Study On Reinforcing And Blocking Effect Of Fully Bonded Bolt

Fully-bonded bolts are bolts that need to be grouted along the entire length of the bolt.No free section is provided in the bolt.The length of this type of bolt is short,which reduces the pollution of the underground space by the construction of the bolt and is generally affected.Good force performance,the reinforcement and blocking effect of the fully-bonded anchor rod in the sliding surface reduces the earth pressure on the supporting structure,thereby reducing the horizontal displacement of the entire supporting soil body,and traditional pile-anchor support Compared with the technology,the deformation control ability of the row pile-full-bonded anchor support is strong,and the cost can be saved.In order to further study the supporting mechanism of the full-bonded anchor and strengthen its application in the project,and provide technical support for the research and compilation of the standard "Technical Specification for Compound Support of Foundation Pit Engineering" of the China Architectural Society-Full-bonded Bolt Support.In this paper,the combination of theoretical analysis,finite element simulation and model test,combined with existing projects,to study the reinforcement and blocking effect of fully bonded anchors.The main research contents and research results of the paper are as follows:(1)The mechanism by which the fully-bonded anchor rod reinforces and blocks the supporting soil in the slip plane is analyzed.On this basis,basic assumptions are introduced,and the fully-bonded anchor-supported soil body is analyzed and derived using the power balance method the calculation formula of equivalent fracture angle and cohesion-like force.(2)Using the simplified stiffness of the fully-bonded anchor,the displacement of the row-pull-bonded bolt support at the anchor head is derived through repeated iterations,and then the displacement of the row-pile-fully-bonded bolt support structure is derived Calculation formula.(3)The model test of the full-bonded anchor and the traditional anchor support is carried out,and the axial force experienced by the anchor in the two support forms is compared.The results show that the anchor has the same excavation depth and the same anchor length in the support Under the conditions,the maximum axial force experienced by the fully-bonded anchor is slightly larger,but the axial force at the front end is less than that of the traditional anchor.(4)Taking the test model as the research object,a fully-bonded anchor support model and a traditional anchor support model are established respectively.By changing the length of the traditional anchor free section,the displacement and deformation of the supporting soil are simulated and analyzed.The research shows that the friction between the grouting body of the fully-bonded anchor and the surrounding soil in the slip plane reduces the displacement of the supporting soil.(5)Combined with the actual project,the theoretical calculation results of the displacement of the row of pile-full-bonded anchor supporting system deduced in this paper are compared with the monitoring data of engineering examples to verify the applicability of the method.