Study on the Mechanical Properties and Failure Law of Composite Rocks with Coplanar Double Fissures
In order to investigate the impact of fissure configuration attributes on the mechanical behavior,failure mode,and crack propagation law of layered composite rocks,a study was carried out on pre-fabricated composite rocks with coplanar double fissures.Indoor uniaxial compression tests and a digital image acquisition module were used to analyze the mechanical properties and failure characteristics of rock samples with various fissure lengths and angles.The following conclusions are drawn.Firstly,the peak stress and elastic modulus of rock samples increase with the increase of fissure angle,while decrease with the increase of fissure length.The degradation coefficient k displays a decrement with increasing fissure angle and an increment with increasing fissure length.Secondly,the failure pattern is influenced by both the fissure angle and the two types of rock materials,with the degree of fragmentation primarily governed by fissure length.Thirdly,the bridging mode of rocks is subject to fissure angle and structural planes.In the four bridging modes,the transfixion trend increases with the increase of fissure angle,but it is no longer transfixion when the fissure angle reaches 90°,and the structural plane will inhibit the transfixion of rock bridge.Fourthly,crack propagation is contingent on fissure length.When the fissure length is below 12 mm,cracks predominantly emerges in the right half of the rock sample,while post-elastic stage cracks are principally observable in the left half.When the fissure length is greater than 12 mm,the crack is evenly distributed on the surface of the rock sample.The research results have a certain guiding significance for the construction and design of practical engineering.
Coplanar double fissuresComposite rockRock-like materialsMechanical propertiesFailure law
万方数据
维普
