1、 摘摘 要要 本桥位于沪蓉国道主干线湖北省宜昌至恩施段K29+245处， 跨越佑溪， 沟宽约110m。 河道与路线正交，河床稳定，河道顺直，平时沟内水量较少，沟底较深，比降较大，泄 洪顺畅。 设计主要分为桥型方案比较和推荐方案设计，桥型方案中拟定了三个比选方案，方 案一为混凝土简支梁桥，方案二为预应力混凝土箱形连续梁桥。方案三为上承式混凝土 箱形拱桥。通过方案比选，最终选用方案三：上承式混凝土箱形拱桥，跨径组成为净跨 径64m拱跨和两边各一跨8m简支板引桥跨。 桥梁全长89.28m，桥面净空为外侧0.5m钢筋混凝土防撞护栏桥面宽净11.0m 0.75m波形钢板防撞护栏，桥面横坡2%。本桥上部为
2、空腹式，下部为重力式实体桥台， 引桥采用轻型桥台和柱式桥墩。 结构计算主要针对上部结构盖梁、立柱、拱箱，下部结构桥台进行了细部尺寸拟定、 内力计算、配筋计算、截面验算。桥梁下部结构为重力式墩，基础采用刚性扩大基础。 本设计仅对1号桥墩进行了强度及稳定性验算。 关键词：关键词：拱轴系数；箱形拱肋；主拱圈内力组合；截面强度； 刚性扩大基础。 Abstract According to the graduation project task paper of the bridge engineering graduates,this bridge is located in section K249
3、+245 of the HuRong national highway in Hubei from yichang to enshi,which crossing the creek youxi.The riverway is orthogonal with the road and is very deep with little river water at ordinary times. Bottom of trench is more depth with much gradient, and flood discharge smoothly. The design maily foc
4、us on the comparison between the project style of the bridge and the design of the recommended style. There are three alternatives on the bridge style,the fist one is a concrete simple beam bridge,the second is a prestressed concrete continuous girder bridge box,and the third one is a open spandrel
5、top-bear arch bridge. Through comparing the three projects,and the third one is the best.The bridge has a net span across 64m arch and an 8m simply supported slab by every side. The bridge is 89.28m at length,with a 0.5m reinforced concrete impact-proof guard railing by the outboard, a net width 11m
6、 and a 0.75m waveform impact-proof guardrail and a 2% deck transverse slope. The upper of the bridge is empty arch and the below is gravity type abutment entities.The approach bridge has a light the abutment and pillar type pier.The structural calculation are mainly aimed at the detail sizes,internal forces,reinforcement and cross section area on the upper capping beam structure,upright column,arch box and the below structure of the bridge abutment.This bridge adopts the gravity type pier
