Research on the Characteristics and Influencing Factors of the Separation Layer of Horizontal Layered Surrounding Rock
Taking the tunnel of the Dongfeng Road in the horizontal layered rock mass in Nanning City as the background,the characteristics and influencing factors of the separation layer of horizontal layered surrounding rock are studied through theoretical analysis and field tests.The formation of the separation layer is caused by the uncoor-dinated deformation between adjacent strata.When the thickness or mechanical properties of adjacent rock strata are quite different,the separation layer of the surrounding rock of the tunnel will occur.In addition,the generation of the separation layer is also affected by factors such as the rock mass structure,the mechanical properties of sur-rounding rock,ground stress and the cavern size.The generation and development range of the separation layer is also affected by the location of the critical layer:the closer the critical layer is to the excavation section,the smaller the influence range of the separation layer is due to the support and blocking by the critical layer,and when there is no critical layer in surrounding rock,the influence range of the separation layer is roughly half of the span of the cavern.The study has reference significance for similar projects.
Horizontal layeredRock mass tunnelSeparation layer characteristicsCritical layer
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