单跨空间框架结构单柱顶升作用下损伤研究

Research on damage development of single-span space frame structure under single-column lifting

工程中常采用断柱顶升法纠正倾斜的框架结构,但该方法在相邻构件出现顶升量差异时易导致结构发生二次损伤。根据实际顶升纠偏工程提取单跨双向空间框架结构模型,研究单柱顶升作用下相邻梁柱损伤的发展。对比了三个不同梁柱线刚度比下试验模型的顶升端荷载-位移曲线、开裂位置分布、主要裂缝宽度发展情况以及梁端截面应变发展情况,梁柱开裂位置与损伤发展明显受到梁柱相对线刚度影响。顶升过程中与顶升柱相连梁处于弯剪扭组合受力状态,其顶升方向挠度包含顶升方向变形与扭转作用产生的面外变形,受力与变形情况复杂,而传统框架结构受力分析方法有诸多假设与简化,因此采用基于传统假设的计算方法无法准确预测顶升过程中的框架开裂位置与损伤发展。采用了有限元实体单元建模对其进行模拟,计算结果与试验荷载-位移曲线吻合较好,对梁柱开裂位置预测相对准确。

The jack lifting method is often used in engineering to correct the inclined frame structure,but this method is likely to cause secondary damage to an original structure when the jacking amount of adjacent components is different.According to the actual building lifting correction project,a single-span bidirectional space frame structure model was extracted,and the development of adjacent beam-column damage under the single-column lifting action was studied.The load-displacement curves of the jacking end,the distribution of cracks and development of the width of main cracks,and the cross-sectional strain of the beam end were compared.The beam-column cracking position and damage development are obviously affected by the relative linear stiffness of the beam-column.During the jacking process,the beam connected to the jacking column is in a combined bending,shear and torsion state.The deflection in the jacking direction includes the out-of-plane deformation caused by the deformation in the jacking direction and the torsion,which direct to complicated force and deformation.Traditional frame structure stress analysis method introduces many assumptions and simplifications.Therefore,the calculation method based on traditional assumptions cannot accurately predict the frame cracking position and damage development during the lifting process.Finite element solid element modeling was used,and the calculation results are in good agreement with the test load-displacement curve,and the prediction of the cracking position of the beam and column is relatively accurate.