复杂应力路径下流体饱和砂岩本构模型  

A constitutive model of sandstone with saturation fluid under complex loading paths

作　　者：田斌[1] 卢应发[1] 邵建富[2] 

机构地区：[1]三峡大学土木水电学院水利水电工程系,湖北宜昌443002 [2]法国里尔科技大学里尔力学实验室,法国里尔59655

出　　处：《岩土力学》2007年第S1期58-62,共5页Rock and Soil Mechanics

基　　金：教育部科学技术研究重点项目(No.26097)。

摘　　要：高孔隙率砂岩在不同围压及被不同流体(水及油)饱和时表现出不同的应力-应变特性及不同的破坏过程。复杂应力路径下油和水饱和砂岩的力学试验表明,存在某一临界围压,随着围压的增加,饱和砂岩从以压剪破坏为主,逐渐转变为以孔隙坍塌破坏为主的破坏机制。通过力学试验结果的分析,以两种破坏理论对油和水饱和砂岩的破坏特征进行了力学解释,并应用经典塑性力学的盖帽模型建立了相应的本构模型,应用非线性有限元法进行了数值验证,研究结果表明,提出的模型与试验资料吻合良好,能较好地模拟复杂应力路径下油和水饱和砂岩的破坏机制及模拟注水采油引起的砂岩附加沉降。A different mechanics behaviour and a different failure process are observed of the large porous sanstone with diffrent confining pressures and diffrent saturating fluids(e.g.oil and water) . Laboratory tests under complex loading paths demonstrate that a critical value of confining pressure is proved to exist,when the confining pressure increases,the main pressure-shear failure is changed into slough failure. In this paper,two failure throries are used to explain failure processes of large porous sandstone with water saturation and oil saturation respectively through an analysis of the results of laboratory tests. A constitutive model of the saturating sandstone with different fluids of oil and water is established by using the typical plasticity,and 3-dimensional nonlinear FEM is used to check the elastoplastic model based on the laboratory tests. The numerical results show that the laboratory tests are good in agreement with the mumerical simulation results by using the model of the paper,and the several failure mechanisms under complex loading paths and the additional subsidence of large porous saturating sandstone from oil exploration by hydraulic grouting are also simulated well.

关 键 词：复杂应力路径 饱和砂岩 油饱和 水饱和 本构模型 

分 类 号：TU45[建筑科学—岩土工程]