土钉基坑支护的空间效应研究

利用三维弹塑性模型研究了土钉基坑支护的空间效应，着重对深基坑工程中的阴角、阳角及分段分层开挖等问题进行了计算分析。结果表明，基坑的阴角能大大降低基坑位移和土钉轴力，其影响范围大于开挖深度，直立开挖面的阴角效应比放坡开挖面时的要大；阳角处的位移及土钉轴力明显增大，其影响范围延伸至3倍基坑开挖深度；分段分层开挖支护能充分利用土钉支护的空间效应，其影响范围接近于基坑开挖深度。

Space effect of soil-nailing excavation protection

A three-dimension elastoplastic model had been developed to study the space effect of the soil-nailing excavation protection.The positive corner effect,negative corner effect and layered excavation were emphatically analyzed.The researches showed that: the negative corner of excavation could reduce the displacement of excavation and the force of soil-nail;and its influence was once more than the depth of the excavation;meanwhile,the displacement of the excavation and the force of soil-nailing were much larger in the positive corner;and its influence is near to 3 times of the depth of the excavation;the space effect of soil-nailing pit could be used plenarily by layered excavation;its influence was near to the depth of the excavation.It was proved that three-dimension numeric analysis of the soil-nail structure was very useable.