泥岩非线性蠕变损伤-渗透愈合耦合模型及其应用  

New Coupled Model on Nonlinear Creep Damage and Permeability Healing of Mudstone and Its Application

作　　者：贾善坡[1,2] 于洪丹[2] 伍国军[2] 高敏[1] 龚俊[1] 张力伟[1] 

机构地区：[1]长江大学岩土力学与工程研究中心,湖北荆州434023 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《应用基础与工程科学学报》2016年第2期364-377,共14页Journal of Basic Science and Engineering

基　　金：岩土力学与工程国家重点实验室开放基金(Z013007);国家自然科学基金项目(41102182);湖北省自然科学基金项目(2015CFB194);中国博士后基金项目(2014M551055)

摘　　要：以某泥岩高放废物处置库为研究背景,根据室内试验和现场试验成果,提出了考虑泥岩应变硬化和软化以及蠕变效应的损伤判断准则和修正MohrCoulomb屈服破坏准则,建立了一种新的泥岩非线性黏弹塑性损伤模型;探讨了泥岩的渗透性演化机制,以泥岩损伤-渗透耦合及其自愈合为主线,建立了泥岩损伤-渗流耦合模型及渗透性自愈合演化方程.然后对地下储库施工过程进行了数值模拟,研究结果表明:施工质量对围岩扰动区有明显的影响,人工掘进巷道最大损伤约为0.38,明显大于采用盾构法施工的巷道;开挖后围岩渗透率明显增大,人工掘进巷道约为原岩的109倍,盾构施工巷道约为原岩的24倍;围岩蠕变损伤在巷道施工完成初期增长速度较快,扰动区渗透率略有增大,此后愈合应力和水化学效应对围岩渗透率的影响大于蠕变损伤的影响,扰动区渗透性逐渐恢复,约3年后渗透率愈合到原岩的数量级10^(-19)m^2.所提出的模型能有效地描述泥岩水-力耦合特性,对软岩隧洞长期稳定性的预测与预报具有一定的参考意义.In the context of research of deep nuclear waster disposal,mudstone from underground research laboratory and high-level radioactive waste repository has been studied in various works. In this paper,a nonlinear elasto-viscoplastic model from the modified Mohr-Coulomb criterion was presented based on the experiments in Lab and site of excavation-disturbed zone,which can depict the damage mechanism of hardening,plastic softening behaviours and creep deformation of mudstone. Using the relation between damage and strain,the damage evolution equations were developed in the framework of the irreversible thermodynamics. The laboratory experiments and field tests were performed,and the evolution mechanism of mudstone permeability were discussed and a new fully coupled creep damage model and permeability healing were established with introducing the damage and self-healing effect as the key factors that control the HM coupling of mudstone. Taking a high-level radioactive waste repository of mudstone as background,the construction characteristic of nuclear waste repository was simulated by the proposed models. The results show that the permeability of EDZ( excavation damaged zone) are 108 times and 24 times than that of the original mudstone by manual excavation and shield machine tunneling. The construction quality affects EDZ significantly and the damaged degree of the gallery by shield tunneling is less than that of manual excavation. The creep damage of EDZ increases obviously in the early stage after lining supporting and makes the permeability increased slightly. The permeability of EDZ tends to original mudstone with the order of magnitude of 10^(- 19)m^2 after 3 years because of the crack self-sealing and stress-water action. The proposed model is able to effectively depict the main features of hydro-mechanical behaviors of mudstone and it can be used for predicting the long-term stability of tunnel engineering.

关 键 词：泥岩 非线性蠕变模型 损伤 自愈合 渗透性演化 

分 类 号：TU45[建筑科学—岩土工程]