Dynamic Response Analysis On Sheet-Pile Wall Of Deep Excavation Adjacent To Highway

In the present study,the dynamic responses of sheet-pile wall in deep excavation adjacent to moving vehicle loads of highway were analyzed using the finite element software PLAXIS 3D.In the 3D finite element models of deep excavation adjacent to highway,two types of vehicle were chosen from ASSHTO specification in order to investigate the influences of moving truck loads.The vehicle tire load on the pavement was modeled to reflect the running of vehicles,and several paraneters including vehicle types,vehicle speeds,and clear distances between the highway and the excavation were taken into account.Based on numerical simulations,the influences of the investigated parameters on the response of sheet-pile wall of deep excavation during its construction were studied.To conduct this research,the dynamic equation of a geotechnical system was firstly derived from an infinitesimal soil volume.Furthermore,the dynamic loads for the characteristic of running vehicles were analytically modeled,and the equation of additional dynamic load of vehicles was presented in the stochastic process.Subsequently,the aforementioned simulations were performed by using the finite element software PLAXIS 3D to study the dynamic response of sheet-pile wall with fully coupled and uncoupled solid-fluid analyses.Finally,the comparison between these various approaches are briefly demonstrated and concluded.In accordance of the numerical results from the above-mentioned analyses,the observations and conclusions can be highlighted as follows:(1)The parameters such as vehicle loads,vehicle speeds,and the clear distances between the excavation and the highway have significant impacts on the behaviors of retaining wall.Therefore,the appropriate material properties of sheet-pile wall and strut system shall be carefully selected,and the embedded depth of the wall must be sufficient.(2)It is noticed that with the increase of the clear distance between the highway and the excavation,the effect of vehicle load distribution on the upper part of wall may slightly decrease;however,the effect shall be still large on the lower part of the sheet-pile wall.(3)The variation of total pore water pressure and effective stress behind the sheet-pile wall are extremely small and hence shall be negligible becaxise of the short-studied period and the low permeability of soil layer beneath the wall tip.(4)The obtained results including wall displacement,wall bending moment,total pore water pressure and effective stress behind the wall from fully coupled and uncoupled solid-fluid analyses are almost the same.In this case,it is recommended to apply the more effective uncoupled solid-fluid method since the calculation requires lesser time consuming.