期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
Energy analysis of stability of twin shallow tunnels based on nonlinear failure criterion 被引量:2
1
作者 张佳华 许敬叔 张标 《Journal of Central South University》 SCIE EI CAS 2014年第12期4669-4676,共8页
Based on nonlinear Mohr-Coulomb failure criterion, the analytical solutions of stability number and supporting force on twin shallow tunnels were derived using upper bound theorem of limit analysis. The optimized solu... Based on nonlinear Mohr-Coulomb failure criterion, the analytical solutions of stability number and supporting force on twin shallow tunnels were derived using upper bound theorem of limit analysis. The optimized solutions were obtained by the technique of sequential quadratic programming. When nonlinear coefficient equals 1 and internal friction angle equals 0, the nonlinear Mohr-Coulomb failure criterion degenerates into linear failure criterion. The calculated results of stability number in this work were compared with previous results, and the agreement verifies the effectiveness of the present method. Under the condition of nonlinear Mohr-Coulomb failure criterion, the results show that the supporting force on twin shallow tunnels obviously increases when the nonlinear coefficient, burial depth, ground load or pore water pressure coefficients increase. When the clear distance is 0.5to 1.0 times the diameter of tunnel, the supporting force of twin shallow tunnels reaches its maximum value, which means that the tunnels are the easiest to collapse. While the clear distance increases to 3.5 times the diameter of tunnel, the calculation for twin shallow tunnels can be carried out by the method for independent single shallow tunnel. Therefore, 3.5 times the diameter of tunnel serves as a critical value to determine whether twin shallow tunnels influence each other. In designing twin shallow tunnels,appropriate clear distance value must be selected according to its change rules and actual topographic conditions, meanwhile, the influences of nonlinear failure criterion of soil materials and pore water must be completely considered. During the excavation process, supporting system should be intensified at the positions of larger burial depth or ground load to avoid collapses. 展开更多
关键词 nonlinear failure criterion twin shallow tunnels upper bound theorem stability number supporting force clear distance
下载PDF
Upper-Bound Limit Analysis of the Multi-Layer Slope Stability and Failure Mode Based on Generalized Horizontal Slice Method
2
作者 Huawei Zhang Changdong Li +5 位作者 Wenqiang Chen Ni Xie Guihua Wang Wenmin Yao Xihui Jiang Jingjing Long 《Journal of Earth Science》 SCIE CAS CSCD 2024年第3期929-940,共12页
Multi-layer slopes are widely found in clay residue receiving fields.A generalized horizontal slice method(GHSM)for assessing the stability of multi-layer slopes that considers the energy dissipation between adjacent ... Multi-layer slopes are widely found in clay residue receiving fields.A generalized horizontal slice method(GHSM)for assessing the stability of multi-layer slopes that considers the energy dissipation between adjacent horizontal slices is presented.In view of the upper-bound limit analysis theory,the energy equation is derived and the ultimate failure mode is generated by comparing the sliding surface passing through the slope toe(mode A)with that below(mode B).In addition,the influence of the number of slices on the stability coefficients in the GHSM is studied and the stable value is obtained.Compared to the original method(Chen’s method),the GHSM can acquire more precise results,which takes into account the energy dissipation in the inner sliding soil mass.Moreover,the GHSM,limit equilibrium method(LEM)and numerical simulation method(NSM)are applied to analyze the stability of a multi-layer slope with different slope angles and the results of the safety factor and failure mode are very close in each case.The ultimate failure modes are shown to be mode B when the slope angle is not more than 28°.It illustrates that the determination of the ultimate sliding surface requires comparison of multiple failure modes,not only mode A. 展开更多
关键词 stability and failure mode slope stability generalized horizontal slice method upperbound limit analysis energy dissipation geotechnical engineering.
原文传递
Finite element analysis of steep excavation slope failure by CFS theory 被引量:2
3
作者 Huihong Cheng Huai Zhang +1 位作者 Bojing Zhu Yaolin Shi 《Earthquake Science》 CSCD 2012年第2期177-185,共9页
The distribution of Coulomb failure stress (CFS) change in the steep excavation slope is calculated by finite element method in this paper, and the failure mechanics under different conditions have been investigated... The distribution of Coulomb failure stress (CFS) change in the steep excavation slope is calculated by finite element method in this paper, and the failure mechanics under different conditions have been investigated. Comparing the CFSs before and after the slope excavation (stress loading and unloading processes), the dangerous internal zone and the most likely failure external area are attained. Given the shear cracks on the top surface while tensile stress or cracks along the toe of the slope, we analyze the high cutting-angle steep slope in Kaixian county of the Three Gorges Reservoir region. We bring forward that the peak value of CFS after excavation can reach to the order of 0.1 MPa, which is greatly higher than that of before. Our preliminary results are useful for optimizing the reinforcement structure during the steep slope stabilization engineering. 展开更多
关键词 Coulomb failure stress stabilization and failure evaluation steep slope excavation
下载PDF
Stability analysis of slope in strain-softening soils using local arc-length solution scheme 被引量:3
4
作者 WANG Xiang-rong RONG Qi-guo +1 位作者 SUN Shu-li WANG Hui 《Journal of Mountain Science》 SCIE CSCD 2017年第1期175-187,共13页
Soils with strain-softening behavior — manifesting as a reduction of strength with increasing plastic strain — are commonly found in the natural environment. For slopes in these soils,a progressive failure mechanism... Soils with strain-softening behavior — manifesting as a reduction of strength with increasing plastic strain — are commonly found in the natural environment. For slopes in these soils,a progressive failure mechanism can occur due to a reduction of strength with increasing strain. Finite element method based numerical approaches have been widely performed for simulating such failure mechanism,owning to their ability for tracing the formation and development of the localized shear strain. However,the reliability of the currently used approaches are often affected by poor convergence or significant mesh-dependency,and their applicability is limited by the use of complicated soil models. This paper aims to overcome these limitations by developing a finite element approach using a local arc-length controlled iterative algorithm as the solution strategy. In the proposed finite element approach,the soils are simulated with an elastoplastic constitutive model in conjunction with the Mohr-Coulomb yield function. The strain-softening behavior is represented by a piece-wise linearrelationship between the Mohr-Coulomb strength parameters and the deviatoric plastic strain. To assess the reliability of the proposed finite element approach,comparisons of the numerical solutions obtained by different finite element methods and meshes with various qualities are presented. Moreover,a landslide triggered by excavation in a real expressway construction project is analyzed by the presented finite element approach to demonstrate its applicability for practical engineering problems. 展开更多
