柱支承双向板及板柱节点的设计与研究
|
摘要
冲切面斜裂缝过早发生和最终的冲切破坏严重地影响着板柱节点的延性,制约着整个结构的抗震性能。在已有研究成果和板柱节点破坏机理的基础上,提出了柱支承双向板小震不裂、中震弹性、大震仍能继续承受竖向荷载作用效应和地震作用效应,保持结构完整性的抗震设防目标。建立了实现抗震设防目标的正截面和斜截面计算的应力表达式。将小震的最大主剪应力不大于混凝土轴心抗拉强度标准值作为控制板厚的指标。正截面极限状态承载力计算中,计入了斜裂缝发生后的剪力补偿。工程实例表明,按照现行规范的构造要求和中震弹性的抗震设防目标设计的柱支承双向板及板柱节点,没有发生塑性铰,符合强节点的抗震设计原则。
Shear stresses caused by unbalanced moment at slab-column connection may result in diagonally cracking earlier in concrete core and consequently punching failure,which has great influences on ductility of the structure.Following the failure mechanism revealed by experiments,seismic performance objective is proposed for two way column-supported slab with respect to three seismic design target levels.The slab shall be designed to be not cracked in concrete core for small earthquake,to be elastic for moderate earthquake and to keep capability to transfer both vertical and horizontal forces for severe earthquake.The minimum slab thickness is required for that diagonal shear stress at the critical section shall be no more than characteristic tensile strength of concrete,ftk,during small earthquake.Shear compensation shall be included in ultimate state design of flexural strength,as the core is diagonally cracked during severe earthquake.A design illustration shows that slab-column connection,designed in accordance with the presented objectives,does not yield in push-over analysis.
Shear stresses caused by unbalanced moment at slab-column connection may result in diagonally cracking earlier in concrete core and consequently punching failure,which has great influences on ductility of the structure.Following the failure mechanism revealed by experiments,seismic performance objective is proposed for two way column-supported slab with respect to three seismic design target levels.The slab shall be designed to be not cracked in concrete core for small earthquake,to be elastic for moderate earthquake and to keep capability to transfer both vertical and horizontal forces for severe earthquake.The minimum slab thickness is required for that diagonal shear stress at the critical section shall be no more than characteristic tensile strength of concrete,ftk,during small earthquake.Shear compensation shall be included in ultimate state design of flexural strength,as the core is diagonally cracked during severe earthquake.A design illustration shows that slab-column connection,designed in accordance with the presented objectives,does not yield in push-over analysis.
引文
[1]Hanson N W,Hanson J M.Shear and moment transferbetween concrete slabs and columns[J].Journal of thePCAResearch and Development Laboratories,1968,10(1):2-16.
[2]Corley W G,Hawkins N M.Shearhead reinforcementfor slabs[J].Journal of ACI,1968,65(10):811-824.
[3]Ghali A.An efficient solution to punching of slabs[J].Concrete International,1989,11(6):50-54.
[4]ACI 318R-02 Building code requirements forstructural concrete and commentary[S].2002.
[5]楼板及基础冲切强度专题组.钢筋混凝土板和基础冲切强度的试验研究[J].建筑结构学报,1987,8(4):12-22.(Research Group on Punching Strength ofFloor Slabs and Footings.Experimental investigation ofpunching strength of reinforced concrete slabs andfootings[J].Journal of BuildingStructures,1987,8(4):12-22.(in Chinese))
[6]舒兆发,李定国.配置抗冲切钢筋的混凝土板柱连接的强度和性能试验研究[J].湖南大学学报,1987,14(1):39-51.(SHU Zhaofa,LI Dingguo.Experimental investigation on strength and performanceof concrete slab-column connections with shearreinforcement[J].Journal of Hunan University,1987,14(1):39-51.(in Chinese))
[7]郑建岚,郑作僬.钢筋混凝土板的冲切强度的试验研究[J].福州大学学报,1992,20(2):65-71.(ZHENG Jianlan,ZHENG Zuoqiao.Research on testresults of punching strength of reinforced concrete slabs[J].Journal of Fuzhou University(Natural Science),1992,20(2):65-71.(in Chinese))
[8]陈才堡.传递剪力和不平衡弯矩的内柱板柱节点强度[J].建筑结构学报,1987,8(4):50-60.(CHENCaibao.Strength of slab-column connection in interiorcolumn with transfer of shear and unbalanced moment[J].Journal of Building Structures,1987,8(4):50-60.(in Chinese))
[9]陶学康,王逸.无粘结预应力混凝土板的冲切设计及计算[J].建筑科学,1989,5(6):27-31.(TAOXuekang,WANG Yi.Design and analysis of punchingof unbonded post-tensioned concrete slabs[J].Building Science.1989,5(6):27-31.(in Chinese))
[10]周军,吕西林.混凝土平板结构中柱节点在剪力与不平衡弯矩共同作用下的分析研究[J].建筑结构学报,1997,18(5):32-42.(ZHOU Jun,LU Xilin.Analysis of interior slab-column connection in RC flatslab structures under shear and unbalanced moment[J].Journal of Building Structures,1997,18(5):32-42.(in Chinese))
[11]吕西林,马云昌,胡再龙.板柱节点在剪力和反复荷载作用下的非线性有限元分析[J].地震工程与工程振动,1998,18(4):68-75.(LU Xilin,MAYunchang,HU Zailong.Nonlinear analysis of slab-column connections under shear and reversedunbalanced moment[J].Earthquake Engineering andEngineering Vibration,1998,18(4):68-75.(inChinese))
[12]Marti P.Design of concrete slabs for transverse shear[J].ACI Structural Journal,1990,87(2):180-190.
