岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2013年
z2期
3636-3642
,共7页
李栋%何兴玲%覃乐%康勇%周东平%郭臣业
李棟%何興玲%覃樂%康勇%週東平%郭臣業
리동%하흥령%담악%강용%주동평%곽신업
隧道工程%特大跨超浅埋隧道%下穿天桥%稳定性控制%双侧壁导坑法
隧道工程%特大跨超淺埋隧道%下穿天橋%穩定性控製%雙側壁導坑法
수도공정%특대과초천매수도%하천천교%은정성공제%쌍측벽도갱법
tunnelling engineering%ultra shallow-buried tunnel with super large-span%crossing bridge%stability control%both sides heading method
针对重庆花卉园地铁隧道洞室开挖复杂条件,在分析隧道稳定性关键影响因素和数值模拟基础上,提出相应控制措施,并结合现场监测对特大跨超浅埋隧道下穿天桥过程稳定性进行研究。结果表明:(1)特大跨超浅埋隧道开挖后难以成拱,引起地层变形明显,导致2#桥桩累计沉降和沉降速率均超过预警值,需采取相应补偿地层损失措施;(2)隧道偏载现象较明显,且各处等效应力集中对扁平率变化敏感程度不同,拱脚最为敏感,拱顶基本不随之改变而改变;(3)特大跨超浅埋隧道变形主要受各部开挖影响,其中核心土开挖造成的变形占主要部分,两侧上洞开挖造成的变形次之,是重点控制部位;(4)采用双侧壁导坑法并辅以超前小导管注浆、回填注浆及浅孔微震光面爆破等措施能有效控制特大跨超浅埋隧道下穿天桥稳定性。
針對重慶花卉園地鐵隧道洞室開挖複雜條件,在分析隧道穩定性關鍵影響因素和數值模擬基礎上,提齣相應控製措施,併結閤現場鑑測對特大跨超淺埋隧道下穿天橋過程穩定性進行研究。結果錶明:(1)特大跨超淺埋隧道開挖後難以成拱,引起地層變形明顯,導緻2#橋樁纍計沉降和沉降速率均超過預警值,需採取相應補償地層損失措施;(2)隧道偏載現象較明顯,且各處等效應力集中對扁平率變化敏感程度不同,拱腳最為敏感,拱頂基本不隨之改變而改變;(3)特大跨超淺埋隧道變形主要受各部開挖影響,其中覈心土開挖造成的變形佔主要部分,兩側上洞開挖造成的變形次之,是重點控製部位;(4)採用雙側壁導坑法併輔以超前小導管註漿、迴填註漿及淺孔微震光麵爆破等措施能有效控製特大跨超淺埋隧道下穿天橋穩定性。
침대중경화훼완지철수도동실개알복잡조건,재분석수도은정성관건영향인소화수치모의기출상,제출상응공제조시,병결합현장감측대특대과초천매수도하천천교과정은정성진행연구。결과표명:(1)특대과초천매수도개알후난이성공,인기지층변형명현,도치2#교장루계침강화침강속솔균초과예경치,수채취상응보상지층손실조시;(2)수도편재현상교명현,차각처등효응력집중대편평솔변화민감정도불동,공각최위민감,공정기본불수지개변이개변;(3)특대과초천매수도변형주요수각부개알영향,기중핵심토개알조성적변형점주요부분,량측상동개알조성적변형차지,시중점공제부위;(4)채용쌍측벽도갱법병보이초전소도관주장、회전주장급천공미진광면폭파등조시능유효공제특대과초천매수도하천천교은정성。
By analyzing the key effect factors of the stability and using numerical simulation for the complex excavation condition of Huahuiyuan metro tunnel,the corresponding control methods were proposed. And the stability of ultra shallow-buried tunnel with super large-span in the process of crossing bridge was investigated based on the monitoring results from excavation site. The results show that:(1) It′s difficult to form an arch after the ultra shallow-buried tunnel with super large-span excavation and the obvious ground deformation caused by the excavation shows skewed which lead to the subsidence of No.2 pile exceeds the warning value. So,some strengthening measures must be taken. (2) The phenomenon of equivalent stress concentration in different parts of the tunnel structure has different sensitivities to the change of flat rate:the most sensitive part is skewback while the equivalent stress concentration in the vault does not change along with the flat rate. (3) The deformations of ultra shallow-buried tunnel with super large-span are mainly influenced by the excavation of each part,in which the dominant deformation is caused by core soil excavation and then by upper hole excavation. As a result,both of them are the key control parts. (4) Both sides heading method assisted by advanced small pipe grouting, backfilling grouting,short-hole micro seismic blasting and so on can control the ultra shallow-buried tunnel with super large-span stability in the process of crossing bridge effectively.