Study on Gradation Characteristics and Arching Effect of Talus in Southwest China
To explore the arching effect and arch height evolution law of the rock skeleton in talus surrounding the tunnel,a sleeve test and theoretical analysis were used to analyze the influence of gradation,water content,and filled soil content on the arching effect of the skeleton-type talus.The relationship between the maximum distanceℎfrom the tunnel crown to the natural equilibrium arch of the surrounding rock and the horizontal calculation distance of the arch axis was derived.The study shows that the stress transmission path of the talus is not uniformly distributed and is directly related to the constraints.The effectiveness of reducing the ground arch height among the three factors(grading,water content,and filled soil content)is as follows:increasing water content>increasing filled soil con-tent>increasing gradation uniformity.The relationship between the maximum distanceℎfrom the tunnel crown to the natural equilibrium arch of the surrounding rock and the horizontal calculation distance of the arch axis is a quadratic function,being consistent with the sleeve test results.The quadratic term represents the stress equilibrium condition,andℎis positively correlated with the interlocking strength of the talus,influenced by the relative grain size and compaction degree of the rock blocks.
Tunnel engineeringTalusSleeve testInterlocking strength of talusNatural equilibrium arch
万方数据
维普
