桩土软化作用特性的研究

STUDY ON THE SOFTENED PROPERTY OF PILE-SOIL SYSTEM

根据静力学理论,研究了线性软化和非线性软化模式的桩土系统在外荷载作用下,桩身位移满足的微分方程解释解。提出了相应的桩土系统分布参数的正反演方法,已知桩土力学参数时,可计算不同桩顶沉降下对应的荷载、桩身内力和位移;也可根据实测的静荷试桩数据,通过作理论计算与实测曲线拟合分析处理,确定桩土系统的力学参数。试验桩的综合对比结果表明了本方法有较好的应用效果。通过实例,研究了软化模型的桩基承载力和桩径的非线性相关特性以及摩阻力和端承力发挥过程的不同步性,该研究结果对桩的承载力机理研究有重要意义。

Based on the mechanics, theory, differential equations and solutions of pile displacement of linear softened mold and nonlinear softened mold under load on pile top are studied. The corresponding methods of direct and inverse problems to calculate the distribution parameters of the pile-soil system are advanced. Under the condition the mechanics parameters of the pile-soil system are known, the capacity, internal force along the pile axis, friction, bearing resistance and displacement can be computed according to the top settlement. The mechanics parameters of pile-soil system can also be determined through matching the theoretical load-settlement curve with the test toad-settlement curve in field. The results of comparisons between theory and test show that this method is fairly effective. Besides, the nonlinear relative property between capacity and pile diameter and the property, the friction and the bearing resistance do not come into effect at the same time as the pile with softened mold. These study results are important to the research on the performance mechanism of pile under load.