热-力作用对岩石热破坏模式及其阈值影响的数值模拟

1.教育部 西部矿井开采及灾害防治重点实验室,陕西 西安 710054; 2.西安科技大学 安全科学与工程学院,陕西 西安 710054; 3.西部煤矿安全教育部工程研究中心,陕西 西安 710054

RFPA; 温度阈值; 声发射; 声发射能量; 热-力耦合

Numerical simulation on effect of temperature-pressure on the failure mode and threshold of the rock
XIAO Yang1,2,3,ZHOU Yi-feng2,MA Li1,2,3,LU Jun-hui2

(1.Key Laboratory of Western Mine Exploration and Hazard Prevention,Ministry of Education,Xi'an 710054,China; 2.College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 3.Western Coal Mine Safety Engineering Research Center of the Ministry of Education,Xi'an 710054,China)

RFPA; temperature threshold; AE; AE energy; thermal mechanical coupling

DOI: 10.13800/j.cnki.xakjdxxb.2017.0505

备注

物理实验研究温度对岩石热破坏的影响,并不能够反映岩石内部热破坏应力场及温度场的移动,文中运用RFPA-thermal软件,建立了热-力耦合数学模型,模拟了岩石的热破坏过程。得到了温度对岩样热破坏模式、温度阈值、声发射(AE)特征等。结果 表明:在固定压力下,随温度的升高,孔裂隙演化逐渐加快,主要是沿着原有裂隙的通道继续延长和加宽,同时也有部分新生裂隙产生。在300 ℃附近时,裂隙发展迅速加快,此温度是其温度阈值。AE次数和其能量随温度升高呈指数增长,并得到了相应的拟合公式。

The study of temperature effect on thermal destruction of rock using physical experiments can't reflect movement of the stress field and temperature field of heat damage inside the rock.The RFPA-thermal software is employed to build a thermo-mechanical coupled mathematical model to simulates the thermal destruction of rocks on setting simulation program in this paper.The pattern of thermal damage,the threshold temperature,acoustic emission(AE)characteristics of rock sample are obtained from the simulation.The results show that as the temperature increase under fixed pressure,the evolution of crack and fracture gradually accelerate,which mainly continue extends and widens along the existing crack and fracture.Meanwhile,there some more new fractures generate during the process.Cracks develop rapidly accelerated around 300 ℃ that is the temperature threshold.AE account and its energy represent exponentially growth with increasing temperature,and the corresponding fitting formula is got.