Under Normal Use Limit State Of Reinforced Concrete Slab Structure Reliability Research

The huge casualties and economic losses are caused by reinforced concrete slab collapse frequently. These security and failures problems of civil engineering structures draw much attention, so that the structure reliability evaluation in the serviceability limit state has become a hot area for experts. Based on this background, the paper does more in-depth research on the reliability, sensitivity and durability assessment of reinforced concrete slab and slab bridge.To make use of structural components maximum crack width, deflection, concrete structure carbonation threshold as the resistance of external load, and the crack width, deflection, concrete which structure generated during the normal as the action effects of external load. Consider with probability distribution types of random variables in each limit state equation. Writing the improved FORM reliability program by numerical analysis software MATLAB which to analysis the reliability index of reinforced concrete two-way slabs, one-way slab in five kind of floor highly effective, strength grade of concrete, thickness of protective layer, effective calculation span, load effect ratio. Furthermore analysis the sensitivity coefficient of reliability index,give a classification of deflection failure.The carbonation reliability indexes of the existing reinforced concrete slab bridge in the design service life were calculated. The remaining life curve of carbonation based on durability was fitted.Results show that the reliability index and sensitivity of crack, deflection and carbonization depth were influenced by the random variables of the slab structure that thickness of protective layer, component effective height, axial tensile strength of concrete, compressive strength and load effect ratio at different degrees in the serviceability limit state. Through the research of this paper, the calculation results can provide effective suggestions for the applicability and durability evaluation of the slab structure under serviceability limit state, which also can provide some reference for engineering design.