摘要
地处深水环境中的安庆长江铁路大桥3号、4号桥塔墩基础采用大直径变径桩,桩长分别达108m和110m,钻孔深度达143m,桩基施工难度大,质量标准要求高,风险多。为防范超深大直径桩基施工过程中塌孔、断桩、沉渣厚度超标、强度不足等不可接受质量风险事故,通过人工创建稳固的钻孔环境防范塌孔或断桩;钻杆上配置稳定器确保超深桩孔垂直;实施清水法钻孔工艺和钢筋笼二次下放到位减小沉渣厚度;管理上实行责任包保制度,配制性能优良混凝土,配备产能足够水上混凝土工厂,控制导管埋深,确保灌注快速完成;采用相应的先进检测手段,避免了桩身缺陷。
The foundations of the pylon pier 3 and pylon pier 4 of Anqing Changjiang River Railway Bridge, which are located in deep-water environment, are made up of the large diameter piles with variable diameters, the lengths of the piles reach up to 108 m and 110 m respectively, and the drilling depth extends downwards to 143 m. The construction of the pile foundations shows great difficulty and is risk pervasive, and the quality standard is demanding. In order to a- void the unacceptable quality risk accidents, such as hole collapse, pile breaking, the sediment thickness in excess of standards and low strength, a secure drilling environment was created artifi- cially to prevent the happening of hole collapse and pile breaking. The drill bars were equipped with stabilizers to ensure the verticality of very deep pile holes. The drilling technique of clean wa- ter method was used together with lowering the steel casing for the second time into places to re- duce the thickness of sediments. For management, the responsibility system for guarantee was fol- lowed. To ensure the rapid completion of concrete casting, the concrete with good quality was pre- pared, the over-water concrete plant with sufficient production ability was built, and the buried depth of the ducts was controlled. Moreover, the related advanced testing measures were taken to prevent the occurrence of pile shaft defects.
出处
《世界桥梁》
北大核心
2013年第5期39-43,共5页
World Bridges
关键词
铁路桥
钻孔灌注桩
变直径桩
清水钻
稳定器
二次下放
质量控制
railway bridge
bored pile
pile with variable diameter
clean water drill
stabilizer
lowering for the second time
quality control
作者简介
作者简介：范学梅（1964一），女，工程师，2003年毕业于南京工业大学交通土建工程专业，2012年毕业于南京工业大学工程管理专业（E—mail：274460269@qq．com）。
