中文摘要：

根据顶推连续梁通常具有等截面、等跨（或中间跨采用等跨径、边跨采用较小跨径）的特征，应用以一次落架思想和力法建立的三弯矩方程组，利用数列及其极限，将顶推分2个阶段推得了顶推中连续梁中间各支点弯矩的解析表达式，借此讨论并揭示了项推中连续梁中间各支点弯矩值随该连续梁两端支承处弯矩和主梁恒载集度的变化规律。根据顶推前端主梁支点弯矩最小的原则，推得了导梁合理长度的计算公式，借助于数值分析得到：导梁抗弯刚度的合理值应为主梁抗弯刚度的0．2倍。进一步给出了导梁参数取合理值时各控制内力的大小。结合实际工程，阐述导梁常用结构形式与设计原则。

英文摘要：

According to the common characteristics of continuous beam built by incremental launching method, including constant cross-section and equal span （or equal span at the inner spans but less at the outer spans） , using three-moment equations based on the thinking of lowering the formwork once only and force method, by means of sequence of number and its limit, the expressions of bending moments at the inner supports for continuous beam during two phases of incremental launching process were educed. Based on these results, the evolutions of bending moments at the inner supports of continuous beam with the moments at the two outer supports and the uniformly distributed dead load of the deck during incremental launching were discussed and disclosed. On the principle of minimum bending moment of the deck at the front support, the formula of the reasonable length of the launching nose was deducted. It was gained by means of numerical analysis that the reasonable ratio of the flexural stiffness of the nose to that of the deck is 0.2. Furthermore, the control internal forces were presented when nose parameters were reasonable. Combining some practical projects, the common structural types and design principles were explained.