Steel Plastic Geogrid Performance Testing and its Application in the Reduction of Spring Back of Shotcrete

In order to solve the problems of high springback of sprayed concrete and high dust concentration in the boltnetting support of underground engineering, research the mechanical properties of steel plastic geogrid and analyze the application of steel plastic geogrid replacing the metal net in the reduction of concrete through theoretical study, laboratory test, field test and contrast analysis, thus got the conclusion that: (1) Through the analysis of influence factors of the springback of surrounding rock supporting sprayed concrete, classification is carried on with the sampling survey method. The interaction between the metal net and concrete is the main factor to influence the springback of the concrete. (2) Study the performance differences of the steel plastic geogrid and the metal net. With the advantages of tensile strength, strong durability and injection connection, steel plastic geogrid has stronger applicability, safety and stability in adjusting the stress of the surrounding rock of the roadway and coordinating its deformation. (3)Through the tensile test and the deflection test, study the relationship between the tensile strength and external load under different aperture, thus establish the relation curve between the maximum deflection and load. (4) Through the roadway engineering construction and the analysis of the data of the field test, steel plastic geogrid can greatly reduce the springback of sprayed concrete which can guide the design and construction of underground bolt-netting support engineering.