Study on Retaining and Protecting for Foundation Excavation of Daihe Bridge Built on Permeable Soil

Based on the principle of water and soil separated calculation of permeable soil layer under the influence of seepage,the retaining and protecting for the foundation excavation of Daihe bridge piers is designed and calculated,the deformation value of the supporting structure and the settlement value of the soil mass around the foundation pit are obtained by using the finite element analysis software.In the process of the on-the-spot excavation of foundation pit and during the rain,a track monitoring for the support deformation and surface subsidence is implemented by the properly established motoring points.And by the comparison of the calculated maximum deformation value and the actually measured maximum deformation value of the supporting structures,it is found that they match well,and that such properties as the supporting strength,the stiffness,stability and piping resistance are up to the standard of the technical specifications of building foundation pit engineering test.