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1.
岩体结构面抗剪强度估算方法研究进展   总被引:2,自引:0,他引:2  
结构面抗剪强度是工程岩体稳定性评价的重要参数,经验估算方法是获得结构面抗剪强度参数的有效途径之一。随着研究的不断深入,估算方法有可能替代直剪试验直接提供岩体结构面抗剪强度。本文介绍了岩体结构面抗剪强度经验估算方法的研究现状,评述了经验估算方法不同公式的特点,并指出经验估算方法的发展趋势。  相似文献   

2.
岩体结构面抗剪强度是影响岩体稳定性的重要指标。根据Jaeger单一结构面强度理论,岩石三轴剪切破坏面上的受力情况可看作岩石单一结构面剪切,利用岩石三轴压缩剪切破坏后的残余变形试验方法与岩体结构面直剪试验方法对比分析,得出岩体剪切面的抗剪强度。  相似文献   

3.
基于巴顿 (Barton)岩体质量评价 ,用霍克 (Hoek)经验方法推求岩体抗剪强度参数 ,为工程设计提供参考 ;同时探讨节理岩体强度研究方法及其在工程实践中的应用。结果表明霍克经验方法是确定岩体抗剪强度的有效方法 ,在工程勘测设计中具有重要的参考应用价值。  相似文献   

4.
大梁山隧道围岩稳定性研究   总被引:1,自引:0,他引:1  
在野外隧道工程地质条件调查的基础上,通过岩体结构分析判断潜在破坏方式,经验估算方法获取节理抗剪强度参数,运用块体理论评价了大梁山隧道的围岩稳定性。  相似文献   

5.
“岩体结构面抗剪强度经验估算方法的应用研究”项目(编号:2002C21012)是浙江省科技厅于2002年立项的省级重点科研计划项目。由金华职业技术学院副院长杜时贵教授主持。项目完成了合同所要求的典型岩体结构面表面形态概化模型的抽取、  相似文献   

6.
直剪试验剪切面积计算方法对抗剪强度的影响   总被引:1,自引:0,他引:1  
现行直剪试验抗剪强度计算中忽视了剪切过程中随剪切位移的增大、剪切面在不断减小的实际情况,没有考虑剪切面面积对抗剪强度的影响,使得试验结果偏离试样的真实强度。为了分析剪切面面积对抗剪强度的影响,该文重新建立数学模型,提出了3种剪切面面积计算方法,通过加装剪切位移量测系统对直剪仪进行改装并进行了试验验证,分析了剪切面面积对抗剪强度的影响。研究成果提高了直剪试验抗剪强度计算的精度,使得试验结果更接近试样的真实强度。  相似文献   

7.
用有限元强度折减法计算出的安全系数作为评价隧道围岩稳定性的指标,借助于ANSYS程序,使用莫尔-库仑等面积圆屈服准则,计算嵩山隧道的安全系数,通过分析比较确定最优开挖方案;对隧道的开挖支护过程进行数值模拟,分析应力场、位移场、塑性区和支护结构内力变化规律,为隧道工程施工提供理论指导。  相似文献   

8.
针对解决《土工试验方法标准》三轴试验中,黏性土抗剪强度指标出现的变异问题,提出一种黏性土试样组合方法,准确测定黏性土抗剪强度指标值在原有的一组相同物理性质(含水率,液塑限,级配)黏性土三轴试样的基础上,增加一组或两组相同物理性质试样,通过系统软件对试样进行完备组合,重新形成黏性土抗剪强度指标值样本基数,取其样本数的平均值为黏性土抗剪强度指标.通过试验验证了试样组合方法能有效避免三轴试验中出现的互不包容的莫尔圆,或黏聚力c出现负值试验结果,并在不增加试样数量的前提下,扩大了黏性土抗剪强度指标的样本基数,从而可准确测定抗剪强度指标值组合方法的提出为黏性土抗剪强度指标的测定提供一定的参考价值.  相似文献   

