Study On Stability Of Assembly Steel Pile-steel Plate Recyclable Work Well Support Structure

As a temporary structure,the work well supporting structure has such characteristics as a small excavation section and short service life.For current concrete supporting technology,it needs high cost and long construction period.The project cost does not match the service period,and it is difficult to dismantle.Recently it is becoming more and more important to how to improve social and economic benefits,accelerate construction progress,and incorporate green environmental protection concepts while ensuring its safety.In this study,we proposed a brand-new supporting structure of a working well by combining the merits of the structural steel piles,beams,plates,and the water absorption and expansion performance of waterstops at the joints between two steel components.Meanwhile,The internal forces and deformation of the structure during the excavation of the working well will be analyzed by both finite element method and the in-situ full-scale experiment,in order to provide a theoretical basis for the design and field construction of this kind of work well.The main research contents and conclusions of this paper are as follows:(1)According to the characteristics of assembly steel pile-steel plate recyclable work well Support Structure,the force characteristics and working mechanism of the new work well support structure are analyzed.The calculation formula of internal force deformation of this new type of working shaft supporting structure based on elastic pivot method is deduced.(2)A three-dimensional refined numerical model was established by the finite cloud software ABAQUS.To verify the correctness of the simulation results,a fullscale structure was built,and the in-situ structural horizontal displacement and bending moment were measured under the construction load of the excavator.A comparison between the simulation and the measurement methods indicates that the monitoring results of the force and deformation of the supporting structure are basically consistent with the numerical calculation results,which proves the feasibility of the numerical method to guide the design of the new working well structure.(3)Based on the numerical model verified by the full-scale test,the influence of construction urcharge load,construction surcharge locations and design parameters on the force and deformation of the supporting structure are analyzed.The results show that the construction urcharge load has a significant effect on the horizontal displacement of support piles.When the construction urcharge load exceeds a certain value,the deformation curve of the support pile gradually changes from a "convex shape" to a "triangular" deformation mode,which shows the pile has the risk of instability.The force and deformation value of the supporting structure shows a decreasing trend with the increase of the load acting distance.When the load acting distance exceeds a certain value,the construction urcharge load has basically no effect on the force and deformation of the supporting structure.Orthogonal test test results show that the supporting pile type is the main control index for the bending moment and horizontal displacement of the supporting structure.