摘要
针对交通荷载诱发路基土单元体发生主应力轴连续旋转的情况,借助GCTS空心圆柱扭剪仪对碱渣固化轻质土开展了一系列竖向和扭转耦合剪切试验,揭示了其在不同大主应力方向角、中主应力系数、振动频率以及密度影响下的动强度演化及刚度衰减规律。结果表明,动强度随大主应力方向角α的增大显著减小,在α=90°时减幅达21.5%~26.7%,中主应力系数在0~0.75变化时,动强度先增大后减小,同等破坏振次下,动强度随振动频率和密度的增大而增大;碱渣固化轻质土切线刚度发展分为硬化、衰减和稳定3个阶段,存在一个临界屈服应变,数值介于0.25%~0.5%,且不因初始应力状态和循环荷载振动频率而改变;切线刚度受各因素影响程度不同,构建了能反映其与广义剪应变间非线性关系的刚度衰减模型。研究结果可为道路工程长期服役性能的提高提供数据支撑。
Aiming at the continuous rotation of principal stress axis of subgrade soil element induced by traffic load,a series of vertical-torsional coupled shear tests were conducted on solidified lightweight soil of soda residue with GCTS hollow cylindrical torsional apparatus.The tests aimed to reveal the evolution of dynamic strength and stiffness degradation under varying major principal stress direction angles,intermediate principal stress coefficients,vibration frequencies,and densities.The results show that the dynamic strength decreases significantly as the major principal stress direction angleαincreases,with a reduction of 21.5%to 26.7%observed atα=90°.As the intermediate principal stress coefficient varies from 0 to 0.75,the dynamic strength initially increases and then decreases.Under the same number of cycles to failure,the dynamic strength increases with both vibration frequency and density.The tangent stiffness development of solidified lightweight soil of soda residue can be divided into three stages:hardening,degradation,and stabilization.A critical yield strain exists between 0.25%and 0.5%,which remains unaffected by the initial stress state and the vibration frequency of cyclic loading.The influence of different factors on tangent stiffness varies,and a stiffness degradation model reflecting its nonlinear relationship with generalized shear strain was established.The findings provide data support for improving the long term service performance of road engineering。
作者
杨少坤
任毅青
庞辉
任鹏
杨爱武
刘钦
YANG Shaokun;REN Yiqing;PANG Hui;REN Peng;YANG Aiwu;LIU Qin(Training Base,Army Engineering University of PLA,Xuzhou 221004,China;College of Environmental Science and Engineering,Donghua University,Shanghai 201620,China)
出处
《陆军工程大学学报》
2025年第6期96-104,共9页
Journal of Army Engineering University of PLA
基金
国家自然科学基金面上项目(42177119,42377141)。
关键词
碱渣固化轻质土
主应力旋转
动强度
切线刚度
广义剪应变
solidified lightweight soil of soda residue
principal stress rotation
dynamic strength
tangent stiffness
generalized shear strain
