摘要
从体积方面考虑水平盐穴适合于我国较薄的层状盐岩,但它有可能与夹层相交。为分析夹层对水平盐穴应力和破损的影响,建立一种含夹层水平盐穴的模型。基于夹层单元受力平衡和界面上荷载传递机制,推导出界面和夹层的应力解析解。并将应力公式与莫尔–库仑准则相结合,对界面滑移和围岩塑性区进行分析。研究表明:界面剪应力与盐岩夹层的相对位移成正比;盐穴附近界面剪应力最大,该处最易发生界面滑移,并且界面剪应力随夹层弹性模量和夹层厚度增大;夹层的平衡方程表明夹层径向应力的导数与界面剪应力有关,而界面剪应力的方向在中性点发生改变,所以夹层径向应力先减小再增大;主应力σ_1和σ_3分别为切向应力和径向应力,夹层切向应力和盐岩相等,而夹层径向应力小于盐岩,所以夹层塑性区的范围大于盐岩。
In terms of its volume, horizontal salt cavern is appropriate for the thin bedded salt in China, but it would probably intersect with the interlayer. In order to analyze the effects of interlayer on stress and failure of horizontal salt cavern, a model of horizontal salt cavern with interlayer was built. The analytic solutions of stresses of the interlayer and the interface were obtained based on the force balance of the interlayer element and the mechanism of load transfer on the interface. Then the stress formulas and the Mohr-Coulomb criterion were combined together to analyze the interface sliding and the plastic zone of the surrounding rock. It was found that the shear stress on the interface was proportional to the relative displacement of the salt rock and the interlayer. The shear stress on the interface attained its maximum near the salt cavern, and the interface sliding most easily occurred there. The shear stress on the interface increased with the elasticity modulus and the thickness of interlayer. The equilibrium equation of the interlayer indicated that the derivative of the radial stress in the interlayer was related to the shear stress on the interface. The direction of the shear stress changed at the neutral point. Therefore, the radial stress in the interlayer decreased first and then increased. The principle stresses σ1 and σ3 were the tangential stress and the radial stress. The tangential stress of the interlayer was equal to that of the salt rock and the radial stress of the interlayer was less than that of the salt rock. So the plastic zone of the interlayer was wider than that of the salt rock.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2017年第A01期3314-3320,共7页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(41272391
51404241
41472285)~~
关键词
岩石力学
水平盐穴
夹层
界面
荷载传递法
应力分布
破损机制
rock mechanics
horizontal salt cavern
interlayer
interface
load transfer method
stress distribution
failure mechanism
