中文摘要：

合龙方式是连续刚构桥施工中需要重点关注的问题,合龙段内置劲性骨架设计缺乏明确说明.考虑预应力空间效应,混凝土三维收缩徐变特性和施工过程分析,建立了预应力混凝土连续刚构桥的三维精细化数值模型.对合龙段分别采用内置劲性骨架和外置劲性骨架的合龙段短、长期力学特性进行了对比分析.对内置劲性骨架的含钢率、截面形式进行参数分析.研究结果表明：内、外置骨架锁定的合龙段短、长期应力分布基本相同,顶板长期应力较短期应力平均增加20.6%,底板处相应减少30.5%.内置骨架锁定更易形成顶板的长期应力分布不均,但由于合龙段顶板压应力储备较大,其影响较小.内置劲性骨架含钢率越高,合龙段顶板的纵向正应力分布不均越明显,含钢率对底板应力的短、长期效应影响均相对较小.实际设计中可考虑采用的含钢率设计范围为0.27%-1.02%.含钢率相同的情况下,内置劲性骨架截面形式对合龙段纵向正应力短、长期效应影响很小.

英文摘要：

Closure option is need to focus on the construction of long span continuous rigid-frame bridge and the design of inner stiff skeleton at closure segment lacks of a clear illustration. A refinement numerical finite element model of continuous prestressed concrete rigid frame bridge was proposed which consider the space effect of prestress, three dimensional effect of concrete shrinkage, creep properties and analysis of construction process. Short-term and long-term mechanical properties of closure segments were analyzed which was respectively equipped with inner stiff skeleton or external stiff skeleton. Steel ratio and section type of inner stiff skeleton were analyzed. The results show that：Stress distribution of closure segment which was equipped with inner skeleton or external skeleton is basically same, long-term stress of top plates at closure segment increases about 20. 6% than short-term stress on average, bottom plates correspondingly reduce about 30. 5%. It is easy to form long-term stress uneven distribution of top plates with inner stiff skeleton lock, but due to the enough compressive stress reserves at closure segment, it effect is negligible. The higher steel ratio of inner stiff skeleton, the more obvious uneven distribution of top plates longitudinal stress, the short and long-term effect of steel ratio upon bottom plates longitudinal stress are relatively small. The steel ratio could ranges between 0. 27% - 1.02% in actual design. With the same steel ratio, the skeleton section have negligible effect on short and long term longitudinal stress at closure segment.