A new theoretical model of heterogeneous soil-pile interaction (HSPI) in torsion is developed in this study to analyze the behavior of an end-bearing pile under torque. By assuming the surrounding soil as an elastic continuum following a power law variation in shear modulus depth, new governing equations are established for the torsional deformation of the continuous heterogeneous soil and pile system subjected to torque. Separation of variables and principles of Sturm-Liouville theory are applied to solving the governing equations of the pile and soil, taking into account the interaction conditions between the pile and soil. Rigorous solutions are obtained for the twist angle and internal torque along the pile shaft, as well as the shear stress with depth provided by the surrounding soil. Validation of the present HSPI model by comparing with previous theoretical and experimental data indicates the applicability and superiority of the derived solutions. The HSPI model is subsequently applied to conduct extensive arithmetic examples for investigating the torsional response of piles accounting for complex soil heterogeneity patterns and pile configurations. The obtained results can contribute to a deeper understanding of the operational mechanics involved in torsionally loaded piles in heterogeneous soil.

中文翻译：

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一种用于研究扭转荷载桩的非均质土-桩相互作用的新理论模型


本文开发了一种新的扭转非均质土桩相互作用 （HSPI） 理论模型，以分析端部承载桩在扭矩下的行为。通过假设周围土体是遵循剪切模量深度幂律变化的弹性连续体，为连续非均质土和桩系统在扭矩作用下的扭转变形建立了新的控制方程。考虑到桩和土之间的相互作用条件，将 Sturm-Liouville 理论的变量和原理分离应用于求解桩和土壤的控制方程。对于沿桩轴的扭转角和内部扭矩，以及周围土壤提供的随深度的剪应力，获得了严格的解决方案。通过与以前的理论和实验数据进行比较，验证了所推导解的适用性和优越性。随后，HSPI 模型被应用于进行广泛的算术示例，以研究解释复杂土壤异质性模式和桩配置的桩的扭转响应。所获得的结果有助于更深入地理解非均质土中扭转加载桩所涉及的操作力学。