含三维内置断裂面新型材料断裂体破裂过程研究

Study on failure process of fractured rock by using a new material containing three-dimensional internal fracture surfaces

由于不透明的内含裂隙的岩石类材料难以直接观测其破裂过程和开展含三维裂隙试验的复杂性等原因,目前含三维断裂面岩体的破裂研究还处于初期阶段。研制一种完全透明、在较低温度下拉压强度比可达1/6.6的树脂材料,其与岩石特性的相似性比前人有大幅度提高。建立一整套可制作含多断裂面试件的工艺流程和相应的模具及技术,并初步开展含单个和双个内置椭圆形断裂面试件在单轴加载下的试验。研究次生裂纹扩展和试件破裂规律与应力-应变关系。试验结果表明:试件的破裂大致经历4个阶段。含三维断裂体试件的破裂比二维情况复杂得多,产生多种不同形态的新裂纹。

As it is difficult to observe the failure process directly and carry out the tests on opaque rock-like materials with built-in 3D cracks, in geophysical and geomechanical field, the study on the failure of fracture surface is still in its early stage. A new transparent material whose tension-compression strength ratio can reach 1/6.6 at low temperature was developed. Its properties are more similar to the rock than previous materials made by scholars. A set of technological process and casting mould which makes specimens with multi cracks was developed and the tests under uniaxial compression were conducted. Besides, the stress-strain relationship, the propagation process of secondary cracks and the regularity of the fracture of specimens were studied as well. The results show that the destruction of the specimens goes through about four stages before the fracture of specimen. Many different fracture characters for the specimens with 3D cracks, which are much more complex than that of with 2D cracks are discovered.