酸化岩石在动静组合作用下的力学性能及岩爆机理研究

发布时间：2019-05-17 10:13

【摘要】：深部岩石力学问题是岩石力学与地下工程领域研究的焦点问题,在深部地下工程开采过程中,深部岩石由于开挖卸荷致使岩体应力重分布,储存在岩石内的能量突然释放出来,致使岩爆灾害的产生。岩爆发生机理极为复杂,与深部岩体所处的周边环境密切相关。在深部地下环境中,深部岩石受到高地应力产生的静载以及工程扰动或地震产生的动载共同作用。此外,酸性水溶液广泛存在于地下深部工程,深部岩石长期处于酸性溶液浸泡,其力学性能与浅部岩石完全不同。基于地下深部工程的实际情况,本文开展了酸化岩石在动静组合作用下的力学性能及岩爆机理研究,为深部地下工程的岩爆机理研究以及岩爆预测提供参考。首先,采用取芯机及磨石机对岩石进行取芯并打磨,制备大理岩及红砂岩的岩石试样,采用切割机将岩样尺寸制定为50×25mm以及50×100mm的圆柱体试件。其次,将浓盐酸用水稀释,配制得到PH=4的酸性溶液,并用PH测试笔进行溶液PH值的测定,将上述试样置于该酸性溶液中养护30d,所测得的每隔12小时酸性溶液的PH值后用胶头滴管滴加盐酸保持溶液酸性维持在PH=4,利用万能压力试验机测得岩石的单轴抗压强度以及单轴抗拉强度。然后在霍普金森压杆上进行动静组合作用下岩石的动态力学试验,采用二波法对试验数据进行处理得到了岩样的动态破坏应力-应变关系曲线,并根据能量理论对岩爆动力学机理进行了研究。本文研究得出如下结论:1、化学腐蚀作用下岩石单轴抗压及抗拉强度显著下降,且单轴抗压强度较抗拉强度下降更为明显。大理岩较红砂岩的质量损伤更大,且大理岩的力学性能比红砂岩变化的更为明显。2、在冲击动载作用下,酸化后红砂岩的动态抗压强度远大于酸化后大理岩的动态抗压强度,且红砂岩与大理岩的动态抗压强度均随着冲击气压的增大而增大。轴向静载及围压能显著提高岩石的动态抗压强度。3、在一维及三维动静组合作用下,随着冲击气压或平均应变率的增加,岩样破碎的碎块颗粒直径明显降低,有着显著的应变率相关性。4、动静组合作用下酸化红砂岩的动态抗压强度随着红砂岩吸收能量的增大而增大,经计算发现本试验中的酸化岩石不具有岩爆倾向性。
[Abstract]:The problem of deep rock mechanics is the focus of research in the field of rock mechanics and underground engineering. In the process of deep underground engineering mining, the stress redistribution of rock mass is caused by excavation and unloading of deep rock, and the energy stored in the rock is suddenly released. Resulting in the emergence of rock burst disasters. The mechanism of rock burst is very complex, which is closely related to the surrounding environment of deep rock mass. In the deep underground environment, the deep rock is subjected to the static load caused by the high ground stress and the dynamic load caused by the engineering disturbance or earthquake. In addition, acidic aqueous solution widely exists in deep underground engineering, and the deep rock is immersed in acidic solution for a long time, and its mechanical properties are completely different from those of shallow rock. Based on the actual situation of deep underground engineering, the mechanical properties and rock burst mechanism of acidified rock under the action of dynamic and static combination are studied in this paper, which provides a reference for the study of rock burst mechanism and rock burst prediction of deep underground engineering. Firstly, the rock samples of marble and red sandstone are prepared by coring and grinding with coring machine and grinding machine, and the cylinder specimens with the size of 50 脳 25mm and 50 脳 100mm are determined by cutting machine. Secondly, the acid solution of PH=4 was prepared by dilute the concentrated hydrochloric acid with water, and the PH value of the solution was determined by PH test pen, and the sample was preserved in the acidic solution for 30 days. The PH value of the acid solution was measured every 12 hours, and then the acid of the solution was maintained by adding hydrochloric acid to the rubber drop tube. The uniaxial compressive strength and uniaxial tensile strength of the rock were measured by the universal pressure tester in PH=4,. Then the dynamic mechanical test of rock under the action of dynamic and static combination is carried out on Hopkinson pressure bar, and the dynamic failure stress-strain relationship curve of rock sample is obtained by using two-wave method to process the test data. According to the energy theory, the dynamic mechanism of rock burst is studied. In this paper, the following conclusions are drawn: 1. The uniaxial compressive strength and tensile strength of rock under chemical corrosion are significantly decreased, and the uniaxial compressive strength is more obvious than the tensile strength. The mass damage of Dali rock is greater than that of red sandstone, and the mechanical properties of marble are more obvious than those of red sandstone. 2. Under impact dynamic load, the dynamic compressive strength of acidified red sandstone is much greater than that of acidified marble. The dynamic compressive strength of red sandstone and marble increases with the increase of impact pressure. Axial static load and confining pressure can significantly improve the dynamic compressive strength of rock. 3. Under the action of one-dimensional and three-dimensional dynamic and static combination, with the increase of impact pressure or average strain rate, the particle diameter of broken rock sample decreases obviously. There is a significant strain rate correlation. 4. The dynamic compressive strength of acidified red sandstone increases with the increase of absorption energy of red sandstone under the action of dynamic and static combination. It is found that the acidified rock in this experiment does not have rockburst tendency.
【学位授予单位】：华东交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45

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