【摘要】 悬索桥基准索股线形随着索股跨度、温度及两端高差变化而变化,为实现悬索桥基准索股现场的快速定位与调整,研究一套高效、实用的基准索股线形施工控制计算方法。通过理论推导编制了考虑索鞍切点变化的索股线形计算程序,建立了基于悬链线理论的索股跨中标高影响公式和调索公式。以某悬索桥为工程背景,进行参数分析,得到索股跨中标高随索股跨度、温度、两端高差变化的影响公式,与传统的抛物线、悬链线公式计算结果进行对比分析,结果表明:考虑索鞍切点变化的索股线形计算程序的计算结果与设计结果吻合较好,误差为毫米级,具有较高的精度。与传统抛物线、悬链线公式相比,考虑切点位置变化的索股跨中标高影响系数随着影响因素的变化而变化,可近似为斜直线。索股跨中标高对温度和索股两端间距的变化比较敏感,影响系数在2左右,施工中应对桥塔偏位和温度进行严格的监测,必要时采取相应调整措施。无论索股跨度、温度及两端高差单独发生任意变化,还是发生任意组合变化,该影响公式和调索公式都能保证一定的精度,误差不超过0.2%,而悬链线公式最大误差为0.81%,抛物线公式最大误差达到8%,此时已经不能满足工程精度的要求。更多还原

【Abstract】 The geometric shape of datum strands of suspension bridge varies with the span, temperature and height difference of the two ends. In order to realize rapidly positioning and adjustment of datum strands of suspension bridge at the construction site, a set of effective and practical calculation method for construction control of geometric shape of datum strands is studied. The shape calculation program of cable strand considering the change of tangent point is compiled through theoretical derivation, and the effect formula for calculating the midspan elevation of the cable strand and the strand adjustment formula based on the catenary theory are established. Taking a suspension bridge as the engineering background, the parametric analysis is carried out, the formulas of the mid span elevation of cable strands varies with span length, temperature and height difference between two ends are obtained, whose calculation result is compared with those by the traditional parabolic and catenary formulas. The result shows that(1) the calculation result of the calculation program of cable strand geometric shape considering the change of saddle tangent point is in good agreement with the design result, the error is in millimeter order, it has higher accuracy;(2) compared with the traditional parabolic and catenary formulas, the influence coefficient of mid-span elevation of cable strands considering the change of tangent position varies with the influencing factors, and the shape of influence coefficient can be approximated as an oblique line;(3) the mid-span elevation of cable strands is sensitive to the changes of temperature and the distance between the two ends of the cable strands, the influence coefficient is about 2, so the temperature of cable strands and the displacement of main pylon should be strictly monitored and some effective measures should be taken when necessary in the construction;(4) whether the cable strand span, temperature and the difference between the two ends are individually and arbitrarily changed, or any combination changes, the effect formula and the strand adjustment formula can guarantee certain precision, the error is not more than 0.2%, while the maximum error of the catenary formula is 0.81%, and the maximum error of the parabolic formula is 8%, they cannot meet the requirements of engineering accuracy.更多还原