考虑基质吸力影响的重塑黄土的临界状态模型  

Critical state model of remolded loess considering matrix suction

作　　者：任占雷 李泽杰 段梦强 翁效林[2,3] REN Zhanlei;LI Zejie;DUAN Mengqiang;WENG Xiaolin(East China Engineering Construction Management Co.,Ltd.,Hangzhou,Zhejiang 311121,China;School of Highway,Chang’an University,Xi’an,Shaanxi 710064,China;Key Laboratory of Geotechnical Engineering for Green and Intelligent Transport,Xi’an,Shaanxi 710064,China)

机构地区：[1]浙江华东工程建设管理有限公司,浙江杭州311121 [2]长安大学公路学院,陕西西安710064 [3]西安市绿色智慧交通岩土工程重点实验室,陕西西安710064

出　　处：《公路交通科技》2025年第3期104-114,共11页Journal of Highway and Transportation Research and Development

基　　金：中国电建集团华东勘测设计研究院有限公司科研项目(HDY-CGHT29-20240177Y);秦创原“科学家+工程师”队伍建设项目(S2024-YD-QCYK-0027)。

摘　　要：【目标】探寻更贴合重塑黄土的结构变化规律和硬化特性。【方法】根据不同基质吸力条件下的重塑黄土压缩演化规律,运用临界状态土力学原理,以基质吸力、应力及应变为主要变量,构建了一种能够描述重塑黄土应力-应变关系的本构模型。该模型将不同基质吸力条件下的重塑黄土等向压缩曲线予以对比,采用无相关联流动法则,确定了不同基质吸力条件下重塑黄土的基本参数及其演化方程。模型共有8个参数,均可通过压缩试验和标准三轴剪切试验获得。【结果】重塑黄土的基质吸力越大,达屈服态所需剪切应力越大;初始孔隙比较大时,稳定态体应变较小,且稳定态体应变与弹性压缩段斜率成正比。【结论】经过与现有试验结果比较后,发现本研究模型不仅可以较好地反映基质吸力对重塑黄土结构强度、变形特性及结构演化规律的影响,而且能较为合理地预测重塑黄土的硬化特性。所提出的这种临界状态重塑黄土模型进一步加深了黄土力学特性的理解及研究,也为更精确地计算黄土地基变形提供了一定的理论支持。[Objective]The study explores the structural variation rules and hardening characteristics of remolded loess more closely.[Method]Based on the compression evolution rule of remolded loess under different matrix suction conditions,the principles of critical state soil mechanics were applied.Taking the matrix suction,stress and strain as the main variables,a constitutive model,describing the stress-strain relation of remolded loess,was constructed.The model compared the isotropic compression curves of remolded loess under different matric suction conditions.The non-associated flow rule was adopted to determine the basic parameters and their evolution equations of remolded loess under different matric suction conditions.The model had a total of 8 parameters,all of which could be obtained through compression test and standard triaxial shear test.[Result]The greater the matrix suction of remolded loess,the greater the shear stress required to reach the yield state.When the initial void ratio is large,the volumetric strain in steady state is small.The volumetric strain in steady state is proportional to the slope of elastic compression section.[Conclusion]Compared with the current test results,it is found that the proposed model can not only better reflect the influence of matrix suction on structural strength,deformation characteristics and structural evolution rules of remolded loess,but also reasonably predict the hardening characteristics of remolded loess.The proposed critical state remolded loess model further deepens the understanding and study on the mechanical properties of loess.It also provides the certain theoretical support for more accurate calculation on the loess foundation deformation.

关 键 词：道路工程 临界状态理论 模型推演 重塑黄土 基质吸力 硬化特性 

分 类 号：U416.1[交通运输工程—道路与铁道工程]