【作者】 李涛；

【导师】 张土乔； 张仪萍；

【作者基本信息】 浙江大学 ， 市政工程， 2006， 博士

【摘要】 本文基于连续介质大变形理论、Biot固结理论和纽曼随机有限元理论，建立了大变形固结纽曼随机有限元分析方法，并开发了相应有限元计算程序。在此基础上，对软土路基大变形固结问题作了初步研究。主要成果包括： (1)以一维固结模型为例，在确定性计算方面对比了小变形固结有限元法、大变形固结有限元法和Terzaghi解析法的计算结果；在随机性计算方面对比了大变形固结纽曼随机有限元法和Monte-Carlo随机有限元法计算结果，验证了本文有限元程序的正确性和有效性。 (2)受大变形的影响，在纽曼随机有限元求解过程中，刚度矩阵波动值也含有未知量增量的相关项。论文提出采用修正牛顿法的余量迭代算法来计算刚度矩阵波动值非线性部分，并进一步探讨了刚度矩阵波动值的近似算法，大大提高了随机有限元计算效率，同时又保证了足够的计算精度。 (3)对一简化的软土路基模型进行大变形固结随机有限元分析。详细分析了软土路基沉降、侧向位移和孔压等均值、标准差随时间变化规律及空间分布规律；并探讨了随机变量和随机场参数对软土路基沉降和孔压的影响。 (4)以实际工程为例，将地表沉降和孔压实测数据与有限元计算结果进行对比，并对沉降、孔压标准差进行随机有限元分析，初步探讨了大变形固结纽曼随机有限元法在实际工程中的应用。 本文主要创新之处在于： (1)基于连续介质大变形理论、Biot固结理论和纽曼随机有限元理论，建立了大变形固结纽曼随机有限元分析方法，并开发了相应有限元计算程序。 (2)针对随机有限元刚度矩阵波动值的计算，提出采用修正牛顿法的余量迭代算法来计算其非线性部分，并进一步探讨了刚度矩阵波动值的近似算法，提高了大变形固结随机有限元计算效率。 (3)采用大变形固结随机有限元程序对软土路基固结变形问题作了较系统的分析，探讨了沉降、侧向位移和孔压等均值、标准差随时间和空间的变化规律。更多还原

【Abstract】 Based on the large deformation theory of continuum material, Biot’s consolidation theory and Neumann stochastic FEM, the large deformation consolidation Neumann stochastic FEM (LDCNSFEM) theory had established. A program of LDCNSFEM was designed to analyze soft-clay road embankment. The research work was mainly concerned with the following four aspects.(1) Taking the one-dimensional model for example, the result of large deformation consolidation FEM was compared with that of small deformation consolidation FEM result and Terzaghi analytical solution. The result of LDCNSFEM was compared with that of Monte-Carlo SFEM. All results show that the program developed this paper is validity and affectivity.(2) With the impact of large deformation consolidation, the fluctuate part of rigidity matrix was contained fundamental unknown quantity. The residual iteration method in modification of the Newton Method was used to dealt with the non-linear part of fluctuate part of rigidity matrix, and the approximate calculation methods of fluctuate part of rigidity matrix were discussed. The approximate algorithms are chosen to simplify FEM calculation, which improve the efficiency and not to damage the accuracy of solution.(3) The FEM calculation of simplified soft-clay road embankment model was carried out. The laws of time-dependent and distribution in special of mean and variance of settlement, horizontal deformation and water press were analyzed in detail. The influence of stochastic parameter and random field parameter study on the simplified soft-clay road embankment model was studied.(4) Through the example of the practical project, the observed data of settlement and water press were compared with FEM results. The variance of settlement and water press was analysis in detail, and the applicability of large deformation consolidation Neumann stochastic FEM in the practical project was also discussed.The innovations in this paper maybe include:(1) The LDCNSFEM theory and program were proposd based on the large deformation theory, Biot’s consolidation theory and Neumann stochastic FEM.(2) The residual iteration method in modification of the Newton Method was used to dealt with the non-linear part of fluctuate part of rigidity matrix, and the approximate algorithm to the fluctuate part of rigidity matrix in stochastic FEM was designed to improve LDCNSFEM program efficiency.更多还原