| The supporting structure of row pile composite fully bonded bolt is a composite supporting system composed of row pile,concrete surface and full-length bonded bolt.The end of fully bonded bolt is fixed on the concrete surface by anchor plate and locking device.The fully bonded bolt supporting structure with row piles not only has the economy of row piles soil nailing wall supporting,but also has the ability to control the deformation of traditional pile anchor supporting.Compared with the pile anchor structure,The fully bonded bolt supporting structure with row piles can effectively shorten the length of bolts,reduce the diameter of piles,reduce the disturbance to the surrounding soil,reasonably control the cost,and has both safety and resistance to deformation.Now,the fully bonded bolt supporting structure with row piles has been successfully applied in hundreds of projects in China.It has produced huge economic and environmental benefits.But at present,the research of row plie composite fully bonded bolt surpporting structure is limited to the overall stress,stability and deformation.Problems related to the stress of the anchor plate,the design and checking calculation of the concrete surface are not clear.In order to further study the mechanism of fully bonded bolt surpporting with row piles,further popularize the supporting technology,strengthen its application in engineering.It also provides technical support for the compilation of the fully bonded bolt surpporting part of the Chinese Architectural Society Standard “technical standard for composite support of foundation pit engineering”.Thesis makes a detailed study of the force on the anchor plate of the fully bonded bolt and the design checking calculation of the concrete surface.This paper uses a combined with model test and finite element simulation,combined with engineering examples.The main research work of this paper is as follows:(1)In this thesis,the model test of the supporting structure with row piles fully bonded bolt is carried out,the punching shear resistance of concrete surface and soil reaction behind the wall of anchor plate are studied.By changing the applied load,the magnitude and calculation method of the soil reaction behind the wall of the anchor plate under different displacement conditions are studied.As well as design and checking calculation of concrete surface considering soil reaction.The working mechanism of the row pile fully bonded bolt supporting structure is deeply analyzed.(2)Based on the model test of the supporting structure with row pile fully bonded bolt,using MIDAS GTS finite element software established the three-dimensional numerical model.The excavation condition of the foundation pit and the stress of the supporting structure under the loading condition are simulated and analyzed.Detailed analysis and study row pile fully bonded bolt supporting structure of displacement change of soil,the magnitude and change law of soil reaction and stress of concrete surface.The results of numerical simulation and model test are compared and analyzed.(3)Combined with engineering example,this paper studies and analyzes the supporting effect of row plie fully bonded bolt supporting structure.The calculation results of soil reaction calculation and surface layer checking formula of anchor plate are conpared wih the field monitoring data of foundation pit project in Zheng Zhou.Verifying the applicability of design and checking calculation method of concrete surface considering soil reaction force effect.It provides a reference for the design parameters of similar foundation pit engineering. |
