机构地区:[1]东北林业大学土木工程学院,黑龙江哈尔滨150040 [2]辽宁省交通规划设计院,辽宁沈阳110005 [3]石家庄铁道大学土木工程学院,河北石家庄050043
出 处:《交通运输工程学报》2015年第3期52-61,共10页Journal of Traffic and Transportation Engineering
基 金:国家自然科学基金项目(51278315);黑龙江省博士后基金项目(LBH-Z14013)
摘 要:为了研究斜拉桥转体施工过程中各构件的力学特性,建立了国内首例单点平铰转体斜拉桥的三维数值仿真模型,并使用实测数据进行校核。运用刚体绕定轴转动理论推导了斜拉桥在转体过程中的角加速度。针对加速转动和匀速转动2个典型施工阶段,研究了桥梁水平转体施工过程中主梁、塔、墩、牛腿、转轴与转盘的受力状态,分析了角速度和角加速度在斜拉桥转体过程中对桥梁受力的影响规律,计算了合理的施工角速度和角加速度。计算结果表明:在匀速转动过程中,各控制截面的应力变化与角速度的平方近似成正比例关系,在现场实测角速度为0.01rad·min-1时,控制截面应力最大变化值仅为-2.00Pa;在加速转动过程中,主梁横断面应力沿主梁中心线斜对称分布,设计角加速度为6.5×10-3 rad·s-2时,塔根实心段的下缘应力变化值为-3.33 MPa,应力变化显著,从牛腿底端开始,桥墩各截面沿高度方向所承受的转矩作用逐渐减小。可见,在匀速转动过程中,角速度对主梁断面应力的影响可忽略;在加速转动过程中,应对斜拉桥转体的角加速度给予明确限制,保证施工安全,缩短转体时间。In order to reveal the mechanical properties of each component of cable-stayed bridge in rotation construction process, the 3D numerical simulation model of the first domestic single-point flat-hinge cable-stayed bridge of China was built, and was verified by using the measured data. The angular acceleration of cable-stayed bridge in rotation construction process was deduced according to the theory of rigid body rotation around a fixed axle. In view of two typical construction stages of accelerating rotation and uniform rotation, the stress states of main girder, tower, pier, bracket, shaft and dial were researched. In the rotation process of cable-stayed bridge, the influence laws of angular velocity and angular acceleration on bridge stress were revealed, and the reasonable construction angular velocity and angular acceleration were calculated. Calculation result indicates that in the process of uniform rotation, the normal stress change of control section is approximately direct proportional to the square of angular velocity. When the measured angular velocity is O. O1 rad ~ rain-1 ~ the maximum stress changing value of control section is only --2. O0 Pa. In the process of accelerating rotation, the stress of main girder cross section presents skew symmetric distribution along the center line of main girder, and when the measured angular acceleration is 6.5)〈 10-3 rad ~ s-z , the stress changing value of tower root solid section at lower edge is --3.33 MPa, and the stress changes significantly. In the process of accelerating rotation, start from the bracket bottom, the torque of each pier cross section along the height direction decreases. So in the process of uniform rotation, the influence of angular velocity on the stress of main girder section may be ignored. In the process of accelerating rotation, in order to ensure the construction safety and shorten the rotation time, the rotation angular acceleration of cable-stayed bridge should be limited. 4 tabs, 19 figs, 25 refs.
关 键 词:桥梁工程 斜拉桥 转体施工 空间应力 力学特性 水平转体 匀速转动 加速转动
分 类 号:U448.27[建筑科学—桥梁与隧道工程]
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