摘要
为了研究深厚湿陷性黄土地基非埋式桩板结构路基的承载机制,选取试验段典型断面进行元器件布置与长期观测;考虑桩土相互作用,依据等刚度的原则引入综合转动刚度的概念,建立了纵、横向平面分析模型,对非埋式桩板结构的受力与变形特性进行测试分析。实测结果表明:结构主筋应力测试值与理论值相差10%～30%,吻合较好,最大值出现在托梁支座断面上侧,为60.60MPa;桩侧土体承受约95%的荷载,且未产生负摩阻力;桩板结构的荷载传递规律与传统路基不同,桩基将荷载传递到更深的持力层,改善了路基软弱土体部分的受力状态;轨道结构完工半年后,承台板顶面最大累计沉降出现在中跨跨中断面,为1.0mm,满足沉降控制要求。
Sensor components were disposed at the typical section of test subgrade, and the bearing capacity mechanism of non-embedded pile-plank structure in deep collapsible loess foundations was studied by long-term observation. The pile-soil interaction was considered, the concept of comprehensive rotation stiffness was introduced based on the principle of equal stiffness, the vertical and horizontal plane models of the subgrade were installed, and the deformation and mechanical characteristic of the structure were analyzed. Measured result shows that the test value of structural main reinforcement stress agree well with the theoretical calculation value, the difference is about 10%-30~//00, and the maximum reinforcement stress of 60. 60 MPa appears at the cross section of joist. Pile side earth bears about 95% of total load, and no negative friction is produced. The load transfer law of the structure is different from that of traditional subgrade, load can be transferred to deeper bearing layer by pile foundation, which improves the stress state of soft soil section. Half a year, after the laying completion of track construction, the largest accumulated settlement of top surface for bearing plank occurs at the cross section of mid-span, which is 1.0 mm, and meets the requirement of settlement control. 1 tab, 12 figs, 15 refs.
出处
《交通运输工程学报》
EI
CSCD
北大核心
2012年第1期19-24,共6页
Journal of Traffic and Transportation Engineering
基金
铁道部科技研究开发计划重点项目(2006G004-B
2008G031-C)
中央高校基本科研业务费专项资金项目(SWJTU09CX004)
关键词
非埋式桩板结构
深厚湿陷性黄土
现场试验
承载机制
变形特性
荷载传递规律
non-embedded pile-plank structure
deep collapsible loess
field test
bearing capacitymechanism
deformation properties
load transfer law
