工程地质学报2024，Vol.32Issue(3)：825-839,15.DOI:10.13544/j.cnki.jeg.2023-0424
怒江夏里段变质砂岩不同卸荷速率下破坏特性研究
STUDY ON DAMAGE CHARACTERISTICS OF METAMORPHIC SAND-STONE IN THE XIALI SECTION OF NU RIVER UNDER DIFFERENT UN-LOADING RATES
摘要
Abstract
The different excavation rates of tunnels have obvious effects on the mechanical properties of rock mass.This paper selects widely exposed metamorphic sandstone in the Nu River tectonic me'lange belt to carry out true triaxial unloading tests under different unloading rates.The tests use stress and strain monitoring,acoustic emission monitoring,numerical simulation,and other methods to explore the deformation and failure modes and characteris-tics of the rock under different unloading rates.The test results indicate that the increase in unloading rate causes the number of tension cracks to continue to increase and the failure mode of the rock to become more complex,with symbiotic morphological characteristics of tension cracks and shear cracks appearing.According to the law of energy evolution,as the unloading rate increases,the proportion of elastic strain energy of the rock mass increases,and the proportion of dissipated energy decreases.The energy used for rock mass destruction under peak stress increa-ses,and the sample failure becomes more severe.The change in acoustic emission energy appears in the unloading stage.High unloading rates produce the smallest damage deformation and less energy damage.In the destruction stage,damage occurs earlier,resulting in more severe damage.Numerical simulation tests show that as the unloa-ding rate increases,the rock mass gradually transitions from shear failure to tension failure,and the elastic strain energy and dissipation energy are consistent with the indoor test rules.The faster the unloading rate,the more com-plex the rock failure becomes.关键词
变质砂岩/真三轴/卸荷速率/能量演化/数值模拟Key words
Metamorphic sandstone/True-triaxial/Unloading rate/Energy evolution/Numerical simulation引用本文复制引用
赵宁,王炀,郭长宝,简文星,刘造保..怒江夏里段变质砂岩不同卸荷速率下破坏特性研究[J].工程地质学报,2024,32(3):825-839,15.基金项目
地质力学研究所基本科研业务费(资助号:DZLXJK202210),中国地质调查局项目(资助号:DD20190319,DD20221816)This research is supported by the Fundamental Science Foundation of Institute of Geomechanics(Grant No.DZLXJK202210)and China Geological Survey Project(Grant Nos.DD20190319,DD20221816). （资助号:DZLXJK202210）
