西安建筑科技大学学报(自然科学版)

对于传统分析方法无法精准表征围岩的实际变形以及参数演化问题,在H-B准则和应变软化模型结合下选定塑性应变增量作为软化参数,并且假设强度参数随软化参数成线性函数关系.求解塑性区的解答时,将塑性区分成微元圆环,并假设每个圆环的径向应力沿半径向内均匀递减,从而建立每个微元圆环的平衡微分方程、本构方程、几何方程及相邻两微元之间的应力增量和应变增量的关系.最终建立了的圆形隧道在弹塑性交界面以及塑性区内的应力场、应变场和位移场的表达式,并将推导得到的理论表达式通过编程在MATLAB中实现了精准的数值计算,同时验证了程序运行的正确性.在完成上述研究内容以后,下一步将其应用到现场工程隧道中去论证建立理论模型和数值运算程序的实用性,为实现工程现场的稳定性监控和预警做准备.

For the traditional analysis method, the actual deformation of the surrounding rock and the parameter evolution problem cannot be accurately characterized. The plastic strain increment is selected as the softening parameter under the combination of the H-B criterion and the strain softening model, and the strength parameter is assumed to be linearly related to the softening parameter. When solving the solution of the plastic zone, the plasticity is divided into micro-rings, and the radial stress of each ring is uniformly decreased inward along the radius, thus establishing the equilibrium differential equation and constitutive equation of each micro-ring. The geometric equation and the relationship between the stress increment and the strain increment between two adjacent microelements. Finally, the expressions of the stress field, strain field and displacement field of the circular tunnel in the elastoplastic interface and the plastic zone are established, and the theoretical expressions derived are accurately calculated by programming in MATLAB. Verifies the correctness of the program running. After completing the above research content, the next step is to apply it to the field engineering tunnel to demonstrate the practicality of establishing theoretical models and numerical calculation programs, in preparation for the stability monitoring and early warning of the project site.

引言
1 问题的提出
2 问题的理论求解
3 实例验证
4 结论

图1 应变软化材料的应力 - 应变关系曲线<br/>Fig.1 Stress-strain curves of strain softening materials

图1 应变软化材料的应力 - 应变关系曲线
Fig.1 Stress-strain curves of strain softening materials

图2 原岩应力状态下初始应力场示意图<br/>Fig.2 Sketch map of the primary stress field under the condition of original rock stress

图2 原岩应力状态下初始应力场示意图
Fig.2 Sketch map of the primary stress field under the condition of original rock stress

图3 弹塑性交界面处解答示意图<br/>Fig.3 Sketch map of elastic-plastic interface

图3 弹塑性交界面处解答示意图
Fig.3 Sketch map of elastic-plastic interface

图4 围岩弹 - 塑性区域划分<br/>Fig.4 Sketch map of the division of surrounding rock at elastic-plastic interface

图4 围岩弹 - 塑性区域划分
Fig.4 Sketch map of the division of surrounding rock at elastic-plastic interface

图5 塑性区域微元圆环示意图<br/>Fig.5 Sketch map of micro ring in plastic zone

图5 塑性区域微元圆环示意图
Fig.5 Sketch map of micro ring in plastic zone

图6 径向应力σr<br/>Fig.6 radial stress map(σr)

图6 径向应力σr
Fig.6 radial stress map(σr)

图7 环向应力σθ图<br/>Fig.7 Hoop stress map(σθ)

图7 环向应力σθ图
Fig.7 Hoop stress map(σθ)

图8 (a)径向应变εr图<br/>Fig.8 (a)Radial strain map(εr)

图8 (a)径向应变εr图
Fig.8 (a)Radial strain map(εr)

图8 (b)环向应变εθ图<br/>Fig.8 (b)Hoop stress map(εθ)

图8 (b)环向应变εθ图
Fig.8 (b)Hoop stress map(εθ)

图8 (c)径向位移u图<br/>Fig.8 (c)Radial displacement map(u)

图8 (c)径向位移u图
Fig.8 (c)Radial displacement map(u)

图9 r=10b径向应力σr图<br/>Fig.9 Radial strain map(r=10b)

图9 r=10b径向应力σr图
Fig.9 Radial strain map(r=10b)

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备注

引言

1 问题的提出

2 问题的理论求解

3 实例验证

4 结论

期刊信息