| At present,with the gradual deepening of coal mining in the country,under the influence of deep high ground stress,the surrounding rock is relatively loose and broken after the excava tion of the roadway,which is prone to large deformation of the surrounding rock,failure of sup porting components,roof fall and other instability damage.At the same time,due to the design of the roadway It will inevitably pass through weak strata,which can easily induce the above problems.In view of the problems such as large deformation of surrounding rock after excavat ion of deep soft rock roadway and difficulty in stable control,this thesis proposes the concept a nd technology of full-length prestressed anchoring support,and adopts the method of combinin g laboratory test,theoretical analysis and numerical simulation to reveal The full-length prestre ssed anchoring support mechanism,and the typical soft and broken stratum roadway is selecte d for technical application and promotion.The research results have important engineering val ue and reality for guiding the design of soft rock roadway anchoring support and ensuring the s afety and stability of soft rock roadway.significance.The main work of this thesis includes the following three aspects:1.The anchoring technology,advantages and disadvantages of conventional prestressed b olts are analyzed,and the realization technology based on fast and slow-setting anchoring agen t and the realization technology based on fast-setting anchoring agent combined with grouting reinforcement are proposed.The combined high-strength grouting bolt and the new high-streng th hollow grouting anchor cable were carried out,and the indoor basic mechanical performanc e test was carried out to verify the performance advantages of the new high-strength full-length prestressed anchor and support.2.In the FLAC-3D software,the embedded PILE structural elements are modified to reali ze the effective simulation of the full-length prestressed anchor support.Based on typical road ways,the full-length prestressed bolt-grouting support conditions are systematically considere d,considering factors such as in-situ stress,original rock strength grade coefficient,bolt length,bolt spacing,grouting strengthening index,and bolt prestress.The comparative study on the c ontrol effect of lower roadway excavation and surrounding rock support revealed the full-lengt h prestressed anchoring support mechanism.At the same time,the sensitivity indicators of vari ous influencing factors were established,the sensitivities of various influencing factors were id entified,and engineering suggestions were given.3.Based on the typical soft and broken stratum roadway of the No.1 Mine of Pingdingsh an Tianan Coal Industry Co.,Ltd.as the engineering support,in view of the deformation and d amage of the surrounding rock on site,based on the new full-length prestressed anchoring supp ort technology proposed in this thesis,the site roadway surrounding is designed.The rock resto ration and reinforcement plan was carried out,and the on-site application implementation and monitoring were carried out,and the on-site monitoring data was obtained and analyzed,which further verified the supporting effect and supporting advantages of the new full-length prestres sed anchoring support. |
