软化Drucker-Prager材料强度参数的测定方法

发布时间：2018-01-17 12:27

本文关键词：软化Drucker-Prager材料强度参数的测定方法　出处：《岩石力学与工程学报》2014年06期 　论文类型：期刊论文

【摘要】：通过回顾Drucker-Prager材料强度参数随内变量变化时应该满足的本构关系,给出在常规三轴试验机工况下的简化表达。选择轴向塑性压应变作为内变量,得到内变量增量与应变增量和应力增量之间的关系,从而得出各试验记录点对应的内变量。为通过多次试验确定对应同一内变量的2个强度参数,把各次试验的应力在均匀离散的内变量点上进行插值,使各次试验对同一内变量按屈服面方程求解强度参数的方程成为可能。得到一种不预设强度参数变化模式也可确定强度参数变化规律的方法。实例分析结果显示试验材料的2个强度参数变化趋势并不一致,不同围压下轴向应力达到峰值对应的内变量也不同,这与围压可提高强度极限并推迟强度极限到来的观点是一致的。
[Abstract]:By reviewing the constitutive relations that the strength parameters of Drucker-Prager materials should satisfy when they change with internal variables. The simplified expression under the condition of conventional triaxial testing machine is given. The relationship between the increment of internal variable and the increment of strain and stress is obtained by selecting the axial plastic compressive strain as the internal variable. In order to determine two strength parameters corresponding to the same internal variable through multiple tests, the stress of each test is interpolated on the point of uniform discrete internal variable. It is possible for each experiment to solve the equation of strength parameter according to yield surface equation for the same internal variable. A method of determining the variation law of strength parameter without preset strength parameter change mode is obtained. The result of example analysis shows that the change rule of strength parameter can also be determined. The change trend of two strength parameters is not consistent. The internal variables corresponding to the peak value of axial stress under different confining pressures are also different, which is consistent with the view that confining pressure can increase the strength limit and delay the arrival of the strength limit.
【作者单位】：煤炭科学研究总院矿山安全技术研究分院;北京大学工学院;
【基金】：煤炭科学研究总院科技发展基金资助项目(2011CX04)
【分类号】：TU45
【正文快照】： 1引言岩土体或类岩土体的承载能力或抗破坏能力是采矿、水利等领域中大规模的岩土工程要考虑的问题。材料的塑性软化引起岩土体失稳是岩土体的主要破坏形式。由于岩土材料本构的复杂性、岩土软化参数测定和岩土体稳定性计算方面的困难,工程中把岩土材料抽象为更简单的理想弹塑

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