FLAC 3D �����������й㷺Ӧ�õ������������ij��������Ϊ��������������ǽ֧����ƣ������� FLAC 3D ���������ǽ֧��ǰ�������ֵģ�⡣�ڻ��ӿ�����ɺ󣬱�ǽλ��һ��Ϊ 20 �� 40 cm�����λ��Ϊ 45 cm����������ǽ֧���󣬱�ǽ��λ��Ϊ 2 �� 4 cm�����λ��Ϊ 6 cm���Աȱ���������ǽ֧���ܹ���Ч����ֹ���ӵı��Σ�ά�ֻ��ӵ��ȶ���ͬʱ�����������������ֲ����������������ڲ���ȡ֧����ʩ������½����������ƻ���

FLAC 3D software is widely used in geotechnical engineering�� Based on the background of a foun- dation pit in some district��the authors projected the soil nailed wall supporting design and carried out numerical modeling around the soil nailed supporting using FLAC 3D�� When the excavation of foundation pit completed��the displacement of side wall commonly was 20 ��40 cm��and the maximum was 45 cm�� After adopting the soil nailed wall supporting��the displacement was 2 �� 4 cm��and the maximum was 6 cm�� The contrast showed that the soil nailed wall can prevent the transformation of foundation pit effectively and keep the pit steady�� On the basis of axial force distribution of soil nailing��the foundation pit sliding failure will happen when the supporting measure does not adopt��