Study On The Effect Rule For The Settlement Of The Surface And Nearby Bridge Pile Caused By The Shallow Buried Covered Constraction Of Subway Station

It is very important engineering application value to study on the effect rule of thesurface and bridge pile caused by the shallow-buried excavation constraction of the citysubway station under the complex condition. This paper depends on the subject of the Beijingsubway10#line Lianhua bridge station, and the above problems were studied by theoryanalysis, numerical simulation and site monitoring methods. The main contents andconclusions are followed:(1) The influencing factors of the layer deformation caused by the constraction of theshallow-buried excavation main include: burial depth, the layer soil characteristic,underground water, the ratio of earth covering thickness and fly-past, constraction way,support method, excavation driving, etc. The influencing factors of the nearby pile foundationare layer horizontal deformation and layer vertical deformation.(2) Depending on the engineering geology survey of the Beijing subway10#lineLianhua bridge station was introduced, the projects of the PBA method constraction andmonitoring were drafted. The deformation of the surface and nearby pile caused by theconstraction was forecasted by the FLAC3D numerical simulation calculation, so the saftyand rationality of the constraction project can be guaranteed.(3) The study of the FLAC shows: the settlement of surface and bridge pile caused by theshallow-buried excavation PBA method main occur two stages: the standard pilot hole wasexcavated completely and center arch constraction. The settlement of bridge pile appears therule that is “gradual settlement一speed-up settlement一settlement stable” followingconstraction, and the settlement value change small following the distance between the pileand station center line enlarge. (4) The standard and main measures were extracted, in order to control the deformationof the surface and nearby bridge pile. The result shows that simulation settlement matcheswith the measured settlement fundamentally, the settlement deformation value are within thepermissible deformation, so the settlement control technique extracted is effective.