9.
土与结构相互作用问题涉及实际工程的多个方面,研究土-结构接触面力学特性是解决该问题的基础。通过对常规非饱和直剪仪进行改造,并利用改造的非饱和直剪仪进行非饱和砂土-结构接触面剪切试验,研究了基质吸力、结构面类型和净法向应力对接触面抗剪强度的影响。结果表明:基质吸力对非饱和砂土-结构接触面的界面黏聚力影响较大,对界面摩擦角影响较小;随着基质吸力的增加,非饱和砂土-混凝土接触面的抗剪强度先增大后减小,存在峰值效应;基质吸力对非饱和砂土-钢接触面的抗剪强度影响较小,基质吸力不变的条件下,随着净法向应力的增加,砂土-钢接触面的抗剪强度呈非线性增长;净法向应力对非饱和砂土-结构接触面对应基质吸力的界面摩擦角(δb)的影响较小。最后,建立了基于峰值效应的非饱和砂土-混凝土接触面抗剪强度公式。  相似文献   

10.
层状岩体具有明显的各向异性的力学特性,其抗剪强度应该是相对于层面方向的函数。对此作曾提出过一个层状岩体C、ψ值的经验表达式,现将其与前人的试验结果进行对比,看到二吻合较好,在此基础上,引入横观各向同性体的本构关系和其中的C、ψ值是随方向变化的Mohr-Coulomb准则,编制了相应的三维弹塑性有限元程序,并以一个地下洞室为背景,分别就岩体为横观各向同性和均匀介质的情况进行了模拟计算与对比,得出了有益的结论。  相似文献   

11.
屈服和破坏是岩土工程中最基础也是最为重要的问题,在岩土工程的安全评价、设计等相关研究中,用破坏准则判别破坏模式以及对安全性进行评价。在对几种常用的岩石力学强度理论进行分类比较的基础上,希望能应用强度准则更准确地解决工程实际问题。  相似文献   

12.
Based on the strength reduction method and strain-softening model,a method for progressive failure analysis of strain-softening slopes was presented in this paper.The mutation is more pronounced in strain-softening analysis,and the mutation of displacement at slope crest was taken as critical failure criterion.An engineering example was provided to demonstrate the validity of the present method.This method was applied to a cut slope in an industry site.The results are as follows:(1) The factor of safety and the critical slip surface obtained by the present method are between those by peak and residual strength.The analysis with peak strength would lead to non-conservative results,but that with residual strength tends to be overly conservative.(2) The thickness of the shear zone considering strain-softening behaviour is narrower than that with non-softening analysis.(3) The failure of slope is the process of the initiation,propagation and connection of potential failure surface.The strength parameters are mobilized to a non-uniform degree while progressive failure occurs in the slope.(4) The factor of safety increases with the increase of residual shear strain threshold and elastic modulus.The failure mode of slope changes from shallow slip to deep slip.Poisson’s ratio and dilation angle have little effect on the results.  相似文献   

13.
应用双剪理论对岩石在三轴压缩载荷下的强度特性进行了较系统的理论分析,并将分析结果与已有实验作了对比。研究表明,在岩石的强度特性方面,用双剪理论所得分析结果与实验事实较吻合。  相似文献   

14.
In order to evaluate the seismic behavior of confined RC column-composite beam joints, five interior joints were tested under low cyclic reversed load. The weakening extent of flanges, the number of studs, and whether to reinforce weakened flanges were used as parameters in designing these five joints. Failure characteristics, hysteretic curves, skeleton curves, ductility, energy dissipation, strength degradation, and stiffness degradation were analyzed. The test results revealed that the steel beam flanges in the joints were equivalent to the tie rod. Weakened flanges resulted in poor seismic behavior; however, the seismic behavior could be improved by increasing studs and reinforcing weakened flanges. The joint steel plate hoops, equivalent to stirrups, did not yield when the maximum load was reached, but yielded when the failure load was reached for the joints with shear failure. Increasing stud-type joints and reinforcing flange-type joints ensured good seismic behavior and met project requirements. Based on the experimental results, the failure mechanism of the joints was discussed, and the shear capacity equations of the joints was presented.  相似文献   

