空心高桥墩墩身混凝土裂纹的预防措施

Preventive measures of cracks in high and hollow pier

某新建铁路双线特大桥为主跨192 m三跨预应力混凝土连续刚构,其跨度在同类型桥梁中目前属于亚洲第一。主桥2#墩墩高98 m,3#墩墩高69 m,混凝土强度级别为C40和C55,使用CB-240悬臂模板施工。由于结构尺寸较大和气温的影响,本结构在施工中极有可能出现裂纹。针对该工程这个问题,施工前进行认真的研究分析,制定有效的裂纹预防措施,并对实际施工中出现的裂纹进行原因分析,提出了相应的处理方法。

One newly-built super-large railway bridge with double-line is a bridge of prestressed concrete of continuous rigid girder with three spans of which the main span extends 192m, ranked Asia first in terms of span of its same type.The second pier of the main bridge is 98 m high while the third pier is 69 m high with concrete strength class as C40 and C50 respectively,both of which are constructed with CB-240 cantilevered formwork.The structure is likely to have cracks during construction due to its large scale and the temperature influence.Aimed to solve this prob- lem, the in-depth study and analysis are conducted before constructing, the effective precautions against cracks are set up, and in addition, the corresponding solutions for cracks are proposed during construction after analyzing the reasons for cracking.