港珠澳大桥钢桥面沥青铺装结构设计

Design of Asphalt Pavement Structure on Steel Deck of Hong Kong-Zhuhai-Macao Bridge

港珠澳大桥钢桥面铺装标准高、规模大、施工环境复杂,在分析实桥结构、交通、气候、施工条件的基础上,对该桥钢桥面铺装结构进行设计。以工程病害率、成熟程度、施工可控性、抗疲劳性能、高温稳定性、重载承受能力为评价指标,对多种典型铺装方案进行综合评定,最终推荐浇注式沥青混合料+改性沥青SMA方案。通过工艺改进,确定采用MA配合比设计方法和GA生产工艺制备浇注式沥青混合料 GMA。铺装结构设计为:对钢板表面喷砂除锈后,按顺序涂装防腐层、防水层、黏结层,然后在行车道范围内依次铺装30mm浇注式沥青混合料GMA 10+38mm改性沥青SMA 13(层间洒布改性乳化沥青);在中央分隔带范围内铺装68mm全厚式浇注式沥青混合料。该铺装方案符合全寿命设计理念,具有综合性能优、质量可靠度高、施工效率高等优点。钢桥面铺装实施过程与验收结果均表明该铺装方案合理、可行。

The pavement on steel deck of the Hong Kong-Zhuhai-Macao Bridge has characteristics of high standard, large scale, and complex construction environment. Consequently, we presented the design of the steel deck pavement structure of the bridge by analyzing the real bridge structure, traffic, climate, and construction condition. Firstly, taking the engineering disease rate, degree of maturity, construction controllability, fatigue resistance, high temperature stability, and heavy loading capacity as evaluation indexes, we comprehensively evaluated a variety of typical pavement schemes, and recommended the scheme of guss asphalt + modified SMA. Secondly, through improvement of technology, the mixture design method of MA and the production technology of GA were used to prepare GMA. Finally, the designed pavement structure could be determined as follows: the anti-corrosive coating, waterproof coating, and adhesive coating were sequentially constructed after derusting on the steel deck by sandblast. Then 30 mm-thick GMA-10 + 38 mm-thick modified asphalt SMA-13 (modified emulsified asphalt shall be spread in layers) was paved successively within the carriageway. And 68 mm-thick GMA was paved within the medial strip. The pavement scheme has the advantages of excellent comprehensive performance, high quality reliability, and fast construction efficiency, and conforms to the whole life design concept. From the perspective of the implementation process and acceptance results of steel bridge deck pavement, the design scheme of steel bridge deck pavement is reasonable and feasible.