Resaerch On The Deformation And Stabality Of Soil-nail Wall With Deep Mixed Pile And Anchor Cable In Excavation

The composite soil-nail wall(CSNW)which was formed by soil-nail,pre-stresse-d anchor cable and the mixed pile is widely used in engineering.But the composite structure has been few studied so far.In this paper,combining with engineering exa-mples,the working properties will be studied in detail by using the finite element pr-ogram-Midas/GTS(Geotechnical and Tunnel Analysis System).The research result and the conclusions are as follows.1.By comparing with the date which is acquired by foundation monitoring and the fi-nite element conclusion,the fact that the finite element conclusion method can simu-late the working performance commendably.2.The deformation state of the CSNW is changed obviously because of the existing of the mixed pile.The largest lateral deformation of the foundation pit exists in the mid-dle section of the excavation face.The biggest axial force of the soil-nail exists in the head of it.The axial force decrease along the soil-nail.3.The pre-stress can reduce the lateral deformation effectively.In order to reduce the lateral deformation of the pit foundation,the pre-stress can arranged in the middle of it.4.In the progress of stability conclusion of the foundation pit,it's unreasonable to treat the strength reduction factor which correspond to the convergence point as the stabil-ity coefficient.There is a inflection point in the relation curve of the strength reduc-tion factor and lateral deformation of the pit foundation.It's reasonable to select the strength reduction factor which respond to the inflection point as the stability coeffi-cient.5.There are many factors which can change the stability coefficient of the pit founda-tion,but the critical one is the length of the soil-nail which arranged in the bottom of the excavation face.