| 基于统一强度理论深埋圆形隧道围岩的剪胀分析 |
| |
| 引用本文： | 王凤云,钱德玲.基于统一强度理论深埋圆形隧道围岩的剪胀分析[J].岩土力学,2019,40(5):1966-1976. |
| |
| 作者姓名： | 王凤云 钱德玲 |
| |
| 作者单位： | 1. 合肥工业大学 土木与水利工程学院，安徽 合肥 230009；2. 安徽建筑大学 土木工程学院，安徽 合肥 230022 |
| |
| 基金项目： | 国家自然基金资助项目（No. 51378168）。 |
| |
| 摘 要： | 基于连续介质理论中岩体的剪胀角与围压和塑性剪切应变密切相关，隧洞周边岩体的应力状态因开挖卸荷而发生应力重分布，迫使其围压由原地应力逐渐衰减，塑性剪切应变不断增加，引起剪胀效应呈非线性变化。首先，基于统一强度理论和非关联流动法则，将潜在塑性区围岩按等围压释放划分为若干同心圆，提出了考虑中间主应力和非线性剪胀性的有限差分法，计算应变软化围岩的力学问题，并以实例验证其正确性。其次，通过参数分析，研究塑性区内岩体的剪胀角受中间主应力、临界软化系数和支护力的影响规律。研究结果表明，中间主应力主要影响剪胀角的峰值，随着中间主应力效应增加，剪胀峰值增加；临界软化系数主要影响剪胀角的变化率，随着临界软化系数的增加，剪胀角变化缓慢；中间主应力和临界软化系数共同影响塑性区剪胀角的变化；随着支护力的增加，洞壁处的剪胀角增加；双剪强度理论计算的位移值较小，应谨慎采用，同时采用Mohr-Coulomb强度准则时可以适当考虑围岩的承载潜力。
|
| 关 键 词： | 隧道 统一强度理论 中间主应力 应变软化 非线性剪胀 |
| 收稿时间： | 2017-12-21 |
Dilatancy analysis for a circular tunnel excavated in rock mass based on unified strength theory |
| |
| WANG Feng-yun,QIAN De-ling.Dilatancy analysis for a circular tunnel excavated in rock mass based on unified strength theory[J].Rock and Soil Mechanics,2019,40(5):1966-1976. |
| |
| Authors: | WANG Feng-yun QIAN De-ling |
| |
| Institution: | 1. Scool of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, Anhui 230009, China;
2. School of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui 230022, China |
| |
| Abstract: | Based on the continuum theory, the dilatancy angle is related to the confining stress and plastic shear strain. Due to the tunnel excavation, the confining stress of rock mass decreases from the initial stress to the support force, while the plastic shear strain increases. Thus the dilatancy coefficient varies nonlinear. In this study, based on the unified strength failure criterion and non-associated flow rule, the potential plastic zone was divided into a finite number of concentric rings according to the equal decreased confining stress. A finite difference method was proposed by considering the effects of the intermediate principal stress and nonlinear dilatancy. Then the accuracy of this method was further verified using example analysis. The parameter analysis was conducted to study the effects of the intermediate principal stress, the critical softening parameter and the support load on the dilatancy angle in the plastic zone of rock mass. It was found that the peak dilatancy increased with the increase of the intermediate principal stress. The variation rate of dilatancy angle became slowly with the increase of the critical softening parameter. The intermediate principal stress and the critical softening parameter showed corporate effects on the variation of dilatancy angle in the plastic zone. The dilatancy angle at the tunnel wall increased with the increase of the support load. The double shear strength criterion should be used cautiously in the tunnel because the calculated displacement at the tunnel wall is small. Additionally, when the Mohr-Coulomb strength criterion is used, it is proper to consider the bearing potential of rock mass. |
| |
| Keywords: | tunnels unified strength theory intermediate stress strain-softening behavior nonlinear dilatancy |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《岩土力学》浏览原始摘要信息 |
| 点击此处可从《岩土力学》下载免费的PDF全文 |
