一个考虑土的各向异性的孔压公式及其应用.pdfVIP

第26 卷第9 期 岩 土 力 学 Vol.26 No.9 2005 年9 月 Rock and Soil Mechanics Sep. 2005 文章编号：1000－7598 －(2005) 09―1349―07 一个考虑土的各向异性的孔压公式及其应用 1, 2 1, 2 1 高彦斌 ，徐 超 ，汤 竞 （1. 同济大学 岩土工程重点实验室，上海 200092 ；2. 同济大学 地下建筑与工程系，上海 200092 ） 摘 要：为了研究粘土的各向异性对孔压生成的影响，在修正剑桥模型的基础上，采用关口-太田应力比概念、结合邢义川- 郑颖人方程，构造了一个各向异性旋转屈服面，建立了一个各向异性弹塑性本构模型；据此推导出一个各向异性孔压表达式， 该式可以考虑Lode 角以及主应力轴的平面旋转对孔压的影响；并采用新的孔压表达式着重分析了三轴应力状态下Lode 角旋 转以及主应力轴旋转所造成的孔压发展，并对条形荷载下的平面应变各向异性粘土地基中的孔压发展进行了计算。计算结果 表明，地基中由于Lode 角旋转造成的孔压不明显，但在荷载边角位置主应力轴旋转造成的孔压不容忽视，尤其是在埋深相 对较浅的位置。 关 键 词：土；各向异性；孔压公式；本构模型 中图分类号：TU 452 文献标识码：A A pore pressure equation for anisotropic clay and its application GAO Yan-bin1,2, XU Chao1,2, TANG Jing1 (1. Key Laboratory of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 2. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China) Abstract ：The effect of anisotropy on the pore pressure development for clay is investigated. A rotational yield surface is presented by introducing the Sekiguchi-Ohta stress ratio and Xin’s failure equation into the Modified Cam Model; and an anisotropic elastoplastic model is built. Based on this model, a new anisotropic pore pressure equation is presented, which can account for the pore pressure development induced by the rotation of Lode angle and principal stress. The equation is used to study the pore pressure development induced by the rotation of the Lode angle and stress axis direction under triaxial stress state. Finally, the pore pressure development in the plane strain anisotropic clay foundation under an strip load is analyzed by the equation. R