Construction Research And Control Of The Large Section Flat Roof Straight Wall In Sand And Gravel Stratum

In the construction of municipal projects by all types of pipelines,ground buildings elevation,settlement control specifications and other aspects of the constraints,the dug up the structure have to use the flat-topped wall form.The construction of flat-topped straight-wall excavated tunnel is difficult and risky.If the design or construction technology is improper,the problems such as construction collapse,land subsidence and lining leakage are easy to occur.In this paper,a large cross-section underground corridor for the engineering background,around the control of sand and gravel large-section flat-topped straight wall excavation and reinforcement measures to the impact of surrounding ground,The formation-structure model is established by finite element analysis method.The whole process of strata and structure in the whole process of excavation by CRD(cross-partition method),The excavation sequence,excavation sequence,excavation footage,grouting reinforcement scheme and supporting and dismantling sequence of different guide holes are analyzed for the displacement and surface displacement at the key control point of the large section flat-topped straight wall structure.And the influence of the settlement on the ground surface and the top of the tunnel is given,and the economic and rational construction technology is given.The results of construction monitoring during the actual project coincide well with the predicted results obtained by finite element method,which further validates the necessity and effectiveness of the study on the construction technology of the large-section flat-to-straight wall embedded excavation by using the finite element method.Large cross-section flat straight wall more appropriate USES after the first pilot tunnel excavation under,intermediate before they are on both sides of the excavation sequence;Excavation should be in 0.5 m;Before the excavation in arch grouting reinforcement measures;Temporary support in the next door and baffle plate(middle)demolition,appropriate used interval dismantled?Practice shows that this paper USES the analysis method and put forward the construction technology of advanced applicable,can be used for reference in the similar projects.