The composite supporting technology of soil nailing and bolting was developed from soil nailing technology; this technology is simple in construction

short construction period

low cost and has some other unique advantages. Although it has been widely used in engineering

but the theory of the composite supporting system is still imperfect and needs to be improved. Therefore it is essential to carry out model tests to deepen the knowledge of the composite system of soil nails and anchors. Through multiple sets of model tests

the internal force distribution of soil nailing

foundation soil displacement field are obtained in different loading locations and different construction stages. The effect of the support has been evaluated. The results show that: if there is a large additional load very close to the pit slope

a straight line sliding surface is prone to occur; otherwise

usually occurs a arc-shaped one. Soil anchors is very effective to prevent the slip surface occur through the slope

so if the additional load is close to the slope

anchors should be arranged in the middle and upper positions of the slope; if the addtional load is far from the slope

anchors should be arranged in the lower position instead.