The results indicate that the stress path is not affected by changing the initial effective mean stress if the shear stress ratio remains the same 也就是说，如果保持相同的剪应力比，由初始有效平均正应力归一化的有效应力路径不受初始有效平均正应力的影响。
The main problems widely seen in the previous studies are ( 1 ) inadequate modeling of initially anisotropically consolidated soil and ( 2 ) numerical vulnerability associated with the stress path in the vicinity of the failure line 以前模型普遍存在的问题有： ( 1 )不能模拟初始偏压固结的情况； ( 2 )当应力路径接近破坏线时数值稳定性差。
It is suggested that the true triaxial test under different stress paths should be performed to derive reasonable anisotropic yield criterion and further to develop nonlinear anisotropic elastic - plastic constitutive model 建议通过复杂应力条件下不同应力路径的真三轴试验，建立合理的各向异性屈服准则，进而建立各向异性非线性弹塑性模型。
At last , the finite element method , the strength reduction method and limit equilibrium method , nature slopes and excavation slopes , lateral stress unloading model and axial loading model are analyzed and discussed relatively 最后，就有限元法、强度折减法和极限平衡法，自然边坡与挖方边坡，围压卸荷应力路径模型分析与轴向加荷应力路径模型分析进行了比较讨论。
The results indicate that stress - strain curves with different water contents , consolidation stresses and stress paths are evidently dissimilar , which are correspondingly described with softening elastic - plastic model , ideal elastic - plastic model and hyperbolic elastic model 研究表明，原状黄土含水量不同、固结围压不同、应力路径不同、应力应变曲线亦显著不同，可以由软化弹塑性模型、理想弹塑性模型或双曲线弹性模型描述。
The conclusions have been deduced from the detailed analysis of a set of experimental results as below : 1 ) the formula of tangent young ' s modulus et has been established during the unloading process ; 2 ) the shearing features of the samples are similar to undrained test even though there are draining paths so the possion ratio of the sample is about 0 . 5 ; 3 ) unloading paths have little effects on the shearing strength parameters 通过对试验结果的分析得到： 1 )任一时刻土体的切线弹性模量公式； 2 )卸载情况下尽管存在排水通道，但试样仍基本上表现为不排水的性状，按广义虎克定律得到的泊松比在0 . 5附近； 3 )卸荷应力路径对土体的强度参数影响不大。
In this paper , some present experimental methods of shear strength parameters are briefly described and the shortcomings of them are pointed out . then in order to obtain the right shear strength parameters for design of deep pit excavation , the author did a lot of normal tri - axial cu experiments and tri - axial cu tests that can simulate the actual process of excavation using soil sample of different depth 本论文首先介绍了现有一些确定土体抗剪强度指标的方法及其适用范围并指出不足，然后从正确确定适合基坑设计中土体抗剪强度指标的角度出发，对不同深度下各层土体分别进行常规三轴固结不排水试验和模拟深基坑开挖过程应力路径的固结不排水卸荷试验。
This paper discussed about the changes of stress state on effect of soil properties . the reason of surface settlement and layer losses is that the stress state is not primeval one in and after tunneling construction . therefore it is necessary to select strength data in actual stress path in making tunnel deformation and stability analysis with continuous media mechanics 本文讨论了隧道施工过程中，由于应力状态的变化对土性的影响， ，隧道施工之所以造成地表沉降和地层损失，是因为隧道施工过程中以及隧道施工结束后土层的应力状态已经不是原始应力状态，因此在选用连续介质力学方法对隧道施工进行变形和稳定性分析时，必须采用实际应力路径下强度参数。
The paper points out the factor of safety by means of finite element method , the strength reduction method and limit equilibrium method decreases in turn . according to analysis of the strength reduction method , the stability of the cutting slope is less than the stability of nature slope . according to the results by the finite element method , the factor of safety calculated by axial loading stress - strain model is less than the factor of safety by lateral unloading stress - strain model 表明有限元法、强度折减法、极限平衡法得出的安全系数依次降低；依据强度折减法分析，相同条件下，挖方边坡的安全系数较自然边坡的安全系数小；依据有限元西安理工大学硕士学位论文法分析，轴向加荷应力路径模型确定的安全系数较围压卸荷应力路径模型确定的安全系数小。
At the moment , the basic theory of loading mechanics is always used to search the problem of rock mass failure , but unloading and loading have different stress road and different destruction effect , so there are much difference in destruction mechanics and deformation between unloading and loading mechanics , if loading mechanics is used to study the destruction property of tunnel excavation and its stability , the result which agree to real engineering cannot be obtained 目前一直沿用加载岩体力学方面的基本理论研究失稳问题，但本文认为：由于卸荷与连续加载具有完全不同的应力路径和破坏效应，在破坏机理、二者引起的岩体的变形和破坏特性方面都有很大的不同，因此用加载力学来研究开挖卸荷破坏的力学特性及其稳定性，这显然不能得出与实际工程一致的结果。
