JQX900型导梁式架桥机隧道口架设24m双线整孔箱梁施工工序及成本分析

JQX900型下导梁式过隧道型架桥机主要用于200～350km铁路客运专线20m、24m、32m双线整孔预应力箱形混凝土梁的架设。在石太客运专线Z9标段，该架桥机经32—24m变跨作业，通过运梁车驮运实现桥间短途运输，并在穿越双线隧道后，于隧道口成功架设了3×24m双线整孔箱梁。此文从JQX900型架桥机隧道口架梁的施工工序入手，针对各单项工序进行了成本分析，以期为同类工程积累施工造价资料。

Construction sequence and cost analysis of 24 m double line box girders erected at tunnel portal by JQX900 bridging machine

The JQX900 bottom conducting beam and through tunnel bridging machine is mainly used for the erection by single lift of 20 m,24 m and 32 m span prestressed concrete double line box girders of railway passenger dedicated lines operating at the speed of 200~350 km.In the Z9 tendered section on Shi-Tai passenger dedicated line,this bridging machine,through the 3224 m span change operation,realized a bridge-to-bridge short distance haul of its being carried on the girder transport car,and after running without fail through the double line tunnel,succeeded in installing the 3 x 24 m double track box girders with the whole span by single lift at the tunnel portal.This article,starting with the construction sequence of girder erection at tunnel portal by the same machine,makes a cost analysis of each respective sequence with a view to accumulating construction cost data for similar projects in the future.