[13]扶长生,刘春明,李永双,等.薄弱连接板的应力分析及抗震设计[J].建筑结构,2008,38(3):106-110.(FU Changsheng,LIU Chunming,LI Yongshuang,etal.Structural seismic design and analysis of linking RCslab in tall-building[J].Building Structure,2008,38(3):106-110.(in Chinese))
[14]ATC 40 Seismic evaluation and retrofit of concretebuildings[S].1996.
[2]Corley W G,Hawkins N M.Shearhead reinforcementfor slabs[J].Journal of ACI,1968,65(10):811-824.
[3]Ghali A.An efficient solution to punching of slabs[J].Concrete International,1989,11(6):50-54.
[4]ACI 318R-02 Building code requirements forstructural concrete and commentary[S].2002.
[5]楼板及基础冲切强度专题组.钢筋混凝土板和基础冲切强度的试验研究[J].建筑结构学报,1987,8(4):12-22.(Research Group on Punching Strength ofFloor Slabs and Footings.Experimental investigation ofpunching strength of reinforced concrete slabs andfootings[J].Journal of BuildingStructures,1987,8(4):12-22.(in Chinese))
[6]舒兆发,李定国.配置抗冲切钢筋的混凝土板柱连接的强度和性能试验研究[J].湖南大学学报,1987,14(1):39-51.(SHU Zhaofa,LI Dingguo.Experimental investigation on strength and performanceof concrete slab-column connections with shearreinforcement[J].Journal of Hunan University,1987,14(1):39-51.(in Chinese))
[7]郑建岚,郑作僬.钢筋混凝土板的冲切强度的试验研究[J].福州大学学报,1992,20(2):65-71.(ZHENG Jianlan,ZHENG Zuoqiao.Research on testresults of punching strength of reinforced concrete slabs[J].Journal of Fuzhou University(Natural Science),1992,20(2):65-71.(in Chinese))
[8]陈才堡.传递剪力和不平衡弯矩的内柱板柱节点强度[J].建筑结构学报,1987,8(4):50-60.(CHENCaibao.Strength of slab-column connection in interiorcolumn with transfer of shear and unbalanced moment[J].Journal of Building Structures,1987,8(4):50-60.(in Chinese))
[9]陶学康,王逸.无粘结预应力混凝土板的冲切设计及计算[J].建筑科学,1989,5(6):27-31.(TAOXuekang,WANG Yi.Design and analysis of punchingof unbonded post-tensioned concrete slabs[J].Building Science.1989,5(6):27-31.(in Chinese))
[10]周军,吕西林.混凝土平板结构中柱节点在剪力与不平衡弯矩共同作用下的分析研究[J].建筑结构学报,1997,18(5):32-42.(ZHOU Jun,LU Xilin.Analysis of interior slab-column connection in RC flatslab structures under shear and unbalanced moment[J].Journal of Building Structures,1997,18(5):32-42.(in Chinese))
[11]吕西林,马云昌,胡再龙.板柱节点在剪力和反复荷载作用下的非线性有限元分析[J].地震工程与工程振动,1998,18(4):68-75.(LU Xilin,MAYunchang,HU Zailong.Nonlinear analysis of slab-column connections under shear and reversedunbalanced moment[J].Earthquake Engineering andEngineering Vibration,1998,18(4):68-75.(inChinese))
[12]Marti P.Design of concrete slabs for transverse shear[J].ACI Structural Journal,1990,87(2):180-190.
[13]扶长生,刘春明,李永双,等.薄弱连接板的应力分析及抗震设计[J].建筑结构,2008,38(3):106-110.(FU Changsheng,LIU Chunming,LI Yongshuang,etal.Structural seismic design and analysis of linking RCslab in tall-building[J].Building Structure,2008,38(3):106-110.(in Chinese))
[14]ATC 40 Seismic evaluation and retrofit of concretebuildings[S].1996.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心