摘要
针对双塔单跨混合梁自锚式悬索桥传统上"先缆后梁"总体架设方法修建临时锚固体系造价高、工期长,且由临时锚固体系转换到永久锚固体系过程中工序复杂及"先梁后缆"总体架设方法工期长、成本高、风险大的弊端和不足,以株洲枫溪大桥为工程背景,提出"缆梁同步"施工方案。分析了不同跨径、垂跨比下锚固处空缆水平力的大小,计算了单墩所能抵抗最大不平衡水平力的量值,确定了该施工方案的可行范围。研究结果表明:(1)锚固处空缆水平力随跨径的增大而增大,随垂跨比的增大而减小。(2)跨径100~300m、垂跨比1/6.0~1/4.0、锚固处空缆水平力在2 900kN以内;跨径100~300m、垂跨比1/8.0~1/6.0以及跨径300~450m、垂跨比1/6.0~1/4.0时,锚固处空缆水平力在6 400kN以内;跨径300~450m、垂跨比1/8.0~1/6.0时,锚固处空缆水平力都在6 400kN以上,最大值超过10 000kN。(3)该不平衡水平力由锚固处以下边墩承受,跨径100~300m、垂跨比1/6.0~1/4.0的该类桥梁可实施该方案。(4)墩顶适量配重,或边墩受拉区配置一定预应力筋,或在设计阶段增大边墩截面或惯性矩,能使该方案在墩高更高、跨径更大而垂跨比更小的该类桥梁中实施。该成果在依托工程中的应用效果良好。
Aiming at the construction of the ＂erecting cable before constructing beam＂ in the traditional erection of the self-anchored suspension bridge of the double-tower single-span hybrid beam, the temporary anchorage cost is high, and from the temporary anchor system to the permanent anchoring system process complex process defects, the overall erection method of ＂erecting cable before constructing beam＂ with long duration, high cost, lack of risk, the construction plan of ＂ cable beam synchronization＂ based on the construction of Zhuzhou Fengxi Bridge is put forward, the difference of horizontal force of free cable an- chorage between the span and raise-span ratio is analyzed, and the calculated value of the single-pier can resist the maximum unbalanced horizontal force and determine the feasible range of the construction scheme. The results show that：①The horizontal force of free cable increases with the increase of the span, and decreases with the increase of the span ratio at the anchor.②When Span of 100-300 m, raise-span ratio in the 1/6.0-1/4.0 the horizontal force of free cable is within 2 900 kN; when span of 100-300m, rise-span ratio in the 1/ 8.0-1/6.0, the span between the 300-450 m, rise-span ratio between 1/6.0-1/4.0, the horizontal force of free cable is within 6 400 kN; when span in the 300-450 m, rise-span ratio in 1/8.0-1/6.0, the horizontal force of free cable is above6400 kN, the maximum value is more than 10 000 kN.③The unbalanced horizontal force is supported by the lower pier of the cable anchor, which can meet the span of 100-300 m, and the rise-span ratio is between 1/6.0-1/4.0.④The appropriate top of the dome or the edge of the pendulum area of a certain pre-stressed tendons, or in the design stage to increase the side pier section or moment of inertia can make the program implemented in the bridge with higher pier height, larger span and smaller span ratio. The engineering application showed the proposed method effective and accurate.
出处
《长沙理工大学学报（自然科学版）》
CAS
2017年第2期41-48,共8页
Journal of Changsha University of Science and Technology:Natural Science
基金
国家自然科学基金资助项目(51378080)
关键词
自锚式悬索桥
混合梁
缆梁同步
单墩
水平力
跨径
垂跨比
self-anchored suspension bridge
hybrid beam
cable-girder synchronization
single-pie
horizontal force
span
raise-span ratio
作者简介
李传习（1963-），男，湖南衡南人，长沙理工大学教授，博士生导师，主要从事桥梁结构理论与新技术方面的研究。
