【摘要】 地基土的变形模量值不仅和土层所受的先期固结压力大小直接相关,还受桩土作用产生的附加体积应变的影响.首先,针对岩土散体材料分析其本构关系的主要影响因素,研究模量随埋藏深度和体积应变的变化规律,并对Duncan--Chang本构模型进行抗拉模量值修正.其次,综合考虑岩土材料拉压模量不等修正以及桩土作用位移边界特点,应用变分理论推导桩土作用造成的位移、应变和应力场理论解答.最后,应用已有的经典土压力理论和小孔扩张理论对理论推导结果进行对比和分析验证.研究结果对桩基础设计施工、相应环境保护措施的选择和设计有较大的指导作用.更多还原

【Abstract】 The size of modulus is directly related to the value of pre-consolidation pressure and the additional volume strain due to pile-soil interaction for geotechnical materials. First, the paper analyzes the main factors of constitutive models for the materials, considering its changes with depth and volumetric strain. Tensile modulus in Duncan-Chang constitutive model is revised based on the above analysis. Then, the mechanical model due to pile-soil interaction is established considering the efect of the displacement boundary of the interaction and the above-mentioned non-linearity of the materials. The theoretical solutions of soil displacement, strain and stress, are obtained based on the variation principle. Finally, comparisons are made to prove the reasonability of the results, using the classical CEM results and the passive soil pressure theory.更多还原