JIPlKIC 结构设计原理 The principle of structure design 7.1.3 Construction requirements (1)Rectangular cross-section for the most common form of Section height h is greater than 600mm,use more eccentric compression Shaped or box-shaped cross section. Circular section is mainly used for column Pier,Pile Foundation
(1) Rectangular cross-section for the most common form of Section height h is greater than 600mm, use more eccentric compression Shaped or box-shaped cross section. Circular section is mainly used for column Pier, Pile Foundation. §7.1.3 Construction requirements
JPKIC 结构设计原理 jhepnihplestncturedesig (2)Cross-section dimensions:Rectangular cross-section should not be less than the minimum size 300mm,length of the side ratio of 1.5-3, the long side in the direction of bending. (3)Vertical steel Large eccentric compression: A+4=1%~3% A Eccentric Compression: A+A=0.5%~2% A
(2) Cross-section dimensions: Rectangular cross-section should not be less than the minimum size 300mm, length of the side ratio of 1.5-3, the long side in the direction of bending. (3) Vertical steel Large eccentric compression: Eccentric Compression: =1%~3% + = A As As =0.5%~2% + = A As As
JPKIC 结构设计原理 The principle of structure design S 7.2 Flexural Characteristics And Failure Modes S 7.2.1 The failure modes of eccentric compression N M (=Neo) Figure7-4eccentric compression
Figure7-4eccentric compression N e0 N M（=Ne0） §7.2 Flexural Characteristics And Failure Modes §7.2.1 The failure modes of eccentric compression
JPKIC 结构设计原理 Tfepmieipleistrcturdesign 1.Tensile failure-big eccentric compressive damage Produce conditions:(e/h)large relative eccentricity, And the tension reinforcement configuration Debu too much. FAlLURE Some tension,some pressure,tensile reinforcement stress Yield strength is reached first,and then,concrete is pushed Chopped up to yield strength of compression reinforcement Bearing components Set depends upon the strength and tensile reinforcement quantity. Destruction of nature:plastic failure
1. Tensile failure - big eccentric compressive damage Destruction of nature: plastic failure. Produce conditions: (e/h)large relative eccentricity, And the tension reinforcement configuration Debu too much. Some tension, some pressure, tensile reinforcement stress Yield strength is reached first, and then, concrete is pushed Chopped up to yield strength of compression reinforcement. Bearing components Set depends upon the strength and tensile reinforcement quantity. FAILURE： N N
JPKic 结构设计原理 2.Compressive damage-damage to small eccentric compression The principle of structure design ●Produce conditions: (1)A very small eccentricity. (2)(h)smaller eccentricity,or eccentricity larger and more tensile reinforcement. (3)(e/centricity is small,but the pressure from the far side of the vertical bar a small number,while the N side of the bar near the longitudinal forces more time. FAILURE:Generally near the longitudinal force reached the limits of the first side of the concrete compressive strain and crushed the side of the steel reaches the yield strength of longitudinal force from either side of the steel in tension or compression,usually fail to yield strength.Capacity depends on the compression component of concrete compressive strength and steel strength. Destruction of nature:Brittle failure
⚫ Produce conditions: (1) A very small eccentricity. (2) smaller eccentricity, or eccentricity larger and more tensile reinforcement. (3) eccentricity is small, but the pressure from the far side of the vertical bar a small number, while the N side of the bar near the longitudinal forces more time. ⚫ FAILURE:Generally near the longitudinal force reached the limits of the first side of the concrete compressive strain and crushed the side of the steel reaches the yield strength of longitudinal force from either side of the steel in tension or compression, usually fail to yield strength. Capacity depends on the compression component of concrete compressive strength and steel strength. ⚫ Destruction of nature: Brittle failure. ( / ) 0 e h ( / ) 0 e h N N 2. Compressive damage - damage to small eccentric compression