论文部分内容阅读
本文提出了系统研究岩石在脆性范围内的扩容,蠕变及松驰性状的初步报告. 文中全面地描述了新型的8000KN伺服控制的多功能三轴仪.在常应变率为5×10~(-5)/sec,对四组16个房山花岗岩和济南辉长岩试件进行了从100MPa到400MPa的各种围压和从25°到250℃的各种温度的试验.根据以前提出的蠕变扩容本构方程(陈、康,1980,1983),介绍了一种确定扩容参数n,D~*和C的新方法.试验经果表明扩容随着温度的增加而增加,随着围压的增加而受到抑制。为了进一步研究在线性和扩容阶段与时间有关的变形,进行了蠕变和松驰实验.在围压和温度分別为100和200MPa,7℃和200℃的条件下,采用梯级加载对房山花岗岩进行了二个蠕变试验.用这种方法还能从一个试件获得蠕变和扩容依赖于偏应力和时间的关系。最后,在围压分別为100MPa和200MPa,和温度分别为7℃和200℃的条件下,采用随时间变化的梯级应变,对花岗岩进行了二个松驰试验.从所得的应力—应变关系中确定出蠕变和松驰在扩容开始时的临界值f~*.文中还分析了与时间有关的扩容过程,并指出它与裂纹的增长、接合和产生,而导致的结构变化有关.
This paper presents a systematic study of the preliminary reports on the expansion, creep, and relaxation properties of rocks in the brittle range. This article describes a new type of 8000KN servo-controlled multifunctional triaxial apparatus. The constant strain rate is 5×10~( -5)/sec. Tests of various confining pressures from 100 MPa to 400 MPa and various temperatures from 25° to 250°C were carried out on four groups of 16 Fangshan granites and Jinan gabbros. According to the previously proposed creep Variable-expansion constitutive equations (Chen and Kang, 1980, 1983) introduce a new method for determining the expansion parameters n, D, and C. Test results show that the expansion increases with increasing temperature, with confining pressure The increase was inhibited. In order to further study the time-dependent deformations in the linear and dilatation stages, creep and relaxation experiments were carried out. At a confining pressure and temperatures of 100 and 200 MPa, 7°C and 200°C, respectively, stepped loading was used to carry out the Fangshan granite. Two creep tests. Creep and expansion can also be obtained from a test piece in this way depending on the relationship between deviatoric stress and time. Finally, under the conditions of confining pressures of 100 MPa and 200 MPa, and temperatures of 7°C and 200°C respectively, two relaxation tests were performed on the granite using stepwise strain over time. From the resulting stress-strain relationship The critical value f~* of creep and relaxation at the beginning of expansion is determined. The time-dependent expansion process is also analyzed and it is pointed out that it is related to the growth, jointing and generation of cracks, and the resulting structural changes.