摘要
【目标】针对传统土压力理论未充分考虑中主应力影响的问题,建立考虑双剪中主应力影响的土压力计算模型,揭示中主应力对土压力的作用机制,为岩土工程设计提供更精准的理论依据。【方法】基于双剪统一强度理论,根据考虑中主应力影响系数的Drucker-Prage屈服准则与Mohr-Coulomb屈服准则的特殊位置关系,推导了6种抗剪强度指标;结合朗肯土压力理论,推导得到考虑双剪中主应力的主动土压力和被动土压力计算公式。【结果】在考虑双剪中主应力对抗剪强度指标与土压力的影响下,主动土压力随着中主应力影响系数的增大呈非线性减小,被动土压力随着中主应力影响系数的增大呈非线性增大。朗肯主动土压力较本文土压力模型计算结果偏大,朗肯被动土压力较本文土压力模型计算结果偏小。【结论】考虑了中间主应力的模型,可以更充分发挥土的强度潜力。采用不考虑中间主应力影响的朗肯被动土压力进行支挡结构设计,误差较大,且偏于不安全设计。
[Objective]The traditional earth pressure theory did not fully consider the influence of intermediate principal stress.The study systematically analyzed the influences of double-shear intermediate principal stress on earth pressure,so as to establish the calculation model.The mechanism of intermediate principal stress on earth pressure was investigated to provide accurate theoretical basis for geotechnical engineering design.[Method]Based on the unified strength theory of double-shear,six types of shear strength parameters were derived by analyzing the specific positional relation between Drucker-Prager yield criterion and Mohr-Coulomb yield criterion,which considered the intermediate principal stress influence coefficients.Furthermore,unified with Rankine’s earth pressure theory,the formulas for active and passive earth pressures incorporating double-shear intermediate principal stress were derived.[Result]Considering the influence of double-shear intermediate principal stress on both shear strength parameters and earth pressure,the active earth pressure decreases nonlinearly with the increase of intermediate principal stress influence coefficient.While the passive earth pressure increases nonlinearly as the coefficient increases.The active earth pressure result with Rankine’s earth pressure theory is larger than that with the proposed earth pressure calculation model.The passive earth pressure result with Rankine’s earth pressure theory is less than that with the proposed earth pressure calculation model.[Conclusion]The model considering intermediate principal stress can make full use of the strength potential of soil.The support structure,designed with Rankine’s passive earth pressure theory neglecting influences of intermediate principal stress,has large error and tends to be unsafe.
作者
夏琼
罗以欢
王旭
XIA Qiong;LUO Yihuan;WANG Xu(National Demonstration Center for Experimental Civil Engineering Education,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China;Yunnan Infrastructure Investment Co.,Ltd.,Kunming,Yunnan 650500,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China)
出处
《公路交通科技》
北大核心
2025年第7期89-98,共10页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51868038)
甘肃省道路桥梁与地下工程重点实验室开放基金项目(GSDQ-KF2020-2)。
关键词
道路工程
中主应力
理论推导
土压力
D-P屈服准则
road engineering
intermediate principal stress
theoretical derivation
earth pressure
D-P yield criterion
