The Characters Of Group Excavation And The Analysis Of The Interaction Based On HSS Model

With the expansion of urban construction scale and the functional diversificationof underground space, several foundation pits were excavated synchronized or insuccession during the development of large undergroud space,thus the interactioneffect of group excavation highlights out.So far,the research on excavation home andabroad mostly focus on single-pit, only a small number of scholars focus on theadjacent pits,as for the research of group pits, almost no one is concerned aboutit.With the increase of large-scale underground space development engineeringprojects, group excavation engineering will become more and more popular.soresearch the force-deformation law of group foundation pits and the interactioneffect between pits will contribute to the optimization of construction process andcost savings.On the basis of suming up the construction experience of three large groupexcavation engineerings and the common soil constitutive models, use the largegeotechnical three-dimensional finite element analysis software Z-Soil.PC toeatablish three-dimensional finite element model for different support systems underdifferent depth of excavation, with the HSS soil constitutive model.Then forstep-slope shallow foundation pits, mainly analyzed the soil deformation underdifferent excavation sequence and soil strength reduction. During the analysis, theimpact of ground water was considered. For medium excavation depthpile-retaining group pits,mainly analyzed the soil deformation andforce-deformation of supporting structure of simultaneously pit groups spacing2H，As well as the impact of distance between pits on soil deformation and theforce-deformation of piles.For undergroud continuous wall-internal support deepgroup pits,mainly analyzed the soil deformation and force-deformation ofundergroud continuous wall under the excavation sequence of middle-left-right, aswell as the impact of different excavation sequence and the distance between pits onsoil deformation and the force-deformation of undergroud continuous wall.From those analysis, the uplift law of pits bottom,the deformation law of embankments between pits and the force-deformation law of retaining structurewere got. On this basis, analyzed the influence of undergroud water， soilquality,distance between pits，excavation sequence to the group pits.