Abstract:

The stability analysis and its protection in the excavation and unloading course of loess slope occupy an important position in the slope engineering. One centrifugal model test of non-reinforcement slope and two centrifugal model tests of soil nailing reinforcement slopes are performed on the centrifuge at Southwest Jiaotong University. The deformation characteristics, reinforcement effect of soil nailing and the stability in the excavation and unloading course of loess slopes are studied. Results of centrifuge model tests show that soil nailing can greatly increase the stability of loess slopes. Due to the anchoring effect of soil nailing, the range of deformation is wider, but magnitude is smaller, and the largest deformation is not in the surface, but in the anchor region of the nailed slope. Non-reinforcement loess slope has the potential failure surface of about 40cm below its crest. The models were substantially stable against failure and deformation due to soil nailing. The reinforcement with unequal length of soil nails is superior to that of equal length of soil nails for the resistance to slope failure. The research results provide references for excavation and reinforcement of loess slopes.

Key words: loess, excavation, soil nailing reinforcement, centrifuge model test