【摘要】 运用弹塑性有限元程序计算基坑支护结构和土体的应力状态,采用优化方法来研究基坑支护结构偏离土体方向使土体达到主动极限平衡时的主动极限位移。大量数值计算表明:主动极限位移随土层深度增加而增加,但到一定深度后其增量为零。在此基础上研究了上海软土地区基坑支护结构主动极限位移的近似公式,并推导归纳了基坑支护结构考虑位移的非极限土压力计算公式,工程实测资料证实了该近似公式的有效性和实用性。更多还原

【Abstract】 Stress status of supporting structure and the retained soil was analyzed with elasto-plastic FEM in foundation pit, and the active limiting displacement of supporting structure when the retained soil is active limiting equilibrium was calculated with“artificial participation”optimization. Large scale numeric calculation shows that the active limiting displacement is increasing with the depth of retained soil, and that the increment is zero when the soil depth reach some degree. An approximate formula of active limiting displacement of supporting structure in foundation pit is proposed in Shang- hai soft soil, furthermore, the approximate formula of unlimited earth pressure based on the displace- ment of supporting structure is proposed. The in situ measurement shows the availability and utiliza- tion of the two approximate formulae.更多还原