浅谈山区大跨连续刚构桥梁结构计算和设计

大跨径预应力混凝土连续刚构桥梁由于其特有结构类型,采用墩梁固结可以适用于山区高速公路的峡谷地形。具有良好的力学性能、抗震性能和耐久性,后期维护成本低。在80~200m跨径范围内具有较好的经济性。在大跨连续刚构桥梁结构设计过程中,要根据地形地质特点选择合适的跨径、墩高,并据此来设定截面形式、几何尺寸、预应力配束。在设计过程中要进行正截面和斜截面抗裂验算、最大应力验算、箱梁截面抗弯和抗剪承载力验算等。已通车的PC刚构桥梁在运营中普遍出现了跨中挠度过大,因此在前期设计时应设置后期补强措施。

Elementary Discussion on Structural Calculation and Design of Long-span Continuous Rigid Frame Bridge in Mountainous Area

Due to its unique structure,the long-span continuous rigid frame bridge adopts pier-beam consolidation and can be applied to the canyon terrain of mountain expressways.It has good mechanical properties,seismic performance and durability,and low maintenance cost in the later period.It is economical in the span of 80~200 meters.In the process of long-span continuous rigid frame bridge structure design,the appropriate span and pier height should be selected according to the topographic and geological characteristics,and the cross-sectional form,geometric size,and pre-stress distribution of the bridge should be determined accordingly.In the design process,check calculation of normal section crack resistance,diagonal section crack resistance check calculation,maximum compressive stress check calculation,box girder section bending and shear bearing capacity check calculations are required.The long-span continuous rigid frame bridges that have been built generally have different degrees of mid-span deflection problems during operation.Therefore,post-reinforcement measures should be set in the early design.