[Article Information]

Research on Blasting Failure Characteristics and Strain Evolution Law of Bearing Column



FEI Hong-lu,LI Wen-yan,WEI Shi-zhong,SHAN Jie,ZHEN Shuai




Abstract


Abstract: In order to analyze the failure characteristics and strain evolution law of reinforced concrete columns after blasting under different amount of explosives per unit area and section stresses,blasting tests of 12 reinforced concrete columns were carried out by using a self-developed test system with uniaxial inertial dynamic loading model,which is based on the theory of elastic mechanics. When the upper section stress of the reinforced concrete columns was 0 MPa,the corresponding amounts of explosives per unit area were 0. 11 kg /m2 ,0. 23 kg /m2 , 0. 27 kg /m2 ,respectively. When the upper section stress was 2 MPa,the corresponding amounts of explosives per unit area were 0. 13 kg /m2 ,0. 18 kg /m2 ,0. 23 kg /m2 ,respectively. When the upper section stress was 3 MPa,the corresponding amounts of explosives per unit area were 0. 18 kg /m2 ,0. 23 kg /m2 ,0. 32 kg /m2 ,respectively. When the upper cross-sectional stress was 4 MPa,the corresponding amounts of explosives per unit area were 0. 13 kg /m2 , 0. 18 kg /m2 ,0. 23 kg /m2 ,respectively. In addition,numerical simulation software was used to analyze the impact of different section stresses on blasting effect. The longitudinal central axis crushing distance is defined to describe the crushing range of the column after blasting,and the central axis crushing distance and strain evolution law are analyzed under different influencing factors through theoretical deduction,field experiment and numerical simulation. The analysis results show that with the increase of section stress,the greater the coupling tangential stress close to the central axis,and the coupling tangential tensile stress which is perpendicular to the loading direction is relatively reduced. When the amount of explosive per unit area is less than 0. 15 kg /m2 ,the crushing range of the central axis of the column decreases with the increase of the section stress. When the amount of explosive per unit area is more than 0. 15 kg /m2 ,with the increase of section stress,the crushing range continues to increase. The peak of tangential tensile strain shows an upward trend,and the absolute value of the peak radial compressive strain gradually decreases. When the section stress is fixed,the crushing range of the column increases with the increase of the amount of explosive per unit area,but the growth rate decreases with the increase of the amount of explosive per unit area. Meanwhile,the peak of the tangential tensile strain of the column increases,and the absolute value of the peak radial compressive strain also shows an upward trend. With the increase of section stress,the crushing range in the column damage cloud is increasing,and the crack tends to extend axially with the load,which further verifies the correctness of the test conclusions.



Key words: explosive loads; reinforced concrete columns; section stress; amount of explosive per unit area; destructive characteristics; strain evolution laws





Chinese Information


标题: 承载立柱爆破破坏特征及应变演化规律研究



作者: 费鸿禄,李文焱,魏世众,山 杰,甄 帅



摘要: 为分析不同单位面积炸药量及不同截面应力下的钢筋混凝土立柱爆破后破坏特征及应变演化规 律,以弹性力学理论为基础,利用自主研制的单轴惯性动载力学模型试验系统对 12 个钢筋混凝土立柱进行 爆破试验。当钢筋混凝土立柱上部截面应力为 0 MPa 时对应单位面积炸药量为 0. 11 kg /m2 、0. 23 kg /m2 、 0. 27 kg /m2 ; 上部截面应力为 2 MPa 时对应单位面积炸药量为 0. 13 kg /m2 、0. 18 kg /m2 、0. 23 kg /m2 ; 上部截 面应力为 3 MPa 时对应单位面积炸药量为 0. 18 kg /m2 、0. 23 kg /m2 、0. 32 kg /m2 ; 上部截面应力为 4 MPa 时对 应单位面积炸药量为 0. 13 kg /m2 、0. 18 kg /m2 、0. 23 kg /m2 ,并且运用数值仿真模拟软件对不同截面应力影响 爆破效果进行模拟分析。定义纵向中轴线破碎距离来描述立柱爆破后的破碎范围,通过理论推导、现场试验 及数值模拟软件分析不同影响因素下的中轴线破碎距离及应变演化规律得出: 随着截面应力的增加,越接近 中轴线的耦合切向应力越大,与加载方向垂直的耦合切向拉应力相对减小; 当单位面积炸药量约小于 0. 15 kg /m2 时,随立柱截面应力增大,立柱中轴线破碎距离不断减小; 当单位面积炸药量约大于 0. 15 kg /m2 时,随着截面应力的递增,中轴线破碎距离不断增大,立柱的切向拉应变峰值呈上升趋势,径向压应变峰值绝 对值逐渐减小; 当截面应力一定时,随着单位面积炸药量的增加,立柱纵向中轴线破碎距离增大,但是增长幅 度却随着单位面积炸药量的增加而减小,同时立柱的切向拉应变峰值增大,径向压应变峰值绝对值也呈上升 趋势; 随着截面应力的增大,立柱损伤云图中轴线上损伤距离不断增大,且裂纹倾向于加载轴向扩展,进一步 验证试验结论的正确性。



关键词: 爆炸荷载; 钢筋混凝土立柱; 截面应力; 单位面积炸药量; 破坏特征; 应变演化规律



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