Drucker-Prager系列屈服准则在稳定分析中的应用研究

Studies of application of Drucker-Prager yield criteria to stability analysis

Drucker-Prager(下简称D-P)系列屈服准则作为Mohr-Coulomb(下简称M-C)准则的修正模型在岩土工程中得到了广泛的使用。然而采用不同的D-P系列屈服准则可能会得到差距较大的结果,因此,选用合适的D-P系列屈服准则十分重要。在研究了D-P系列屈服准则与M-C准则之间的对应关系之后,指出D-P系列屈服准则对应的Lode角取值较为有限,难以反映出材料在丰富受力状态下的M-C准则屈服强度,将其取值范围扩大至-30°～30°,并以某边坡和向家坝泄12坝段抗滑稳定分析为例,对如何选用合适的D-P系列屈服准则这一问题进行了研究,提出了具体的选择方法。研究结果表明,只要选用的D-P系列屈服准则对应的Lode角能反映影响边坡和坝基稳定的关键部位的受力状态,就能够得到较好的结果,将D-P系列屈服准则对应的Lode角取值范围扩大至-30°～30°也是必要的。

The Drucker-Prager yield criteria are widely used in geotechnical engineering as modified models of Mohr-Coulomb criterion. Great differences may be made between results with different Drucker-Prager yield criteria. It is important to select a proper Drucker-Prager yield criterion in geotechnical engineering analysis. The range of Lode angle of Drucker-Prager yield criterion is too limit to reflect more stressed conditions and should be enlarged from --30° to 30° is pointed out. Studies of section how to select a proper Drucker-Prager yield criterion are made based on stability analyses of a certain slope and that of dam #12 foundation of the Xiangjiaba Project. Studies show that more reasonable results can be achieved if the Lode angle of Drucker-Prager yield criterion selected can reflect the stressed condition of important parts which play important roles in maintaining stability of dam foundation or slope; and it is necessary to enlarge the range of Lode angle of Drucker-Prager yield criterion.