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Component proportioning and design based on ACI 318
Published in Mark Aschheim, Enrique Hernández-Montes, Dimitrios Vamvatsikos, Design of Reinforced Concrete Buildings for Seismic Performance, 2019
Mark Aschheim, Enrique Hernández-Montes, Dimitrios Vamvatsikos
Column transverse reinforcement provides ductility to column sections yielding in flexure and contributes to shear strength. To provide ductility, the transverse reinforcement must provide sufficient lateral restraint to longitudinal bars to delay buckling to larger strains, and must laterally confine the concrete enclosed within the transverse reinforcement. The lateral confinement increases the compressive strength and longitudinal strain capacity of the confined concrete. To develop the lateral confining stresses requires that the transverse reinforcement undergo lateral strain. The lateral strains typically develop after the cover concrete has spalled off.
Mechanical principles of static engineering systems
Published in Alan Darbyshire, Charles Gibson, Mechanical Engineering, 2023
Alan Darbyshire, Charles Gibson
When a material is loaded in tension, as shown in Figure 1.46, there is a tendency for its length to increase and its width or thickness to decrease. When loaded in compression, the opposite tends to occur. The deformation is measured as longitudinal strain in the direction of loading and lateral strain at right angles to the direction of loading.
Simple Stresses and Strains
Published in B. Raghu Kumar, Strength of Materials, 2022
The lateral strain is proportional to longitudinal strain if the material is homogeneous and isotropic. A material is homogeneous if it has the same composition throughout the body; hence elastic properties are same at every point in the body. Isotropic materials have the same elastic properties in all directions.
Development and application of three-directional compression testing system for gangue backfill in deep mine
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Bing Liang, Pengfei Wu, Yu Yang, Xiaodong Liu, Jiaxu Jin, Beifang Wang, Bo Hu
The deformation of the gangue sample was similar to that of the uniaxial compression when it was only laterally loaded. Because of the low initial lateral stress, the deformation of the gangue sample increased linearly with the loading stress. The results showed that the lateral strain of 0–10mm sized gangue under 2 MPa lateral confining pressure was the smallest, while that of 50–60mm sized gangue under 10 MPa lateral confining pressure was the largest. The lateral strain of gangue was positively correlated with the lateral stress and particle size. However, the lateral stress was the main factor causing the lateral strain of gangue sample, which means that the influence of the lateral stress on the lateral strain was greater than that of the particle size on the lateral strain.
Elastoplastic modelling the creep behaviour of cataclastic rock under multi-stage deviatoric stress
Published in European Journal of Environmental and Civil Engineering, 2018
Y. Zhang, X.D. Zhang, J.F. Shao, Y. Jia, Y.L. Wang
It is important to remark that a threshold stress exists in the process of creep. The lateral strain is significantly lower than axial strain when the deviatoric stress is smaller than the threshold value. Meanwhile, we can consider that no creep behaviour appears. The lateral strain gradually begins to be dominant as the deviatoric stress exceeds threshold value. It is indicated that such threshold stress marks the start of micro-fracturing, and it is observed that the threshold under confining pressure of 1.0, 1.5 and 2.0 MPa is 2.5, 3.25 and 4.00 MPa, respectively. The main feature associated with failure is large axial plastic deformation and large steady strain rate due to a long-term accumulation action of creep effect. In addition, the creep strain obviously decreases with increasing confining pressure. It is also concluded that both the yield stress and the failure stress increase as the confining stress increases.
Gas permeability evolution of granite under confining pressure unloading tests
Published in European Journal of Environmental and Civil Engineering, 2021
Dawei Hu, Jun Li, Hui Zhou, Jingjing Lu, Dongdong Ma, Fan Zhang
According to the stress path diagram in Figure 3(a), the gas permeability measurement in each cycle is performed after the deviatoric stress has been unloaded to zero. The stress–strain curve of granite under confining pressure of 7 MPa is shown in Figure 4. It is worth noting that, the rock sample is under hydrostatic pressure without deviatoric stress loading before the first cycle (C1) and then the first gas permeability measurement is performed. It is observed that the axial and lateral strain increases with the cycle number, and irreversible axial deformation in each cycle is larger than irreversible lateral deformation. Moreover, significantly larger lateral deformation in last cycle (C6) than that in previous cycles can be found.