摘要
结构面作为岩体的薄弱环节往往决定了岩体的整体稳定性,为揭示结构面失稳的诱发机制,分析了滑动面形成过程中的受力和能量特征,建立了渐变失稳型结构面失稳的能量关系,并基于无量纲能量因子给出了单次扰动下结构面失稳的能量判据。利用三滑块模型和简化的折线型剪切本构关系定量分析了滑块稳定性的主要影响因素。分析发现,采用折线型本构时,失稳能量因子阈值可表示为结构面初始状态、材料变形本构特征的函数,其大小与名义极限应变的平方以及初始剪切力与极限抗力相对大小的平方成正比,而与扰动参数无关;单次扰动时,扰动频率越高,诱发失稳所需的扰动力越大。基于能量的理论分析得到的主要结论与极限平衡法的分析结果及相关试验结果揭示的一般规律吻合。所提无量纲能量因子判据为防控由结构面失稳而诱发的工程灾害提供了新的思路。
Structural planes,as weak links in rock masses,often determine the overall stability of the rock mass.To reveal the triggering mechanism of structural plane instability,the mechanical and energy characteristics during the formation of sliding surfaces are analyzed.The energy relationship for the progressive instability of structural planes is established,and an energy criterion for structural plane instability under single disturbance is proposed based on a dimensionless energy factor.The main influencing factors of block stability were quantitatively analyzed with a three-block model and a simplified bilinear shear constitutive relation.The analysis revealed that when adopting the bilinear constitutive relation,the threshold of the instability energy factor can be expressed as a function of the initial state of the structural plane and the constitutive characteristics of the material deformation.Its magnitude is proportional to the square of the nominal ultimate strain and the square of the relative magnitude of the initial shear force to the ultimate resistance,while being independent of disturbance parameters.Under single disturbance,higher disturbance frequencies require greater disturbing forces to induce instability.The main conclusions derived from the energy-based theoretical analysis are consistent with the results obtained from limit equilibrium methods and the general patterns revealed by relevant experimental results.The proposed dimensionless energy factor criterion provides a new perspective for preventing engineering disasters induced by structural plane instability.
作者
杨嘉楠
范鹏贤
李杰
王明洋
吴学震
YANG Jianan;FAN Pengxian;LI Jie;WANG Mingyang;WU Xuezhen(College of National Defence Engineering,Army Engineering University of PLA,Nanjing 210007,China;College of Civil Engineering,Fuzhou University,Fuzhou 350108,China)
出处
《陆军工程大学学报》
2025年第6期8-16,共9页
Journal of Army Engineering University of PLA
基金
国家自然科学基金(52438007,52279120)。
关键词
结构面
扰动
失稳
能量因子
名义极限剪切应变
structural plane
disturbance
instability
energy factor
nominal limit shear strain
