跨高速连续梁主跨整体拆除施工技术

Construction Technique of Integral Demolition of Continuous Beam Main Span Crossing a Highway

福州绕城高速公路青口互通立交桥需拆除后新建,其中跨沈海高速连续梁桥B、C匝道桥主跨长32m,采用SMPT多轴平板车组成移动式拆桥装置一次拆除。移动式拆桥装置由多轴运输车机组、施工支架、顶部可调支撑系统共同组成。移动式拆桥装置行驶至连续梁的主跨下方,先启动多轴车机组液压系统使装置整体升高至接近桥梁底板,启动顶部可调支撑液压系统,使装置与桥梁底板贴紧,然后用金刚石绳锯将梁段切断,最后由移动式拆桥装置将连续梁主跨整体移运至落梁场地。拆除前采用BIM技术预演拆除过程,进一步细化工序、优化施工方案。在拆除过程中对梁体应力、位移以及贝雷梁和钢管立柱应力进行监控,确保施工安全。运用移动式拆桥装置实现了主跨整体安全、快速拆除。

The Qingkou Interchange on the Fuzhou Loop Expressway had to be dismantled and rebuilt.The ramp bridges B and C of the continuous beam bridge crossing the Shenyang-Haikou Expressway had a main span length of 32 m each,which were dismantled at one go with the movable demolition equipment formed of SMPT multi-axle flatbed trucks.The movable demolition equipment comprises the multi-axle transportation trucks,construction scaffoldings and the adjustable supporting system mounted on the top of the equipment.The movable demolition equipment was moved under the main span of the continuous beam,the hydraulic system of the multi-axle transportation trucks was started to integrally lift the equipment to a height close to the bottom of the beam,the adjustable supporting hydraulic system at the top of the equipment was started to make the equipment and the base plate of the beam closely touched,and the beam segment was cut off by the diamond wire saw and the continuous beam main span was integrally moved to the storage site by the movable demolition equipment.Before demolition,the BIM technique was used to simulate the dismantling process,further refine the procedure and optimize the construction scheme.During the dismantling process,the stresses,displacement in the beam and the stresses in the bailey truss and steel tube columns were monitored.The integral,safe and rapid demolition of the main span was realized by using the movable demolition equipment.