Please wait a minute...
J4  2012, Vol. 46 Issue (7): 1248-1254    DOI: 10.3785/j.issn.1008-973X.2012.07.015
    
Modified STM model for calculating inclined section strength of
reinforcement concrete cap beam of single column pier
XIANG Yi-qiang1, LIU Cheng-xi1, TANG Guo-bin1, CHEN Xue-jiang2,
WU Tian-zhen2, LUO Xiao-feng1
1. Department of Civil Engineering, Zhejiang University, Hangzhou 310058, China; 2. Taizhou Highway
Port and Waterway Engineering Supervision Consulting Limited Company, Taizhou 317000, China
Download:   PDF(0KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

A modified strut and tie model was presented to predict ultimate strength of cap beam of single column pier aiming at design of cap beam of single column pier in ultimate limit stage. The nonlinear analysis of a severe cracking cap beam was conducted using smeared cracking model in ANSYS for reinforced concrete. Results show that the beam theory and deep beam theory are not appropriate for the analysis of such member with small depth-span ratio where the stress distribution is very complicated. Then the strut-and-tie model (STM) based on Mohr-Coulomb failure criterion was presented by considering the bent up steel bar, the stirrup and tensile strength of concrete contribution on restricting shear crack in the reinforced concrete cap beam. The model described the real behavior feature of cap beam in the failure stage. The effectiveness and applicability of the presented model used in different depth-span ratio was compared with other theories. The values by the presented model accorded well with the results obtained by finite element model.



Published: 01 July 2012
CLC:  U 445.72  
Cite this article:

XIANG Yi-qiang,LIU Cheng-xi,TANG Guo-bin,CHEN Xue-jiang,WU Tian-zhen. Modified STM model for calculating inclined section strength of
reinforcement concrete cap beam of single column pier. J4, 2012, 46(7): 1248-1254.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2012.07.015     OR     http://www.zjujournals.com/eng/Y2012/V46/I7/1248


计算独柱墩帽梁承载力的改进撑杆-系杆模型

针对独柱式桥墩帽梁在承载能力极限状态下的设计计算问题,提出改进的撑杆-系杆模型来预测该类结构的极限承载力.以某座独柱式桥墩发生严重开裂的桥墩帽梁为背景,利用ANSYS的有限元弥散裂缝模型对开裂的桥墩进行非线性分析.计算结果说明,对于钢筋混凝土独柱墩帽梁这类剪跨比较小的构件,帽梁的弯剪复合受力十分复杂,基于经典的欧拉伯努利梁理论和铁木辛柯梁理论的设计计算方法不合适.对比数值分析的结果,提出基于节点区域双向拉压破坏的改进撑杆系杆体系模型.该模型进一步考虑了弯起钢筋、箍筋以及混凝土抗拉强度对斜裂缝开展的限制作用,更能反映独柱墩帽梁在破坏阶段的受力特征.对比独柱墩帽梁常用的剪跨比下各理论的适用性可知,该改进模型结果与有限元模型的计算结果吻合.

