刀具与岩石相互作用模型及破岩规律研究

发布时间：2018-05-17 06:05

本文选题：破岩效率 + 节理特征　；参考：《大连理工大学》2013年硕士论文

【摘要】：随着现代经济的高速发展,人们的日常生活面临着环境污染、交通阻塞等诸多问题。地下空间的开发利用能够从一定程度上解决这些问题,因而地下空间成为世界各国的建设主流,地下不再是阴冷潮湿的场所,而成为人类生态空间的又一延伸。盾构施工具有低噪音、低振动、施工安全等特点,同时对地上建筑物以及交通运输等均产生较小影响,凭借这些优越性,盾构施工法得到了广泛应用,成为隧道、地铁、水利水电等地下空间工程建设中的一种主要施工方法。盾构施工主要是通过掘进机刀盘上布置的刀具滚压、切削岩体而完成掘进,刀具与岩体的相互作用情况直接关系到掘进机的工作效率。因而,研究岩体在掘进机刀具作用下的破碎特性具有重要的理论价值和工程指导意义。本文在国家自然科学基金项目(51079017、51274053)、全国优秀博士论文专项基金项目(200960)、国家基础研究计划(973)项目(2011CB13500)资助下,采用RFPA软件对掘进机滚刀作用下岩体破碎机理进行数值模拟研究,完成了以下主要内容： 1.通过阅读相关文献,归纳、总结了国内外学者关于刀具破岩在理论、物理实验和数值模拟等方面的研究现况。 2.基于岩石真实破裂过程分析方法,通过采用多种破坏准则,实现刀具破岩过程中的拉伸开裂、剪切破坏和接触挤压作用的模拟。建立多滚刀以不同作用方式侵入完整岩体和单滚刀侵入节理岩体的二维数值模型,模拟了刀头作用下岩体的破碎过程,探讨了刀头作用方式、围压、刀间距和节理特征等对破坏模式、破岩角、刀头作用载荷以及裂纹扩展能力的影响规律,与物理实验具有较好的一致性。研究结果表明： (1)滚刀相位角的存在对岩石的破碎模式和破碎效率有着重要的影响,滚刀顺次加刀优于同时加刀。 (2)围压增大,裂纹向深部扩展能力降低。相同围压下顺次加载时存在最优刀间距。同时加载时,随着围压的增加,最优刀间距逐渐增加。 (3)倾斜节理导致刀头两侧裂纹的不对称扩展,节理有利于刀头与节理之间产生贯通裂纹,提高了破岩效率,但节理阻止了侧向裂纹的穿透扩展。 (4)随着节理倾角的增大,跃进点载荷、残余载荷平均值、侵入量表现出先减小而后又增大的V型走势。节理倾角--定时,跃进点对应的载荷、侵入量随着节理间距的增大而增大,密集的节理分布有利于提高掘进效率。 3.建立刀具与岩石的三维相互作用模型,通过物理实验和数值模拟的对比,更深层次地揭示刀具破岩机理,同时探讨了围压对岩石破碎特性的影响规律。研究结果表明： (1)刀头侵入岩石不断重复着加载一挤密一破坏的过程,刀头下部的核心区和损伤区不断扩大,最终导致裂纹形成、岩样破坏。 (2)围压不同,岩石中裂纹扩展模式不同,损伤分布区域不同。随着围压的增大,跃进点载荷、刀头侵入量以及抗侵入系数增大,而载荷跃进幅度、破岩角随之减小,岩石的抗侵入能力增强。
[Abstract]:With the rapid development of modern economy, people's daily life is faced with environmental pollution, traffic congestion and many other problems. The development and utilization of underground space can solve these problems to a certain extent. Therefore, underground space has become the mainstream of the world's construction, underground is no longer a place of cold and damp, and it becomes the ecological space of human beings. An extension.
Shield construction has the characteristics of low noise, low vibration, construction safety and so on. At the same time, it has a small influence on the ground buildings and transportation. By virtue of these advantages, the shield construction method has been widely used. It has become a main construction method in the construction of underground space engineering, such as tunnel, subway, water conservancy and hydropower and so on. The main shield construction is the construction of the shield construction. The interaction between cutting tools and rock mass is directly related to the working efficiency of the roadheader by cutting the cutting tool on the cutter plate of the boring machine and cutting rock mass, and the interaction between the cutting tool and the rock mass is directly related to the working efficiency of the roadheader. Therefore, it is of great theoretical and engineering significance to study the fracture characteristics of the rock mass under the action of the cutting tool.
In this paper, under the National Natural Science Foundation Project (5107901751274053), the National Excellent Doctoral Dissertation special fund project (200960), the national basic research plan (973) project (2011CB13500), the RFPA software is used to simulate the rock breaking mechanism of the rock mass under the action of the boring machine, and the following main contents are completed:
1. by reading related literature, the research status of cutting tools for rock breaking in theory, physical experiment and numerical simulation is summarized and summarized.
2. based on the analysis method of rock real fracture process, by using a variety of failure criteria, the simulation of tensile cracking, shear failure and contact extrusion in the cutting process of cutting tools is realized. The two-dimensional numerical model of multiple hob invading the whole rock mass and single hob invading the jointed rock mass is established in different ways, and the rock mass under the action of the knife head is simulated. The effect of the mode of action of the knife head, the confining pressure, the spacing of the knife and the joint characteristics on the failure mode, the rock breaking angle, the working load of the cutter head and the crack propagation ability are discussed, which are in good agreement with the physical experiment. The results show that:
(1) the existence of hob's phase angle has an important influence on the crushing mode and crushing efficiency of the rock, and the hob's sequential addition is superior to that of the cutter at the same time.
(2) when the confining pressure increases, the ability of crack to deep expansion is reduced. The optimal tool spacing exists in the same confining pressure. At the same time, the optimal tool spacing increases with the increase of confining pressure.
(3) the slanting joint leads to the asymmetric expansion of the cracks on both sides of the cutter head, which helps to produce a penetrating crack between the cutter head and the joint and improves the efficiency of rock breaking, but the joint prevents the penetration and expansion of the lateral crack.
(4) with the increase of the joint angle, the load of the jump point and the mean value of the residual load, the invasion quantity shows the trend of the V type which decreases first and then increases. The joint inclination - time and the load corresponding to the jump point increase with the increase of the joint space, and the distribution of dense joints is beneficial to improving the driving efficiency.
3. the three-dimensional interaction model of cutting tool and rock is established. Through the comparison of physical experiments and numerical simulation, the mechanism of rock breaking is revealed deeper and the influence of confining pressure on rock breaking characteristics is discussed. The results show that:
(1) the knife head invaded the rock continuously and repeated the process of loading and compaction. The core area and the damage area in the lower part of the knife were expanding, which eventually resulted in the formation of the cracks and the failure of the rock.
(2) with the different confining pressure, the crack propagation modes in the rock are different, and the damage distribution area is different. With the increase of the confining pressure, the load of the jump point, the increase of the penetration and the anti intrusion coefficient of the cutter head, the load jump amplitude, the rock breaking angle decrease, and the rock's anti intrusion ability is enhanced.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU94;TU45

【参考文献】