摘要
处于深厚软土区的铁路桥梁,桥下堆载与重车通行极易引起桥墩沉降及倾斜等病害。以大丽铁路某特大桥为工程依托,开展植筋技术在既有铁路桥梁桥墩基础沉降病害加固中的应用研究。提出了“桩基加固+既有桥墩植筋连接+包护钢筋混凝土承台”的加固方案,计算分析主控轴力作用下桥墩植筋体的布置形式、承载力、根数及锚固深度等技术参数,并与现场施工数据进行对比,验证计算结果的可靠性。结果表明:(1)采用直径20mm的植筋,锚固深度为1000mm;采用直径25mm的植筋,锚固深度为1300mm。(2)桥墩范围内,最多可以植筋440根;计算得出,在桥墩植筋范围内,植筋根数大于317,即可满足承载力要求。(3)施工设计图的植筋根数采用378是考虑了一定的安全系数及其他因素。工程实践表明,以植筋技术为主的加固方案对铁路桥墩基础沉降及倾斜病害的控制效果明显。
Diseases such as settlement and tilt of bridge piers were easy to occur under underbridge heaped load and heavy vehicle traffic in deep soft soil area. Based on a super large bridge in DaLi Railway,the application of planting bar technology in strengthening solution for settlement disease of pier foundation of existing railway bridges was carried out. The reinforcement scheme,which included pile foundation reinforcement,planting bar connection in existing piers and protection of reinforced concrete cap,was put forward. The technical parameters such as arrangement form,bearing capacity,amount and anchoring depth of planting bars of pier were calculated and analyzed under the action of main control axial force,and the calculation results were in good agreement with the field test data. The results showed that:( 1) When the planting bar with diameter of 20 mm was used,the anchorage depth was 1 000 mm;while when the planting bar with diameter of 25 mm was used,the anchorage depth was 1 300 mm.( 2) Maximum number of planting bar was 440 in the range of the bridge pier. The calculation results showed that when the number of planting bar was greater than 317,it could meet the bearing capacity requirements.( 3) The number of planting bar was 378 in the construction design drawing because of considering a certain safety factor and other factors. The engineering practice has shown that the reinforcement scheme based on planting bar technology is effective in controlling the foundation settlement and tilt of existing railway bridge piers.
作者
郑汝亮
Zheng Ruliang(Central Yunnan Railway Construction Headquarters of China Railway Kunming Bureau Group Co. ,Ltd. ,Kunming 650011,China)
出处
《铁道勘察》
2019年第4期104-107,共4页
Railway Investigation and Surveying
关键词
植筋技术
既有铁路
桥梁
加固
Planting bar technology
Existing railway
Bridge
Reinforcement