[1] JTG D622004,公路钢筋混凝土和预应力混凝土桥涵设计规范[S]. 北京: 人民交通出版社, 2004.
[2] AASHTO LRFD bridge design specifications SI units [S]. 3rd ed. Washington D.C.: American Association of State Highway and Transportation Officials, 2004.
[3] Canadian Standards Association. Design of concrete structure: structures design [S]. Rexdale (ON): Canadian Standards Association, 1994.
[4] SCHLAICH J, SCHAEFER K, JENNEWEIN M. Toward a consistent design of structural concrete [J]. PCI Journal, 1987, 32(3):74-150.
[5] MARTI P. Basic tool of reinforced concrete beam design [J]. Journal of the American Concrete Institute, 1985, 82(1): 46-56.
[6] FOSTER S J, MALIK A R. Evaluation of efficiency factor models used in strutand tie modeling of nonflexural members [J]. Journal of Structural Engineering, 2002, 128(5): 569-577.
[7] TAN K H, TONG K, TANG C Y. Direct strutandtie model for prestressed deep beams [J]. Journal of Structural Engineering, 2001, 127(9): 1076-1084.
[8] RAMIREZ J A. Struttie design of pretensioned concrete members [J]. ACI Materials Journal, 1994, 91(5): 572-578.
[9] PARK J, KUCHMA D. Strutandtie model analysis for strength prediction of deep beam [J]. ACI Structural Journal, 2007, 104(6): 657-666.
[10] 项贻强,李毅,王晖. 独柱T型桥墩裂缝成因分析及加固方法研究[J]. 中国市政工程,2005, 6:18-19.
XIANG Yiqiang, LI Yi, WANG Hui. Study on cracks cause analysis and reinforcement method of single column pier with T Shape[J]. China Municipal Engineering, 2005,6: 18-19.
[11] 王曦婧,叶见曙,王毅,等. 实体式混凝土桥墩裂缝成因分析及加固方法研究[J]. 现代交通技术, 2005, 2(5): 35-38.
WANG Xijing, YE Jianshu, WANG Yi, et al. Research on structural analysis method of solid concrete pier strengthening [J]. Modern Transportation Technology, 2005, 2(5): 35-38.
[12] 刘洪瑞,薛兴伟,刘智君. 单柱盖梁柱顶弯矩折减的三维有限元分析及工程应用[J]. 中外公路, 2010, 30(2):118-121.
LIU Hongrui, XUE Xingwei, LIU Zhijun. 3D FEM analysis of moment reduction of single column pier cap beam and its application [J]. Journal of China and Foreign Highway, 2010, 30(2): 118-121.
[13] 项贻强,唐国斌,陈孟冲,等. 某钢筋混凝土独柱伸臂桥墩开裂的加固设计及分析[J].江南大学学报,2010,9(6):674-679.
XIANG Yiqiang, TANG Guobin, CHEN Mengchong, et al. Reinforcement design and analysis of the typical reinforced concrete singlecolumn cantilever pier [J]. Journal of Jiangnan University, 2010, 9(6): 674-679.
[14] 项贻强,唐国斌,晁春峰,等. 某连续箱梁桥钢筋混凝土独柱桥墩开裂机理的弹塑性分析[C]∥第16届桥梁学术会议论文集(下). 北京:人民交通出版社,2010:805-811.
XIANG Yiqiang, TANG Guobin, CHAO Chunfeng, et al. Elastoplastic analysis of cracking mechanism of R.C. cap beam of single column pier in continuous box girder bridge [C]∥Proceedings of 16th Bridges Conference. Beijing: China Communications Press, 2010: 805-811.
[15] 王新敏. Ansys工程结构数值分析[M]. 北京: 人民交通出版社, 2007: 479-482.
[16] HOGNESTAD E, HONSON N W, MCHENRY D. Concrete stress distribution in ultimate strength design [J]. ACI Journal Proceedings, 1955, 22 (6): 455-479.

[17] TAN K H, LU H Y. Shear behavior of large reinforced concrete deep beams and code comparisons [J]. ACI Structural Journal, 1999, 96(5): 836-845.
[18] TJHIN T N, KUCHMA D A. Integrated analysis and design tool for the strutandtie method [J]. Engineering Structures, 2007, 29(11): 3042-3052.
[19] ZHANG N, TAN K. Direct strutandtie model for single span and continuous deep beams [J]. Engineering Structures, 2007, 29(11): 2987-3001.
[20] TAN K H, TANG C Y, TONG K. A direct method for deep beams with web reinforcement [J]. Magazine of Concrete Research, 2003, 55(1): 53-63.
[21] WANG G, MENG S. Modified strutandtie model for prestressed concrete deep beams [J]. Engineering Structures, 2008, 30(12): 3489-3496.
[22] KWAK H, NOH S. Determination of strutandtie models using evolutionary structural optimization [J]. Engineering Structures, 2006(28): 1440-1449.
[23] BELARBI A, HSU T T C. Constitutive laws of concrete in tension and reinforcing bars stiffened by concrete [J]. ACI Structural Journal, 1994, 91(4): 465-474.
[24] TAN K H, CHENG G H. Size effect on shear strength of deep beams: investigating with strutandtie model [J]. Journal of Structural Engineering, 2006, 132(5): 673-685.
[25] KIM J K, YI S T, PARK C K, et al. Size effect on compressive strength of plain and spirally reinforced concrete cylinders [J]. ACI Structural Journal, 1999, 96(1): 88-94.
[26] ACI Committee 318. Building code requirements for structural concrete (ACI31899) and commentary (318R99) [S]. Farmington Hills: American Concrete Institute, 2004.

No related articles found!