所建立的颗粒流试样的力学特性进行研究。同时采用新加载程序，分析加载速率和冻结期时步对颗粒流试样力学特性的影响。随后利用量纲分析法研究簇平行黏结模型中微观参数对宏观参数的影响，建立岩石材料宏观参数(弹性模量、泊松比、单轴抗压强度和单轴抗拉强度)与簇平行黏结模型中微观参数间的半定量关系。相关模拟结果表明：(1)利用传统加载程序计算得出的岩石应力-应变曲线是不准确的，它高估了单轴抗压强度、单轴抗拉强度和弹性模量，且不能真实再现岩石峰后脆性特征；2种加载程序得出的岩石破坏形态差异很大。(2)结合新加载程序，簇平行黏结模型能得到合理的单轴抗压强度和单轴抗拉强度比值(UCS/TS)。在准静态范围内，加载速率与强度值没有相关性，这与试验结果吻合，加载速率对岩石应力-应变曲线的影响主要在峰后阶段。(3)弹性模量主要与颗粒接触模量和颗粒接触刚度比相关，而泊松比主要与接触刚度比相关。为得到相同的泊松比值，簇平行黏结模型中的接触刚度比应大于平行黏结模型中的接触刚度比。单轴抗压强度和单轴抗拉强度主要受平行黏结强度比控制，另外单轴抗压强度受簇中颗粒数影响较大。
수선분별채용전통가재정서화신가재정서，대이용족평행점결모형소건립적과립류시양적역학특성진행연구。동시채용신가재정서，분석가재속솔화동결기시보대과립류시양역학특성적영향。수후이용량강분석법연구족평행점결모형중미관삼수대굉관삼수적영향，건립암석재료굉관삼수(탄성모량、박송비、단축항압강도화단축항랍강도)여족평행점결모형중미관삼수간적반정량관계。상관모의결과표명：(1)이용전통가재정서계산득출적암석응력-응변곡선시불준학적，타고고료단축항압강도、단축항랍강도화탄성모량，차불능진실재현암석봉후취성특정；2충가재정서득출적암석파배형태차이흔대。(2)결합신가재정서，족평행점결모형능득도합리적단축항압강도화단축항랍강도비치(UCS/TS)。재준정태범위내，가재속솔여강도치몰유상관성，저여시험결과문합，가재속솔대암석응력-응변곡선적영향주요재봉후계단。(3)탄성모량주요여과립접촉모량화과립접촉강도비상관，이박송비주요여접촉강도비상관。위득도상동적박송비치，족평행점결모형중적접촉강도비응대우평행점결모형중적접촉강도비。단축항압강도화단축항랍강도주요수평행점결강도비공제，령외단축항압강도수족중과립수영향교대。
Based on the new and conventional loading procedures,the rock mechanical behaviors are simulated through using the clump parallel-bond model(CPBM) to conduct a series of numerical experiments at the specimen scale. Meanwhile,using the new developed loading procedure,the effects of loading rate and frozen period on the stress-strain response of a particle model are investigated. Furthermore,the effects of microscopic parameters on macroscopic parameters of the specimen,which is modeled by the CPBM,are studied using the dimensional analysis. Certain semi-quantification relationships between macroscopic parameters,such as the elastic modulus,Poisson′s ratio,uniaxial compressive strength(UCS) and tensile strength(TS),and microscopic parameters of the specimen are established. The related numerical results have demonstrated that:(1) When using the conventional loading procedure,the produced stress-strain curve is incorrect;the elastic modulus,UCS and TS are overestimated;while the post-peak mechanical response of brittle rock with brittle behaviour cannot be reproduced. The failure patterns of the specimens under different loading procedures are totally different. (2) When using the new loading procedure,the CPBM can be used to reproduce a high ratio of the uniaxial compressive strength to tensile strength(UCS/TS>10). The strength is independent on the loading rate in the quasi-static range,which is consistent with the experimental results. Meanwhile,the effect of loading rate is mainly concentrated on the post-peak range of the stress-strain curves. (3) Elastic modulus is mainly determined by the particle contact modulus and contact stiffness ratio. Poisson′s ratio is mainly determined by the contact stiffness ratio. Compared with the conventional parallel-bond model,in order to obtain the same Poisson′s ratio in the calibration,a larger value of the contact stiffness ratio should be chosen in the CPBM. The UCS and TS can be scaled by either the parallel-bond shear strength or the parallel-bond normal strength,depending on the ratio of the two quantities. The UCS is also dependent on the number of particles in one clump.