摘要
昆明轨道交通某地铁车站基坑开挖上跨某高速公路隧道,基坑坑底距隧道拱顶的最小距离为8.0 m,基坑南侧为高陡边坡,环境复杂,施工风险大。为研究基坑开挖对下卧大跨公路隧道结构的影响,提出了考虑土中残余应力和基坑支护结构影响的附加应力计算方法,建立了隧道隆起变形分析的解析计算模型和三维数值模拟验证模型,分别计算了无隧道保护措施、采取地层加固、同时采取地层加固和抗拔桩3种不同工况,研究不同保护措施下隧道附加变形和附加内力的大小、分布形态及其变形控制效果,并与实测结果进行了对比分析。结果表明:隧道附加变形的解析解和数值模拟结果接近,且与实测值吻合较好。基坑开挖对下方公路隧道的影响大,导致隧道出现不均匀纵向隆起变形并明显改变隧道结构受力大小和分布形态,影响范围约4~5倍基坑开挖宽度。注浆加固措施对控制隧道隆起变形和附加内力的效果明显,而设置抗拔桩的效果稍弱。隧道保护措施的改变对隧道结构内力分布形态的影响小。
The excavation of foundation pit at a subway station in kunming rail transit is located above a highway tunnel.The minimum distance between the bottom of the foundation pit and tunnel vault is 8.0 m,and the south side of the foundation pit is a high and steep slope,so the construction is highly risky and the environment is complicated.To investigate the influence of excavation on underlying large-span highway tunnel,an additional stress calculation method considering the residual stress in soil and the supporting structure of foundation pit is put forward,and the analytical calculation model and 3 D numerical simulation model for the analysis of uplift deformation of tunnel are established.The 3 calculation cases,including no protective measure,stratum consolidation,stratum consolidation and uplift piles are calculated.The size,distribution shape and deformation control effect of additional deformation and additional internal force of tunnel under different protection measures are studied and compared with the measured result.The result shows that(1)The analytical solution and numerical simulation result of the additional deformation of the tunnel are close and agree well with the measured values.(2)The excavation may significantly affect the underlying tunnel,it causes the uneven longitudinal uplift deformation and alters the force size and distribution pattern of the tunnel structure significantly,and the influence range is about 4-5 times of the width of foundation pit.(3)The grouting reinforcement measure is clearly more effective than setting the uplift piles in controlling tunnel uplift deformation and additional internal forces.Changing the tunnel protective measures has a miner impact on the structural internal force distribution pattern.
作者
丁祖德
计霞飞
张博
任志华
DING Zu-de;JI Xia-fei;ZHANG Bo;REN Zhi-hua(School of Civil Engineering,Kunming University of Science and Technology,Kunming Yunnan 650500,China;Yunnan Highway Science and Technology Research Institute,Kunming Yunnan 650051,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2020年第2期107-115,共9页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51768028,51308270)
云南省交通运输厅科技项目(云交科2016A-01).
关键词
隧道工程
基坑开挖
附加应力
纵向变形
保护措施
tunnel engineering
foundation pit excavation
additional stress
longitudinal deformation
protective measure
作者简介
丁祖德(1979-),男,湖南汉寿人,博士,副教授.(dzdvsdt@163.com)
