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钢筋混凝土构件纵向受力钢筋最小配筋百分率μ_(min)的规定是一个较复杂的问题。它既涉及结构的安全要求,又涉及经济政策。特别是,主要从经济政策角度确定μ_(min)时,其可靠度水准应该有较合理和准确的分析依据。我国现行规范(TJ10-74)的规定与其它各国规范相比偏低较多。为此,“最小配筋百分率的确定”一文对现行规范提出了修正。文献[1]考虑到混凝土抗拉标准强度R_l~b及钢筋抗拉标准强度R_f~b对μ_(min)的影响,从而推导出公式:并计算了相应于不同R_f~b,R_v~b,h及h。值的μ_(min)。我们认为,采用定值法推导得出的(1)式,求解μ_(min)有很大的局限和不合理性。它只能考虑标准强度的影响,而不能充分反映材料性能、标准强度取值水准、几何尺寸,计算公式精确性等变异性对μ_(min)的影响,也不能反映μ_(min)的可靠度水准。因此,本文采
The regulation of the minimum reinforcement ratio μ_(min) of the reinforced concrete member longitudinal reinforcement steel is a more complicated problem. It involves both the structural safety requirements and the economic policies. In particular, when determining μ_(min) mainly from the perspective of economic policy, the reliability level should have reasonable and accurate analysis basis. The regulations of China’s current regulations (TJ 10-74) are much lower than those of other countries. For this reason, the article “Determining the Percentage of Minimum Reinforcements” proposes amendments to the current specification. The literature [1] took into account the influence of tensile strength R_l~b of concrete and tensile strength R_f~b of steel bar on μ_(min), and derived the formula: and calculated the corresponding R_f~b, R_v~b, h and h. The value of μ_(min). We believe that the formula (1) deduced by the fixed-value method has large limitations and irrationalities in solving μ_(min). It can only consider the influence of the standard intensity, and can not fully reflect the influence of the variability of the material performance, the level of the standard intensity, the geometric size, the accuracy of the calculation formula, etc. on the μ_(min), nor can it reflect the reliability of the μ_(min). level. Therefore, this article