15.
碾压混凝土筑坝具有节省投资,施工速度快及简化温控技术等优点,因此在国内外得到了广泛推广,但随之而来的层间抗剪特性成为急待解决的问题,层间抗剪强度已成为决定碾压混凝土坝抗滑稳定的重要因素,结合同家“八·五”科技攻关项目“普定碾压混凝土拱坝层间抗剪特性研究”,本文进行了碾压混凝土立方试件单轴及多轴抗剪试验,建议了多轴抗剪破坏准则,可以作为工程设计的依据。  相似文献   

16.
对强地震多发区黄河黑山峡下游段岩体破坏特征进行了分析,研究表明,地震作用下裂隙的生成与地震波的传播具有同时性、继承性和纵横渡在岩体破坏中的拉张和剪切共同作用的双重性等特点.对岩体地震破坏机理及岩体地震破坏模型进行了初步探讨.同时对地震破坏后岩体地球物理特性的变化进行了研究,发现研究区大范围地球物理参数明显变异,说明强震对坚硬的岩体同样具有严重的破坏性.  相似文献   

17.
Failure criterion of saturated soft clay is studied under cyclic loads through different experiments. A large number of cyclic torsional shear and cyclic triaxial tests on saturated soft clay under unconsolidated undrained condition are conducted. From the test result analysis, it is seen that the failure of saturated soft clay under static and cyclic loads satisfies Mises criterion. The result from different test stress states is not related to the test stress states or confining pressures. It can be applied in general stress states. Then according to the Mises criterion, the equivalent relationship on failure moment between the test stress state and the general stress state can be established. So the cyclic mechanics characteristics of saturated soft clay at failure moment are clarified in this paper. Furthermore, a theory basis is provided for using pseudo-static elasto-plastic cyclic strength model to evaluate cyclic bearing capacity.  相似文献   

18.
为研究钢筋锈蚀后再生混凝土框架节点的破坏特征和抗震性能,对钢筋未锈蚀、锈蚀而保护层未开裂、平均锈胀裂缝宽度为0.2mm及平均锈胀裂缝宽度为0.4mm四种情况下的再生混凝土及普通混凝土框架边节点,进行了低周反复荷载对比试验;观察节点的受力过程及破坏形态,分析试件的荷载一位移滞回曲线、承载能力、强度和刚度退化、延性以及耗能能力等力学特性.结果表明:相同锈蚀程度下,再生混凝土节点的强度比普通混凝土节点小,再生混凝土节点的刚度退化比普通混凝土节点严重,再生混凝土节点表现出更好的延性,再生混凝土耗能较普通混凝土耗能弱;随着钢筋锈蚀程度的增加,再生混凝土与普通混凝土节点的强度降低,刚度减小,延性减小,耗能能力降低.  相似文献   

19.
To evaluate the strength attenuation law of soft rock in the western mining area of China, we established an evolution model for the strength parameters of soft mudstone at the post-peak stage by employing a tri-linear strain softening model. In the model, a stiffness degradation coefficient co and a softening modulus coefficient a were introduced to take into account the stiff- ness degradation, and the subsequent yield surfaces at post-peak stage were all assumed to meet the Molar-Coulomb yield criterion. Furthermore, attenuation laws of stiffness and strength parameters of soft mudstone were analyzed according to an engineering case. Finally, the model's accuracy was verified by comparison of results from numerical calculation and tri-axial compression tests. Results showed that the attenuation of the friction angle was dominated mainly by the instantaneous stress states and damage features, while the attenuation law of cohesion was also related to the plastic behavior. The degradation rates of strength param- eters decreased with increasing confining pressure and the friction angle tended towards its initial value. Residual strengths were also enhanced with increasing confming pressure. The results indicate that the evolution model can accurately describe the strain softening behavior of soft rock.  相似文献   

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