摘要
通过对隧道群桩-衬砌支护联合承载体系和无地基改良下关键部位的受力及变形进行对比,经分析后提出隧底群桩荷载简化模型。研究结果表明:群桩-衬砌支护联合承载体系下结构竖向位移明显减小,其中拱顶和仰拱的竖向位移得到明显控制,且在隧道纵向中部位置的竖向应力有明显减小,整体受力更趋于均匀。所以,群桩-衬砌支护联合承载体系对改善隧道基底深厚软弱地层下的沉降和洞室关键部位应力有显著作用,同时,给出不同关键设计参数(桩长、桩径、桩间距)下隧底群桩荷载简化模型分布函数,可利用该分布函数进行桩顶荷载估算。
This paper has made a comparison of force and deformation between the tunnel pile group-lining support combined bearing system and the key positions without foundation improvement, and then presented a simplified model of load on pile group at the bottom of tunnel. The result shows that the vertical displacement of combined pile group-lining support bearing system structure is obviously reduced, wherein the vertical displacement of the roof and invert is well controlled, and in the middle of tunnel longitudinally, the vertical stress is decreased significantly as well, thus the force tends to uniform as a whole. Therefore, the Pile group-lining support joint bearing system has significant effect on improving the subsidence of tunnel bottom with the weak base deep stratum and the stress of key parts thereof. At the same time, the simplified model distribution function of load on pile group under different key design parameters （ pile length, pile diameter, pile spacing） is given, with which the pile top load may be estimated.
出处
《路基工程》
2015年第3期88-93,共6页
Subgrade Engineering
基金
国家自然科学基金(51178400
51278425)
中国铁路总公司重点课题(2014G004-H)
关键词
隧道
群桩
软弱地层
数值分析
简化设计
tunnel
pile group
soft strata
numerical analysis
simplified design
