钢筋混凝土偏心受压柱长期变形随机分析
doi: 10.3969/j.issn.0258-2724.2014.04.010
Long-Term Random Deflection of Eccentrically Loaded RC Column
-
摘要: 混凝土收缩徐变具有显著的不确定性,需要采用随机方法进行有概率保证意义的长期变形分析.采用基于响应面的蒙特卡洛抽样技术,将GL2000模型中影响混凝土结构长期变形的因素作为随机变量,建立了混凝土结构的长期变形随机性分析模型.利用该模型进行了钢筋混凝土偏心受压柱长期变形随机分析,并考察了混凝土抗拉强度对长期变形的影响.在算例中,当偏心率接近1.0时,抗拉强度的敏感性系数达到峰值0.6,然后逐渐降低;当偏心率为1.6时,抗拉强度的敏感性系数基本为0.分析结果表明,钢筋混凝土柱开裂前,混凝土抗拉强度对其长期变形没有影响;随着偏心率的增大,混凝土开裂程度加深,其对长期变形的影响逐渐增大至峰值而后逐渐减小.Abstract: Owing to the randomness of shrinkage and creep of concrete, random analysis method should be adopted to provide probabilistic guarantee for the analysis of concrete long-term random deflection. Stochastic variables for the long-term analysis with GL2000 model about creep and shrinkage of concrete were presented. Combining Monte Carlo sampling with the response surface method, the stochastic analysis model was established, which is on time-variant deflection of concrete structure. The long-term deflection of reinforce concrete (RC) columns were analyzed using this model. The influences of tensile strength of concrete on long-term deflection of RC columns were considered. The case study shows that when eccentricity ratio is increased to 1.0, the sensitivity of tensile strength reaches a peak of near 0.6 and then decreases gradually. Afterwards, when eccentricity ratio is 1.6, the sensitivity value is reduced to zero. The tensile strength of concrete has no effect on long-term deflection of columns prior to the crack of concrete. With the increase of eccentricity ratio, the effects of tensile strength of concrete will grow to peak and drop down gradually.
-
BAŽANT Z, LI Guanghua. Unbiased statistical comparison of creep and shrinkage prediction models[J]. ACI Materials Journal, 2008, 105(6): 610-621. MADSEN H, BAŽANT Z. Uncertainty analysis of creep and shrinkage effects in concrete structures[J]. ACI Journal, 1983, 80: 116-127. YANG I. Uncertainty and sensitivity analysis of time-dependent effects in concrete structures[J]. Engineering Structures, 2007, 29(7): 1366-1374. GOEL R, KUMAR R, PAUL D K. Comparative study of various creep and shrinkage prediction models for concrete[J]. Journal of Materials in Civil Engineering, ASCE, 2007, 19(3): 249-260. GARDNER N J, LOCKMAN M J. Design provisions for drying shrinkage and creep of normal-strength concrete[J]. ACI Material Journal, 2001, 98(2): 159-167. KEITEL H, OSBURG A D. Uncertainty and sensitivity analysis of creep models for uncorrelated and correlated input parameters[J]. Engineering Structures 2010, 32(11): 3758-3767. Al-HARTHYA S, FRANGOPOL D M. Reliability-based design of prestressed concrete beams[J]. Journal of Structural Engineering, ASCE, 1994, 120(11): 3156-3177. LAUMET P. Reliability-based deterioration model for deflection limit state girder bridges. Michigan: The University of Michigan, 2006. VAL D V, STEWART M G, MELCHERS R E. Effect of reinforcement corrosion on reliability of highway bridges[J]. Engineering Structures, 1998, 20(11): 1010-1019. 徐腾飞. 钢管混凝土非线性稳定承载能力与可靠度分析[D]. 成都:西南交通大学,2010. 徐腾飞,赵人达,向天宇,等. 钢管混凝土高墩非线性稳定承载能力可靠度分析[J]. 土木建筑与环境工程,2010,32(2): 60-63. XU Tengfei, ZHAO Renda, XIANG Tianyu, et al. Reliability analysis of ultimate bearing capacity of concrete-filled tube high piers[J]. Journal of Civil, Architectural & Environment Engineering, 2010, 32(2): 60-63. XU Tengfei, XIANG Tianyu, ZHAN Yulin, et al. Reliability analysis of circular concrete-filled steel tube with material and geometrical nonlinearity[J]. Journal of Modern Transportation, 2012, 20(3): 103-107. LIU P L, Der KIUREGHIAN A. Finite element reliability of geometrical nonlinear uncertain structures[J]. Journal of Engineering Mechanics, 1991, 117(8): 1806-1825. WEN Qingjie. Long-term effect analysis of prestressed concrete box-girder bridge widening[J]. Construction and Building Materials, 2011, 25(4): 1580-1586. 向天宇,童育强,赵人达. 基于退化梁单元的混凝土结构徐变分析[J]. 工程力学,2006,23(4): 140-143. XIANG Tianyu, TONG Yuqiang, ZHAO Renda. Creep analysis of concrete structure by degenerated beam element [J]. Engineering Mechanics, 2006, 23(4): 140-143. 占玉林,向天宇,赵人达. 几何非线性结构的徐变效应分析[J]. 工程力学,2006,23(7): 45-48. ZHAN Yulin, XIANG Tianyu, ZHAO Renda. Creep effect analysis of geometric nonlinear structure[J]. Engineering Mechanics, 2006, 23(7): 45-48.
点击查看大图
计量
- 文章访问数: 1021
- HTML全文浏览量: 67
- PDF下载量: 534
- 被引次数: 0