摘要
为分析饱和地基动力反应，讨论了用ｕ－ｐ 格式有限元数值解法。将土视为两相体，考虑水的渗流与土骨架变形的相互影响。引入考虑饱和土两相性情况下的传输边界，用以模拟地基无限性。推导了加入传输边界后的有限元方程，讨论了相应总体方程的无条件稳定交叉求解方法。通过饱和有限厚土层表面受条形简谐荷载作用的算例，对比两种不同的人工边界（自由边界、传输边界），并结合算例讨论了渗透系数对位移和孔压的影响及有限厚土层截止频率的存在和产生机理等有关问题。分析表明当量纲１ 的传输边界距离大于４ 时， 计算精度将满足实用要求； 另外，渗透系数的重要影响也说明了在饱和地基动力计算中考虑渗流的必要性。
Numerical procedures were discussed for the dynamic analysis of saturated soil foundation by u p scheme finite elements. The soil was treated as a two phase mixture and the interactive influence of fluid flow and solid deformation was considered. A transmitting boundary was introduced to simulate infinite soil region by finite elements, considering the two phase nature of the soil. An unconditionally stable staggered procedure was adopted for solutioning global equations. As numerical examples, the dynamic responseed of a saturated soil layer under vertical harmonic load, is analyzed. The influence of permeability on the dynamic response, the existence and cause of cutoff frequency of a soil layer in finite thickness were also discussed. The results show that the accuracy is enough when the transmitting boundary normalized distance is greater than 4. The permeability variation may have a significant influence on the soil foundation dynamic response, especially for soft soils, which indicates the necessity for considering the fluid flow in the analysis.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
1999年第12期82-85,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金!(59478028)
关键词
无限地基
饱和土
土动力学
有限元
动力分析
infinite soil foundation
saturated soil
soil dynamics
artificial boundary
transmitting boundary
cutoff frequency