关键词 Strain-softening Progressive failure Slope stability Local arc-length scheme Numerical simulation
下载PDF
Geotechnical investigations and remediation design for failure of tunnel portal section: a case study in northern Turkey 被引量:7
5
作者 Ayberk KAYA Kadir KARAMAN Fikri BULUT 《Journal of Mountain Science》 SCIE CSCD 2017年第6期1140-1160,共21页
Mass movements are very common problems in the eastern Black Sea region of Turkey due to its climate conditions, geological, and geomorphological characteristics. High slope angle, weathering, dense rainfalls, and ant... Mass movements are very common problems in the eastern Black Sea region of Turkey due to its climate conditions, geological, and geomorphological characteristics. High slope angle, weathering, dense rainfalls, and anthropogenic impacts are generally reported as the most important triggering factors in the region. Following the portal slope excavations in the entrance section of Cankurtaran tunnel, located in the region, where the highly weathered andesitic tuff crops out, a circular toe failure occurred. The main target of the present study is to investigate the causes and occurrence mechanism of this failure and to determine the feasible remedial measures against it using finite element method(FEM) in four stages. These stages are slope stability analyses for pre-and postexcavation cases, and remediation design assessments for slope and tunnel. The results of the FEM-SSR analyses indicated that the insufficient initial support design and weathering of the andesitic tuffs are the main factors that caused the portal failure. After installing a rock retaining wall with jet grout columns and reinforced slope benching applications, the factor of safety increased from 0.83 to 2.80. In addition toslope stability evaluation, the Rock Mass Rating(RMR), Rock Mass Quality(Q) and New Austrian Tunneling Method(NATM) systems were also utilized as empirical methods to characterize the tunnel ground and to determine the tunnel support design. The performance of the suggested empirical support design, induced stress distributions and deformations were analyzed by means of numerical modelling. Finally, it was concluded that the recommended stabilization technique was essential for the dynamic long-term stability and prevents the effects of failure. Additionally, the FEM method gives useful and reasonably reliable results in evaluating the stability of cut slopes and tunnels excavated both in continuous and discontinuous rock masses. 展开更多
关键词 Portal failure stability analysis Finite element method Tunnel support design Remedial measures Rock Mass Rating(RMR) Rock Mass Quality(Q) New Austrian Tunneling Method(NATM)
下载PDF
Determination and stability analysis of ultimate open-pit slope under geomechanical uncertainty 被引量:10
6
作者 Ali Moradi Afrapoli Morteza Osanloo 《International Journal of Mining Science and Technology》 SCIE EI 2014年第1期105-110,共6页
In open-pit mines,pit slope as one of the important parameters affects the mine economy and total minable reserve,and it is also affected by different uncertainties which arising from many sources.One of the most crit... In open-pit mines,pit slope as one of the important parameters affects the mine economy and total minable reserve,and it is also affected by different uncertainties which arising from many sources.One of the most critical sources of uncertainty effects on the pit slope design is rock mass geomechanical properties.By comparing the probability of failure resulted from deterministic procedure and probabilistic one,this paper investigated the effects of aforesaid uncertainties on open-pit slope stability in metal mines.In this way,to reduce the effect of variance,it implemented Latin Hypercube Sampling(LHS)technique.Furthermore,a hypothesis test was exerted to compare the effects on two cases in Middle East.Subsequently,the investigation approved high influence of geomechanical uncertainties on overall pit steepness and stability in both iron and copper mines,though on the first case the effects were just over. 展开更多
关键词 Safety factor Probability of failure Geomechanical property uncertainty Overall pit slope stability analysis
下载PDF
Limits to foundation displacement of an extra high voltage transmission tower in a mining subsidence area 被引量:10
7
作者 Shu Qianjin Yuan Guanglin +1 位作者 Guo Guangli Zhang Yunfeit 《International Journal of Mining Science and Technology》 2012年第1期13-18,共6页
Given the background of a transmission tower erected on a particular mining subsidence area,we used finite element modeling to analyze the anti-deformation performance of transmission towers under a number of differen... Given the background of a transmission tower erected on a particular mining subsidence area,we used finite element modeling to analyze the anti-deformation performance of transmission towers under a number of different load conditions,including horizontal foundation displacement,uneven vertical downward displacement,wind loads and icing conditions.The results show that the failure in stability of a single steel angle iron represents the limit of the tower given ground deformation.We calculated the corresponding limits of foundation displacements.The results indicate that compression displacement of the foundation is more dangerous than tension displacement.Under complex foundation displacement conditions,horizontal foundation displacement is a key factor leading to failure in the stability of towers.Under conditions of compression or tension displacement of the foundation,wind load becomes the key factor.Towers do not fail when foundation displacements are smaller than 1% (under tension) or 0.5% (under horizontal compression or single foundation subsidence) of the distance between two supports. 展开更多
关键词 Mining subsidence area Electricity transmission tower Foundation displacement limit Finite element analysis Limit state stability failure
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部