The shear strength of some concrete materials should be analyzed based on elastic-plastic theory in petroleum, water conservancy, tunnel engineering, and so on. The majority of researches concentrate mainly on the tensile and compressive strength of concretes, but few have studied the shear strength. Concrete materials have been increasingly applied broadly to geotechnical engineering. Thus, investigating the shear strength characteristics of concretes is of great importance. To study the characteristics of shear strength of concrete materials, the theoretical relationship between concrete’s compressive and shear strengths was discussed in the uniaxial, biaxial, and triaxial stress states. The concrete strength envelopes under the biaxial and uniaxial compressive strength were studied. Given the concrete shear strength, the overload method and the finite difference software FLAC3D were used to investigate the concrete failure modes and ultimate bearing capacities. Results show that the theoretical formula under the 3D stress-bearing condition is only applicable to the circumstance with equal compressive strengths under the biaxial and uniaxial conditions, which conforms to 3D Mohr’s circle theory. 3D Mohr’s circle theory is not totally applicable to concrete materials where the concrete compressive strength under the biaxial condition is larger than that under the uniaxial condition. Concrete material gains its shear strength 47 percent from its frictional force while the rest form cohesive force. The study results can provide a certain basis and reference for analyzing the shear strength characteristics of concrete materials.
Theoretical and Numerical Study of Shear Strength of Concrete Material
