鋼管混凝土軸壓短柱界限套箍系數

吳鵬+趙均海+張常光+朱倩+李艷

建筑科學與工程學報2014年文章編號：16732049(2014)01008307

收稿日期：20131011

基金項目：國家自然科學基金項目(41202191)；陜西省自然科學基礎研究計劃項目(2011JM7002)；

教育部高等學校博士學科點專項科研基金項目(20110205130001)

作者簡介：吳鵬（1988），男，甘肅張掖人，工學碩士研究生

摘要：基于統一強度理論，借助鋼管混凝土軸壓短柱極限承載力計算公式的推導，得出了極限狀態時鋼管和混凝土之間的側壓力，提出了界限套箍系數的概念，并給出界限套箍系數的計算公式，同時分析了不同套箍系數時鋼管的三向應力和鋼管混凝土短柱的軸壓應力應變曲線出現不同發展趨勢的原因，且理論分析得出的結論與相關文獻的試驗結果一致，說明分析過程的合理性；最后對影響因素進行了分析，根據分析結果提出了實用建議，并發現相關參考文獻的界限套箍系數為該研究結果的特例。

關鍵詞：鋼管混凝土；統一強度理論；軸壓；套箍系數；應力應變曲線

中圖分類號：TU398.9文獻標志碼：A

Boundary Casing Hoop Coefficient for Concretefilled Steel Tubular

Stub Columns Under Axial CompressionWU Peng, ZHAO Junhai, ZHANG Changguang, ZHU Qian, LI Yan

（School of Civil Engineering, Changan University, Xian 710061, Shaanxi, China）Abstract: Based on unified strength theory, a ultimate bearing capacity calculation formula for concretefilled steel tubular stub columns under axial compression was proposed. The lateral pressure between the steel tube and concrete was given in the ultimate state. The concept of limit casing hoop coefficient was presented, and the calculation formulae of limit casing hoop coefficient were given. Meanwhile, the limit value of casing hoop coefficient was defined to analyze the reasons for different development trends with different casing hoop coefficients appeared in axial compression stressstrain curve, and the theoretical analysis results were similar to the experiment results in relevant literature, and the rationality of analysis process was pointed out. Finally, parametric studies were carried out to analyze the influencing factors, and the practical suggestions were put forward due to the analysis results. It was also found that the limit casing hoop coefficient of relevant references was a special case for this study.

Key words: concretefilled steel tube; unified strength theory; axial compression; casing hoop coefficient; stressstrain curve

0引言

鋼管混凝土是鋼管內填充混凝土形成的構件，它具有承載力大、塑性和韌性好、施工方便等特點［1］，已被廣泛應用于工程實際［2］。目前，確定鋼管混凝土軸壓短柱極限承載力時所遵循的基本概念是：鋼管對核心混凝土提供了約束，使混凝土處于三向受壓的應力狀態，從而提高了承載力，并認為達到極限狀態時鋼管環向已經屈服［320］。但不少研究者發現，在構件達到極限狀態時，鋼管環向并未屈服［2］；……