摘要
圆锥贯入试验(CPT)广泛应用于土体力学与渗透特性的评价。然而,现有经验公式多建立于干燥或饱和条件下,难以准确反映非饱和状态下吸力对贯入阻力的影响,易导致土体性质评估偏差。为此,文章基于有限元方法,采用简化的弹塑性Mohr-Coulomb本构模型,并引入吸力相关的表观黏聚力,以模拟非饱和砂土中吸力对锥阻力的影响。研究结果表明:非饱和砂土的锥尖阻力显著高于饱和状态,且吸力效应受侧限压力控制;当吸力为25 kPa时,锥尖阻力在侧限压力50 kPa和100 kPa下分别提高约20%和30%;当吸力增至200 kPa时,对应增幅分别约为9%和26%。应力集中出现在锥体上端区域,水平应力的影响范围约为6倍锥半径,明显大于垂直应力约2倍锥半径的作用范围,体现出显著的各向异性。
Cone penetration test(CPT)is widely used to evaluate soil mechanical and hydraulic properties.However,most existing empirical formulas are developed for dry or fully saturated conditions and therefore fail to capture the influence of matric suction on penetration resistance in unsaturated states,potentially leading to biased soil property assessments.In this study,a finite element model incorporating a simplified elastoplastic Mohr-Coulomb constitutive framework is developed,in which suction effects are represented by an apparent cohesion term.The results show that cone tip resistance in unsaturated sand is significantly higher than that in saturated conditions,and the suction effect is strongly dependent on confining pressure.At a suction of 25 kPa,the cone tip resistance increases by approximately 20%and 30%under confining pressures of 50 kPa and 100 kPa,respectively.When the suction increases to 200 kPa,the corresponding increases are about 9%and 26%.Stress concentration occurs in the upper region of the cone,the horizontal stress influences an area of approximately 6 times of the cone radius,which is significantly larger than that of vertical stress(about 2 times of the cone radius),demonstraing pronounced anisotropy.
作者
廖秋彬
LIAO Qiubin(Guangdong Provincial Construction Engineering Group Co.,Ltd.,Guangzhou Guangdong,511340,China)
出处
《江西水利科技》
2026年第1期13-17,24,共6页
Jiangxi Hydraulic Science & Technology
