青藏铁路开心岭1#特大桥桩基、承台施工技术

研究目的:多年冻土区的工程建设是世界性难题之一。在青藏高原冻土区的桥梁施工中,作者在如何制订合理的施工组织设计、钻孔机械的选型、工序衔接等方面进行探讨,为类似工程的施工提供经验。研究结果:在青藏铁路开心岭1#特大桥的桩基、承台施工中,应用相应的施工技术,使工程建设顺利且质量可靠,解决了冻土区的桥梁桩基钻孔难等施工难题。研究结论:在冻土区的桥梁桩基施工中,最好采用大功率旋挖钻机干法快速成孔,混凝土灌注过程不得中断。各项准备要充分,工序衔接要合理,挖土(钻孔)要快速,土体开挖(钻孔)后暴露时间要短,必要时采取防晒措施,尽最快速度灌注混凝土,混凝土养护措施要可靠。

Construction Technique for Pile Foundation and Cap of Pile Trestle of Kaixinling Bridge 1# on Qinghai- Tibet Railway Line

Research purposes: The construction in permafrost area is one of difficult problems over the world. In cause of construction of bridge in permafrost area, the author made exploration on how to work out rational plan of construction organization, how to select model of drilling machinery and how to connect the construction procedures in order to provide construction experience to similar construction. Research results:The relative construction technique was applied in construction of pile foundation and cap of pile trestle of Kaixinling Bridge 1~# on Qinghai-Tibet Railway and solved the difficult problem of drilling on the pile foundation of bridge in permafrost area. Research conclusions:In construction of pile foundation of bridge in permafrost area, it was better to use big power rotary drilling machine for rapid cavity making, but the follwing things should be noted:the process of concrete grouting had not to be interrupted, full preparation would be done, the connection of procedures would be short after excavation ( drilling ) would be quick, the time of soil exposure would be short after excavation (drilling) and the measure against sunshine would be taken if necessary, the speed of grouting concrete would be as quick as possible and the measure for maintaining concrete would be reliable.