任意干湿路径下非饱和土的水力耦合本构模型  

HYDRO-MECHANICAL COUPLING CONSTITUTIVE MODEL OF UNSATURATED SOILS WITH ARBITRARY DRYING-WETTING PATHS

作　　者：李幻 李云飞 樊铁兵 张益贤 黄志全 LI Huan;LI Yunfei;FAN Tiebing;ZHANG Yixian;HUANG Zhiquan(College of Geosciences and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450000,China;The Fifth Reasearch&Design Corporation of CNN.,Zhengzhou 450052,China;Luoyang Institute of Science and Technology,Luoyang 471023,China)

机构地区：[1]华北水利水电大学地球科学与工程学院,中国郑州450000 [2]河南中核五院研究设计有限公司,中国郑州450052 [3]洛阳理工学院,中国洛阳471023

出　　处：《工程地质学报》2023年第1期43-50,共8页Journal of Engineering Geology

基　　金：国家自然科学基金(资助号:U1704243);河南省中原科技创新领军人才计划“膨胀土灌溉边坡亲水响应机理研究”;河南省重点研发专项(资助号:221111321500)。

摘　　要：大量试验表明饱和土样经历脱湿过程进入吸湿阶段后,在高饱和度区域,残余气体会以封闭气泡的形式分布在土样孔隙中,此时土样呈现较大的压缩性,当吸湿过程结束基质吸力再为0 kPa时,土样并不会达到完全饱和状态。韦昌富等(2008)提出的非饱和土的本构模型没有考虑残余含气量的影响,认为土样在吸湿过程后仍能达到完全饱和状态,这与实际情况有一定偏差。为了更精确地模拟真实情况,基于考虑不同残余含气量的毛细滞回内变量理论和忽视残余含气量影响的非饱和土的水力耦合本构模型,提出了考虑不同残余含气量影响的非饱和土的修正本构模型。通过和实测数据的比较,修正模型可以较好地模拟任意干湿路径下的非饱和土力学特性。A large number of tests have shown that after the saturated soil sample enters the hygroscopic stage in the dehumidification process, residual gas would be distributed in the pore of the soil sample in the form of closed bubbles in the high-saturation area. At this time, the soil sample shows great compressibility. When the matric suction is 0 kPa after the hygroscopic process, the soil sample would not reach full saturation state. Wei et al.(2008)put forward the constitutive model of unsaturated soil without considering the influence of the residual gas content, and considering the soil sample after moisture absorption process could still achieve fully saturated state, which has certain deviation with the actual situation. In order to simulate the real situation more accurately, this paper proposes a modified constitutive model for unsaturated soils with different residual gas contents. The modified model is based on the theory of capillary hysteresis internal variables and the hydraulic coupling constitutive model for unsaturated soils. The modified model is verified with the measured data and can well simulate the influence of any wet and dry path on the mechanical properties of unsaturated soil.

关 键 词：非饱和土 残余含气量 本构模型 毛细滞回 

分 类 号：TU431[建筑科学—岩土工程]