洞庭湖区高速公路桥梁PHC管桩适应性研究  

Study on Adaptability of PHC Pipe Piles for Expressway Bridges in Dongting Lake Area

作　　者：王卿 盖永斌 李瑜 刘勇 陈光 WANG Qing;GAI Yong-bin;LI Yu;LIU Yong;CHEN Guang(Hunan Provincial Communications Planning,Survey&Design Institute Co.,Ltd.,Changsha Hunan 410219,China)

机构地区：[1]湖南省交通规划勘察设计院有限公司,湖南长沙410219

出　　处：《公路交通科技》2023年第9期99-105,共7页Journal of Highway and Transportation Research and Development

基　　金：湖南省交通科技项目(201933);湖南省企业科技创新创业团队支持计划项目(201913)。

摘　　要：为践行“绿色公路”的发展理念,减少桥梁基础施工对洞庭湖区生态环境的破坏,以位于洞庭湖区的湖南省首个装配式桥梁基础工程——伍市至益阳高速公路中小跨径桥梁为依托,提出了桥梁PHC管桩设计方案。为验证高速公路桥梁PHC管桩对于洞庭湖区地质条件的适应性,在3个工点进行了6根PHC管桩锤击沉桩工艺试验,分别采用堆载试验法和自平衡试验法对PHC管桩的竖向承载力特性进行了研究,并将现场试验结果与两种理论公式的计算结果进行了对比分析。结果表明:PHC管桩锤击沉桩工艺对洞庭湖区地质条件具有良好的适应性;PHC管桩试桩在加载破坏之前,沉降变形随着桩顶荷载的增大而增大,近似呈线性发展趋势;PHC管桩试桩加载至破坏时,桩顶沉降量急剧增大,呈现出典型的摩擦桩刺入破坏模式;PHC管桩能有效发挥桩端承载力,平均端阻力约占竖向承载力的31%,为典型的端承摩擦型桩;分布式光纤监测结果显示各土层PHC管桩侧摩阻力发挥良好,由于PHC管桩沉桩过程中会产生挤土效应,各土层实测侧摩阻力均明显高于地勘报告建议值;PHC管桩单桩竖向承载力试验值与《建筑桩基技术规范》的计算结果吻合良好,同时可保证有一定的安全系数。In order to implement the development concept of“green highway”and reduce the damage of the ecological environment of Dongting Lake area caused by bridge foundation construction,relying on the first fabricated bridge foundation project in Hunan province(small and medium-span bridges of Wushi-Yiyang expressway)located in Dongting Lake area,the design scheme of bridge PHC pipe piles is proposed.In order to verify the adaptability of the PHC pipe piles for expressway bridges to the geological condition of Dongting Lake area,the hammering and sinking process test on 6 PHC pipe piles are carried out at 3 sites.The vertical bearing capacity characteristics of the PHC pipe piles are studied by using the heap load test method and the self-balancing test method respectively,and the field test result is compared with the calculation result of the 2 theoretical calculation results.The result shows that(1)PHC pipe pile hammering and sinking process has good adaptability to the geological condition of Dongting Lake area;(2)the settlement deformation of the test PHC pipe pile increases with the increase of pile top load before loading failure,approximately showing a linear development trend;(3)when the test PHC pipe pile is loaded to failure,the settlement at the pile top increases sharply,presenting typical friction pile penetration failure mode;(4)the PHC pipe pile can effectively exert the bearing capacity of the pile end,its average end resistance accounts for about 31%of the vertical bearing capacity,and the PHC pipe is typical end bearing friction pile;(5)the distributed fiber optic monitoring result shows that the side friction resistance of the PHC pipe pile in each soil layer is well performed,and the measured side friction resistance of each soil layer is significantly higher than the recommended value in the geological survey report due to the squeezing effect during the sinking process of the pile;(6)the test value of vertical bearing capacity of the single PHC pipe pile is in good agreement with the calculatio

关 键 词：桥梁工程 PHC管桩 自平衡试验 工艺适应性 竖向承载力 

分 类 号：U448.14[建筑科学—桥梁与隧道工程]