大跨度P.C.变截面连续箱梁和连续刚构设计绘图CAD软件研究
摘要：本文根据大跨度P.C.变截面连续箱梁和连续刚构的技术特点和设计实践，结合计算机辅助设计技术，分析了大跨度P.C.变截面连续箱梁（刚构）设计绘图CAD软件的需求；基于软件的易用性、健壮性和可扩展性，阐述了软件研发技术要点和模块架构设计，实现该类桥梁的三维可视化智能设计。
关键字：变截面连续箱梁；变截面连续刚构；桥梁软件；CAD；辅助设计The Research of Large-span P.C. Continuous Box Girder and Continuous Steel Frame with Variable Cross Section Design and Drawing System
Abstract：Based on the technical characteristic and design practice of long-span P.C. variable cross-section continuous box bridge and continuous rigid frame bridge, Combined with the technology of Computer-aided design, the design and drawing CAD software requirements of long-span P.C. variable cross-section continuous box bridge and continuous rigid frame bridge is analyzed in this paper; Based on the software usability, robustness and expandability, R&D technical points and the modular architecture design of the software is described in the paper. The software enables three-dimensional visualization intelligent design of all kinds of bridge.
Key words: Continuous Box Girder with Variable Cross Section; Continuous Steel Frame with Variable Cross Section; Bridge software; CAD; Aided Design
1.引言
预应力混凝土（P.C.）变截面连续箱梁和连续刚构是公路中常见的桥型，相对于等截面现浇箱梁和装配式桥梁而言跨越能力较强，相对于斜拉桥和悬索桥而言建设费用较低，所采用的主材-混凝土相对于钢材而言便于就地取材且造价较低，因此在桥梁建设中得到了广泛使用，尤其在山区高速公路上更是跨越沟壑和河流的首选大跨度桥梁方案，该类桥梁常用跨径范围是50m～165m，最大跨径已经超过300m。
我国公路建设由东部平原微丘地区向西部山区延伸，受复杂地形条件限制，一条高速公路中可能存在一座甚至是多座大跨度的变截面连续箱梁或连续刚构桥，并成为整个线路中的重点工程及控制性工程。一方面，该类桥梁设计方案可能经多次反复，对设计周期影响较大，采用传统手工绘图时，其设计进度及设计质量均难以保障；与此同时，现有桥梁设计软件主要集中在结构计算领域，仅有